1
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Tao J, Zhu L, Zhu L, Lei L, Zhao G. Colloidal lignin particle reinforces the stability of Pickering emulsions prepared with zein nanoparticle. Food Chem 2024; 460:140581. [PMID: 39067384 DOI: 10.1016/j.foodchem.2024.140581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 06/29/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
Zein nanoparticle (ZNP) is at the forefront of research on Pickering emulsions, valued for its self-assembling and surfactant-free nature. Nevertheless, its emulsion stability is undermined by inadequate amphiphilicity. Colloidal lignin particle (CLP), characterized by its antithetical charge and amphiphilic nature, appears the promising for augmenting the stability of ZNP-based emulsion. This study meticulously investigated the impact of CLP on the colloidal properties and emulsifying performance of ZNP. The results revealed that electrostatic interactions between ZNP and CLP significantly mitigated the charge of ZNP and improved its hydrophilic/lipophilic balance. Under optimized conditions (1.0 wt% particle concentration, pH 4.0, 50% oil content), CLP notably reduced droplet sizes (41-225 μm) and enhanced the stability of ZNP-based Pickering emulsion, particularly at ZNP/CLP ratios of 6:4 and 5:5. In nature, CLP improved the stability ZNP-based Pickering emulsions via increased interfacial adsorption, enhanced steric hindrance, and reinforced viscous structure.
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Affiliation(s)
- Jianming Tao
- College of Food Science, Southwest University, Chongqing 400715, PR China.
| | - Lijun Zhu
- College of Food Science, Southwest University, Chongqing 400715, PR China
| | - Luyi Zhu
- College of Food Science, Southwest University, Chongqing 400715, PR China
| | - Lin Lei
- College of Food Science, Southwest University, Chongqing 400715, PR China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Chongqing 400715, PR China.
| | - Guohua Zhao
- College of Food Science, Southwest University, Chongqing 400715, PR China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Chongqing 400715, PR China.
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2
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Yang M, Cheng S, LÜ L, Han Z, He J. Synergistic stabilization of a menthol Pickering emulsion by zein nanoparticles and starch nanocrystals: Preparation, structural characterization, and functional properties. PLoS One 2024; 19:e0303964. [PMID: 38843222 PMCID: PMC11156346 DOI: 10.1371/journal.pone.0303964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 05/04/2024] [Indexed: 06/09/2024] Open
Abstract
A Pickering emulsion was synergistically stabilised with zein nanoparticles (ZNPs) and starch nanocrystals (SNCs) to prepare it for menthol loading. After response surface optimisation of the emulsion preparation conditions, a Pickering emulsion prepared with a ZNPs:SNCs ratio of 1:1, a particle concentration of 2 wt% and a water:oil ratio of 1:1 provided the highest menthol encapsulation rate of the emulsions tested (83%) with good storage stability within 30 days. We examined the bilayer interface structure of the emulsion by optical microscopy, scanning electron microscopy, and confocal laser scanning microscopy. The results of simulated digestion experiments showed that the release rate of free fatty acid was 75.06 ± 1.23%, which ensured bioavailability. At the same time, the emulsions facilitated the slow release of menthol. Bacteriostatic studies revealed that the Pickering emulsion had a protective effect on menthol, with the most significant inhibitory effects on Escherichia coli and Staphylococcus aureus under the same conditions. Overall, this study proposes a novel approach for the application and development of l-menthol by combining it with Pickering emulsion.
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Affiliation(s)
- Minghe Yang
- School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
| | - Shujin Cheng
- School of Bioengineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
- General Tobacco Group Co., Ltd, Jinan, China
| | - Lei LÜ
- School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
| | - Zhonghui Han
- School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
| | - Jinxing He
- School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, China
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3
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Yin C, Chen X, Zhang H, Xue Y, Dong H, Mao X. Pickering emulsion biocatalysis: Bridging interfacial design with enzymatic reactions. Biotechnol Adv 2024; 72:108338. [PMID: 38460741 DOI: 10.1016/j.biotechadv.2024.108338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 01/21/2024] [Accepted: 03/05/2024] [Indexed: 03/11/2024]
Abstract
Non-homogeneous enzyme-catalyzed systems are more widely used than homogeneous systems. Distinguished from the conventional biphasic approach, Pickering emulsion stabilized by ultrafine solid particles opens up an innovative platform for biocatalysis. Their vast specific surface area significantly enhances enzyme-substrate interactions, dramatically increasing catalytic efficiency. This review comprehensively explores various aspects of Pickering emulsion biocatalysis, provides insights into the multiple types and mechanisms of its catalysis, and offers strategies for material design, enzyme immobilization, emulsion formation control, and reactor design. Characterization methods are summarized for the determination of drop size, emulsion type, interface morphology, and emulsion potential. Furthermore, recent reports on the design of stimuli-responsive reaction systems are reviewed, enabling the simple control of demulsification. Moreover, the review explores applications of Pickering emulsion in single-step, cascade, and continuous flow reactions and outlines the challenges and future directions for the field. Overall, we provide a review focusing on Pickering emulsions catalysis, which can draw the attention of researchers in the field of catalytic system design, further empowering next-generation bioprocessing.
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Affiliation(s)
- Chengmei Yin
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China
| | - Xiangyao Chen
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China
| | - Haiyang Zhang
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China
| | - Yong Xue
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China
| | - Hao Dong
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China.
| | - Xiangzhao Mao
- State Key Laboratory of Marine Food Processing and Safety Control, College of Food Science and Engineering, Ocean University of China, Qingdao 266404, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Qingdao Key Laboratory of Food Biotechnology, Qingdao 266404, PR China; Key Laboratory of Biological Processing of Aquatic Products, China National Light Industry, Qingdao 266404, PR China
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4
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Niedner L, Kickelbick G. Amphiphilic titania Janus nanoparticles containing ionic groups prepared in oil-water Pickering emulsion. NANOSCALE 2024; 16:7396-7408. [PMID: 38445431 DOI: 10.1039/d3nr04907h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Titania nanoparticles with a diameter of 8 nm underwent an anisotropic modification using apolar 6-bromohexylphosphonic acid and cationic polar N,N,N-trimethyl-6-phosphonohexan-1-aminium bromide. The Janus modification was achieved through a straightforward one-step Pickering emulsion approach using toluene-water mixtures. The resulting Janus particles were compared with isotropically and statistically modified titania particles, where either a single coupling agent is attached to the surface or both coupling agents are assembled over the surface randomly, respectively. The covalent binding of the phosphonic acids to the titania surface was confirmed by FTIR and 31P solid-state CP-MAS NMR analyses. The grafting density was assessed using TGA, elemental analysis, and ICP-MS, revealing grafting densities of 0.1 mmol g-1 to 0.5 mmol g-1 for the cationic coupling agent and 1.2 mmol g-1 to 1.5 mmol g-1 for the apolar coupling agent, respectively. ζ-Potential titration measurements of both pristine and modified particles revealed isoelectric points at pH 4.5 to 9.3, depending on the type of modification. The ability of the particles to stabilize Pickering emulsions was tested under various conditions, with statistically and Janus-modified particles demonstrating a significant increase in stabilization compared to their isotropically modified counterparts. Furthermore, Janus particles were deposited onto glass substrates by a simple layer-by-layer approach. Through the self-assembly of these Janus particles, the glass substrate's properties could be tailored from hydrophilic to hydrophobic to hydrophilic, depending on the dipping cycle.
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Affiliation(s)
- Lucas Niedner
- Saarland University, Inorganic Solid State Chemistry, Campus, Building C4 1, 66123 Saarbrücken, Germany.
| | - Guido Kickelbick
- Saarland University, Inorganic Solid State Chemistry, Campus, Building C4 1, 66123 Saarbrücken, Germany.
- Saarene - Saarland Center for Energy Materials and Sustainability, Campus C4 2, 66123 Saarbrücken, Germany
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5
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Ali DC, Zhang X, Wang Z. Adding nanoparticles to improve emulsion efficiency and enhance microbial degradation in Pickering emulsions. Appl Microbiol Biotechnol 2023; 107:5843-5854. [PMID: 37466667 DOI: 10.1007/s00253-023-12688-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/02/2023] [Accepted: 07/09/2023] [Indexed: 07/20/2023]
Abstract
Interfacial microbial degradation of alkane in Pickering emulsions stabilized by hydrophobic bacterial cells is a new mechanism for microbial degradation of water-insoluble chemicals, where both water-insoluble chemicals in the oil phase and water-soluble nutrients (such as nitrogen and phosphorus) in the water phase are bio-accessible to living microorganisms anchoring onto the oil-water interfaces. In the present work, super-hydrophobic Mycobacterium sp. (contact angle 168.6°) degradation of tetradecane was set up as a model. Addition of fumed SiO2 particles (Aerosil® R974) as a new strategy was developed to enhance tetradecane degradation where the biodegradation rate (based on the accumulated biomass) increased by approximately 80%. The enhanced effect of SiO2 particles on the tetradecane degradation attributed to the synergistic effect of SiO2 particles on the emulsion efficiency of Pickering emulsions stabilized by bacterial cells and then on the enhancement of interfacial microbial degradation in Pickering emulsions. KEY POINTS: • Interfacial microbial degradation in bacterial cells stabilized Pickering emulsions. • Adding fumed SiO2 particles to enhance microbial degradation of tetradecane. • Correlation relationship between emulsion efficiency and interfacial microbial degradation.
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Affiliation(s)
- Daniel Chikere Ali
- State Key Laboratory of Microbial Metabolism, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China
| | - Xuehong Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China
| | - Zhilong Wang
- State Key Laboratory of Microbial Metabolism, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China.
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6
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Benyaya M, Bolzinger MA, Chevalier Y, Ensenat S, Bordes C. Pickering emulsions stabilized with differently charged particles. SOFT MATTER 2023. [PMID: 37318280 DOI: 10.1039/d3sm00305a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
For addressing health issues and ecological concerns, the cosmetic and pharmaceutical industries are facing the challenge of designing emulsions without the use of surfactants. Emulsions stabilized by colloidal particles, known as Pickering emulsions, are promising in this matter. In this article, three different types of particles (neutral, anionic and cationic) are used alone or in binary mixtures as stabilizers of Pickering emulsions. The influence of the particles' charge on the emulsions' properties and the synergies between the different types of particles are studied. It is demonstrated that the kinetics of adsorption of the particles at the water/oil interface control the coverage and their organization at the droplet surface, rather than their interactions after adsorption. Binary mixtures of differently charged particles are a powerful way to control the droplet coverage and the particle loading in the emulsions. In particular, the combination of anionic and cationic particles led to smaller droplets and higher particle coverage of emulsion droplets.
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Affiliation(s)
- Mathis Benyaya
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5007, Laboratoire d'Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), 43 bd du 11 Novembre 1918, 69622, Villeurbanne, France.
| | - Marie-Alexandrine Bolzinger
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5007, Laboratoire d'Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), 43 bd du 11 Novembre 1918, 69622, Villeurbanne, France.
| | - Yves Chevalier
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5007, Laboratoire d'Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), 43 bd du 11 Novembre 1918, 69622, Villeurbanne, France.
| | - Salomé Ensenat
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5007, Laboratoire d'Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), 43 bd du 11 Novembre 1918, 69622, Villeurbanne, France.
| | - Claire Bordes
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5007, Laboratoire d'Automatique, de Génie des Procédés et de Génie Pharmaceutique (LAGEPP), 43 bd du 11 Novembre 1918, 69622, Villeurbanne, France.
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7
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Zhang Y, Ye Z, Li C, Chen Q, Aljuhani W, Huang Y, Xu X, Wu C, Bell SEJ, Xu Y. General approach to surface-accessible plasmonic Pickering emulsions for SERS sensing and interfacial catalysis. Nat Commun 2023; 14:1392. [PMID: 36914627 PMCID: PMC10011407 DOI: 10.1038/s41467-023-37001-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
Pickering emulsions represent an important class of functional materials with potential applications in sustainability and healthcare. Currently, the synthesis of Pickering emulsions relies heavily on the use of strongly adsorbing molecular modifiers to tune the surface chemistry of the nanoparticle constituents. This approach is inconvenient and potentially a dead-end for many applications since the adsorbed modifiers prevent interactions between the functional nanosurface and its surroundings. Here, we demonstrate a general modifier-free approach to construct Pickering emulsions by using a combination of stabilizer particles, which stabilize the emulsion droplet, and a second population of unmodified functional particles that sit alongside the stabilizers at the interface. Freeing Pickering emulsions from chemical modifiers unlocks their potential across a range of applications including plasmonic sensing and interfacial catalysis that have previously been challenging to achieve. More broadly, this strategy provides an approach to the development of surface-accessible nanomaterials with enhanced and/or additional properties from a wide range of nano-building blocks including organic nanocrystals, carbonaceous materials, metals and oxides.
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Affiliation(s)
- Yingrui Zhang
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Ziwei Ye
- Key Laboratory for Advanced Materials, Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, PR China
| | - Chunchun Li
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Qinglu Chen
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Wafaa Aljuhani
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Yiming Huang
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai, 200433, PR China
| | - Chunfei Wu
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Steven E J Bell
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK
| | - Yikai Xu
- School of Chemistry and Chemical Engineering, Queen's University Belfast, University Road, Belfast, BT7 1NN, UK.
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8
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Hydrophobic interaction at the O/W interface: Impacts on the interfacial stability, encapsulation and bioaccessibility of polyphenols. Food Hydrocoll 2023. [DOI: 10.1016/j.foodhyd.2023.108622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
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9
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Madhavan N, Deshpande AP, Mani E, Basavaraj MG. Electrostatic Heteroaggregation: Fundamentals and Applications in Interfacial Engineering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:2112-2134. [PMID: 36727572 DOI: 10.1021/acs.langmuir.2c02681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The aggregation of oppositely charged soft materials (particles, surfactants, polyelectrolytes, etc.) that differ in one or more physical or chemical attributes, broadly referred to as electrostatic heteroaggregation, has been an active area of research for several decades now. While electrostatic heteroaggregation (EHA) is relevant to diverse fields such as environmental engineering, food technology, and pharmaceutical formulations, more recently there has been a resurgence to explore various aspects of this phenomenon in the context of interface stabilization and the development of functional materials. In this Feature Article, we provide an overview of the recent contributions of our group to this exciting field with particular emphasis on fundamental studies of electrostatic heteroaggregation between oppositely charged systems in the bulk, at interfaces, and across the bulk/interface. The influence of the size and shape of particles and the surface charge of heteroaggregates on the formation of Pickering emulsions and their utilization in the development of porous ceramics is discussed.
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Affiliation(s)
- Nithin Madhavan
- Polymer Engineering and Colloid Sciences Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, IIT P.O., Chennai600036, India
| | - Abhijit P Deshpande
- Polymer Engineering and Colloid Sciences Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, IIT P.O., Chennai600036, India
| | - Ethayaraja Mani
- Polymer Engineering and Colloid Sciences Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, IIT P.O., Chennai600036, India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Sciences Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Sardar Patel Road, Adyar, IIT P.O., Chennai600036, India
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10
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Chen Y, Wang S, Ma Q, Wu X, Guo Q, Luo X, Tao L, Shen X. Utilizing endosomal capture for tumor therapy via membrane-lytic mechanism-based Pickering emulsion. J Control Release 2023; 354:523-537. [PMID: 36657600 DOI: 10.1016/j.jconrel.2023.01.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/21/2023]
Abstract
Nanocarriers are easily captured by endosomes, where the abundant hydrolases inevitably destroy the nanocarriers and the drugs they carry, ultimately resulting in a compromised or lost therapeutic efficacy. Herein, we report a membrane-lytic mechanism-based Pickering emulsion that can in turn utilize this seemingly unfavorable endosomal capture behavior for tumor therapy. This Pickering emulsion is constructed as an oil-in-water (O/W) emulsion stabilized by the hybrid nanoparticles (HNPs) composed of two molecules with opposite charges, cetyl trimethylamine bromide (CTAB) and linoleic acid (LA), through electrostatic interaction (defined as HNPs@PE). After HNPs@PE enters the lysosomes through macropinocytosis-mediated endocytosis, LA can be protonated in response to the acidic stimulus, and causing the swelling or disintegration of HNPs due to the disrupted electrostatic interaction. The released CTAB holds strong membrane-lytic activity and can directly damage the lysosomal membranes. Under the acidic condition and the participation of excessive iron ions (II) in lysosomes, LA induces lipid peroxidation and the resulting lipid peroxides (LPO) will oxidize the lysosomal membranes, collectively causing the leakage of lysosome membranes and the release of contents into cytoplasm. Subsequently, the diffused CTAB and LPO will continue to attack the mitochondrial membranes and cell membranes, resulting in the death of different types of tumor cells both in vitro and in vivo due to membrane damage. This Pickering emulsion with membrane-lytic ability represents a potential self-anticancer nanocarrier.
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Affiliation(s)
- Ying Chen
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China.
| | - Sibu Wang
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China
| | - Qin Ma
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China
| | - Xingjie Wu
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China
| | - Qianqian Guo
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China
| | - Xinghong Luo
- Jiangsu Simcere Pharmaceutical Co, Ltd., State Key Laboratory of Translational Medicine and Innovative Drug, 699-18 Xuanwu Avenue, Nanjing 210042,China
| | - Ling Tao
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China.
| | - Xiangchun Shen
- The State Key Laboratory of Functions and Applications of Medicinal Plants & School of Pharmaceutical Sciences, Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China; The Department of Pharmacology of Materia Medical (the High Efficacy Application of Natural Medicinal Resources Engineering Center of Guizhou Province, the Key Laboratory of Optimal Utilization of Natural Medicine Resources), Guizhou Medical University, University Town, Guian New District, Guiyang 550025, China.
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11
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Liu L, Wei J, Ho KM, Chiu KY, Ngai T. Capsules templated from water-in-oil Pickering emulsions for enzyme encapsulation. J Colloid Interface Sci 2023; 629:559-568. [PMID: 36179576 DOI: 10.1016/j.jcis.2022.09.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/17/2022] [Accepted: 09/20/2022] [Indexed: 10/14/2022]
Abstract
HYPOTHESIS Encapsulation of sensitive water-soluble bioactive materials such as fragrances, polyphenols and enzymes poses an immense challenge with capsules templated from water-in-oil (w/o) emulsions. Generation of radicals, heating, and extreme pH that are necessary for shell formation through interfacial reactions may have undesired influences on the active ingredients and thus lower their activity. EXPERIMENTS To overcome these limitations, we present a method to encapsulate sensitive ingredients, whereby capsules are templated from a w/o Pickering emulsion stabilized by binary particles of different hydrophilicity levels; the particles assembled at the water/oil interface are then crosslinked by polydiisocyanate (PHDI) at room temperature and neutral pH. Zein and casein nanoparticles were used as hydrophilic stabilizers and lipase was chosen as a model sensitive biomolecule that was encapsulated in the water core. FINDINGS Our results indicated that the enzymes encapsulated in colloid capsules had higher activity than those encapsulated in traditional w/o Pickering emulsion without shell crosslinking. The capsule structure effectively protected enzymes from the outer environment. This method is well suited for the encapsulation and protection of sensitive ingredients and shows great application in food, drug, and cosmetic industries.
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Affiliation(s)
- Liangdong Liu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Jingjing Wei
- Department of Fine Chemical Engineering, Shenzhen Polytechnic, Nanshan District, Shenzhen, Guangdong, China.
| | - Kin Man Ho
- Xianhong Science (Hong Kong) Co. Ltd, Room 1604, Nanyang Plaza, No. 57 Hung To Road, Kwun Tong, Kowloon, Hong Kong, China
| | - Kwan Yeung Chiu
- Xianhong Science (Hong Kong) Co. Ltd, Room 1604, Nanyang Plaza, No. 57 Hung To Road, Kwun Tong, Kowloon, Hong Kong, China
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
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12
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Correlation Relationship between Phase Inversion of Pickering Emulsions and Biocatalytic Activity of Microbial Transformation of Phytosterols. Catalysts 2022. [DOI: 10.3390/catal13010072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Microbial transformation of hydrophobic phytosterols into the pharmaceutical steroid precursors AD (androst-4-ene-3, 17-dione) and ADD (androst-4-diene-3, 17-dione) in a water–plant oil two-phase system by Mycolicibacterium neoaurum is a paradigm of interfacial biocatalysis in Pickering emulsions stabilized by bacterial cells. In the present work, phase inversion of Pickering emulsions—i.e., Pickering emulsions turning from water-in-oil (W/O) emulsions into oil-in-water (O/W) ones—was observed during microbial transformation in the presence of high concentrations of crystal phytosterols. It was found that there is a correlation relationship between the phase behaviors of Pickering emulsions and the biocatalytic activity of utilizing M. neoaurum as a whole-cell catalyst. Efficient microbial transformation under the high crystal phytosterol loadings was achieved due to the formation of O/W emulsions where interfacial biocatalysis took place. Under the optimal conditions (volume ratio of soybean oil to water: 15:35 mL, phytosterols concentration in the soybean oil: 80 g/L, glucose as co-substrate in the aqueous culture medium: 10 g/L), the concentrations of AD and ADD reached 4.8 g/L based on the whole broth (16 g/L based on the oil phase) after microbial transformation for 9 days.
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Liu L, Ngai T. Pickering Emulsions Stabilized by Binary Mixtures of Colloidal Particles: Synergies between Contrasting Properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13322-13329. [PMID: 36300320 DOI: 10.1021/acs.langmuir.2c02338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Pickering emulsions that are stabilized by colloidal particles have attracted substantial research attention because of their potential applications in various industries. Previously, single colloidal particles have usually been used to fabricate Pickering emulsions and to investigate the stabilization mechanism. However, surface modification of the colloidal stabilizer is normally required to adjust the particle wettability, which often involves chemical modification, the adsorption of a surfactant or polymer, and the addition of an electrolyte. Such a modification is expensive, time-consuming, and thus only partially effective. In this Perspective, we describe an alternative approach that uses binary mixtures of particles as stabilizers and could be an effective solution to the above-described problems with Pickering emulsions. We introduce various types of Pickering emulsions stabilized by binary mixtures of particles with different functional groups, opposite charges, or opposite wettabilities (i.e., they are hydrophilic or hydrophobic). Examples of stabilizing mechanisms are discussed, showing that compared with emulsions stabilized by single colloidal particles, emulsions stabilized by binary mixtures of particles are generated via simpler particle-pretreatment processes and have higher stability and customizable properties and thus can enable the exploration of the next generation of Pickering emulsions.
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Affiliation(s)
- Liangdong Liu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China 00852
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China 00852
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Parajuli S, Hasan MJ, Ureña-Benavides EE. Effect of the Interactions between Oppositely Charged Cellulose Nanocrystals (CNCs) and Chitin Nanocrystals (ChNCs) on the Enhanced Stability of Soybean Oil-in-Water Emulsions. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15196673. [PMID: 36234017 PMCID: PMC9573157 DOI: 10.3390/ma15196673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/07/2022] [Accepted: 09/22/2022] [Indexed: 05/05/2023]
Abstract
Chitin nanocrystals (ChNCs) and cellulose nanocrystals (CNCs) have been recently used to stabilize emulsions; however, they generally require significant amounts of salt, limiting their applicability in food products. In this study, we developed nanoconjugates by mixing positively charged ChNCs and negatively charged CNCs at various ChNC:CNC mass ratios (2:1, 1:1, and 1:2), and utilized them in stabilizing soybean oil-water Pickering emulsions with minimal use of NaCl salt (20 mM) and nanoparticle (NP) concentrations below 1 wt%. The nanoconjugates stabilized the emulsions better than individual CNC or ChNC in terms of a reduced drop growth and less creaming. Oppositely charged CNC and ChNC neutralized each other when their mass ratio was 1:1, leading to significant flocculation in the absence of salt at pH 6. Raman spectroscopy provided evidence for electrostatic interactions between the ChNCs and CNCs, and generated maps suggesting an assembly of ChNC bundles of micron-scale lengths intercalated by similar-size areas predominantly composed of CNC. The previous measurements, in combination with contact angles on nanoparticle films, suggested that the conjugates preferentially exposed the hydrophobic crystalline planes of CNCs and ChNCs at a 1:1 mass ratio, which was also the best ratio at stabilizing soybean oil-water Pickering emulsions.
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Sabapathy M, Md KZ, Kumar H, Ramamirtham S, Mani E, Basavaraj MG. Exploiting Heteroaggregation to Quantify the Contact Angle of Charged Colloids at Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7433-7441. [PMID: 35678741 DOI: 10.1021/acs.langmuir.2c00348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We exploit the aggregation between oppositely charged particles to visualize and quantify the equilibrium position of charged colloidal particles at the fluid-water interface. A dispersion of commercially available charge-stabilized nanoparticles was used as the aqueous phase to create oil-water and air-water interfaces. The colloidal particles whose charge was opposite that of the nanoparticles in the aqueous phase were deposited at the chosen fluid-water interface. Heteroaggregation, i.e., aggregation between oppositely charged particles, leads to the deposition of nanoparticles onto the larger particle located at the interface; however, this only occurs on the surface of the particle in contact with the aqueous phase. This selective deposition of nanoparticles on the surfaces of the particles exposed to water enables the distinct visualization of the circular three-phase contact line around the particles positioned at the fluid-water interface. Since the electrostatic association between the nanoparticles and the colloids at interfaces is strong, the nanoparticle assembly on the larger particles is preserved even after being transferred to solid substrates via dip-coating. This facilitates the easy visualization of the contact line by electron microscopy and the determination of the equilibrium contact angle of colloidal particles (θ) at the fluid-water interface. The suitability of the method is demonstrated by the measurement of the three-phase contact angle of positively and negatively charged polystyrene particles located at fluid-water interfaces by considering particles with sizes varying from 220 nm to 8.71 μm. The study highlights the effect of the size ratio between the nanoparticles in the aqueous phase and the colloidal particles on the accuracy of the measurement of θ.
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Affiliation(s)
- Manigandan Sabapathy
- Advanced Colloid and Interfacial Engineering Laboratory, Department of Chemical Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001, India
| | - Khalid Zubair Md
- Polymer Engineering and Colloid Science Laboratory (PECS), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
| | - Hemant Kumar
- Polymer Engineering and Colloid Science Laboratory (PECS), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
| | - Sashikumar Ramamirtham
- Polymer Engineering and Colloid Science Laboratory (PECS), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
| | - Ethayaraja Mani
- Polymer Engineering and Colloid Science Laboratory (PECS), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science Laboratory (PECS), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600036, India
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Save M, Hellaye ML, de Villedon V, Adoumaz I, Pillet M, Atanase L, Lahcini M, Deniau E, Khoukh A, Pellerin V, Ly I, Dulong V, Schmitt V. Biosourced Polymeric Emulsifiers for Miniemulsion Copolymerization of Myrcene and Styrene: Toward Biobased Waterborne Latex as Pickering Emulsion Stabilizer. Biomacromolecules 2022; 23:2536-2551. [PMID: 35640245 DOI: 10.1021/acs.biomac.2c00257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Biobased waterborne latexes were synthesized by miniemulsion radical copolymerization of a biosourced β-myrcene (My) terpenic monomer and styrene (S). Biobased amphiphilic copolymers were designed to act as stabilizers of the initial monomer droplets and the polymer colloids dispersed in the water phase. Two types of hydrophilic polymer backbones were hydrophobically modified by terpene molecules to synthesize two series of amphiphilic copolymers with various degrees of substitution. The first series consists of poly(acrylic acid) modified with tetrahydrogeraniol moieties (PAA-g-THG) and the second series is based on the polysaccharide carboxymethylpullulan amino-functionalized with dihydromyrcenol moieties (CMP-g-(NH-DHM)). The produced waterborne latexes with diameters between 160 and 300 nm and were composed of polymers with varying glass transition temperatures (Tg, PMy = -60 °C, Tg, P(My-co-S) = -14 °C, Tg, PS = 105 °C) depending on the molar fraction of biobased β-myrcene (fMy,0 = 0, 0.43, or 1). The latexes successfully stabilized dodecane-in-water and water-in-dodecane emulsions for months at all compositions. The waterborne latexes composed of low Tg poly(β-myrcene) caused interesting different behavior during drying of the emulsions compared to polystyrene latexes.
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Affiliation(s)
- Maud Save
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France
| | - Maude Le Hellaye
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France.,CRPP, UMR 5031, Univ. Bordeaux, CNRS, 33600 Pessac, France
| | - Valentine de Villedon
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France.,CRPP, UMR 5031, Univ. Bordeaux, CNRS, 33600 Pessac, France
| | - Ismail Adoumaz
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France.,IMED-Lab, Cadi Ayyad University, Marrakech 40000, Morocco
| | - Marion Pillet
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France
| | - Léonard Atanase
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France
| | | | - Elise Deniau
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France
| | - Abdel Khoukh
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France
| | - Virginie Pellerin
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, 64000 Pau, France
| | - Isabelle Ly
- CRPP, UMR 5031, Univ. Bordeaux, CNRS, 33600 Pessac, France
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Lan M, Zheng J, Huang C, Wang Y, Hu W, Lu S, Liu F, Ou S. Water-In-Oil Pickering Emulsions Stabilized by Microcrystalline Phytosterols in Oil: Fabrication Mechanism and Application as a Salt Release System. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:5408-5416. [PMID: 35439006 DOI: 10.1021/acs.jafc.1c05115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Recently, Pickering emulsions stabilized by edible particles have attracted significant attention from the scientific community and food industry owing to their surfactant-free character. However, those edible particles are mostly used for stabilizing oil-in-water emulsions, whereas those for water-in-oil emulsions are very limited. In this article, stable water-in-oil Pickering emulsions were prepared through dispersing phytosterol particles in oil phase, and the effects of antisolvent treatment, the type of oil, particle concentration, and water fraction on the stability, type, and morphology of these emulsions were investigated. In addition, the release profile of salt as a model aqueous compound from these emulsions has also been studied. Results showed that due to its higher water content, the antisolvent pretreatment of phytosterol in the ethanol/water system facilitated the dispersion of dried phytosterol particles into oil phase as microcrystals. Water-in-oil Pickering emulsions with droplet sizes of 80-100 μm were fabricated at phytosterol concentrations of 1.5-3% w/v and water fractions of 0.2-0.6. The dissolved phytosterol molecules in oil phase could help in emulsion stabilization through interfacial crystallization during emulsification, evidenced by polar microscopic observations. Moreover, the salt release from phytosterol-stabilized Pickering emulsions showed a temperature-dependent profile which could have potential application in a controlled-release system. The current study provided important information for fabrication of stable water-in-oil emulsion using natural particles.
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Affiliation(s)
- Manyu Lan
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
- Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products, Guangzhou 510632, China
| | - Jie Zheng
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
- Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products, Guangzhou 510632, China
| | - Caihuan Huang
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
- Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products, Guangzhou 510632, China
| | - Yong Wang
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
| | - Wenzhong Hu
- Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, College of Life Science, Dalian Minzu University, Dalian 116600, China
| | - Shenglan Lu
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
- Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products, Guangzhou 510632, China
| | - Fu Liu
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
- Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products, Guangzhou 510632, China
| | - Shiyi Ou
- Department of Food Science and Engineering, Jinan University, Guangzhou 510632, PR China
- Guangdong-Hong Kong Joint Innovation Platform for the Safety of Bakery Products, Guangzhou 510632, China
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Xu J, Liu Y, Guo T, Sun G, Luo J, Liu R, Steve Tse YL, Ngai T. Investigation of the Contact Angle and Packing Density of Silica Nanoparticles at a Pickering Emulsion Interface Fixed by UV Polymerization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:4234-4242. [PMID: 35357199 DOI: 10.1021/acs.langmuir.1c03259] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The contact angle of colloidal particles at an oil-water interface plays a crucial role in determining Pickering emulsion stability and emulsion type, but the contact angle cannot be directly determined using conventional methods. In this work, a Pickering emulsion was prepared with photocurable resin as the internal phase containing silica nanoparticle stabilizers. Particles adsorbed at the oil-water interface were then fixed through UV curing, allowing for the investigation of various parameters that influence the contact angle of colloidal particles at the interface. After curing, the contact angle can then be observed using scanning electron microscopy and subsequently measured. The contact angle of interfacial adsorbed silica nanoparticles gradually decreases as the size increases due to the line tension at the three-phase contact line, but, more importantly, we found that the surface chemistry of the silica nanoparticles plays the most important role in determining the contact angle. The fast fixation of solid nanoparticles at emulsion interfaces facilitates accurate measurements of the partition of particles between oil and water, providing a new method for studying the factors that affect Pickering emulsion stability.
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Affiliation(s)
- Jianan Xu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, P. R. China
| | - Yang Liu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T. 999077, Hong Kong SAR
| | - Tiehuang Guo
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, P. R. China
| | - Guanqing Sun
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, P. R. China
| | - Jing Luo
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, P. R. China
| | - Ren Liu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, Jiangsu, P. R. China
| | - Ying-Lung Steve Tse
- Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T. 999077, Hong Kong SAR
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin N.T. 999077, Hong Kong SAR
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Zhao W, Xie H, Zhang X, Wang Z. Crystal substrate inhibition during microbial transformation of phytosterols in Pickering emulsions. Appl Microbiol Biotechnol 2022; 106:2403-2414. [PMID: 35352152 DOI: 10.1007/s00253-022-11889-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/11/2022] [Accepted: 03/19/2022] [Indexed: 11/02/2022]
Abstract
Water-oil interface of bacterial cell-stabilized Pickering emulsions is an exceptional habitat for microbial assimilation of both hydrophobic nutrients solubilized in oil phase and hydrophilic ones solubilized in water phase. Crystal substrate inhibition, i.e., decreasing phytosterol degradation with the increase loading of crystal phytosterols, is always observed during microbial transformation of phytosterols into steroid synthons in Mycolicibacterium sp (China Center of Industrial Culture Collection, CICC 21,097) cell-stabilized Pickering emulsions. In the present work, we confirmed that crystal substrate inhibition was attributed to the interaction between M. neoaurum and phytosterol crystals that led to the detachment of bacterial cells from the oil-water interfaces in bacterial cell-stabilized Pickering emulsions. Under the selected operation condition (25 ml BEHP per 40 ml water, 60 g/L glucose, 25 g/L phytosterols), the product androst-4-ene-3, 17-dione (AD) and androsta-1, 4-dien-3, 17-dione (ADD) concentration increased linearly with the progress of microbial transformation and reached almost 6 g/L at the 11th day. This is a paradigm for microbial transformation of crystal substrates as well as in the presence of other surface active additives (such as chitosan and nonionic surfactants) in bacterial cell-stabilized Pickering emulsions. KEY POINTS: • Microbial transformation of crystal phytosterols in Pickering emulsions • Crystal substrate inhibition occurring during microbial transformation • Interaction between phytosterol crystals and bacterial cells leading to demulsification.
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Affiliation(s)
- Wenyu Zhao
- State Key Laboratory of Microbial Metabolism, and Engineering Research Center of Cell & Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China
| | - Haisheng Xie
- State Key Laboratory of Microbial Metabolism, and Engineering Research Center of Cell & Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China
| | - Xuehong Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China
| | - Zhilong Wang
- State Key Laboratory of Microbial Metabolism, and Engineering Research Center of Cell & Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai, 200240, China.
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20
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Zheng R, Binks BP. Pickering Emulsions Stabilized by Polystyrene Particles Possessing Different Surface Groups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1079-1089. [PMID: 35029394 PMCID: PMC9171833 DOI: 10.1021/acs.langmuir.1c02648] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Colloidal polystyrene (PS) latex particles in water can undergo interesting charge reversal in the presence of particular electrolytes. It is worth exploring the effect of charge reversal on the properties of Pickering emulsions they stabilize. Herein, emulsions stabilized by PS latex particles possessing different surface groups (sulfate, amidine, or carboxyl) were prepared in the presence of tetrapentylammonium bromide (TPeAB) or sodium thiocyanate (NaSCN) electrolytes. The effect of salt concentration on the charge of the particles and their colloid stability was measured. Emulsions were prepared from aqueous dispersions, and their type and stability were determined. The three-phase contact angle of particles at the planar oil-water interface was also measured using a gel trapping technique. It was found that the type of emulsion stabilized by latex particles is dominated by the hydrophobic PS portion on particle surfaces, although their surface charge is strongly affected by electrolyte addition. Preferred emulsions were always water-in-oil with dodecane, and charge reversal had little influence on the emulsion type and stability. However, transitional phase inversion of emulsions stabilized by carboxyl latex particles occurred on adding salt when the oil was a low-viscosity polydimethylsiloxane.
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21
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Guan X, Liu Y, Wan Z, Steve Tse YL, Ngai T. Non-Covalent Reconfigurable Microgel Colloidosomes with a Well-Defined Bilayer Shell. Chem Sci 2022; 13:6205-6216. [PMID: 35733902 PMCID: PMC9159095 DOI: 10.1039/d2sc01082h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/25/2022] [Indexed: 11/25/2022] Open
Abstract
Microgels are extremely interfacially active and are widely used to stabilize emulsions. However, they are commonly used to stabilize oil-in-water emulsions due to their intrinsic hydrophilicity and initially dispersed in water. In addition, there have been no attempts to control microgel structural layers that are formed at the interface and as a result it limits applications of microgel in advanced materials. Here, we show that by introducing octanol into poly(N-isopropylacrylamide-co-methacrylic acid) (PNIPAM-co-MAA) microgels, octanol-swollen microgels can rapidly diffuse from the initially dispersed oil phase onto the water droplet surface. This facilitates the formation of microgel-laden interfacial layers with strong elastic responses and also generates stable inverse water-in-oil Pickering emulsions. These emulsions can be used as templates to produce microgel colloidosomes, herein termed ‘microgelsomes’, with shells that can be fine-tuned from a particle monolayer to a well-defined bilayer. The microgelsomes can then be used to encapsulate and/or anchor nanoparticles, proteins, vitamin C, bio-based nanocrystals or enzymes. Moreover, the programmed release of these substances can be achieved by using ethanol as a trigger to mediate shell permeability. Thus, these reconfigurable microgelsomes with a microgel-bilayer shell can respond to external stimuli and demonstrate tailored properties, which offers novel insights into microgels and promise wider application of Pickering emulsions stabilized by soft colloids. Inverse W/O Pickering emulsions and reconfigurable microgelsomes with a well-defined bilayer structure are prepared from octanol-swollen PNIPAM-co-MAA microgels and the combination of binary microgels, which promise wider application of soft colloids.![]()
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Affiliation(s)
- Xin Guan
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
| | - Yang Liu
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
| | - Zhili Wan
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
- School of Food Science and Technology, South China University of Technology Guangzhou 510640 China
| | - Ying-Lung Steve Tse
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
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22
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Koroleva MY, Yurtov EV. Pickering emulsions: properties, structure, using as colloidosomes and stimuli-responsive emulsions. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Shahid S, Madhavan N, Mukherjee M, Basavaraj MG. Macroporous Ceramic Monolith from Nanoparticle-Polyelectrolyte-Stabilized Pickering Emulsions. J Phys Chem B 2021; 125:13575-13584. [PMID: 34874729 DOI: 10.1021/acs.jpcb.1c08858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, we present a simple and scalable approach for fabricating porous ceramic from emulsions stabilized by a binary mixture of oppositely charged nanoparticles and a polyelectrolyte. The electrostatic heteroaggregation is exploited to form weakly charged particle-polyelectrolyte complexes (PPCs) that readily stabilize oil-in-water emulsions. The concentration of surface-active PPCs is varied to obtain Pickering emulsion gels that can be processed and converted into the macroporous ceramic structure. The polyelectrolyte in the binary mixture not only enables the adsorption of particles to the oil-water interface and renders processability of the emulsions but also acts as a binder. Nearly one-to-one correspondence between the microstructure of the green ceramic obtained after the evaporation of solvents from the gel-like emulsions and the parent emulsions is observed. The green ceramic is further sintered under controlled conditions to obtain a porous ceramic monolith. We demonstrate that the microstructure and the pore size distribution in the final ceramic can be altered by tuning the composition of the individual species used in the emulsion formulation, i.e., by optimization of the particle-polyelectrolyte ratio used in the processing route.
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Affiliation(s)
- Shumaila Shahid
- Polymer Engineering and Colloid Science (PECS) Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
| | - Nithin Madhavan
- Polymer Engineering and Colloid Science (PECS) Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India.,Metal Foams and Porous Materials Lab, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
| | - Manas Mukherjee
- Metal Foams and Porous Materials Lab, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science (PECS) Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
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24
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Upendar S, Mani E, Basavaraj MG. Pickering emulsions stabilized by sphere-spheroid mixtures. J DISPER SCI TECHNOL 2021. [DOI: 10.1080/01932691.2020.1798778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Siliveru Upendar
- Polymer Engineering and Colloid Science Lab (PECS Lab), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Ethayaraja Mani
- Polymer Engineering and Colloid Science Lab (PECS Lab), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Madivala G. Basavaraj
- Polymer Engineering and Colloid Science Lab (PECS Lab), Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
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25
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Stock S, Jakob F, Röhl S, Gräff K, Kühnhammer M, Hondow N, Micklethwaite S, Kraume M, von Klitzing R. Exploring water in oil emulsions simultaneously stabilized by solid hydrophobic silica nanospheres and hydrophilic soft PNIPAM microgel. SOFT MATTER 2021; 17:8258-8268. [PMID: 34550151 DOI: 10.1039/d1sm00942g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A general drawback of microgels is that they do not stabilize water-in-oil (w/o) emulsions of non-polar oils. Simultaneous stabilization with solid hydrophobic nanoparticles and soft hydrophilic microgels overcomes this problem. For a fundamental understanding of this synergistic effect the use of well defined particle systems is crucial. Therefore, the present study investigates the stabilization of water droplets in a highly non-polar oil phase using temperature responsive, soft and hydrophilic PNIPAM microgel particles (MGs) and solid and hydrophobic silica nanospheres (SNs) simultaneously. The SNs are about 20 times smaller than the MGs. In a multiscale approach the resulting emulsions are studied from the nanoscale particle properties over microscale droplet sizes to macroscopic observations. The synergy of the particles allows the stabilization of water-in-oil (w/o) emulsions, which was not possible with MGs alone, and offers a larger internal interface than the stabilization with SNs alone. Furthermore, the incorporation of hydrophilic MGs into a hydrophobic particle layer accelerates the emulsions sedimentation speed. Nevertheless, the droplets are still sufficiently protected against coalescence even in the sediment and can be redispersed by gentle shaking. Based on droplet size measurements and cryo-SEM studies we elaborate a model, which explains the found phenomena.
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Affiliation(s)
- Sebastian Stock
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Franziska Jakob
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Susanne Röhl
- Chair of Chemical and Process Engineering, Technische Universität Berlin, Berlin, Germany
| | - Kevin Gräff
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Matthias Kühnhammer
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds, UK
| | | | - Matthias Kraume
- Chair of Chemical and Process Engineering, Technische Universität Berlin, Berlin, Germany
| | - Regine von Klitzing
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
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26
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Ahmed R, Wang M, Qi Z, Hira NUA, Jiang J, Zhang H, Iqbal S, Wang J, Stuart MA, Guo X. Pickering Emulsions Based on the pH-Responsive Assembly of Food-Grade Chitosan. ACS OMEGA 2021; 6:17915-17922. [PMID: 34308026 PMCID: PMC8295998 DOI: 10.1021/acsomega.1c01490] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/07/2021] [Indexed: 05/07/2023]
Abstract
Few natural, biocompatible, and inexpensive emulsifiers are available because such emulsifiers must satisfy severe requirements, be produced synthetically rather than naturally, be nontoxic, and require minimal effort to produce. Therefore, the synthesis of food-grade and biocompatible nanoparticles as an alternative to surfactants has recently received attention in the industry. However, many previous efforts involved chemical modification of materials or the introduction of secondary cocomponents for emulsion formation. To achieve the goal of simple preparation, we consider here chitosan nanoparticles to prepare Pickering emulsions of food-grade oil through the control of pH, without further chemical modification or extra additives. A mild process can prepare nanoparticles from chitosan by simply increasing the pH from 3.0 to 6.0. The results showed that the average radius of chitosan at pH 6.0 was 170 nm, while large aggregates were formed at pH 6.5. These nanoparticles were utilized to prepare the Pickering emulsion. The average size of emulsion droplets decreased upon increasing the pH from 3.0 to 6.0. Moreover, Pickering emulsions at different oil fractions and nanoparticle concentrations were stable and showed a low creaming index for 45 days. The emulsions were stable against coalescence and flocculation and behaved rheologically as gel-like, shear-thinning fluids (G' > G″). Pickering emulsion prevents the growth of the microorganism (Staphylococcus aureus) at different pH values and chitosan concentrations. These results demonstrate that chitosan nanoparticles could be a cost-effective and biocompatible emulsifier for the food or pharmaceutical industry for encapsulation and bioactive compounds, and Pickering emulsions have promising antibacterial effects for further applications.
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Affiliation(s)
- Rizwan Ahmed
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Mingwei Wang
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Zhiyao Qi
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Noor ul ain Hira
- State
Key Laboratory of Advanced Polymeric Material, School of Materials
Science and Engineering, East China University
of Science and Technology, Shanghai 200237, P. R. China
| | - Jiahui Jiang
- College
of Life Science, Henan Agricultural University, Zhengzhou 450002, P. R. China
| | - Hongsen Zhang
- College
of Life Science, Henan Agricultural University, Zhengzhou 450002, P. R. China
| | - Shahid Iqbal
- School
of Chemical and Environmental Engineering, College of Chemistry, Chemical
Engineering and Materials Science, Soochow
University, Suzhou, Jiangsu 215123, P.
R. China
| | - Junyou Wang
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Martien Abraham
Cohen Stuart
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Xuhong Guo
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
- International
Joint Research Center of Green Energy Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
- Engineering
Research Center of Materials Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Xinjiang 832000, P. R.
China
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27
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Tao S, Jiang H, Gong S, Yin S, Li Y, Ngai T. Pickering Emulsions Simultaneously Stabilized by Starch Nanocrystals and Zein Nanoparticles: Fabrication, Characterization, and Application. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:8577-8584. [PMID: 34219459 DOI: 10.1021/acs.langmuir.1c01088] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Using two types of colloidal particles having natural origins to synergistically stabilize Pickering emulsions is essential for food, cosmetics, and pharmaceutics, especially when neither particle can stabilize the Pickering emulsions alone. The use of two natural stabilizers avoids the complicated surface treatments of particles and the introduction of poisonous or harmful chemicals. In this work, we report an all-natural Pickering emulsion stabilized synergistically by starch nanocrystals and zein protein nanoparticles. Our result shows that the electrostatic interaction between the two types of particles greatly affects their assembled structure at the oil/water interface, which is closely related to the emulsion stability. Specifically, particle bilayers could form with oppositely charged particles at the interface to endow the emulsion with improved stability. As a demonstration, the resultant Pickering emulsions effectively carry β-carotene and have high stability against high temperatures and ultraviolet radiation. This type of all-natural Pickering emulsion is a promising tool to protect and deliver liposoluble bioactive components.
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Affiliation(s)
- Shengnan Tao
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - Hang Jiang
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - Suijing Gong
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - Shouwei Yin
- Research and Development Center of Food Proteins, Department of Food Science and Technology, South China University of Technology, Guangzhou 510640, P. R. China
| | - Yunxing Li
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong
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28
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Kumar H, Dugyala VR, Basavaraj MG. Phase Inversion of Ellipsoid-Stabilized Emulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:7295-7304. [PMID: 34100620 DOI: 10.1021/acs.langmuir.1c00456] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The efficacy of anisotropic particles in Pickering emulsion stabilization, attributed to shape-induced capillary interactions, is well-documented in the literature. In this contribution, we show that the surface of hematite ellipsoids can be modified in situ by the addition of oleic acid to effect transitional phase inversion of Pickering emulsions. Interestingly, incorporation of oleic acid results in the formation of nonspherical emulsion drops. The phase inversion of oil-in-water to water-in-oil and the transition in shape of emulsion drops from spherical to nonspherical is observed in two different particle systems, namely, nanoellipsoids and microellipsoids. The surface of spherical emulsion drops stabilized by particles or particles along with high concentration of oleic acid is found to consist of ellipsoids arranged in a close-packed configuration with their major axis parallel to the interface. In contrast, at intermediate oleic acid concentration, the surface of nonspherical emulsion drops is observed to be covered with loosely packed particle monolayer, with the ellipsoids at the oil/water interface taking up many different orientations. Using contact angle goniometry, the change in the wettability of hematite particles due to adsorption of oleic acid is established to be the mechanism responsible for the phase inversion of Pickering emulsions.
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Affiliation(s)
- Hemant Kumar
- Polymer Engineering and Colloid Science(PECS) Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai - 600036, Tamil Nadu, India
| | - Venkateshwar Rao Dugyala
- Department of Chemical Engineering, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066 Madhya Pradesh, India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science(PECS) Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai - 600036, Tamil Nadu, India
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29
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Kulkarni N, Mani E. Stabilization of water-in-water pickering emulsions by charged particles. J DISPER SCI TECHNOL 2021. [DOI: 10.1080/01932691.2021.1931285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Neha Kulkarni
- Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India
| | - Ethayaraja Mani
- Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai, India
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30
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Liu Z, Hu M, Zhang S, Jiang L, Xie F, Li Y. Oil-in-water Pickering emulsion stabilization with oppositely charged polysaccharide particles: chitin nanocrystals/fucoidan complexes. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:3003-3012. [PMID: 33205457 DOI: 10.1002/jsfa.10934] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/06/2020] [Accepted: 11/17/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Chitin nanocrystals (ChN) are insoluble particles that can be used as stabilizers for Pickering emulsions. Their unique cationic properties and antibacterial activity have generated considerable interest among researchers. However, ChN have remained largely underexplored. Furthermore, the droplets of the emulsions stabilized by ChN are as large as 10-100 μm, and their physical stability requires further improvement. Some studies have shown that the spontaneous reaction of oppositely charged particles can effectively stabilize the emulsions. Positively charged ChN and negatively charged fucoidan (F) were therefore compounded to stabilize Pickering emulsions, and the stability of these emulsions was analyzed qualitatively. RESULTS The results showed that the composite particles comprising two polysaccharides in a mass ratio of 1:1 and at a pH of 2 (ChN1 -F1 -pH 2) possessed the lowest sulfate content (20.1%) and almost zero potential (-3 mV), indicating a high degree of neutralization of the positively charged amino group in ChN and the negatively charged sulfate group in F. Meanwhile, ChN1 -F1 -pH 2 displayed a dense network structure that improved the dispersibility and wettability (contact angle = 9.3°). Fourier transform infrared spectroscopy results confirmed that ChN and F were effectively combined through electrostatic interaction or neutralization to produce a polyelectrolyte complex. Furthermore, the particle size of the Pickering emulsion stabilized by ChN-F was significantly reduced, and the maximum size did not exceed 10 μm; the physical and storage stability also improved. The ChN1 -F1 -pH 2 emulsion presented excellent storage stability; in particular, the emulsions stabilized by ChN1 -F1 -pH 5 and ChN1 -F1 -pH 6 exhibited excellent flocculation stabilities. CONCLUSION The size of the emulsion droplets stabilized by the oppositely charged polysaccharide particles (ChN-F complexes) reduced significantly. Furthermore, by changing the mass ratio and pH, the microstructure and binding degree of the complexes can be adjusted, thereby promoting their adsorption on the oil-water interface and improving the stability of the Pickering emulsion. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Zhao Liu
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Miao Hu
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Shuang Zhang
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Lianzhou Jiang
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Fengying Xie
- College of Food Science, Northeast Agricultural University, Harbin, China
| | - Yang Li
- College of Food Science, Northeast Agricultural University, Harbin, China
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31
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Shahid S, Basavaraj MG. Controlling the microstructure of emulsions by exploiting particle-polyelectrolyte association. J Colloid Interface Sci 2021; 597:409-421. [PMID: 33895698 DOI: 10.1016/j.jcis.2021.03.148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/05/2021] [Accepted: 03/25/2021] [Indexed: 11/20/2022]
Abstract
HYPOTHESIS Albeit solid stabilized emulsions are studied for several decades, the surface of the emulsion drops most often are coated with densely packed and jammed monolayer of particles. However, a control over the area that the particles occupy on the drop surface is necessary, especially in applications involving controlled release of active compounds from emulsions. We hypothesize that it is possible to achieve precise control over the concentration of particles on the surface of emulsions by tailoring the adsorption of different species in a multi-component dispersion used for emulsification. EXPERIMENTS To this end, we carry out emulsification of oil and aqueous dispersions consisting of a combination of oppositely charged colloidal particles and polyelectrolyte. The droplet size distribution and storage stability of the oil-in-water emulsions, the microstructure, the percentage area of the drop surface occupied by the particles and the adsorption behavior of particle-polyelectrolyte binary dispersions are investigated. FINDINGS Our results demonstrate that the association between oppositely charged colloidal particles and polyelectrolyte can be exploited to obtain surface active species that aid in the formation of emulsions. Moreover, we found that the concentration of particle-polyelectrolyte complexes and polyelectrolyte in the dispersions used in emulsification greatly influence the mean diameter of the emulsions and their microstructure. Our findings provide a strategy to achieve control over surface coverage of particles on the emulsion droplets across a wide range - from a theoretically possible maximum, ≈90%, to as low as ≈5%. Interestingly, the emulsions formulated are found to possess excellent storage stability irrespective of the particle coverage on the drop surface.
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Affiliation(s)
- Shumaila Shahid
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai - 600036, Tamil Nadu, India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai - 600036, Tamil Nadu, India.
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32
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Jia K, Guo Y, Yu Y, Zhang J, Yu L, Wen W, Mai Y. pH-Responsive Pickering emulsions stabilized solely by surface-inactive nanoparticles via an unconventional stabilization mechanism. SOFT MATTER 2021; 17:3346-3357. [PMID: 33630989 DOI: 10.1039/d1sm00081k] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Using solely highly hydrophilic particles to stabilize emulsions, especially high internal phase emulsions, has always been an important challenge. Here pH-responsive Pickering emulsions stabilized by a low concentration of bare highly hydrophilic Ludox CL nanoparticles without surface modification or addition of surfactants are developed at neutral pH. The dispersed nanoparticles can be transformed into an aggregate state with a network-like structure near the isoelectric point, which contributes to the stabilization of the emulsions. Moreover, the vdW attraction between particles and droplets also plays a key role in the formation of emulsions, which can make the aggregated nanoparticles adsorb tightly around the droplets rather than penetrate the oil-water interface. The formed protective armor and network-like aggregates separate droplets from each other to prevent coalescence. At a low nanoparticle concentration (0.5 wt%), a high internal phase emulsion can be formed and can last up to half a year. This system can emulsify not only the hydrocarbon oil but also the fluoroalkane oil phase. Finally, organic-inorganic composite particles are fabricated using the template action of the Pickering emulsions. The method of preparing composite particles is more convenient than the traditional Pickering emulsion polymerization which often requires the modification of the surface of the hydrophilic particles or the addition of auxiliary monomers. This study provides a simple green strategy for the preparation of a more stable Pickering emulsion stabilized by surface-inactive nanoparticles and will broaden the scope of applications.
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Affiliation(s)
- Kangle Jia
- Guangdong Provincial Key Laboratory of Industrial Surfactant, Institute of Chemical Engineering, Guangdong Academy of Sciences, Guangzhou 510000, Guangdong, P. R. China.
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33
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Abstract
Particle-stabilised or Pickering emulsions are versatile systems. In the past 10 years a new application has emerged in the field of catalysis to use them as vehicles to carry out catalytic reactions, allowing a more environmentally friendly process with high conversions and selectivities and important advantages for catalyst recovery. As the area has advanced rapidly, the intention of this review is to summarize the latest innovations being reported. An overview is given regarding the kinds of liquid phases comprising the emulsion system, the different types of solid particle stabilizers (whether they contain catalyst or not) and the catalytic reactions studied. A section describing methods for recovering the catalyst is also included, in which various stimuli are discussed. Finally, the importance of using Pickering emulsions to carry out reactions in flow and in multi-step cascade systems is highlighted with various examples to support the benefits of transferring this technology to industrial processes.
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34
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Madhavan N, Mukherjee M, Basavaraj MG. Porous Ceramics via Processable Pickering Emulsion Stabilized by Oppositely Charged Colloids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11645-11654. [PMID: 32894827 DOI: 10.1021/acs.langmuir.0c02339] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report a method to produce processable Pickering emulsions in which electrostatic heteroaggregation of oppositely charged fumed silica and alumina particles is exploited. The ability of weakly charged heteroaggregates to adsorb to the oil-water interface favors the formation of highly stable emulsions. A control over the microstructure and rheology of the Pickering emulsion is demonstrated by tuning parameters such as composition, pH, and total concentration of particles. The Pickering emulsions formed under optimal conditions are found to be gel-like and are excellent templates for the fabrication of porous ceramics. Furthermore, the porous mullite ceramic structure which has exceptional thermal and chemical resistance under harsh environments is obtained by drying and sintering of the emulsion template. The phase evolution, microstructure, and porosity of the resulting ceramic are characterized.
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Affiliation(s)
- Nithin Madhavan
- Metal Foams and Porous Materials Lab, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Manas Mukherjee
- Metal Foams and Porous Materials Lab, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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35
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Water-in-oil emulsions stabilized by surfactants, biopolymers and/or particles: a review. Trends Food Sci Technol 2020. [DOI: 10.1016/j.tifs.2020.07.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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36
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Koroleva M, Yurtov E. Pickering emulsions stabilized with magnetite, gold, and silica nanoparticles: Mathematical modeling and experimental study. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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Cuetos A, Morillo N, Martı Nez Haya B. Coadsorption of Counterionic Colloids at Fluid Interfaces: A Coarse-Grained Simulation Study of Gibbs Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:2877-2885. [PMID: 32118442 DOI: 10.1021/acs.langmuir.9b03886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Monolayers of oppositely charged colloids form versatile self-organizing substrates, with a recognized potential to tailor functional interfaces. In this study, a coarse-grained Monte Carlo simulation approach is laid out to assess the structural properties of Gibbs monolayers, in which one of the counterionic species is partially soluble. It is shown that the composition of this type of monolayer varies in a nontrivial way with surface coverage, as a result of a subtle competition between steric and attractive forces. In the regime of weak electrostatic interactions, the monolayer is depleted of soluble colloids as the surface coverage is increased. At sufficiently strong interactions, the incorporation of soluble colloids is favored at high surface coverage, leading to a re-entrant-type behavior in the expansion/compression isotherms. Strong electrostatic interactions also favor the clustering of the colloids, leading to a range of aggregated configurations, qualitatively resembling those obtained in previous experimental studies. At sufficiently high surface coverage, the clusters collapse into a gel-like percolated mesoscopic structure and eventually into a square crystal lattice configuration. Such interfacial structures are in good agreement with the ones observed in the few experimental investigations available for these systems, showing that the simple methodology introduced in this study provides a valuable predictive framework to anticipate the landscape of interfacial structures that may be produced with oppositely charged colloids, through the modulation of pair interactions and thermodynamical conditions.
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Affiliation(s)
- Alejandro Cuetos
- Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, 41013 Seville, Spain
| | - Neftali Morillo
- Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, 41013 Seville, Spain
| | - Bruno Martı Nez Haya
- Department of Physical, Chemical and Natural Systems, Universidad Pablo de Olavide, 41013 Seville, Spain
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38
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Morozova T, Lee VE, Bizmark N, Datta SS, Prud’homme RK, Nikoubashman A, Priestley RD. In Silico Design Enables the Rapid Production of Surface-Active Colloidal Amphiphiles. ACS CENTRAL SCIENCE 2020; 6:166-173. [PMID: 32123734 PMCID: PMC7047274 DOI: 10.1021/acscentsci.9b00974] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Indexed: 05/02/2023]
Abstract
A new technology platform built on the integration of theory and experiments to enable the design of Janus colloids with precision control of surface anisotropy and amphiphilicity could lead to a disruptive transformation in the next generation of surfactants, photonic or phononic materials, and coatings. Here, we exploit molecular dynamics (MD) simulations to guide the rational design of amphiphilic polymer Janus colloids by Flash NanoPrecipitation (FNP), a method capable of the production of colloids with complex structure without the compromise of reduced scalability. Aided by in silico design, we show in experiments that amphiphilic Janus colloids can be produced using a unique blend of hydrophobic homopolymers and the addition of an amphiphilic block copolymer. The final structure of the colloids depends on the mass fraction of each homopolymer as well as the concentration and composition of the block copolymer additive. To confirm the surface activity of the colloids, we demonstrate their potential to stabilize Pickering emulsions. This hybrid approach of simulations and experiments provides a pathway to designing and manufacturing complex polymeric colloids on an industrial scale.
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Affiliation(s)
- Tatiana
I. Morozova
- Institute
of Physics, Johannes Gutenberg University
Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Victoria E. Lee
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Navid Bizmark
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Princeton
Institute for the Science and Technology of Materials, Princeton, New Jersey 08544, United States
| | - Sujit S. Datta
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Robert K. Prud’homme
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Arash Nikoubashman
- Institute
of Physics, Johannes Gutenberg University
Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Rodney D. Priestley
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Princeton
Institute for the Science and Technology of Materials, Princeton, New Jersey 08544, United States
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39
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Jiang H, Liu L, Li Y, Yin S, Ngai T. Inverse Pickering Emulsion Stabilized by Binary Particles with Contrasting Characteristics and Functionality for Interfacial Biocatalysis. ACS APPLIED MATERIALS & INTERFACES 2020; 12:4989-4997. [PMID: 31909591 DOI: 10.1021/acsami.9b16117] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Water-in-oil (w/o) Pickering emulsions have received considerable attention in biphasic enzymatic catalysis for their advantages of good stability, large interfacial area, and ease of product separation. However, enzymes are commonly encapsulated in the interior of aqueous droplets, which inevitably increases the diffusional resistance to catalysis. Alternatively, enzymes are immobilized or trapped into Pickering stabilizers. Often, however, these approaches suffer from leaching and a decrease of enzyme activity during the chemical treatments. We report here a new Pickering interfacial biocatalysis platform with efficient enzyme encapsulation, binary particle composition, and high catalytic performance. Our approach is based on w/o Pickering emulsions stabilized by binary particles consisting of hard silica and soft, pH-responsive microgel particles. We demonstrate that pH-responsive microgels can simultaneously stabilize a w/o Pickering emulsion, encapsulate enzymes, and catalyze reactions at the water/oil interface. In addition, we show that the coordination with rigid silica nanoparticles as additional stabilizers markedly improves the emulsion structure and will provide a new avenue for the preparation of w/o Pickering emulsion and concept of biphasic catalysis.
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Affiliation(s)
- Hang Jiang
- Department of Chemistry , The Chinese University of Hong Kong , Shatin , N.T., Hong Kong , P. R. China
| | - Liangdong Liu
- Department of Chemistry , The Chinese University of Hong Kong , Shatin , N.T., Hong Kong , P. R. China
| | - Yunxing Li
- Department of Chemistry , The Chinese University of Hong Kong , Shatin , N.T., Hong Kong , P. R. China
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering , Jiangnan University , Wuxi 214122 , P. R. China
| | - Shouwei Yin
- Research and Development Centre of Food Proteins, School of Food Science and Engineering , South China University of Technology , Guangzhou 510640 , P. R. China
| | - To Ngai
- Department of Chemistry , The Chinese University of Hong Kong , Shatin , N.T., Hong Kong , P. R. China
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40
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Tao S, Jiang H, Wang R, Yang C, Li Y, Ngai T. Ultra-stable Pickering emulsion stabilized by a natural particle bilayer. Chem Commun (Camb) 2020; 56:14011-14014. [DOI: 10.1039/d0cc05690a] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An all-natural Pickering emulsion with a Janus interface of particle bilayer is prepared, which has unprecedented stability.
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Affiliation(s)
- Shengnan Tao
- Key Laboratory of Synthetic and Biological Colloids
- Ministry of Education, School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
- China
| | - Hang Jiang
- Department of Chemistry
- The Chinese University of Hong Kong
- Shatin
- China
| | - Rongjie Wang
- Key Laboratory of Synthetic and Biological Colloids
- Ministry of Education, School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
- China
| | - Cheng Yang
- Key Laboratory of Synthetic and Biological Colloids
- Ministry of Education, School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
- China
| | - Yunxing Li
- Key Laboratory of Synthetic and Biological Colloids
- Ministry of Education, School of Chemical and Material Engineering
- Jiangnan University
- Wuxi 214122
- China
| | - To Ngai
- Department of Chemistry
- The Chinese University of Hong Kong
- Shatin
- China
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41
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Zembyla M, Lazidis A, Murray BS, Sarkar A. Water-in-Oil Pickering Emulsions Stabilized by Synergistic Particle-Particle Interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13078-13089. [PMID: 31525933 DOI: 10.1021/acs.langmuir.9b02026] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Here, we report a novel "double Pickering stabilization" of water-in-oil (W/O) emulsions, where complex formation at the interface between Pickering polyphenol particles adsorbing from the oil side and whey protein microgel (WPM) particles coadsorbing from the aqueous side of the interface is investigated. The interfacial complex formation was strongly dependent on the concentration of WPM particles. At low WPM concentrations, both polyphenol crystals and WPM particles are present at the interface and the water droplets were stabilized through their synergistic action, while at higher concentrations, the WPM particles acted as "colloidal glue" between the water droplets and polyphenol crystals, enhancing the water droplet stability for more than 90 days and prevented coalescence. Via this mechanism, the addition of WPM up to 1 wt % gave a significant improvement in the stability of the W/O emulsions, allowing an increase to a 20 wt % water droplet fraction. The evidence suggests that the complex was probably formed due to electrostatic attraction between oppositely charged polyphenol Pickering particles on the oil side of the interface and WPM Pickering particles mainly on the aqueous side of the interface. Interfacial shear viscosity measurements and monolayer (Langmuir trough) experiments at the air-water interface provided further evidence of this strengthening of the film due to the synergistic particle-particle complex formation at the interface.
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Affiliation(s)
- Morfo Zembyla
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition , University of Leeds , Leeds LS2 9JT , U.K
| | - Aris Lazidis
- Nestlé Product Technology Centre York , P. O. Box 204, Haxby Road , York YO91 1XY , U.K
| | - Brent S Murray
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition , University of Leeds , Leeds LS2 9JT , U.K
| | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition , University of Leeds , Leeds LS2 9JT , U.K
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42
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Bago Rodriguez AM, Binks BP, Sekine T. Emulsions Stabilized with Polyelectrolyte Complexes Prepared from a Mixture of a Weak and a Strong Polyelectrolyte. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:6693-6707. [PMID: 31063381 DOI: 10.1021/acs.langmuir.9b00897] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The possibility of stabilizing emulsions with polyelectrolyte complexes (PEC) obtained from the interaction of two non-surface-active oppositely charged polyelectrolytes (PEL) is described. Poly(allylamine hydrochloride) (PAH) and poly(4-styrene sulfonate) sodium salt are selected as the weak cationic and the strong anionic polyelectrolyte, respectively. Aqueous polymer mixtures are investigated by light scattering to determine the size of the complexes and whether precipitation or complex coacervation occurs. The effects of PEL mixing ratio, pH, and PEL concentration are studied in detail. By increasing the pH, the transition precipitate-precipitate/coacervate-coacervate-polymer solution is observed. At low pH, both PEL are fully ionized and therefore precipitates (soft particles) arise as a result of strong electrostatic interactions. By increasing the pH, the degree of ionization of PAH decreases and weak electrostatic interactions ensue, supporting the formation of coacervate droplets. The most stable oil-in-water emulsions are prepared from aqueous mixtures around charge neutralization. Although emulsions can be prepared from coacervate droplet dispersions, their coalescence stability is worse than those stabilized by soft PEC particles. By increasing the PEL concentration, the average droplet diameter decreases and the fraction of cream in the emulsion increases for emulsions prepared with PEC particles, following the limited coalescence model. However, at high concentrations, emulsion stability is slightly worse probably due to extensive aggregation of the particles. Viscous high internal phase emulsions can be prepared at low pH in which oil droplets are deformed. Here, PEC particles are detected only at the oil-water interface. At lower oil content, excess particles form a network in the aqueous phase aiding emulsion stability to coalescence.
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Affiliation(s)
| | - Bernard P Binks
- Department of Chemistry and Biochemistry , University of Hull , Hull HU6 7RX , U.K
| | - Tomoko Sekine
- Shiseido Global Innovation Center , 1-2-11, Takashima , Nishi-ku, Yokohama 220-0011 , Japan
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43
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Yang B, Leclercq L, Schmitt V, Pera-Titus M, Nardello-Rataj V. Colloidal tectonics for tandem synergistic Pickering interfacial catalysis: oxidative cleavage of cyclohexene oxide into adipic acid. Chem Sci 2019; 10:501-507. [PMID: 30713647 PMCID: PMC6334496 DOI: 10.1039/c8sc03345e] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/13/2018] [Indexed: 11/21/2022] Open
Abstract
Supramolecular preorganization and interfacial recognition can provide useful architectures for colloidal building. To this aim, a novel approach, based on colloidal tectonics involving two surface-active particles containing both recognition and catalytic sites, has been developed for controlling the formation and the properties of Pickering emulsions. This was illustrated by the combination of dodecyltrimethylammonium phosphotungstate nanoparticles, [C12]3[PW12O40], and silica particles functionalized with alkyl and sulfonic acid groups, [C n /SO3H]@SiO2. The interfacial self-assembly occurs by the penetration of the alkyl chains of [C n /SO3H]@SiO2 into the [C12]3[PW12O40] supramolecular porous structure constituted of polar and apolar regions. The emulsions were used as a non-nitric acid route for adipic acid synthesis from the one-pot oxidative cleavage of cyclohexene oxide with aqueous H2O2. The catalytic performance was significantly boosted due to the synergistic interactions between the particles.
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Affiliation(s)
- Bingyu Yang
- Univ. Lille , CNRS , Centrale Lille , ENSCL , Univ. Artois , UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide , F-59000 Lille , France . ;
| | - Loïc Leclercq
- Univ. Lille , CNRS , Centrale Lille , ENSCL , Univ. Artois , UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide , F-59000 Lille , France . ;
| | - Véronique Schmitt
- Centre de Recherche Paul Pascal , 115 Avenue du Dr Albert Schweitzer , F-33600 Pessac , France
| | - Marc Pera-Titus
- Eco-Efficient Products and Processes Laboratory (E2P2L) , Xin Zhuang Industrial Zone , UMI 3464 CNRS-Solvay, 3966 Jin Du Road , China .
| | - Véronique Nardello-Rataj
- Univ. Lille , CNRS , Centrale Lille , ENSCL , Univ. Artois , UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide , F-59000 Lille , France . ;
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44
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Anjali TG, Basavaraj MG. Shape-Anisotropic Colloids at Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3-20. [PMID: 29986588 DOI: 10.1021/acs.langmuir.8b01139] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Research in the 1980s demonstrated the formation of monolayers of particles achieved by interfacial particle trapping as a model system for investigating colloids in two dimensions. Since then, microscopy visualization of two-dimensional particle monolayers and quantification of the microstructure have led to significant fundamental understanding of a number of phenomena such as crystallization, freezing and melting transitions, dislocation dynamics, aggregation kinetics, and others. On the application front, particles at curved interfaces, as often the case in particle-stabilized emulsions and foams, have received considerable attention in the last few decades. The growing interest in the search for novel particles and new strategies to effect emulsion stabilization stems from their application in several disciplines. Moreover, particle-stabilized Pickering emulsions and foams can also be used to derive a number of advanced functional materials. Compared to several accounts of research on spherical colloids at fluid-fluid interfaces, investigations of the behavior of shape-anisotropic particles at interfaces, albeit receiving considerable attention in recent years, are still in a nascent stage. The objective of this feature article is to highlight our recent work in this area. In particular, the adsorption of shape-anisotropic particles to interfaces, wetting behavior, interfacial self-assembly, the response of nonspherical-particle-coated interfaces to compression and shear, and their ability to stabilize emulsions are discussed.
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Affiliation(s)
- Thriveni G Anjali
- Polymer Engineering and Colloid Science (PECS) Laboratory, Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai 600 036 , India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science (PECS) Laboratory, Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai 600 036 , India
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Koroleva M, Bidanov D, Yurtov E. Emulsions stabilized with mixed SiO2 and Fe3O4 nanoparticles: mechanisms of stabilization and long-term stability. Phys Chem Chem Phys 2019; 21:1536-1545. [DOI: 10.1039/c8cp05292a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Using SiO2 and Fe3O4 nanoparticles as stabilizers makes it possible to obtain Pickering emulsions with long-term stability to coalescence and creaming.
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Affiliation(s)
- M. Koroleva
- Mendeleev University of Chemical Technology
- Moscow 125047
- Russia
| | - D. Bidanov
- Mendeleev University of Chemical Technology
- Moscow 125047
- Russia
| | - E. Yurtov
- Mendeleev University of Chemical Technology
- Moscow 125047
- Russia
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46
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Cerbelaud M, Aimable A, Videcoq A. Role of Electrostatic Interactions in Oil-in-Water Emulsions Stabilized by Heteroaggregation: An Experimental and Simulation Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:15795-15803. [PMID: 30507135 DOI: 10.1021/acs.langmuir.8b02922] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Oil-in-water emulsion stabilization by heteroaggregation of hydrophilic particles without a surfactant is of importance in a wide range of applications; however, the stabilization mechanism is little described. To shed light on the early stage of the stabilization mechanism, a model system composed of an oil wax phase dispersed in water with oppositely charged colloidal particles is studied experimentally and numerically. Experiments show that the colloids do not penetrate deeply in the oil phase, suggesting that adsorption of the colloidal particles on the wax droplets is mainly due to electrostatic interactions. Experiments and Brownian dynamics simulations show also that when oppositely charged colloidal particles are present in the emulsion, a multilayer coating of heteroaggregated colloidal particles is formed around the wax droplets. This protective coating is expected to prevent from the oil droplet coalescence and therefore to stabilize the emulsion.
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Affiliation(s)
| | - Anne Aimable
- Université Limoges, CNRS, IRCER, UMR 7315 , F-87000 Limoges , France
| | - Arnaud Videcoq
- Université Limoges, CNRS, IRCER, UMR 7315 , F-87000 Limoges , France
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47
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Kang DW, Park BG, Choi KH, Lim JH, Lee SJ, Park BJ. Geometric Effects of Colloidal Particles on Stochastic Interface Adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:8839-8847. [PMID: 29985624 DOI: 10.1021/acs.langmuir.8b01124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The stochastic interface adsorption behaviors of ellipsoid particles were investigated using optical laser tweezers. The particles were brought close to the oil-water interface, attempting to attach forcefully to the interface. Multiple attempts of the particle attachments statistically quantified the dependence of the adsorption probability on the particle aspect ratio. It was found that the adsorption probability proportionally increased with the aspect ratio because of the decrease in electrostatic interactions between the charged particles and the charged interface for higher aspect ratio particles. In addition, the adsorption holding time required for the interface attachments was found to increase as the aspect ratio decreased. Notably, the probabilistic adsorption behaviors of the ellipsoid particles and the holding time dependence revealed that the particle adsorption to the interface occurred stochastically, not deterministically. We also demonstrated that the adsorption behaviors measured on a single-particle scale were consistent with the gravity-induced spontaneous adsorption properties performed on a large scale with regard to the nondeterministic adsorption behaviors and the aspect ratio dependence on the adsorption probability.
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Affiliation(s)
- Dong Woo Kang
- Department of Chemical Engineering , Kyung Hee University , Yongin 17104 , South Korea
| | - Byung Gyu Park
- Department of Polymer Engineering , The University of Suwon , Hwaseong , Gyeonggi 18323 , South Korea
| | - Kyu Hwan Choi
- Department of Chemical Engineering , Kyung Hee University , Yongin 17104 , South Korea
| | - Jin Hyun Lim
- Department of Chemical Engineering , Kyung Hee University , Yongin 17104 , South Korea
| | - Seong Jae Lee
- Department of Polymer Engineering , The University of Suwon , Hwaseong , Gyeonggi 18323 , South Korea
| | - Bum Jun Park
- Department of Chemical Engineering , Kyung Hee University , Yongin 17104 , South Korea
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48
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Upendar S, Mani E, Basavaraj MG. Aggregation and Stabilization of Colloidal Spheroids by Oppositely Charged Spherical Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6511-6521. [PMID: 29758160 DOI: 10.1021/acs.langmuir.8b00645] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Heteroaggregation of colloids is an important yet complex physical process involving colloidal/nanosized particles and is relevant in river delta formation, paper-making, water treatment, blood flocculation, and so on. Despite the earlier studies on oppositely charged spherical colloids, heteroaggregation of colloids of different shapes is less explored. In this regard, we report an experimental study to investigate the colloidal stability of mixture of positively charged spheroidal hematite and negatively charged spherical silica nanoparticles. In this study, pH and surface area ratio (silica to hematite, SS-H) are varied to tune the colloidal stability/instability of the suspension. At pH 6.5 and low SS-H, the silica particles adsorb onto the hematite particles and reduce the effective charge of the latter, leading to aggregation and resulting in unstable dispersions. At higher SS-H, adsorption of silica on hematite leads to overcharging and charge reversal, which leads to a stable dispersion. Similar experiments were performed at pH 2.4 and 3.5, and the crossover from unstable to stable dispersion is observed as a function of SS-H. Calculation of Derjaguin, Landau, Verwey, and Overbeek (DLVO) interaction between particles in the binary mixture, as a function of pH and SS-H, based on the aggregate size and zeta potential, explains the transition from unstable to stable dispersion. The size and zeta potential of heteroaggregates in the dispersion were analyzed by dynamic light scattering (DLS) technique. Adsorption of silica nanoparticles on hematite particles was visualized by scanning electron microscopy (SEM). The study provides a framework based on DLVO interactions to stabilize or destabilize a colloidal dispersion of nonspherical particles by controlled addition of oppositely charged spherical colloids, which is a feat that is not possible with simple salt. The stability ratio ( W) calculated from DLVO interactions demark the unstable-stable dispersion regions, which is found to be in agreement with the experimental results.
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Affiliation(s)
- Siliveru Upendar
- Polymer Engineering and Colloid Science Lab (PECS Lab), Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai - 600 036 , Tamil Nadu , India
| | - Ethayaraja Mani
- Polymer Engineering and Colloid Science Lab (PECS Lab), Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai - 600 036 , Tamil Nadu , India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science Lab (PECS Lab), Department of Chemical Engineering , Indian Institute of Technology Madras , Chennai - 600 036 , Tamil Nadu , India
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49
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Shahid S, Gurram SR, Basavaraj MG. Doubly pH Responsive Emulsions by Exploiting Aggregation of Oppositely Charged Nanoparticles and Polyelectrolytes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5060-5071. [PMID: 29649875 DOI: 10.1021/acs.langmuir.8b00795] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
We present a simple and modular approach to realize highly stable pH responsive Pickering emulsion from mixtures of commercially available oppositely charged nanoparticle and polyelectrolyte. While highly charged nanoparticles and polyelectrolytes when used solely do not stabilize emulsions, we show that the electrostatic attraction between oppositely charged nanoparticles and polyelectrolytes can be exploited to formulate emulsions with long-term stability of up to 8 months. The Ludox CL nanoparticles and poly(4-styrenesulfonate) sodium salt (PSS) when dispersed in aqueous solution at pH 2-11 form particle polyelectrolyte complexes (PPCs) due to heteroaggregation. These complexes are effective in stabilizing oil-in-water Pickering emulsions. We demonstrate that this is due to the formation of weakly charged complexes that are surface active and hence readily adsorbed to the oil-water interface created during emulsification. We show that the composition of nanoparticles and polyelectrolytes in the mixture as well as the pH can be tuned to control the average diameter of the emulsions droplets. Immediate destabilization and doubled responsiveness of the emulsions stabilized by particle polyelectrolyte complexes are illustrated by changing the pH of the stable emulsions formed at intermediate pH to either 1 or 13. The aggregation behavior of nanoparticle-polyelectrolyte mixtures and the effect of various parameters such as mixing fraction, pH, and energy input on the formation of Pickering emulsions is discussed. Furthermore, we show that the formation of near charge neutral aggregates that exhibit optimal wetting conditions is a requirement to accomplish emulsion formation. The visualization of particle polyelectrolyte complexes around the emulsion droplets, their morphology prior to emulsification, and their wetting properties are also investigated to elucidate the mechanism of emulsification.
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Affiliation(s)
- Shumaila Shahid
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering , Indian Institute of Technology , Madras, Chennai 600036 , India
| | - Swaroop Rajesh Gurram
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering , Indian Institute of Technology , Madras, Chennai 600036 , India
| | - Madivala G Basavaraj
- Polymer Engineering and Colloid Science Laboratory, Department of Chemical Engineering , Indian Institute of Technology , Madras, Chennai 600036 , India
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50
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Pentyala P, Shahid M, Ramamirtham S, Basavaraj MG. Porous materials from oppositely charged nanoparticle gel emulsions. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2018.02.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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