1
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Oaki Y, Fujii S. Cascading responses of stimuli-responsive materials. Chem Commun (Camb) 2024; 60:9163-9176. [PMID: 39051149 DOI: 10.1039/d4cc02827a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Responsiveness to stimuli is important in daily life: natural biological activity is governed by continuous stimulus responsiveness. The design of stimuli-responsive materials is required for the development of advanced sensing systems. Although fully controlled stimuli-responsive systems have been constructed in nature, artificial systems remain a challenge. Conventional stimuli-responsive materials show direct responsiveness to an applied stimulus (Stimulus 1), with structural changes in their molecules and organized states. This feature article focuses on cascading responses as a new concept for integrating stimuli-responsive material design. In cascading responses, an original stimulus (Stimulus 1) is converted into other stimuli (Stimulus 2, 3, …, N) through successive conversions. Stimulus N provides the eventual output response. Integration of multiple stimuli-responsive materials is required to achieve cascading responses. Although cascade, domino, and tandem chemical reactions have been reported at the molecular level, they are not used for materials with higher organized structures. In this article, we introduce functional carriers and sensors based on cascading responses as model cases. The concept of cascading responses enables the achievement of transscale responsivity and sensitivity, which are not directly induced by the original stimulus or its responsive material, for the development of advanced dynamic functional materials.
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Affiliation(s)
- Yuya Oaki
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan.
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2
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Yasui T, Fameau A, Park H, Pham TT, Pechmann S, Christiansen S, Yusa S, Hirai T, Nakamura Y, Fujii S. Stimulus-Responsive Gas Marbles as an Amphibious Carrier for Gaseous Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2404728. [PMID: 38924310 PMCID: PMC11348068 DOI: 10.1002/advs.202404728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/01/2024] [Indexed: 06/28/2024]
Abstract
Gas marbles are a new family of particle-stabilized soft dispersed system with a soap bubble-like air-in-water-in-air structure. Herein, stimulus-responsive character is successfully introduced to a gas marble system for the first time using polymer particles carrying a poly(tertiary amine methacrylate) (pKa ≈7) steric stabilizer on their surfaces as a particulate stabilizer. The gas marbles exhibited long-term stability when transferred onto the planar surface of liquid water, provided that the solution pH of the subphase is basic and neutral. In contrast, the use of acidic solutions led to immediate disintegration of the gas marbles, resulting in release of the inner gas. The critical minimum solution pH required for long-term gas marble stability correlates closely with the known pKa value for the poly(tertiary amine methacrylate) stabilizer. It also demonstrates amphibious motions of the gas marbles.
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Affiliation(s)
- Takanori Yasui
- Graduate School of EngineeringOsaka Institute of Technology5‐16‐1, Omiya, Asahi‐kuOsaka535‐8585Japan
| | - Anne‐Laure Fameau
- Université LilleCNRSINRAECentrale LilleUMR 8207 – UMET – Unité Matériaux et TransformationsLilleF‐59000France
| | - Hyoungwon Park
- Department for Correlative Microscopy and Materials DataFraunhofer Institute for Ceramic Technologies and Systems (IKTS)91301ForchheimGermany
| | - Thu Thao Pham
- Department of Applied ChemistryGraduate School of EngineeringUniversity of Hyogo2167 ShoshaHimejiHyogo671‐2280Japan
| | - Sabrina Pechmann
- Department for Correlative Microscopy and Materials DataFraunhofer Institute for Ceramic Technologies and Systems (IKTS)91301ForchheimGermany
| | - Silke Christiansen
- Department for Correlative Microscopy and Materials DataFraunhofer Institute for Ceramic Technologies and Systems (IKTS)91301ForchheimGermany
- Institute for Nanotechnology and Correlative Microscopy gGmbH (INAM gGmbH)91301ForchheimGermany
- Fachbereich PhysikFreie Universität Berlin (FU Berlin)14195BerlinGermany
| | - Shin‐ichi Yusa
- Department of Applied ChemistryGraduate School of EngineeringUniversity of Hyogo2167 ShoshaHimejiHyogo671‐2280Japan
| | - Tomoyasu Hirai
- Department of Applied ChemistryFaculty of Engineering Osaka Institute of Technology5‐16‐1, Omiya, Asahi‐kuOsaka535‐8585Japan
- Nanomaterials Microdevices Research CenterOsaka Institute of Technology5‐16‐1 Omiya, Asahi‐kuOsaka535‐8585Japan
| | - Yoshinobu Nakamura
- Department of Applied ChemistryFaculty of Engineering Osaka Institute of Technology5‐16‐1, Omiya, Asahi‐kuOsaka535‐8585Japan
- Nanomaterials Microdevices Research CenterOsaka Institute of Technology5‐16‐1 Omiya, Asahi‐kuOsaka535‐8585Japan
| | - Syuji Fujii
- Department of Applied ChemistryFaculty of Engineering Osaka Institute of Technology5‐16‐1, Omiya, Asahi‐kuOsaka535‐8585Japan
- Nanomaterials Microdevices Research CenterOsaka Institute of Technology5‐16‐1 Omiya, Asahi‐kuOsaka535‐8585Japan
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3
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Abdeljaoued A, Ruiz BL, Tecle YE, Langner M, Bonakdar N, Bleyer G, Stenner P, Vogel N. Efficient removal of nanoplastics from industrial wastewater through synergetic electrophoretic deposition and particle-stabilized foam formation. Nat Commun 2024; 15:5437. [PMID: 38937451 PMCID: PMC11211448 DOI: 10.1038/s41467-024-48142-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 04/20/2024] [Indexed: 06/29/2024] Open
Abstract
Microplastic particles have been discovered in virtually all ecosystems worldwide, yet they may only represent the surface of a much larger issue. Nanoplastics, with dimensions well below 1 µm, pose an even greater environmental concern. Due to their size, they can infiltrate and disrupt individual cells within organisms, potentially exacerbating ecological impacts. Moreover, their minute dimensions present several hurdles for removal, setting them apart from microplastics. Here, we describe a process to remove colloidally stable nanoplastics from wastewater, which synergistically combines electrophoretic deposition and the formation of particle-stabilized foam. This approach capitalizes on localized changes in particle hydrophilicity induced by pH fluctuations resulting from water electrolysis at the electrode surface. By leveraging these pH shifts to enhance particle attachment to nascent bubbles proximal to the electrode, separation of colloidal particles from aqueous dispersions is achieved. Using poly(methyl methacrylate) (PMMA) colloidal particles as a model, we gain insights into the separation mechanisms, which are subsequently applied to alternative model systems with varying surface properties and materials, as well as to real-world industrial wastewaters from dispersion paints and PMMA fabrication processes. Our investigations demonstrate removal efficiencies surpassing 90%.
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Affiliation(s)
- Amna Abdeljaoued
- Particle Processing, Process Technology & Engineering, Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457, Wolfgang, Germany
- Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Beatriz López Ruiz
- Particle Processing, Process Technology & Engineering, Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457, Wolfgang, Germany
- Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Yikalo-Eyob Tecle
- Particle Processing, Process Technology & Engineering, Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457, Wolfgang, Germany
| | - Marie Langner
- Particle Processing, Process Technology & Engineering, Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457, Wolfgang, Germany
| | - Natalie Bonakdar
- Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Gudrun Bleyer
- Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany
| | - Patrik Stenner
- Particle Processing, Process Technology & Engineering, Evonik Operations GmbH, Rodenbacher Chaussee 4, 63457, Wolfgang, Germany
| | - Nicolas Vogel
- Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058, Erlangen, Germany.
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4
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Xing Y, Zhang L, Yu L, Song A, Hu J. pH-Responsive foams triggered by particles from amino acids with metal ions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120374] [Citation(s) in RCA: 0] [Impact Index Per Article: 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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Aono K, Ueno K, Hamasaki S, Sakurai Y, Yusa SI, Nakamura Y, Fujii S. "Foam Marble" Stabilized with One Type of Polymer Particle. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7603-7610. [PMID: 35666830 DOI: 10.1021/acs.langmuir.2c00869] [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
There has been increasing interest in colloidal particles adsorbed at the air-water interface, which lead to stabilization of aqueous foams and liquid marbles. The wettability of the particles at the interface is known to play an important role in determining the type of air/water dispersed system. Foams are preferably formed using relatively hydrophilic particles, and liquid marbles tend to be formed using relatively hydrophobic particles. In this study, submicrometer-sized polystyrene particles carrying poly(N,N-diethylaminoethyl methacrylate) hairs (PDEA-PS particles), which are synthesized by dispersion polymerization, are demonstrated to work as a particulate stabilizer for both aqueous foams and liquid marbles. A key point for the hydrophilic PDEA-PS particles to stabilize both aqueous foams and liquid marbles, which have been generally stabilized with hydrophilic and hydrophobic particles, respectively, is the wetting mode of the particles with respect to water. The flocculates of PDEA-PS particles adsorb to the air-water interface from the aqueous phase to stabilize foam in a Wenzel mode, and the dried PDEA-PS particles adsorb to the interface as aggregates from the air phase to stabilize liquid marbles in a metastable Cassie-Baxter mode. On the basis of the difference in the wetting mode, stabilization of an air-in-water-in-air multiple gas-liquid dispersed system, named "foam marble", is realized. After the evaporation of water from the foam marble, a porous sphere is successfully obtained with pore sizes of a few tens of micrometers (reflecting the bubble sizes) and a few tens of nanometers (reflecting the gap sizes among the PDEA-PS particles).
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Affiliation(s)
- Kodai Aono
- Division of Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Kazuyuki Ueno
- Division of Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Sho Hamasaki
- Division of Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Yuri Sakurai
- Division of Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Shin-Ichi Yusa
- Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
- Nanomaterials Microdevices Research Center, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
- Nanomaterials Microdevices Research Center, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
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6
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Pickering foams and parameters influencing their characteristics. Adv Colloid Interface Sci 2022; 301:102606. [PMID: 35182930 DOI: 10.1016/j.cis.2022.102606] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/20/2022] [Accepted: 01/26/2022] [Indexed: 11/21/2022]
Abstract
Pickering foams are available in many applications and have been continually gaining interest in the last two decades. Pickering foams are multifaceted, and their characteristics are highly dependent on many factors, such as particle size, charge, hydrophobicity and concentration as well as the charge and concentration of surfactants and salts available in the system. A literature review of these individual studies at first might seem confusing and somewhat contradictory, particularly in multi-component systems with particles and surfactants with different charges in the presence of salts. This paper provides a comprehensive overview of particle-stabilized foams, also known as Pickering foams and froths. Underlying mechanisms of foam stabilization by particles with different morphology, surface chemistry, size and type are reviewed and clarified. This paper also outlines the role of salts and different factors such as pH, temperature and gas type on Pickering foams. Further, we highlight recent developments in Pickering foams in different applications such as food, mining, oil and gas, and wastewater treatment industries, where Pickering foams are abundant. We conclude this overview by presenting important research avenues based on the gaps identified here. The focus of this review is limited to Pickering foams of surfactants with added salts and does not include studies on polymers, proteins, or other macromolecules.
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7
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Vialetto J, Nussbaum N, Bergfreund J, Fischer P, Isa L. Influence of the interfacial tension on the microstructural and mechanical properties of microgels at fluid interfaces. J Colloid Interface Sci 2022; 608:2584-2592. [PMID: 34774321 DOI: 10.1016/j.jcis.2021.10.186] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/21/2021] [Accepted: 10/29/2021] [Indexed: 10/19/2022]
Abstract
Microgels are soft colloidal particles constituted by cross-linked polymer networks with a high potential for applications. In particular, after adsorption at a fluid interface, interfacial tension provides two-dimensional (2D) confinement for microgel monolayers and drives the reconfiguration of the particles, enabling their deployment in foam and emulsion stabilization and in surface patterning for lithography, sensing and optical materials. However, most studies focus on systems of fluids with a high interfacial tension, e.g. alkanes/ or air/water interfaces, which imparts similar properties to the assembled monolayers. Here, instead, we compare two organic fluid phases, hexane and methyl tert-butyl ether, which have markedly different interfacial tension (γ) values with water and thus tune the deformation of adsorbed microgels. We rationalize how γ controls the single-particle morphology, which consequently modulates the structural and mechanical response of the monolayers at varying interfacial compression. Specifically, when γ is low, the microgels are less deformed within the interface plane and their polymer networks can rearrange more easily upon lateral compression, leading to softer monolayers. Selecting interfaces with different surface energy offers an additional control to customize the 2D assembly of soft particles, from the fine-tuning of particle size and interparticle spacing to the tailoring of mechanical properties.
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Affiliation(s)
- Jacopo Vialetto
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
| | - Natalie Nussbaum
- Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Jotam Bergfreund
- Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Peter Fischer
- Institute of Food, Nutrition and Health, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland
| | - Lucio Isa
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.
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8
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Zhang S, Dedovets D, Feng A, Wang K, Pera-Titus M. Pickering Interfacial Catalysis for Aerobic Alcohol Oxidation in Oil Foams. J Am Chem Soc 2022; 144:1729-1738. [PMID: 35073074 PMCID: PMC8815424 DOI: 10.1021/jacs.1c11207] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Oil foams stabilized by surface-active catalytic particles bearing fluorinated chains and Pd nanoparticles allowed fast and efficient aerobic oxidation of a variety of aromatic and aliphatic alcohols compared to bulk catalytic systems at ambient O2 pressure. High foam stability was achieved at low particle concentration (<1 wt %) provided that the contact angle locates in the range 41°-73°. The catalytic performance was strongly affected by the foaming properties, with 7-10 times activity increase in pure O2 compared to nonfoam systems. Intermediate foam stability was required to achieve good catalytic activity, combining large interfacial area and high gas exchange rate. Particles were conveniently recycled with high foamability and catalytic efficiency maintained for at least seven consecutive runs.
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Affiliation(s)
- Shi Zhang
- UMI
3464 CNRS, Solvay, Eco-Efficient Products
and Processes Laboratory (E2P2L), 3966 Jin Du Road, Xin Zhuang Ind. Zone, 201108 Shanghai, China,Laboratoire
du Futur, UMR 5258 CNRS, Université
de Bordeaux, 178 Av.
Dr Albert Schweitzer, 33603 Cedex, Pessac, France
| | - Dmytro Dedovets
- Laboratoire
du Futur, UMR 5258 CNRS, Université
de Bordeaux, 178 Av.
Dr Albert Schweitzer, 33603 Cedex, Pessac, France
| | - Andong Feng
- UMI
3464 CNRS, Solvay, Eco-Efficient Products
and Processes Laboratory (E2P2L), 3966 Jin Du Road, Xin Zhuang Ind. Zone, 201108 Shanghai, China,Laboratoire
du Futur, UMR 5258 CNRS, Université
de Bordeaux, 178 Av.
Dr Albert Schweitzer, 33603 Cedex, Pessac, France
| | - Kang Wang
- Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.
| | - Marc Pera-Titus
- UMI
3464 CNRS, Solvay, Eco-Efficient Products
and Processes Laboratory (E2P2L), 3966 Jin Du Road, Xin Zhuang Ind. Zone, 201108 Shanghai, China,Cardiff
Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, U.K.,
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9
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Vialetto J, Camerin F, Grillo F, Ramakrishna SN, Rovigatti L, Zaccarelli E, Isa L. Effect of Internal Architecture on the Assembly of Soft Particles at Fluid Interfaces. ACS NANO 2021; 15:13105-13117. [PMID: 34328717 PMCID: PMC8388124 DOI: 10.1021/acsnano.1c02486] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Monolayers of soft colloidal particles confined at fluid interfaces are at the core of a broad range of technological processes, from the stabilization of responsive foams and emulsions to advanced lithographic techniques. However, establishing a fundamental relation between their internal architecture, which is controlled during synthesis, and their structural and mechanical properties upon interfacial confinement remains an elusive task. To address this open issue, which defines the monolayer's properties, we synthesize core-shell microgels, whose soft core can be chemically degraded in a controlled fashion. This strategy allows us to obtain a series of particles ranging from analogues of standard batch-synthesized microgels to completely hollow ones after total core removal. Combined experimental and numerical results show that our hollow particles have a thin and deformable shell, leading to a temperature-responsive collapse of the internal cavity and a complete flattening after adsorption at a fluid interface. Mechanical characterization shows that a critical degree of core removal is required to obtain soft disk-like particles at an oil-water interface, which present a distinct response to compression. At low packing fractions, the mechanical response of the monolayer is dominated by the outer polymer chains forming a corona surrounding the particles within the interfacial plane, regardless of the presence of a core. By contrast, at high compression, the absence of a core enables the particles to deform in the direction orthogonal to the interface and to be continuously compressed without altering the monolayer structure. These findings show how fine, single-particle architectural control during synthesis can be engineered to determine the interfacial behavior of microgels, enabling one to link particle conformation with the resulting material properties.
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Affiliation(s)
- Jacopo Vialetto
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Fabrizio Camerin
- CNR
Institute for Complex Systems, Uos Sapienza, P.le A. Moro 2, 00185 Roma, Italy
- Department
of Basic and Applied Sciences for Engineering, Sapienza University of Rome, via A. Scarpa 14, 00161 Roma, Italy
| | - Fabio Grillo
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Shivaprakash N. Ramakrishna
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Lorenzo Rovigatti
- CNR
Institute for Complex Systems, Uos Sapienza, P.le A. Moro 2, 00185 Roma, Italy
- Department
of Physics, Sapienza University of Rome, P.le A. Moro 2, 00185 Roma, Italy
| | - Emanuela Zaccarelli
- CNR
Institute for Complex Systems, Uos Sapienza, P.le A. Moro 2, 00185 Roma, Italy
- Department
of Physics, Sapienza University of Rome, P.le A. Moro 2, 00185 Roma, Italy
| | - Lucio Isa
- Laboratory
for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
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10
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Vialetto J, Anyfantakis M. Exploiting Additives for Directing the Adsorption and Organization of Colloid Particles at Fluid Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9302-9335. [PMID: 34327999 DOI: 10.1021/acs.langmuir.1c01029] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The self-assembly of colloids at fluid interfaces is a well-studied research field both for gaining fundamental insights and for material fabrication. The fluid interface allows the confinement of particles in two dimensions and may act as a template for guiding their organization into soft and reconfigurable structures. Additives (e.g., surfactants, salts, and polymers) in the colloidal suspension are routinely used as a practical and effective tool to drive particle adsorption and tune their interfacial organization. However, some phenomena lying at the heart of the accumulation and self-assembly of particles at fluid interfaces remain poorly understood. This Feature Article aims to critically analyze the mechanisms involved in the adsorption and self-organization of micro- and nanoparticles at various fluid interfaces. In particular, we address the role of additives in both promoting the adsorption of particles from the bulk suspension to the fluid interface and in mediating the interactions between interfacial particles. We emphasize how different types of additives play a crucial role in controlling the interactions between suspended particles and the fluid interface as well as the interactions between adsorbed particles, thus dictating the final self-assembled structure. We also critically summarize the main experimental protocols developed for the complete adsorption of particles initially suspended in the bulk. Furthermore, we highlight some special properties (e.g., reconfigurability upon external stimulation and dissipative self-assembly) and the application potential of structures formed by colloid self-organization at fluid interfaces mediated/promoted by additives. We believe our contribution serves both as a practical roadmap to scientists coming from other fields and as a valuable information resource for all researchers interested in this exciting research field.
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Affiliation(s)
- Jacopo Vialetto
- Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Zürich, Switzerland
| | - Manos Anyfantakis
- Department of Physics and Materials Science, University of Luxembourg, Luxembourg L-1511, Luxembourg
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11
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Terao T, Shiraishi H, Yamazaki M, Hayakawa T, Ohta N, Fujii S, Nakamura Y, Hirai T. Hairy Particles Synthesized by Living Anionic Polymerization-induced Self-assembly and Evaluation of Their Nanostructure. CHEM LETT 2021. [DOI: 10.1246/cl.200957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Toshiki Terao
- Department of Applied Chemistry, Faculty of Engineering, and Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Hibiki Shiraishi
- Department of Applied Chemistry, Faculty of Engineering, and Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Mikito Yamazaki
- Department of Applied Chemistry, Faculty of Engineering, and Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Teruaki Hayakawa
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1-S8-36 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Noboru Ohta
- Japan Synchrotron Radiation Research Institute, SPring-8, Sayo, Hyogo 679-5198, Japan
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, and Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, and Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Tomoyasu Hirai
- Department of Applied Chemistry, Faculty of Engineering, and Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
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12
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Xie Y, Xu Y, Xu J. pH-responsive pickering foam created from self-aggregate polymer using dynamic covalent bond. J Colloid Interface Sci 2021; 597:383-392. [PMID: 33894546 DOI: 10.1016/j.jcis.2021.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/16/2021] [Accepted: 04/02/2021] [Indexed: 12/01/2022]
Abstract
HYPOTHESIS Responsive surfactant systems based on dynamic covalent bond exhibit an unsatisfactory foamability and foam stability, despite their documented functionality in emulsions. As such we anticipate that the foaming performance should be improved by introducing Pickering effect, which is possible when the responsiveness of the dynamic covenant bonds controls not only the hydrophobicity of polymers but also their aggregation behavior (to form nanoparticles). EXPERIMENTS Here we created surface active nanoparticles made from self-aggregated polymers consisting of PAH (polyallylamine hydrochloride)-BA (benzaldehyde). The covalent imine bonds between originally hydrophilic PAH and hydrophobic BA are dynamic in that their formation and breakage is a function of solution pH, confirmed by 1H NMR and dynamic interfacial tension measurement. FINDINGS At pH 7.4, a stable foam is achieved in the PAH-BA (amino to aldehyde ratio at 1:0.2) solution; while at pH 2.5, it defoams due to breakage of dynamic bonds corresponding to the measured diminishing surface activity. The reversibility of foaming-defoaming has been demonstrated by alternatively changing pH for multiple cycles, with the foaming performance persistent. The foam stability can be improved by more hydrophobic compounds e.g. at a lower amino to aldehyde ratio or using PAH-cinnamaldehyde (CA). The reversible and responsive foaming demonstrated in a Pickering system provides a new method to create novel foaming systems with properties desirable to many applications.
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Affiliation(s)
- Yiqian Xie
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan, Shandong 250100, PR China.
| | - Yuan Xu
- School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Jian Xu
- Key Laboratory of Colloid and Interface Chemistry, Shandong University, Ministry of Education, Jinan, Shandong 250100, PR China.
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Tyowua AT, Echendu AM, Yiase SG, Adejo SO, Leke L, Mbawuaga EM, Binks BP. Foaming honey: particle or molecular foaming agent? J DISPER SCI TECHNOL 2020. [DOI: 10.1080/01932691.2020.1845718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Andrew T. Tyowua
- Applied Colloid Science and Cosmeceutical Group, Department of Chemistry, Benue State University, Makurdi, Nigeria
| | - Adebukola M. Echendu
- Applied Colloid Science and Cosmeceutical Group, Department of Chemistry, Benue State University, Makurdi, Nigeria
| | - Stephen G. Yiase
- Applied Colloid Science and Cosmeceutical Group, Department of Chemistry, Benue State University, Makurdi, Nigeria
| | - Sylvester O. Adejo
- Applied Colloid Science and Cosmeceutical Group, Department of Chemistry, Benue State University, Makurdi, Nigeria
| | - Luter Leke
- Applied Colloid Science and Cosmeceutical Group, Department of Chemistry, Benue State University, Makurdi, Nigeria
| | | | - Bernard P. Binks
- Department of Chemistry and Biochemistry, University of Hull, Hull, United Kingdom
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14
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15
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Zhu Y, Chen T, Cui Z, Dai H, Cai L. Stimuli-Responsive Biomass Cellulose Particles Being Able to Reversibly Self-Assemble at Fluid Interface. Front Chem 2020; 8:712. [PMID: 33134247 PMCID: PMC7573168 DOI: 10.3389/fchem.2020.00712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 07/09/2020] [Indexed: 11/13/2022] Open
Abstract
Stimuli-responsive surface-active microcrystalline cellulose (MCC) particles are obtained by interaction with conventional cationic surfactants such as cetyltrimethylammonium bromide (CTAB) in aqueous media, where MCC are in situ hydrophobized by adsorption of the cationic surfactant in water via electrostatic interaction and with the in situ hydrophobization removed by adding an equimolar amount of an anionic surfactant such as sodium dodecyl sulfate (SDS). The trigger is that the electrostatic interaction between the oppositely charged ionic surfactants is stronger than that between the cationic surfactant and the negative charges on particle surfaces, or the anionic surfactant prefers to form ion pairs with the cationic surfactants and thus making them desorbed from surface of MCC. Reversible O/W Pickering emulsions can then be obtained by using the MCC in combination with trace amount of a cationic surfactant and an anionic surfactant, and the anionic surfactant with a longer alkyl chain is more efficient for demulsification. With excellent biocompatibility, biodegradability, and renewability, as well as low toxicity, the biomass cellulose particles that can be made stimuli-responsive and able to reversibly self-assemble at fluid interface become ideal biocompatible particulate materials with extensive applications involving emulsions and foams.
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Affiliation(s)
- Yue Zhu
- School of Chemistry and Chemical Engineering, Nantong University, Nantong, China
| | - Tingting Chen
- School of Chemistry and Chemical Engineering, Nantong University, Nantong, China
| | - Zhenggang Cui
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, China
| | - Hong Dai
- School of Chemistry and Chemical Engineering, Nantong University, Nantong, China
| | - Li Cai
- School of Chemistry and Chemical Engineering, Nantong University, Nantong, China
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16
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17
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pH-Dependent Foam Formation Using Amphoteric Colloidal Polymer Particles. Polymers (Basel) 2020; 12:polym12030511. [PMID: 32120771 PMCID: PMC7182924 DOI: 10.3390/polym12030511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/22/2020] [Accepted: 02/25/2020] [Indexed: 11/29/2022] Open
Abstract
Near-monodispersed micrometer-sized polystyrene (PS) particles carrying amidino and carboxyl groups on their surfaces were synthesized by soap-free emulsion polymerization using an amphoteric free radical initiator. The resulting amphoteric PS particles were characterized in terms of diameter, morphology, disperibility in aqueous media and surface charge using scanning electron microscopy (SEM), optical microscopy (OM), sedimentation rate and electrophoretic measurements. At pH 2.0, where the amidino groups are protonated (positively charged), and at pH 11.0, where the carboxyl groups are deprotonated (negatively charged), the PS particles were well dispersed in aqueous media via electrostatic repulsion. At pH 4.8, where the surface charges are neutral, the PS particles were weakly aggregated. Furthermore, it was confirmed that the PS particles can function as a pH-sensitive foam stabilizer: foamability and foam stability were higher at pH 2.0 and 4.8, where the PS particles can be adsorbed to the air–water interface, and lower at pH 11.0, where the PS particles tend to disperse in bulk aqueous medium. SEM and OM studies indicated that hexagonally close-packed arrays of PS particles were formed on the bubble surfaces and moiré patterns were observed on the dried foams. Moreover, the fragments of dried foams showed iridescent character under white light.
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18
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Fujii S. Stimulus-responsive soft dispersed systems developed based on functional polymer particles: bubbles and liquid marbles. Polym J 2019. [DOI: 10.1038/s41428-019-0233-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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19
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Wu D, Mihali V, Honciuc A. pH-Responsive Pickering Foams Generated by Surfactant-Free Soft Hydrogel Particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:212-221. [PMID: 30540483 DOI: 10.1021/acs.langmuir.8b03342] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pickering foams are foams stabilized by particles and are generally known to have good stability. A special subclass of particle-stabilized foams includes stimuli-responsive Pickering foams that can be formed or deconstructed by applying an external stimuli or changing the environmental conditions; such intelligent particles could find use in many practical applications. Here, we synthesized surfactant-free biocompatible poly[2(diethylamino)ethyl methacrylate] (PDEAEMA) hydrogel particles (HGPs) by emulsion polymerization. The morphology, structure, and surface charge of the HGPs were characterized by TEM, DLS, and the zeta potential, respectively. We have observed that the pH values of the aqueous solution have a strong influence on the formation of the Pickering foams in the presence of PDEAEMA HGPs. Namely, at pH values ≤4.0 no Pickering foams were produced, while at pH values >4.0 stable Pickering foams were formed. Moreover, the height, size and bubble size distribution of Pickering foams are strongly influenced by the pH values of aqueous solution and PDEAEMA HGPs concentration. The formed Pickering foams in basic aqueous solution can all be conveniently deconstructed by changing the pH values to below 4.0. Interestingly, the dried lamellas of the Pickering foams were constituted by either monolayers or multilayers of PDEAEMA HGPs as demonstrated by SEM.
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Affiliation(s)
- Dalin Wu
- Institute of Chemistry and Biotechnology , Zurich University of Applied Sciences , Einsiedlerstrasse 31 , 8820 Waedenswil , Switzerland
| | - Voichita Mihali
- Institute of Chemistry and Biotechnology , Zurich University of Applied Sciences , Einsiedlerstrasse 31 , 8820 Waedenswil , Switzerland
| | - Andrei Honciuc
- Institute of Chemistry and Biotechnology , Zurich University of Applied Sciences , Einsiedlerstrasse 31 , 8820 Waedenswil , Switzerland
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20
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Vasudevan SA, Rauh A, Kröger M, Karg M, Isa L. Dynamics and Wetting Behavior of Core-Shell Soft Particles at a Fluid-Fluid Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:15370-15382. [PMID: 30444370 DOI: 10.1021/acs.langmuir.8b03048] [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 investigate the conformation, position, and dynamics of core-shell nanoparticles (CSNPs) composed of a silica core encapsulated in a cross-linked poly( N-isopropylacrylamide) shell at a water-oil interface for a systematic range of core sizes and shell thicknesses. We first present a free-energy model that we use to predict the CSNP wetting behavior at the interface as a function of its geometrical and compositional properties in the bulk phases, which is in good agreement with our experimental data. Remarkably, based on the knowledge of the polymer shell deformability, the equilibrium particle position relative to the interface plane, an often elusive experimental quantity, can be extracted by measuring its radial dimensions after adsorption. For all the systems studied here, the interfacial dimensions are always larger than in bulk and the particle core resides in a configuration, wherein it just touches the interface or is fully immersed in water. Moreover, the stretched shell induces a larger viscous drag at the interface, which appears to depend solely on the interfacial dimensions, irrespective of the portion of the CSNP surface exposed to the two fluids. Our findings indicate that tailoring the architecture of CSNPs can be used to control their properties at the interface, as of interest for applications including emulsion stabilization and nanopatterning.
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Affiliation(s)
- Siddarth A Vasudevan
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Astrid Rauh
- Physical Chemistry I , University of Bayreuth , Universitätsstr. 30 , 95440 Bayreuth , Germany
- Physical Chemistry I , Heinrich-Heine-University , Universitätsstr. 1 , 40204 Düsseldorf , Germany
| | - Martin Kröger
- Polymer Physics, Department of Materials , ETH Zürich , Leopold-Ruzicka-Weg 4 , 8093 Zürich , Switzerland
| | - Matthias Karg
- Physical Chemistry I , Heinrich-Heine-University , Universitätsstr. 1 , 40204 Düsseldorf , Germany
| | - Lucio Isa
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
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21
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Yan X, Zhai Z, Xu J, Song Z, Shang S, Rao X. CO 2-Responsive Pickering Emulsions Stabilized by a Bio-based Rigid Surfactant with Nanosilica. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:10769-10776. [PMID: 30256645 DOI: 10.1021/acs.jafc.8b03458] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A novel CO2-responsive surfactant, maleopimaric acid glycidyl methacrylate ester 3-(dimethylamino)propylamine imide (MPAGN), based on sustainable resource of rosin was synthesized and used to prepare a kind of CO2-responsive Pickering emulsions with nanosilica. MPAGN can be reversibly responsive to CO2 and N2 between active cationic (MPAGNH+) and inactive nonionic (MPAGN), leading to adsorb on or desorb from the surface of nanosilica, then stabilize or break emulsion. CO2-responsive behavior of MPAGN was verified by cycle change of pH and conductivity with bubbling CO2 and N2 alternately. The type of adsorption of MPAGNH+ at the particle-water interface was explained according to the adsorption isotherms. The mechanisms of stabilization, destabilization, and restabilization of Pickering emulsion were analyzed according to zeta potentials and droplet size. This Pickering emulsion can be reversible between stable and unstable by bubbling CO2 and N2 alternately. Moreover, this emulsifier can be recycled when new oil was added after removing the initial oil. Therefore, it not only has economic benefits but also has an environmentally friendly property.
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Affiliation(s)
- Xinyan Yan
- Institute of Chemical Industry of Forest Products , CAF, National Engineering Lab. for Biomass Chemical Utilization; Key and Open Lab. of Forest Chemical Engineering, SFA; Key Lab. of Biomass Energy and Material . No. 16 Suojinbei Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
| | - Zhaolan Zhai
- Institute of Chemical Industry of Forest Products , CAF, National Engineering Lab. for Biomass Chemical Utilization; Key and Open Lab. of Forest Chemical Engineering, SFA; Key Lab. of Biomass Energy and Material . No. 16 Suojinbei Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
| | - Ji Xu
- Institute of Chemical Industry of Forest Products , CAF, National Engineering Lab. for Biomass Chemical Utilization; Key and Open Lab. of Forest Chemical Engineering, SFA; Key Lab. of Biomass Energy and Material . No. 16 Suojinbei Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
| | - Zhanqian Song
- Institute of Chemical Industry of Forest Products , CAF, National Engineering Lab. for Biomass Chemical Utilization; Key and Open Lab. of Forest Chemical Engineering, SFA; Key Lab. of Biomass Energy and Material . No. 16 Suojinbei Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
| | - Shibin Shang
- Institute of Chemical Industry of Forest Products , CAF, National Engineering Lab. for Biomass Chemical Utilization; Key and Open Lab. of Forest Chemical Engineering, SFA; Key Lab. of Biomass Energy and Material . No. 16 Suojinbei Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
- Research Institute of Forestry New Technology , CAF , No. 1 Xiangshan Road , Haidian District, Beijing , 100091 , China
| | - Xiaoping Rao
- Institute of Chemical Industry of Forest Products , CAF, National Engineering Lab. for Biomass Chemical Utilization; Key and Open Lab. of Forest Chemical Engineering, SFA; Key Lab. of Biomass Energy and Material . No. 16 Suojinbei Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources , Nanjing Forestry University . No. 159 Longpan Road , Xuanwu District, Nanjing , Jiangsu Province 210000 , China
- Research Institute of Forestry New Technology , CAF , No. 1 Xiangshan Road , Haidian District, Beijing , 100091 , China
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22
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Singh R, Panthi K, Weerasooriya U, Mohanty KK. Multistimuli-Responsive Foams Using an Anionic Surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11010-11020. [PMID: 30149723 DOI: 10.1021/acs.langmuir.8b01796] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work, we report a novel class of a commercially available surfactant which shows a multistimuli-responsive behavior toward foam stability. It comprises three components-a hydrophobe (tristyrylphenol), a temperature-sensitive block (polypropylene oxide, PO), and a pH-sensitive moiety (carboxyl group). The hydrophobicity-hydrophilicity balance of the surfactant can be tuned by changing either the pH or temperature of the system. At or below pH 4, the carboxyl functional group is dominantly protonated, resulting in zero foamability. At higher pH, the surfactant exhibits good foamability and foam stability marked with a fine bubble texture (∼200 μm). Foam destabilization could be achieved rapidly by either lowering the pH or bubbling CO2 gas. At a fixed pH in the presence of salt, increasing the temperature to 65 °C resulted in rapid defoaming because of the increased hydrophobicity of the PO chain. This stimuli-induced stabilization and destabilization of foam were found to be reversible. We envisage the use of such a multi-responsive foaming system in diverse applications such as foam-enhanced oil recovery and environmental remediation where spatial and temporal control over foam stability is desirable. The low-cost commercial availability of the surfactant further makes it lucrative.
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Affiliation(s)
- Robin Singh
- Department of Petroleum and Geosystems Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Krishna Panthi
- Department of Petroleum and Geosystems Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Upali Weerasooriya
- Department of Petroleum and Geosystems Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
| | - Kishore K Mohanty
- Department of Petroleum and Geosystems Engineering , The University of Texas at Austin , Austin , Texas 78712 , United States
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23
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Ito M, Takano K, Hanochi H, Asaumi Y, Yusa SI, Nakamura Y, Fujii S. pH-Responsive Aqueous Bubbles Stabilized With Polymer Particles Carrying Poly(4-vinylpyridine) Colloidal Stabilizer. Front Chem 2018; 6:269. [PMID: 30065921 PMCID: PMC6056661 DOI: 10.3389/fchem.2018.00269] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 06/14/2018] [Indexed: 11/28/2022] Open
Abstract
Free radical dispersion polymerization was conducted to synthesize near-monodispersed, micrometer-sized polystyrene (PS) particles carrying pH-responsive poly(4-vinylpyridine) (P4VP) colloidal stabilizer (P4VP-PS particles). The P4VP-PS particles were extensively characterized in terms of morphology, size, size distribution, chemical composition, surface chemistry, and pH-response using optical and scanning electron microscopies, elemental microanalysis, X-ray photoelectron spectroscopy, laser diffraction particle size analysis, and zeta potential measurement. The P4VP-PS particles can work as a pH-responsive stabilizer of aqueous bubbles by adsorption at the air-water interface. At and above pH 4.0, where the particles have partially protonated/non-protonated P4VP stabilizer with relatively hydrophobic character, particle-stabilized bubbles were formed. Optical and scanning electron microscopy studies confirmed that the P4VP-PS particles were adsorbed at the air-water interface of the bubbles in aqueous media. At and below pH 3.0, where the particles have cationic P4VP stabilizer with water-soluble character, no bubble was formed. Rapid disruption of the bubbles can be induced by decreasing the pH; the addition of acid caused the in situ protonation of pyridine groups in P4VP, which impart water-soluble character to the P4VP stabilizer, and the P4VP-PS particles were desorbed from the air-water interface. The bubble stabilization/destabilization cycles could be repeated at least five times.
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Affiliation(s)
- Masaya Ito
- Graduate Course in Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, Osaka, Japan
| | - Koki Takano
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan
| | - Haruka Hanochi
- Graduate Course in Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, Osaka, Japan
| | - Yuta Asaumi
- Graduate Course in Applied Chemistry, Environmental and Biomedical Engineering, Graduate School of Engineering, Osaka Institute of Technology, Osaka, Japan
| | - Shin-Ichi Yusa
- Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo, Hyogo, Japan
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan.,Nanomaterials Microdevices Research Center, Osaka Institute of Technology, Osaka, Japan
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, Osaka, Japan.,Nanomaterials Microdevices Research Center, Osaka Institute of Technology, Osaka, Japan
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24
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Lin Q, Liu KH, Cui ZG, Pei XM, Jiang JZ, Song BL. pH-Responsive Pickering foams stabilized by silica nanoparticles in combination with trace amount of dodecyl dimethyl carboxyl betaine. Colloids Surf A Physicochem Eng Asp 2018. [DOI: 10.1016/j.colsurfa.2018.02.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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Horiguchi Y, Kawakita H, Ohto K, Morisada S. Temperature-responsive Pickering foams stabilized by poly( N -isopropylacrylamide) nanogels. ADV POWDER TECHNOL 2018. [DOI: 10.1016/j.apt.2017.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Fujii S, Yokoyama Y, Nakayama S, Ito M, Yusa SI, Nakamura Y. Gas Bubbles Stabilized by Janus Particles with Varying Hydrophilic-Hydrophobic Surface Characteristics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:933-942. [PMID: 28981288 DOI: 10.1021/acs.langmuir.7b02670] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Micrometer-sized polymer-grafted gold-silica (Au-SiO2) Janus particles were fabricated by vacuum evaporation followed by polymer grafting. The Janus particle diameter, diameter distribution, morphology, surface chemistry, and water wettability were characterized by optical microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and contact angle measurements. The optical microscopy results showed that the polystyrene (PS)-grafted Au-SiO2 Janus particles exhibited monolayer adsorption at the air-water interface and could stabilize bubbles, preventing their coalescence for more than 1 month. The hydrophobic PS-grafted Au and hydrophilic SiO2 surfaces were exposed to the air and water phases, respectively. Bare Au-SiO2 and poly(2-(perfluorobutyl)ethyl methacrylate) (PPFBEM)-grafted Au-SiO2 Janus particles could also stabilize bubbles for up to 2 weeks. By contrast, bare silica particles did not stabilize bubbles and were dispersed in water. The bubbles that formed in the PS-grafted Janus particle system were more stable than those formed in the bare Au-SiO2 Janus particles, PPFBEM-grafted Au-SiO2 Janus particles, and SiO2 particle systems because of the high adsorption energy of the PS-grafted particles at the air-water interface.
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Affiliation(s)
| | | | | | - Masanori Ito
- Graduate School of Engineering, University of Hyogo , 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Shin-Ichi Yusa
- Graduate School of Engineering, University of Hyogo , 2167 Shosha, Himeji, Hyogo 671-2280, Japan
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27
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Azakami Y, Kappl M, Fujii S, Yusa SI, McNamee CE. Effect of the Addition of a Cross-Linker and the Water pH on the Physical Properties of Films of pH-Responsive Polymer Particles at Air/Water Interfaces. ACS OMEGA 2017; 2:7837-7848. [PMID: 31457341 PMCID: PMC6645077 DOI: 10.1021/acsomega.7b01241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/01/2017] [Indexed: 06/10/2023]
Abstract
We investigated how the stiffness and physical properties of films of pH-responsive polystyrene nanoparticles with poly(2-(N,N-dimethylamino)ethylmethacrylate) hairs (PDMA-PS particles) at air/water interfaces could be varied by using the cross-linker of 1,2-bis-(2-iodoethoxy)ethane (BIEE) and by varying the water pH. The physical properties of the film were investigated by using a Langmuir trough, atomic force microscope, and monolayer particle interaction apparatus. Films without large (μm-sized) holes were prepared by reacting BIEE with the PDMA-PS particles in the ethanol spreading solution for times ≤6 h and then by spreading this solution on a pH 5.8 water surface. Longer reaction times or a pH 9.0 water surface gave films with large holes. The holes were the result of the presence of aggregates of various sizes, which could not efficiently pack in the film. The aggregates were formed by interparticle adhesions because of the BIEE presence and physical attractive forces. The pH 5.8 water gave less aggregation than the pH 9.0 water because of the stronger interparticle electrostatic repulsions that resulted from the higher particle charge in pH 5.8 water than pH 9.0 water. The holes in the films could be decreased by reacting BIEE with the PDMA-PS particles on the pH 5.8 or 9.0 water surface, while the film was compressed to give a close packing density. The stiffness of the film of PDMA-PS particles increased, when BIEE was reacted with the PDMA-PS particles in the spreading solution for 1 h and was then spread on a pH 5.8 water surface. The film stiffness, however, did not increase, when BIEE was reacted with PDMA-PS particles on the pH 5.8 or 9.0 water surface for 1 h. This stiffness difference was explained by the fact that the former method gave a thicker film than the latter method.
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Affiliation(s)
- Yuka Azakami
- Department
of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda, Nagano 386-8567, Japan
| | - Michael Kappl
- Max
Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Syuji Fujii
- Department
of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Shin-ichi Yusa
- Department
of Applied Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Cathy E. McNamee
- Department
of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda, Nagano 386-8567, Japan
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28
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Sekido T, Kappl M, Butt HJ, Yusa S, Nakamura Y, Fujii S. Effects of pH on the structure and mechanical properties of dried pH-responsive latex particles. SOFT MATTER 2017; 13:7562-7570. [PMID: 28972614 DOI: 10.1039/c7sm01625e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Micrometer-sized monodisperse polystyrene (PS) particles carrying a pH-responsive poly[2-(diethylamino)ethyl methacrylate] (PDEA) colloidal stabilizer were synthesized via free radical dispersion polymerization. X-ray photoelectron spectroscopy and electrophoretic measurements verified that PDEA covered the PS particle surface. At pH 3.0 and 6.3, where the PDEA is protonated and cationically charged, the PDEA-PS particles were well dispersed in aqueous media thanks to the water soluble PDEA stabilizer and slowly sedimented due to gravity and enriched at the bottom of the glass vials. At pH 10.0, where the PDEA is non-protonated and neutral, the PDEA-PS particles weakly aggregated due to non-hydrated and collapsed PDEA. These PDEA-PS particles and aggregates sedimented to the bottom. The sediment height observed at pH 10.0 was higher than those observed at pH 3.0 and 6.3 in both wet and dry systems, which indicated that a larger porosity was formed at pH 10.0. Mechanical testing experiments confirmed that the fracture toughness of the dried materials decreased with an increase of pH. The fracture toughness was found to be correlated with the degree of particle ordering in the dried particulate materials: more ordered, dense packings lead to a higher fracture toughness compared to amorphous, less dense packings. Thus, we could tune fracture toughness and degree of particle ordering by controlling the pH.
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Affiliation(s)
- T Sekido
- Division of Applied Chemistry, Graduate School of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka, 535-8585, Japan
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Lei L, Xie D, Song B, Jiang J, Pei X, Cui Z. Photoresponsive Foams Generated by a Rigid Surfactant Derived from Dehydroabietic Acid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7908-7916. [PMID: 28735541 DOI: 10.1021/acs.langmuir.7b00934] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Innovation in the structure of surfactants is crucial to the construction of a surfactant-based system with intriguing properties. With dehydroabietic acid as a starting material, a nearly totally rigid azobenzene surfactant (R-azo-Na) was synthesized. The trans-R-azo-Na formed stable foams with half-lives of 636, 656, 976, and 872 min for 0.3, 1, 2, and 4 mmol·L-1 aqueous solutions, respectively. Under UV light irradiation, a fast collapse of the foams was observed, showing an in situ response. The excellent foam stability of trans-R-azo-Na leads to the extremely high photoresponsive efficiency. As revealed by dynamic surface tension and pulsed-field gradient NMR methods, an obvious energy barrier existed in the adsorption/desorption process of trans-R-azo-Na on the air/water interface. The foams formed by trans-R-azo-Na are thus stable against coarsening processes. The results reveal the unique photoresponsive behavior of a surfactant with a rigid hydrophobic skeleton and provide new insights into the structure causing aggregation of surfactants.
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Affiliation(s)
- Lan Lei
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University , Wuxi, Jiangsu 214122, China
| | - Danhua Xie
- Fujian Provincial Key Laboratory of Featured Materials in Biochemical Industry and Fujian Province University Key Laboratory of Green Energy and Environment Catalysis, Ningde Normal University , Ningde, Fujian 352100, China
| | - Binglei Song
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University , Wuxi, Jiangsu 214122, China
| | - Jianzhong Jiang
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University , Wuxi, Jiangsu 214122, China
| | - Xiaomei Pei
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University , Wuxi, Jiangsu 214122, China
| | - Zhenggang Cui
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical & Materials Engineering, Jiangnan University , Wuxi, Jiangsu 214122, China
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30
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Fujii S, Nakamura Y. Stimuli-Responsive Bubbles and Foams Stabilized with Solid Particles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7365-7379. [PMID: 28478676 DOI: 10.1021/acs.langmuir.7b01024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Particle-stabilized bubbles and foams have been observed and used in a wide range of industrial sectors and have been exploited as a technology platform for the production of advanced functional materials. The stability, structure, shape, and movement of these bubbles and foams can be controlled by external stimuli such as the pH, temperature, magnetic fields, ultrasonication, mechanical stress, surfactants, and organic solvents. Stimuli-responsive modes can be categorized into three classes: (i) bubbles/foams whose stability can be controlled by the adsorption/desorption/dissolution of solid particles to/from/at gas-liquid interfaces, (ii) bubbles/foams that can move, and (iii) bubbles/foams that can change their shapes and structures. The stimuli-responsive characteristics of bubbles and foams offer potential applications in the areas of controlled encapsulation, delivery, and release.
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Affiliation(s)
- Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology , 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology , 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
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31
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Liu K, Jiang J, Cui Z, Binks BP. pH-Responsive Pickering Emulsions Stabilized by Silica Nanoparticles in Combination with a Conventional Zwitterionic Surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2296-2305. [PMID: 28191963 DOI: 10.1021/acs.langmuir.6b04459] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
pH-responsive oil-in-water Pickering emulsions were prepared simply by using negatively charged silica nanoparticles in combination with a trace amount of a zwitterionic carboxyl betaine surfactant as stabilizer. Emulsions are stable to coalescence at pH ≤ 5 but phase separate completely at pH > 8.5. In acidic solution, the carboxyl betaine molecules become cationic, allowing them to adsorb on silica nanoparticles via electrostatic interactions, thus hydrophobizing and flocculating them and enhancing their surface activity. Upon increasing the pH, surfactant molecules are converted to zwitterionic form and significantly desorb from particles' surfaces, triggering dehydrophobization and coalescence of oil droplets within the emulsion. The pH-responsive emulsion can be cycled between stable and unstable many times upon alternating the pH of the aqueous phase. The average droplet size in restabilized emulsions at low pH, however, increases gradually after four cycles due to the accumulation of NaCl. Experimental evidence including adsorption isotherms, zeta potentials, microscopy, and three-phase contact angles is given to support the postulated mechanisms.
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Affiliation(s)
- Kaihong Liu
- The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University , 1800 Lihu Road, Wuxi, Jiangsu 214122, P. R. China
| | - Jianzhong Jiang
- The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University , 1800 Lihu Road, Wuxi, Jiangsu 214122, P. R. China
| | - Zhenggang Cui
- The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University , 1800 Lihu Road, Wuxi, Jiangsu 214122, P. R. China
| | - Bernard P Binks
- School of Mathematics and Physical Sciences, University of Hull , Hull HU6 7RX, U.K
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32
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Sekido T, Wooh S, Fuchs R, Kappl M, Nakamura Y, Butt HJ, Fujii S. Controlling the Structure of Supraballs by pH-Responsive Particle Assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1995-2002. [PMID: 28177245 DOI: 10.1021/acs.langmuir.6b04648] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Supraballs of various sizes and compositions can be fabricated via drying of drops of aqueous colloidal dispersions on super-liquid-repellent surfaces with no chemical waste and energy consumption. A "supraball" is a particle composed of colloids. Many properties, such as mechanical strength and porosity, are determined by the ordering of a colloidal assembly. To tune such properties, a colloidal assembly needs to be controlled when supraballs are formed during drying. Here, we introduce a method to control a colloidal assembly of supraballs by adjusting the dispersity of the colloids. Supraballs are fabricated on superamphiphobic surfaces from colloidal aqueous dispersions of polystyrene microparticles carrying pH-responsive poly[2-(diethylamino)ethyl methacrylate]. Drying of dispersion drops at pH 3 on superamphiphobic surfaces leads to the formation of spherical supraballs with densely packed colloids. The pH 10 supraballs are more oblate and consist of more disordered colloids than the pH 3 supraballs, caused by particle aggregates with random sizes and shapes in the pH 10 dispersion. Thus, the shape, crystallinity, porosity, and mechanical properties could be controlled by pH, which allows broader uses of supraballs.
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Affiliation(s)
- Takafumi Sekido
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology , 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Sanghyuk Wooh
- Physics at Interfaces, Max Planck Institute for Polymer Research , Ackermannweg 10, D-55128 Mainz, Germany
| | - Regina Fuchs
- Physics at Interfaces, Max Planck Institute for Polymer Research , Ackermannweg 10, D-55128 Mainz, Germany
| | - Michael Kappl
- Physics at Interfaces, Max Planck Institute for Polymer Research , Ackermannweg 10, D-55128 Mainz, Germany
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology , 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Hans-Jürgen Butt
- Physics at Interfaces, Max Planck Institute for Polymer Research , Ackermannweg 10, D-55128 Mainz, Germany
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology , 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
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33
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McNamee CE, Fujii S, Yusa SI, Kappl M. Physical properties of mixed Langmuir monolayers of polystyrene particles with poly(N,N-dimethylaminoethylmethacrylate) hairs and a poly(2-hydroxyethyl methacrylate) polymer at an air/water interface. SOFT MATTER 2017; 13:1583-1593. [PMID: 28127612 DOI: 10.1039/c6sm02529c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effect of adding a poly(2-hydroxyethyl methacrylate) (PHEMA) polymer to a Langmuir monolayer of polystyrene particles carrying poly(N,N-dimethylaminoethylmethacrylate) hair (PDMA-PS particles) at air/water interfaces on the physical properties of the monolayer was studied. The addition of PHEMA to a PDMA-PS particle monolayer at an air/water interface gave a polymer-like monolayer at low surface pressures and a particle-like monolayer at high surface pressures. The PDMA-PS particles formed small aggregates that were dispersed throughout the PHEMA monolayer at low surface pressures, a result suggesting that the particles were trapped in the PHEMA network. Monolayers of closely packed particles were observed at higher surface pressures, suggesting that PHEMA was squeezed-out at higher surface pressures. The stiffness of the mixed monolayer was independent of the surface pressure, but increased as the ratio of PHEMA in the mixed monolayer increased. This increased stiffness was explained by the immobilization of the PDMA-PS particles by PHEMA.
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Affiliation(s)
- Cathy E McNamee
- Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda, Nagano 386-8567, Japan.
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - Shin-Ichi Yusa
- Department of Applied Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Michael Kappl
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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34
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Fukuoka K, Tomikawa A, Nakamura Y, Fujii S. Aqueous Foams Stabilized with Several Tens of Micrometer-sized Polymer Particles: Effects of Surface Hydrophilic–Hydrophobic Balance on Foamability and Foam Stability. CHEM LETT 2016. [DOI: 10.1246/cl.160182] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Keisuke Fukuoka
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
| | - Akira Tomikawa
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
- Nanomaterials Microdevices Research Center, Osaka Institute of Technology
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
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35
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Nakayama S, Hamasaki S, Ueno K, Mochizuki M, Yusa S, Nakamura Y, Fujii S. Foams stabilized with solid particles carrying stimuli-responsive polymer hairs. SOFT MATTER 2016; 12:4794-4804. [PMID: 27109907 DOI: 10.1039/c6sm00425c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Submicrometer-sized polystyrene (PS) particles carrying stimuli-responsive poly[2-(diethylamino)ethyl methacrylate] (PDEA) hairs with degrees of polymerization of 30, 60 and 90 were synthesized by dispersion polymerization and used as a particulate foam stabilizer. The effects of the composition of these PDEA-PS particles and foam formation conditions on foamability, foam stability and foam microstructures were extensively investigated. The hairy particles were found to work as an effective stabilizer of aqueous foams in basic media, in which the PDEA hairs are not protonated and thus the particle surfaces exhibit suitable wettability at the air-water interface. In contrast, little to no foam or unstable foams were formed in acidic aqueous media, in which the hairs are protonated and are therefore water soluble. Particles carrying longer hairs resulted in greater foamability and more highly stabilized foams that were capable of persisting for more than one month. Foams were found to form in a narrower pH range when using PS particles with longer hairs, due to both entropic and image charge effects. Data obtained from the touch mixer mixing method showed that both foamability and foam stability increased with increases in the concentration of polymer particles up to 10 wt%, because higher concentrations allowed greater air-water interfacial areas to be stabilized. Conversely, only minimal foam was obtained at and above 15 wt% because of the high viscosity of the resulting aqueous particle dispersion. Trials using the homogenizer mixing method showed that foam with a cream-like texture could be formed even at 40 wt% particle concentration as a result of the improved mixing efficiency. Defoamation could be induced by exposing the foams to HCl vapor. Exposure to acidic vapor led to in situ protonation of the 2-(diethylamino)ethyl methacrylate residues, rendering the PDEA hairs hydrophilic and water soluble, and desorption of the PDEA-PS particles from the air-water interface.
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Affiliation(s)
- S Nakayama
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
| | - S Hamasaki
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
| | - K Ueno
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
| | - M Mochizuki
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
| | - S Yusa
- Department of Applied Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Y Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan. and Nanomaterials Microdevices Research Center, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - S Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
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36
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Nakayama S, Yusa S, Nakamura Y, Fujii S. Aqueous foams stabilized by temperature-sensitive hairy polymer particles. SOFT MATTER 2015; 11:9099-9106. [PMID: 26418034 DOI: 10.1039/c5sm02187a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Submicrometer-sized polystyrene (PS) particles carrying poly[2-(diethylamino)ethyl methacrylate] (PDEA) hairs (PDEA-PS particles) were synthesized by free radical dispersion polymerization. The hydrophilicity-hydrophobicity balance of the PDEA could be tuned by varying the temperature at near neutral pH (a lower critical solution temperature of PDEA at pH 6.86, 41 °C) and therefore these sterically-stabilized particles acted as temperature-sensitive stabilizers for aqueous foams. At 25 °C, where the PDEA hairs were hydrated and PDEA-PS particles were colloidally stable in aqueous media, foams were formed which coalesced with time and the size of the bubble increased. At 40 and 45 °C, where the PDEA hairs were partially non-hydrated and PDEA-PS particles were close to flocculation or weakly flocculated, foams were formed and bubble coalescence and size increase speeds were slower than those observed at 25 °C. At and above 50 °C, where the PDEA hairs were non-hydrated and PDEA-PS particles were heavily flocculated in aqueous media, the more stable cream-like foams whose volume was almost the same for 1 week were formed. Scanning electron microscopy studies indicated that the particles mainly adsorbed at the air-water interface as monolayers at 25 °C and as multilayers at and above 40 °C. The foam stability and structure could be controlled by changing the temperature.
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Affiliation(s)
- S Nakayama
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
| | - S Yusa
- Department of Applied Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan
| | - Y Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan. and Nanomaterials Microdevices Research Center, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan
| | - S Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585, Japan.
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37
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Huang J, Cheng F, Binks BP, Yang H. pH-Responsive Gas-Water-Solid Interface for Multiphase Catalysis. J Am Chem Soc 2015; 137:15015-25. [PMID: 26524337 DOI: 10.1021/jacs.5b09790] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Despite their wide utility in laboratory synthesis and industrial fabrication, gas-water-solid multiphase catalysis reactions often suffer from low reaction efficiency because of the low solubility of gases in water. Using a surface-modification protocol, interface-active silica nanoparticles were synthesized. Such nanoparticles can assemble at the gas-water interface, stabilizing micrometer-sized gas bubbles in water, and disassemble by tuning of the aqueous phase pH. The ability to stabilize gas microbubbles can be finely tuned through variation of the surface-modification protocol. As proof of this concept, Pd and Au were deposited on these silica nanoparticles, leading to interface-active catalysts for aqueous hydrogenation and oxidation, respectively. With such catalysts, conventional gas-water-solid multiphase reactions can be transformed to H2 or O2 microbubble reaction systems. The resultant microbubble reaction systems exhibit significant catalysis efficiency enhancement effects compared with conventional multiphase reactions. The significant improvement is attributed to the pronounced increase in reaction interface area that allows for the direct contact of gas, water, and solid phases. At the end of reaction, the microbubbles can be removed from the reaction systems through changing the pH, allowing product separation and catalyst recycling. Interestingly, the alcohol oxidation activation energy for the microbubble systems is much lower than that for the conventional multiphase reaction, also indicating that the developed microbubble system may be a valuable platform to design innovative multiphase catalysis reactions.
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Affiliation(s)
| | | | - Bernard P Binks
- Surfactant & Colloid Group, Department of Chemistry, University of Hull , Hull HU6 7RX, United Kingdom
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38
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Nakayama S, Fukuhara K, Nakamura Y, Fujii S. Hollow Microspheres Fabricated from Aqueous Bubbles Stabilized with Latex Particles. CHEM LETT 2015. [DOI: 10.1246/cl.150161] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Saori Nakayama
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
| | - Kenta Fukuhara
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
| | - Yoshinobu Nakamura
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
- Nanomaterials Microdevices Research Center, Osaka Institute of Technology
| | - Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology
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39
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The forces and physical properties of polymer particulate monolayers at air/aqueous interfaces. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2014.12.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Zhu Y, Jiang J, Liu K, Cui Z, Binks BP. Switchable Pickering emulsions stabilized by silica nanoparticles hydrophobized in situ with a conventional cationic surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3301-7. [PMID: 25736518 DOI: 10.1021/acs.langmuir.5b00295] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A stable oil-in-water Pickering emulsion stabilized by negatively charged silica nanoparticles hydrophobized in situ with a trace amount of a conventional cationic surfactant can be rendered unstable on addition of an equimolar amount of an anionic surfactant. The emulsion can be subsequently restabilized by adding a similar trace amount of cationic surfactant along with rehomogenization. This destabilization-stabilization behavior can be cycled many times, demonstrating that the Pickering emulsion is switchable. The trigger is the stronger electrostatic interaction between the oppositely charged ionic surfactants compared with that between the cationic surfactant and the (initially) negatively charged particle surfaces. The cationic surfactant prefers to form ion pairs with the added anionic surfactant and thus desorbs from particle surfaces rendering them surface-inactive. This access to switchable Pickering emulsions is easier than those employing switchable surfactants, polymers, or surface-active particles, avoiding both the complicated synthesis and the stringent switching conditions.
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Affiliation(s)
- Yue Zhu
- †The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
| | - Jianzhong Jiang
- †The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
| | - Kaihong Liu
- †The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
| | - Zhenggang Cui
- †The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, People's Republic of China
| | - Bernard P Binks
- ‡Surfactant and Colloid Group, Department of Chemistry, University of Hull, Hull HU6 7RX, U.K
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41
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Fujii S, Akiyama K, Nakayama S, Hamasaki S, Yusa SI, Nakamura Y. pH- and temperature-responsive aqueous foams stabilized by hairy latex particles. SOFT MATTER 2015; 11:572-579. [PMID: 25426611 DOI: 10.1039/c4sm02236j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Polystyrene (PS) particles carrying pH- and temperature-responsive poly[2-(dimethylamino)ethyl methacrylate] (PDMA) hairs (PDMA-PS particles) were synthesized by dispersion polymerization. The diameter, diameter distribution, morphology, chemical composition and surface chemistry of the particles were characterized using scanning electron microscopy (SEM), elemental microanalysis, dynamic light scattering and zeta potential measurements. The hydrophilicity-hydrophobicity balance of the PDMA could be tuned by varying both pH and temperature and therefore these sterically stabilized particles acted as doubly stimuli-responsive stabilizers for aqueous foams by adsorption and desorption to/from the air-water interface. At and above pH 6.0, in which range the PDMA hairs were either non-protonated or partially protonated, particle-stabilized foams were formed at both 23 and 55 °C. The foam prepared at 55 °C was the more stable of the two, lasting for at least 24 h, whereas the 23 °C foam destabilized within 24 h. SEM studies indicated that the particles adsorbed at the air-water interface as monolayers at 23 °C and as multilayers at 55 °C. At and below pH 5, in which range the hairs were cationic, hydrophilic and water-soluble, no foam was formed irrespective of temperature. Rapid defoaming could be induced by lowering the solution pH at both temperatures, due to rapid in situ protonation of the PDMA hairs, prompting the PDMA-PS particles to desorb from the air-water interface. The foaming and defoaming cycles could be repeated at least five times.
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Affiliation(s)
- Syuji Fujii
- Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Omiya, Asahi-ku, Osaka 535-8585, Japan.
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42
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Tan J, Yu M, Rao X, Yang J, Zeng Z. Fast and facile one-step synthesis of monodisperse thermo-responsive core–shell microspheres and applications. Polym Chem 2015. [DOI: 10.1039/c5py00889a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly monodisperse PMMA microspheres covered with a thermo-responsive shell were synthesized in a single step by means of photoinitiated RAFT dispersion polymerization at room temperature.
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Affiliation(s)
- Jianbo Tan
- Key Laboratory for Polymeric Composite and Functional Materials of the Ministry of Education
- and Key Laboratory of Designed Synthesis and Application of Polymer Material
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou 510275
| | - Mingguang Yu
- Key Laboratory for Polymeric Composite and Functional Materials of the Ministry of Education
- and Key Laboratory of Designed Synthesis and Application of Polymer Material
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou 510275
| | - Xin Rao
- Key Laboratory for Polymeric Composite and Functional Materials of the Ministry of Education
- and Key Laboratory of Designed Synthesis and Application of Polymer Material
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou 510275
| | - Jianwen Yang
- Key Laboratory for Polymeric Composite and Functional Materials of the Ministry of Education
- and Key Laboratory of Designed Synthesis and Application of Polymer Material
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou 510275
| | - Zhaohua Zeng
- Key Laboratory for Polymeric Composite and Functional Materials of the Ministry of Education
- and Key Laboratory of Designed Synthesis and Application of Polymer Material
- School of Chemistry and Chemical Engineering
- Sun Yat-Sen University
- Guangzhou 510275
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43
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Zhu Y, Jiang J, Cui Z, Binks BP. Responsive aqueous foams stabilised by silica nanoparticles hydrophobised in situ with a switchable surfactant. SOFT MATTER 2014; 10:9739-9745. [PMID: 25365142 DOI: 10.1039/c4sm01970a] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the recent past there has been a growing interest in switchable surfactants and stimuli-responsive surface-active particles, since both have surface activity which is either switchable or controllable and they can be recovered and re-used afterwards. Among various triggers the CO2/N2 trigger is particularly environmentally benign. In this paper a facile protocol to obtain switchable surface-active silica nanoparticles using a CO2/N2 trigger is proposed and their utilization in producing responsive aqueous foams with the same trigger is examined. Using a switchable surfactant, N'-dodecyl-N,N-dimethylacetamidinium bicarbonate, which can be switched between a cationic surfactant and a surface-inactive neutral form by bubbling with CO2 and N2 respectively, bare silica nanoparticles can be hydrophobised in situ to become surface-active nanoparticles and the switch of the surfactant can thus be transferred to the particles. Thus responsive particle-stabilised aqueous foams can be prepared. Compared with foams stabilised by specially synthesized switchable or stimuli-responsive particles, the method reported here is much easier, whereas compared with those stabilised by switchable or stimuli-responsive surfactants the method here requires a relatively low concentration.
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Affiliation(s)
- Yue Zhu
- The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, P. R. China.
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44
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Fameau AL, Carl A, Saint-Jalmes A, von Klitzing R. Responsive Aqueous Foams. Chemphyschem 2014; 16:66-75. [DOI: 10.1002/cphc.201402580] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Indexed: 12/30/2022]
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45
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Whitby CP, Krebsz M. Coalescence in concentrated Pickering emulsions under shear. SOFT MATTER 2014; 10:4848-4854. [PMID: 24862445 DOI: 10.1039/c4sm00491d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have investigated the rheology of concentrated oil-in-water emulsions stabilised by silanised silica nanoparticles. The emulsions behave like highly elastic solids in response to small, uniform strains. They become unstable and begin to break down, however, on yielding. We show that the emulsion elasticity is correlated with the salt concentration in the water and hence the particle aggregation in emulsions at a given drop volume fraction. A supporting observation is that destabilisation is favoured by minimising the attractive interactions between the particles. Microscopic observations revealed that coalesced drops have anisotropic shapes and wrinkled surfaces, direct evidence of the interfacial particle layer acting like a mechanical barrier to bulk emulsion destabilisation.
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Affiliation(s)
- Catherine P Whitby
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Australia.
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Gambinossi F, Chanana M, Mylon SE, Ferri JK. Stimulus-responsive Au@(MeO2MAx-co-OEGMAy) nanoparticles stabilized by non-DLVO interactions: implications of ionic strength and copolymer (x:y) fraction on aggregation kinetics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:1748-1757. [PMID: 24517439 DOI: 10.1021/la403963c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Functionalized nanoparticles can assist in stabilizing fluid-fluid interfaces; however, developing and applying the appropriate surface modification presents a challenge because successful application of these nanomaterials for biotechnological, food processing, and environmental applications requires their long-term stability in elevated ionic strength media. This work studies stimulus responsive polymeric materials based on random copolymers of di(ethylene glycol) methyl ether methacrylate (x = MeO2MA) and oligo(ethylene glycol) methyl ether methacrylate (y= OEGMA) which, when grafted to gold nanoparticles, show significant, tunable, colloidal stability. The nanoparticles Au@(MeO2MAx-co-OEGMAy) display tunable, reversible aggregation that is highly dependent on the (x:y) ratio and ionic strength. Effects of these parameters on the initial rate constant of aggregation (k11) are studied by time-resolved dynamic light scattering (TR-DLS) experiments. At the same nanoparticle concentration, a strong sensitivity to salt concentration is observed. Over less than 300 mM increase in NaCl concentration, we observed a two-order of magnitude increase in aggregation rate constants, 4.2 × 10(-20) < k11 < 1.8 × 10(-18) m(3)s(-1). Additionally, for the same gold nanoparticles, a higher fraction of OEGMA requires a higher salt concentration to induce aggregation. A linear relationship between the critical NaCl coagulation concentration (CCC) and the copolymer composition is observed. Analysis of the experimental data with an extended Derjaguin-Landau-Verwey-Overbeek (xDLVO) theory that includes hydration and osmotic forces is used to explain the stability of these systems. We find the hydration pressure, 2.4 < P(h,0) < 7.2 MPa, scales linearly both with the osmotic pressure and the OEGMA monomer concentration (5 < y < 20%). Specific knowledge of P(h,0)(y, C(NaCl)) enables design of both aggregation kinetics and stability as a function of the copolymer ratio and external stimuli.
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Affiliation(s)
- Filippo Gambinossi
- Department of Chemical and Biomolecular Engineering, Lafayette College , Easton, Pennsylvania 18042, United States
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Ramos J, Forcada J, Hidalgo-Alvarez R. Cationic Polymer Nanoparticles and Nanogels: From Synthesis to Biotechnological Applications. Chem Rev 2013; 114:367-428. [DOI: 10.1021/cr3002643] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Jose Ramos
- POLYMAT,
Bionanoparticles Group, Departamento de Química Aplicada, UFI
11/56, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, Apdo. 1072, 20080 Donostia-San
Sebastián, Spain
| | - Jacqueline Forcada
- POLYMAT,
Bionanoparticles Group, Departamento de Química Aplicada, UFI
11/56, Facultad de Ciencias Químicas, Universidad del País Vasco UPV/EHU, Apdo. 1072, 20080 Donostia-San
Sebastián, Spain
| | - Roque Hidalgo-Alvarez
- Grupo
de Física de Fluidos y Biocoloides, Departamento de Física
Aplicada, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain
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48
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Thiol-terminated hydroxy-functional polymer as a transtab toward polymer latex particles. Colloid Polym Sci 2012. [DOI: 10.1007/s00396-012-2845-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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