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Zhang Y, Zhang Y, Ding R, Zhang K, Guo H, Lin Y. Self-Assembled Nanocarrier Delivery Systems for Bioactive Compounds. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2310838. [PMID: 38214694 DOI: 10.1002/smll.202310838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/25/2023] [Indexed: 01/13/2024]
Abstract
Although bioactive compounds (BCs) have many important functions, their applications are greatly limited due to their own defects. The development of nanocarriers (NCs) technology has gradually overcome the defects of BCs. NCs are equally important as BCs to some extent. Self-assembly (SA) methods to build NCs have many advantages than chemical methods, and SA has significant impact on the structure and function of NCs. However, the relationship among SA mechanism, structure, and function has not been given enough attention. Therefore, from the perspective of bottom-up building mechanism, the concept of SA-structure-function of NCs is emphasized to promote the development of SA-based NCs. First, the conditions and forces for occurring SA are introduced, and then the SA basis and molecular mechanism of protein, polysaccharide, and lipid are summarized. Then, varieties of the structures formed based on SA are introduced in detail. Finally, facing the defects of BCs and how to be well solved by NCs are also elaborated. This review attempts to describe the great significance of constructing artificial NCs to deliver BCs from the aspects of SA-structure-function, so as to promote the development of SA-based NCs and the wide application of BCs.
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Affiliation(s)
- Yafei Zhang
- Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Yuning Zhang
- Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Rui Ding
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100089, China
| | - Kai Zhang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Science and Engineering, Tianjin University of Science and Technology, Tianjin, 300457, China
| | - Huiyuan Guo
- Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100089, China
| | - Yingying Lin
- Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100089, China
- Food Laboratory of Zhongyuan, Luohe, 462300, China
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2
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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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3
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Xie H, Zhao W, Zhang X, Wang Z. Demulsification of Bacteria-Stabilized Pickering Emulsions Using Modified Silica Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2022; 14:24102-24112. [PMID: 35603430 DOI: 10.1021/acsami.2c02526] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Pickering emulsions stabilized by bacteria acting as particle emulsifiers are new platforms for microbial transformations of hydrophobic chemicals. However, their high stability often hampers demulsification during downstream processing. Since the existing methods (like addition of surfactants) to demulsify bacteria-stabilized Pickering emulsions have negative effects, new practical methods need to be developed. Here, using chemically modified fumed silica particles with different hydrophobicity, the demulsification of W/O Pickering emulsions stabilized by Mycobacterium neoaurum whole cells was first studied. The binary particle-stabilized emulsions exhibited phase inversion and dewatering induced by the coalescence of W/O emulsions or creaming of O/W emulsions. The silica particle hydrophobicity and concentration were the important parameters influencing the emulsion type, droplet morphology, and dewatering rate. The highest dewatering rate and largest droplet size were obtained at the inversion point from W/O to O/W. Confocal microscopy showed that no interaction between the bacteria and silica particles existed and the silica particle adsorption at the interface induced the detachment of bacteria from the interface, revealing that there was competitive adsorption between the binary particles at the interface. Based on these results, we suggested that the average hydrophobicity of the binary particles at the interface would determine the emulsion type and stability. Finally, this strategy was successfully applied to the demulsification of the Pickering emulsion formed during microbial transformation of sterols. Overall, this study provides a new strategy to demulsify Pickering emulsions by addition of another particle emulsifier. This is also the first example of separation of products as well as organic phases after microbial transformation in Pickering emulsions.
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Affiliation(s)
- Haisheng Xie
- State Key Laboratory of Microbial Metabolism, Engineering Research Center of Cell & Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan, Shanghai 200240, China
| | - Wenyu Zhao
- State Key Laboratory of Microbial Metabolism, 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, 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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Zhao H, Yang Y, Chen Y, Li J, Wang L, Li C. A review of multiple Pickering emulsions: Solid stabilization, preparation, particle effect, and application. Chem Eng Sci 2022. [DOI: 10.1016/j.ces.2021.117085] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5
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Zhang Z, Li Q, Sun N, Liu Y, Ge S, Che H, Li A. The preparation of stimulus-responsive Pickering emulsion and its application in preparing microspheres. J DISPER SCI TECHNOL 2022. [DOI: 10.1080/01932691.2021.2025070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Zhaoyu Zhang
- School of Materials Science and Engineering, Shandong University of Technology, Zibo, Shandong, P.R. China
| | - Qiuhong Li
- School of Materials Science and Engineering, Shandong University of Technology, Zibo, Shandong, P.R. China
| | - Ning Sun
- School of Materials Science and Engineering, Shandong University of Technology, Zibo, Shandong, P.R. China
| | - Yunxiao Liu
- Dezhou Linglong Tire Co., Ltd, Dezhou, Shandong, P.R. China
| | - Shujin Ge
- School of Materials Science and Engineering, Shandong University of Technology, Zibo, Shandong, P.R. China
| | - Hongyan Che
- School of Materials Science and Engineering, Shandong University of Technology, Zibo, Shandong, P.R. China
| | - Aixiang Li
- School of Materials Science and Engineering, Shandong University of Technology, Zibo, Shandong, P.R. China
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Velandia SF, Marchal P, Lemaitre C, Sadtler V, Roques-Carmes T. Evaluation of the repartition of the particles in Pickering emulsions in relation with their rheological properties. J Colloid Interface Sci 2021; 589:286-297. [PMID: 33472148 DOI: 10.1016/j.jcis.2021.01.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 12/21/2020] [Accepted: 01/03/2021] [Indexed: 10/22/2022]
Abstract
HYPOTHESIS The distribution of particles in Pickering emulsions can be estimated through a percolation-type approach coupled to the evolution of their rheological features with the dispersed phase volume fraction ϕ. EXPERIMENTS The rheological behavior of water-in-dodecane Pickering emulsions stabilized with hydrophobic silica nanoparticles is addressed. The emulsions viscosity and elastic modulus are investigated at ϕ varying from 0.1 to 0.75. Various rheological models are adjusted to the experimental data. FINDINGS The comparison of the elastic modulus evolution of the Pickering emulsions with those of emulsions stabilized with surfactants confirms a major contribution of the particles to the rheological behavior of Pickering emulsions and supports the existence of a three-dimensional network between the droplets. The applied percolation approach allows to quantitively estimate a nanoparticles viscoelastic link between the droplets and opposes the classic vision of interfacial monolayers stabilizing the Pickering emulsions. This network of interconnected particles and droplets contributes significantly to the viscosity as well as the elastic modulus of these emulsions. To our knowledge, the applied percolation-based model is the only one capable of providing a structural explanation while describing the abrupt viscosity and elastic modulus growth of Pickering emulsions across the range of ϕ.
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Affiliation(s)
- Santiago F Velandia
- Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS, Université de Lorraine, 1 rue Grandville, 54001 Nancy, France.
| | - Philippe Marchal
- Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS, Université de Lorraine, 1 rue Grandville, 54001 Nancy, France.
| | - Cécile Lemaitre
- Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS, Université de Lorraine, 1 rue Grandville, 54001 Nancy, France.
| | - Véronique Sadtler
- Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS, Université de Lorraine, 1 rue Grandville, 54001 Nancy, France.
| | - Thibault Roques-Carmes
- Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS, Université de Lorraine, 1 rue Grandville, 54001 Nancy, France.
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Sadgar AL, Deore TS, Jayaram RV. Pickering Interfacial Catalysis-Knoevenagel Condensation in Magnesium Oxide-Stabilized Pickering Emulsion. ACS OMEGA 2020; 5:12224-12235. [PMID: 32548405 PMCID: PMC7271354 DOI: 10.1021/acsomega.0c00819] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 05/07/2020] [Indexed: 06/01/2023]
Abstract
In the present study, a novel catalytic route for the Knoevenagel condensation reaction has been developed by Pickering interfacial catalysis using magnesium oxide (MgO) as both an emulsion stabilizer and a base catalyst. MgO was prepared by the precipitation method using sodium hydroxide or ammonium hydroxide as the precipitating agent and calcined at different temperatures. The calcined samples were characterized by XRD, SEM, TEM, AFM, BET, and DLS techniques. The catalytic application of the emulsions stabilized by MgO was investigated for the Knoevenagel condensation reaction of benzaldehyde and its derivatives with malononitrile. All of the reactions were carried out at an ambient temperature (30 °C) under static conditions without stirring. Both the emulsion-stabilizing ability and the catalytic activity of MgO were found to be affected by the method of preparation, calcination temperature, and the nature of the oil phase. It was observed that the method of preparation varied the texture and morphology of MgO and thus the stability and droplet size of the emulsion formed. This was further reflected in the catalytic activity. The highest yield (87%) of the condensation product was obtained with MgO prepared by precipitation using a strong base (NaOH) and further calcined at 400 °C. The developed catalytic system offers several green chemistry advantages such as reusable solid-base catalyst and use of a single material as both emulsion stabilizer and catalyst. Room-temperature reaction under static conditions is an additional advantage of the developed catalytic system.
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Rahman SE, Laal-Dehghani N, Christopher GF. Interfacial Viscoelasticity of Self-Assembled Hydrophobic/Hydrophilic Particles at an Air/Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13116-13125. [PMID: 31539264 DOI: 10.1021/acs.langmuir.9b02251] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hydrophobic/hydrophilic mixtures of latex particles at an air/water interface self-assemble, creating space filling, interconnected aggregates as the relative surface fractions of the dissimilar particles approach 0.5, which is reflected both in qualitative observation and fractal dimension of the microstructure. It is hypothesized that this change in microstructure occurs due to an asymmetry in the electrostatic interaction between similar and dissimilar particles caused by polarization of hydrophilic particles by hydrophobic particles. The changes in both microstructure and interparticle interactions significantly impact the interfacial viscoelasticity. As greater shape complexity is observed, interfacial complex moduli can increase by as much as 3 orders of magnitude and interfaces become more elastic.
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Affiliation(s)
- Syed Ehsanur Rahman
- Department of Mechanical Engineering , Texas Tech University , Lubbock , Texas 79409 , United States
| | - Nader Laal-Dehghani
- Department of Chemical Engineering , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Gordon F Christopher
- Department of Mechanical Engineering , Texas Tech University , Lubbock , Texas 79409 , United States
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9
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Modifying interfacial interparticle forces to alter microstructure and viscoelasticity of densely packed particle laden interfaces. J Colloid Interface Sci 2019; 536:30-41. [DOI: 10.1016/j.jcis.2018.10.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 11/20/2022]
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10
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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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11
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Stehl D, Milojević N, Stock S, Schomäcker R, von Klitzing R. Synergistic Effects of a Rhodium Catalyst on Particle-Stabilized Pickering Emulsions for the Hydroformylation of a Long-Chain Olefin. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b04619] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dmitrij Stehl
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
| | - Nataša Milojević
- Department of Chemistry, Technische Universität Berlin, Berlin, Germany
| | - Sebastian Stock
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
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12
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Binks BP, Olusanya SO. Phase Inversion of Colored Pickering Emulsions Stabilized by Organic Pigment Particle Mixtures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5040-5051. [PMID: 29676155 DOI: 10.1021/acs.langmuir.8b00715] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Pickering emulsions stabilized by a mixture of colored organic pigment particles of different hydrophobicity have been investigated at equal oil/water ratio and a fixed overall particle concentration by several complementary methods. Transitional phase inversion of emulsions from water-in-oil to oil-in-water can be effected by increasing the fraction of hydrophilic pigment orange in mixtures with either hydrophobic pigment yellow, red, indigo, or blue. In two mixtures, we find that a distinct change in the color of emulsions occurs at phase inversion. Although the fraction of pigment orange required depends on the particular hydrophobic pigment selected, phase inversion occurs at a similar surface energy of the particle mixture, which lies between that of the hydrophilic pigment and those of the hydrophobic pigments. We show that both pigment types are present at the oil-water interface simultaneously, giving rise to emulsions that are extremely stable to coalescence. The average drop size for both emulsion types increases toward phase inversion, in line with an increase in the extent of sedimentation/creaming at long times.
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Affiliation(s)
- Bernard P Binks
- School of Mathematics and Physical Sciences , University of Hull , Hull HU6 7RX , United Kingdom
| | - Samuel O Olusanya
- School of Mathematics and Physical Sciences , University of Hull , Hull HU6 7RX , United Kingdom
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13
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Study of the properties of oil, particles, and water on particle adsorption dynamics at an oil/water interface using the colloidal probe technique. Chem Eng Res Des 2016. [DOI: 10.1016/j.cherd.2016.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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14
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Zhou Q, Sun Y, Yi S, Wang K, Luo G. Investigation of droplet coalescence in nanoparticle suspensions by a microfluidic collision experiment. SOFT MATTER 2016; 12:1674-1682. [PMID: 26701864 DOI: 10.1039/c5sm02924d] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Understanding the phenomenon of droplet coalescence in nanoparticle suspensions is extremely important for the preparation of Pickering emulsions. A microfluidic platform, which can provide compulsive droplet collisions, was developed to imitate the droplet coalescence process in the early stages of emulsification. Microscope videos showed the variations in the droplet coalescence percentage, droplet contact time, and liquid film drainage time in different working systems containing 158-306 nm polystyrene (PS) particles in the continuous oil phase. The intersections of the half and total droplet contact times as well as the liquid film drainage time indicated the transitions of coalescence percentage. The additional hydrodynamic resistance in the liquid film between the approaching interfaces caused by the embedded hydrophobic nanoparticles was understood to be the main reason for reduced droplet coalescence, whereas hydrophilic particles were found to promote coalescence. As a novel method, the microfluidic collision experiment provided accurate and quantitative data for analyzing the formation of Pickering emulsions.
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Affiliation(s)
- Qianqian Zhou
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
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15
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Snoeyink C, Barman S, Christopher GF. Contact angle distribution of particles at fluid interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:891-897. [PMID: 25548951 DOI: 10.1021/la5040195] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Recent measurements have implied a distribution of interfacially adsorbed particles' contact angles; however, it has been impossible to measure statistically significant numbers for these contact angles noninvasively in situ. Using a new microscopy method that allows nanometer-scale resolution of particle's 3D positions on an interface, we have measured the contact angles for thousands of latex particles at an oil/water interface. Furthermore, these measurements are dynamic, allowing the observation of the particle contact angle with high temporal resolution, resulting in hundreds of thousands of individual contact angle measurements. The contact angle has been found to fit a normal distribution with a standard deviation of 19.3°, which is much larger than previously recorded. Furthermore, the technique used allows the effect of measurement error, constrained interfacial diffusion, and particle property variation on the contact angle distribution to be individually evaluated. Because of the ability to measure the contact angle noninvasively, the results provide previously unobtainable, unique data on the dynamics and distribution of the adsorbed particles' contact angle.
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Affiliation(s)
- Craig Snoeyink
- Department of Mechanical Engineering, Texas Tech University , Lubbock, Texas 79409-1035, United States
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16
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Barman S, Christopher GF. Simultaneous interfacial rheology and microstructure measurement of densely aggregated particle laden interfaces using a modified double wall ring interfacial rheometer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:9752-9760. [PMID: 25068732 DOI: 10.1021/la502329s] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The study of particle laden interfaces has increased significantly due to the increasing industrial use of particle stabilized foams and Pickering emulsions, whose bulk rheology and stability are highly dependent on particle laden interface's interfacial rheology, which is a function of interfacial microstructure. To understand the physical mechanisms that dictate interfacial rheology of particle laden interfaces requires correlating rheology to microstructure. To achieve this goal, a double wall ring interfacial rheometer has been modified to allow real time, simultaneous interfacial visualization and shear rheology measurements. The development of this tool is outlined, and its ability to provide novel and unique measurements is demonstrated on a sample system. This tool has been used to examine the role of microstructure on the steady shear rheology of densely packed, aggregated particle laden interfaces at three surface concentrations. Through examination of the rheology and analysis of interfacial microstructure response to shear, a transition from shear thinning due to aggregated cluster breakup to yielding at a slip plane within the interface has been identified. Interestingly, it is found that aggregated interfaces transition to yielding well before they reached a jammed state. Furthermore, these systems undergo significant shear induced order when densely packed. These results indicate that the mechanics of these interfaces are not simply jammed or unjammed and that the interfacial rheology relationship with microstructure can give us significant insight into understanding how to engineer particle laden interfaces in the future. By examining both rheology and microstructure, the mechanisms that dictate observed rheology are now understood and can be used to predict and control the rheology of the interface.
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Affiliation(s)
- Sourav Barman
- Department of Mechanical Engineering, Texas Tech University , Lubbock, Texas 79409-1021, United States
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17
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Günther F, Frijters S, Harting J. Timescales of emulsion formation caused by anisotropic particles. SOFT MATTER 2014; 10:4977-89. [PMID: 24888563 DOI: 10.1039/c3sm53186d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Particle stabilized emulsions have received much interest in the recent past, but our understanding of the dynamics of emulsion formation is still limited. For simple spherical particles, the time dependent growth of fluid domains is dominated by the formation of droplets, particle adsorption and coalescence of droplets (Ostwald ripening), which eventually can be almost fully blocked due to the presence of the particles. Ellipsoidal particles are known to be more efficient stabilizers of fluid interfaces than spherical particles and their anisotropic shape and the related additional rotational degrees of freedom have an impact on the dynamics of emulsion formation. In this paper, we investigate this point by means of simple model systems consisting of a single ellipsoidal particle or a particle ensemble at a flat interface as well as a particle ensemble at a spherical interface. By applying combined multicomponent lattice Boltzmann and molecular dynamics simulations we demonstrate that the anisotropic shape of ellipsoidal particles causes two additional timescales to be of relevance in the dynamics of emulsion formation: a relatively short timescale can be attributed to the adsorption of single particles and the involved rotation of particles towards the interface. As soon as the interface is jammed, however, capillary interactions between the particles cause a local reordering on very long timescales leading to a continuous change in the interface configuration and increase of the interfacial area. This effect can be utilized to counteract the thermodynamic instability of particle stabilized emulsions and thus offers the possibility to produce emulsions with exceptional stability.
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Affiliation(s)
- Florian Günther
- Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, NL-5600MB Eindhoven, The Netherlands.
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18
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Particle self-assembly at ionic liquid-based interfaces. Adv Colloid Interface Sci 2014; 206:92-105. [PMID: 24230971 DOI: 10.1016/j.cis.2013.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/31/2013] [Accepted: 09/20/2013] [Indexed: 11/20/2022]
Abstract
This review presents an overview of the nature of ionic liquid (IL)-based interfaces and self-assembled particle morphologies of IL-in-water, oil- and water-in-IL, and novel IL-in-IL Pickering emulsions with emphasis on their unique phenomena, by means of experimental and computational studies. In IL-in-water Pickering emulsions, particles formed monolayers at ionic liquid-water interfaces and were close-packed on fully covered emulsion droplets or aggregated on partially covered droplets. Interestingly, other than equilibrating at the ionic liquid-water interfaces, microparticles with certain surface chemistries were extracted into the ionic liquid phase with a high efficiency. These experimental findings were supported by potential of mean force calculations, which showed large energy drops as hydrophobic particles crossed the interface into the IL phase. In the oil- and water-in-IL Pickering emulsions, microparticles with acidic surface chemistries formed monolayer bridges between the internal phase droplets rather than residing at the oil/water-ionic liquid interfaces, a significant deviation from traditional Pickering emulsion morphology. Molecular dynamics simulations revealed aspects of the mechanism behind this bridging phenomenon, including the role of the droplet phase, surface chemistry, and inter-particle film. Novel IL-in-IL Pickering emulsions exhibited an array of self-assembled morphologies including the previously observed particle absorption and bridging phenomena. The appearance of these morphologies depended on the particle surface chemistry as well as the ILs used. The incorporation of particle self-assembly with ionic liquid science allows for new applications at the intersection of these two fields, and have the potential to be numerous due to the tunability of the ionic liquids and particles incorporated, as well as the particle morphology by combining certain groups of particle surface chemistry, IL type (protic or aprotic), and whether oil or water is incorporated.
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Frost DS, Ngan M, Dai LL. Spontaneous transport of microparticles across liquid-liquid interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9310-9315. [PMID: 23802838 DOI: 10.1021/la4022905] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Transporting micrometer-sized particles through the liquid-liquid interface generally requires high shear force and sometimes surfactant functionalization. Without these aids, particles adhere to the interface due to strong capillary forces (can be on the order of 10(6) kT). Thus, spontaneous transport of microparticles through the liquid-liquid interface has not yet been reported. However, we present a new phenomenon here: some ionic liquids (ILs) possess powerful extraction capabilities and can cause microparticles to migrate across the interface without the aid of any shear forces. Both single particles and clusters of particles were observed to adsorb to, then "jump" across the interface and finally detach. In the absence of external mixing, particles as large as 4 μm (in diameter) could completely penetrate the IL/water interface, despite the significant adhesive forces. We have presented a hypothesis that these forces were overcome by ions dissolved in the non-IL phase, which helped by covering the particle surfaces, allowing for more favorable interactions with the IL.
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Affiliation(s)
- Denzil S Frost
- School for Engineering of Matter, Transport, and Engineering, Arizona State University, Tempe, Arizona 85287, USA
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Zou J, Frost DS, Dai LL. Effects of gelator 12-hydroxystearic acid (12-HSA) on ionic liquid based Pickering emulsions. Colloids Surf A Physicochem Eng Asp 2012. [DOI: 10.1016/j.colsurfa.2012.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Frost DS, Schoepf JJ, Nofen EM, Dai LL. Understanding droplet bridging in ionic liquid-based Pickering emulsions. J Colloid Interface Sci 2012; 383:103-9. [DOI: 10.1016/j.jcis.2012.06.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 06/01/2012] [Accepted: 06/02/2012] [Indexed: 11/30/2022]
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Du K, Liddle JA, Berglund AJ. Three-dimensional real-time tracking of nanoparticles at an oil-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:9181-8. [PMID: 22667449 DOI: 10.1021/la300292r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Single-particle tracking with real-time feedback control can be used to study three-dimensional nanoparticle transport dynamics. We apply the method to study the behavior of adsorbed nanoparticles at a silicone oil-water interface in a microemulsion system over a range of particles sizes from 24 nm to 2000 nm. The diffusion coefficient of large particles (>200 nm) scales inversely with particle size, while smaller particles exhibit an unexpected increase in drag force at the interface. The technique can be applied in the future to study three-dimensional dynamics in a range of systems, including complex fluids, gels, biological cells, and geological media.
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Affiliation(s)
- Kan Du
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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Zhou J, Wang L, Qiao X, Binks BP, Sun K. Pickering emulsions stabilized by surface-modified Fe3O4 nanoparticles. J Colloid Interface Sci 2011; 367:213-24. [PMID: 22126704 DOI: 10.1016/j.jcis.2011.11.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 08/25/2011] [Accepted: 11/01/2011] [Indexed: 11/18/2022]
Abstract
Unmodified Fe(3)O(4) nanoparticles do not stabilize Pickering emulsions of a polar oil like butyl butyrate. In order to obtain stable emulsions, the Fe(3)O(4) nanoparticles were modified by either carboxylic acid (RCOOH) or silane coupling agents (RSi(OC(2)H(5))(3)) to increase their hydrophobicity. The influence of such surface modification on the stability of the resultant Pickering emulsions was investigated in detail for both a non-polar oil (dodecane) and butyl butyrate in mixtures with water. The stability of dodecane-in-water emulsions in the presence of carboxylic acid-coated particles decreases as the length of the alkyl group (R) and the coating extent increase. However, such particles are incapable of stabilizing butyl butyrate-water emulsions even when the carboxylic acid length is decreased to two. However, the silane-coated Fe(3)O(4) nanoparticles can stabilize butyl butyrate-in-water emulsions, and they also increase the stability of dodecane-in-water emulsions. Thermal gravimetric analysis indicates that the molar quantity of silane reagent is much higher than that of carboxylic acid on nanoparticle surfaces after modification, raising their hydrophobicity and enabling enhanced stability of the resultant polar oil-water emulsions.
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Affiliation(s)
- Jun Zhou
- State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
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Walker EM, Frost DS, Dai LL. Particle self-assembly in oil-in-ionic liquid Pickering emulsions. J Colloid Interface Sci 2011; 363:307-13. [DOI: 10.1016/j.jcis.2011.07.056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 07/15/2011] [Accepted: 07/18/2011] [Indexed: 10/17/2022]
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Ma H, Dai LL. Particle self-assembly in ionic liquid-in-water Pickering emulsions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:508-512. [PMID: 21166452 DOI: 10.1021/la103828x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report the self-assembly of a single species or a binary mixture of microparticles in ionic liquid-in-water Pickering emulsions, with emphases on the interfacial self-assembled particle structure and the partitioning preference of free particles in the dispersed and continuous phases. The particles form monolayers at ionic liquid-water interfaces and are close-packed on fully covered emulsion droplets or aggregated on partially covered droplets. In contrast to those at oil-water interfaces, no long-range-ordered colloidal lattices are observed. Interestingly, other than equilibrating at the ionic liquid-water interfaces, the microparticles also exhibit a partitioning preference in the dispersed and continuous phases: the sulfate-treated polystyrene (S-PS) and aldehyde-sulfate-treated polystyrene (AS-PS) microparticles are extracted to the ionic liquid phase with a high extraction efficiency, whereas the amine-treated polystyrene (A-PS) microparticles remain in the water phase.
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Affiliation(s)
- Huan Ma
- School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, Arizona 85287, United States
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Tigges B, Dederichs T, Möller M, Liu T, Richtering W, Weichold O. Interfacial properties of emulsions stabilized with surfactant and nonsurfactant coated boehmite nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17913-17918. [PMID: 21028858 DOI: 10.1021/la102761k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The properties of emulsions stabilized with surface-modified boehmite particles of 26 and 8 nm in diameter have been investigated. The surface-modified particles were prepared by mixing aqueous dispersions of cationic boehmite particles with aqueous solutions of the surfactant p-dodecylbenzenesulfonic acid (DBSA) or the nonsurfactant p-toluenesulfonic acid (TSA). For the 26 nm particles, interfacial tension measurements indicate that p-dodecylbenzenesulfonic acid partitions between the particle surface and the oil-water interface, while p-toluenesulfonic acid remains on the particle surface. The partitioning of p-dodecylbenzenesulfonic acid supports the formation of emulsions, although in the absence of the particles the same surfactant concentration is not sufficient for emulsion stabilization. Due to the fast exchange kinetics, p-dodecylbenzenesulfonic acid is gradually replaced by particles. At equilibrium, the interfacial tension in the presence of the surface-modified particles is between the values for the pure particles and the pure surfactant solutions. However, the interfacial tension is independent of the surfactant concentration used in the preparation of the particles. Reducing the particle size to 8 nm leads to increased emulsion stability, and thus, the minimum particle concentration required to prepare stable emulsions was reduced to 0.1 g/L. However, above approximately 3.5 mmol/L of the sulfonic acids, the small particles dissolve slowly, and the emulsion stability is lost. This mechanism can be used to trigger the collapse of the emulsions.
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Affiliation(s)
- Britta Tigges
- DWI an der RWTH Aachen e. V. und Institut für Technische und Makromolekulare Chemie der RWTH Aachen, Pauwelsstr. 8, D-52056 Aachen, Germany
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Ma H, Dai LL. Structure of multi-component colloidal lattices at oil-water interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11210-11215. [PMID: 19731947 DOI: 10.1021/la9021036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have successfully assembled two-component S-PS/AS-PS (sulfate-treated polystyrene/aldehyde sulfate-treated polystyrene) and three-component S-PS/AS-PS/C-PS (sulfate-treated polystyrene/aldehyde sulfate-treated polystyrene/carboxylate-treated polystyrene) colloidal lattices at poly(dimethylsiloxane)-water interfaces. The colloidal particles assemble into long-range-ordered structure and oscillate around their equilibrium positions. Different types of particles distribute randomly in the lattice with no obvious phase separation. In the two-component colloidal lattices, the S-PS particles form mostly sixfold lattice sites, whereas the AS-PS particles largely form fivefold defect sites. The calculated attractive capillary force is stronger for the AS-PS particles, which likely explains their tendency to aggregate compared to the S-PS particles. In addition, we have performed total force calculation and extrapolated the surface charge densities of the particles in the oil phase.
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Affiliation(s)
- Huan Ma
- Department of Chemical Engineering, Arizona State University, Tempe, Arizona 85287, USA
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Schelero N, Lichtenfeld H, Zastrow H, Möhwald H, Dubois M, Zemb T. Single particle light scattering method for studying aging properties of Pickering emulsions stabilized by catanionic crystals. Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2008.12.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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