1
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Hengsbach R, Fink G, Simon U. 1H-NMR studies on the volume phase transition of DNA-modified pNipmam microgels. SOFT MATTER 2024; 20:330-337. [PMID: 38087892 DOI: 10.1039/d3sm01124k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
DNA functionalized pNipmam microgels, which have recently been introduced, are examined at different concentrations of sodium chloride and in PBS solutions via temperature dependent 1H-NMR measurements and are compared to pure pNipmam microgels. We show that the DNA modification shifts the volume phase transition temperature towards lower temperatures and the addition of salt and PBS further supports this effect in both materials. Thermodynamic values, i.e. enthalpy, entropy and Gibbs free energy, are determined via a non-linear fit which can be applied directly to the measurement data without further linearization.
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Affiliation(s)
- Rebecca Hengsbach
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, D-52074 Aachen, Germany.
| | - Gerhard Fink
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, D-52074 Aachen, Germany.
| | - Ulrich Simon
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, D-52074 Aachen, Germany.
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2
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Rey M, Kolker J, Richards JA, Malhotra I, Glen TS, Li NYD, Laidlaw FHJ, Renggli D, Vermant J, Schofield AB, Fujii S, Löwen H, Clegg PS. Interactions between interfaces dictate stimuli-responsive emulsion behaviour. Nat Commun 2023; 14:6723. [PMID: 37872193 PMCID: PMC10593850 DOI: 10.1038/s41467-023-42379-z] [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: 11/07/2022] [Accepted: 10/10/2023] [Indexed: 10/25/2023] Open
Abstract
Stimuli-responsive emulsions offer a dual advantage, combining long-term storage with controlled release triggered by external cues such as pH or temperature changes. This study establishes that thermo-responsive emulsion behaviour is primarily determined by interactions between, rather than within, interfaces. Consequently, the stability of these emulsions is intricately tied to the nature of the stabilizing microgel particles - whether they are more polymeric or colloidal, and the morphology they assume at the liquid interface. The colloidal properties of the microgels provide the foundation for the long-term stability of Pickering emulsions. However, limited deformability can lead to non-responsive emulsions. Conversely, the polymeric properties of the microgels enable them to spread and flatten at the liquid interface, enabling stimuli-responsive behaviour. Furthermore, microgels shared between two emulsion droplets in flocculated emulsions facilitate stimuli-responsiveness, regardless of their internal architecture. This underscores the pivotal role of microgel morphology and the forces they exert on liquid interfaces in the control and design of stimuli-responsive emulsions and interfaces.
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Affiliation(s)
- Marcel Rey
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK.
- Department of Physics, University of Gothenburg, SE-41296, Gothenburg, Sweden.
| | - Jannis Kolker
- Institute for Theoretical Physics II: Soft Matter, Heinrich-Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - James A Richards
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Isha Malhotra
- Institute for Theoretical Physics II: Soft Matter, Heinrich-Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Thomas S Glen
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - N Y Denise Li
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Fraser H J Laidlaw
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - Damian Renggli
- Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland
| | - Jan Vermant
- Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland
| | - Andrew B Schofield
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
| | - 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
| | - Hartmut Löwen
- Institute for Theoretical Physics II: Soft Matter, Heinrich-Heine University Düsseldorf, D-40225, Düsseldorf, Germany
| | - Paul S Clegg
- School of Physics and Astronomy, The University of Edinburgh, Peter Guthrie Tait Road, Edinburgh, EH9 3FD, UK
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3
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Lim HP, Ng SSD, Dasa DB, Adnan SA, Tey BT, Chan ES, Ho KW, Ooi CW. Dual (pH and thermal) stimuli-responsive Pickering emulsion stabilized by chitosan-carrageenan composite microgels. Int J Biol Macromol 2023; 232:123461. [PMID: 36720328 DOI: 10.1016/j.ijbiomac.2023.123461] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/29/2022] [Accepted: 01/25/2023] [Indexed: 01/31/2023]
Abstract
Formulation of water-in-oil (W/O) Pickering emulsion (PE) for food applications has been largely restricted by the limited choices of food-grade Pickering emulsifiers. In this study, composite microgels made of chitosan and carrageenan were explored as a dual (pH and thermal) stimuli-responsive Pickering emulsifier for the stabilization of W/O PE. The chitosan-carrageenan (CS-CRG) composite microgels not only exhibited pH- and thermo-responsiveness, but also displayed enhanced lipophilicity as compared to the discrete polymers. The stability of the CS-CRG-stabilized W/O PE system (CS-CRG PE) was governed by CS:CRG mass ratio and oil fractions used. The CS-CRG PE remained stable at acidic pH and at temperatures below 40 °C. The instability of CS-CRG composite microgels at alkaline pH and at temperatures above 40 °C rendered the demulsification of CS-CRG PE. This stimuli-responsive W/O PE could unlock new opportunities for the development of stimuli-responsive W/O PE using food-grade materials.
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Affiliation(s)
- Hui-Peng Lim
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia; Monash-Industry Plant Oils Research Laboratory (MIPO), Monash University Malaysia, Selangor, Malaysia
| | - Shiuh-Shen Desmond Ng
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia
| | - Dhanushkaa Buddha Dasa
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia
| | - Sarah Anisa Adnan
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia
| | - Beng-Ti Tey
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia; Advanced Engineering Platform, Monash University Malaysia, Selangor, Malaysia
| | - Eng-Seng Chan
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia; Monash-Industry Plant Oils Research Laboratory (MIPO), Monash University Malaysia, Selangor, Malaysia
| | - Kiang-Wei Ho
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia
| | - Chien-Wei Ooi
- Chemical Engineering Discipline, School of Engineering, Monash University Malaysia, Selangor, Malaysia; Monash-Industry Plant Oils Research Laboratory (MIPO), Monash University Malaysia, Selangor, Malaysia; Advanced Engineering Platform, Monash University Malaysia, Selangor, Malaysia.
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4
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Petrunin AV, Bochenek S, Richtering W, Scotti A. Harnessing the polymer-particle duality of ultra-soft nanogels to stabilise smart emulsions. Phys Chem Chem Phys 2023; 25:2810-2820. [PMID: 36052753 DOI: 10.1039/d2cp02700c] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Micro- and nanogels are widely used to stabilise emulsions and simultaneously implement their responsiveness to the external stimuli. One of the factors that improves the emulsion stability is the nanogel softness. Here, we study how the softest nanogels that can be synthesised with precipitation polymerisation of N-isopropylacrylamide (NIPAM), the ultra-low crosslinked (ULC) nanogels, stabilise oil-in-water emulsions. We show that ULC nanogels can efficiently stabilise emulsions already at low mass concentrations. These emulsions are resistant to droplet flocculation, stable against coalescence, and can be easily broken upon an increase in temperature. The resistance to flocculation of the ULC-stabilised emulsion droplets is similar to the one of emulsions stabilised by linear pNIPAM. In contrast, the stability against coalescence and the temperature-responsiveness closely resemble those of emulsions stabilised by regularly crosslinked pNIPAM nanogels. The reason for this combination of properties is that ULC nanogels can be thought of as colloids in between flexible macromolecules and particles. As a polymer, ULC nanogels can efficiently stretch at the interface and cover it uniformly. As a regularly crosslinked nanogel particle, ULC nanogels protect emulsion droplets against coalescence by providing a steric barrier and rapidly respond to changes in external stimuli thus breaking the emulsion. This polymer-particle duality of ULC nanogels can be exploited to improve the properties of emulsions for various applications, for example in heterogeneous catalysis or in food science.
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Affiliation(s)
| | - Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
| | - Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
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5
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Tatry MC, Laurichesse E, Vermant J, Ravaine V, Schmitt V. Interfacial rheology of model water-air microgels laden interfaces: Effect of cross-linking. J Colloid Interface Sci 2023; 629:288-299. [PMID: 36155924 DOI: 10.1016/j.jcis.2022.08.157] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/22/2022] [Accepted: 08/25/2022] [Indexed: 11/20/2022]
Abstract
HYPOTHESIS The mechanical properties of model air/water interfaces covered by poly(N-isopropylacrylamide) microgels depend on the microgels deformability or in other words on the amount of cross-linker added during synthesis. EXPERIMENTS The study is carried out by measuring the apparent dilational, the compression and the shear moduli using three complementary methods: (1) the pendant drop method with perturbative areas, (2) the Langmuir trough compression, and (3) shear rheology using a double wall ring cell mounted onto a Langmuir through. FINDINGS In the range of surface coverages studied, the interfaces exhibit a solid-like behavior and elasticity goes through a maximum as a function of the surface pressure. This is observable whatever the investigation method. This maximum elasticity depends on the microgel deformability: the softer the microgels the higher the value of the moduli. The mechanical behavior of model interfaces is discussed, taking into account the core-shell structure of the particles and their packing at the interface.
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Affiliation(s)
- Marie-Charlotte Tatry
- Centre de Recherche Paul Pascal (CRPP), UMR 5031, Univ. Bordeaux, CNRS, 115 Avenue du Dr Albert Schweitzer, 33600 Pessac, France; Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, 33400 Talence, France.
| | - Eric Laurichesse
- Centre de Recherche Paul Pascal (CRPP), UMR 5031, Univ. Bordeaux, CNRS, 115 Avenue du Dr Albert Schweitzer, 33600 Pessac, France.
| | - Jan Vermant
- Laboratory of Soft Materials, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, CH-8093 Zurich, Switzerland.
| | - Valérie Ravaine
- Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, 33400 Talence, France.
| | - Véronique Schmitt
- Centre de Recherche Paul Pascal (CRPP), UMR 5031, Univ. Bordeaux, CNRS, 115 Avenue du Dr Albert Schweitzer, 33600 Pessac, France.
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6
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Kühnhammer M, Gräff K, Loran E, Soltwedel O, Löhmann O, Frielinghaus H, von Klitzing R. Structure formation of PNIPAM microgels in foams and foam films. SOFT MATTER 2022; 18:9249-9262. [PMID: 36440620 DOI: 10.1039/d2sm01021f] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Responsive aqueous foams are very interesting from a fundamental point of view and for various applications like foam flooding or foam flotation. In this study thermoresponsive microgels (MGs) made from poly(N-isopropyl-acrylamide) (PNIPAM) with varying cross-linker content, are used as foam stabilisers. The foams obtained are thermoresponsive and can be destabilised by increasing the temperature. The structuring of MGs inside the foam films is investigated with small-angle neutron scattering and in a thin film pressure balance. The foam films are inhomogeneous and form a network-like structure, in which thin and MG depleted zones with a thickness of ca. 30 nm are interspersed in a continuous network of thick MG containing areas with a thickness of several 100 nm. The thickness of this continuous network is related to the elastic modulus of the individual MGs, which was determined by atomic force microscopy indentation experiments. Both, the elastic moduli and foam film thicknesses, indicate a correlation to the network elasticity of the MGs predicted by the affine network model.
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Affiliation(s)
- Matthias Kühnhammer
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Kevin Gräff
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Edwin Loran
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Olaf Soltwedel
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Oliver Löhmann
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
| | - Henrich Frielinghaus
- Jülich Center for Neutron Science at the Heinz Maier Leibnitz Zentrum, Forschungszentrum Jülich GmbH, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Regine von Klitzing
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Hochschulstraße 8, 64289 Darmstadt, Germany.
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7
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Feller D, Karg M. Fluid interface-assisted assembly of soft microgels: recent developments for structures beyond hexagonal packing. SOFT MATTER 2022; 18:6301-6312. [PMID: 35993260 DOI: 10.1039/d2sm00872f] [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
Microgels adsorb to air/water and oil/water interfaces - a process driven by a significant reduction in interfacial tension. Depending on the available interface area per microgel, strong lateral deformation can be observed. Typically, hexagonally ordered structures appear spontaneously upon contact of the microgel shells. Transfer from the interface to solid substrates gives access to macroscopically sized microgel monolayers that are interesting for photonic and plasmonic studies as well as colloid-based lithography, for example. Significant efforts have been made to understand the phase behavior of microgels at different interfaces and to explore the available parameter space for achieving complex tessellations. In this review, we will discuss the most recent developments in the realization of microgel monolayers with structures beyond hexagonal packing.
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Affiliation(s)
- Déborah Feller
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
| | - Matthias Karg
- Institut für Physikalische Chemie I: Kolloide und Nanooptik, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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8
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Ni L, Yu C, Wei Q, Liu D, Qiu J. Pickering Emulsion Catalysis: Interfacial Chemistry, Catalyst Design, Challenges, and Perspectives. Angew Chem Int Ed Engl 2022; 61:e202115885. [PMID: 35524649 DOI: 10.1002/anie.202115885] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Indexed: 12/17/2022]
Abstract
Pickering emulsions are particle-stabilized surfactant-free dispersions composed of two immiscible liquid phases, and emerge as attractive catalysis platform to surpass traditional technique barrier in some cases. In this review, we have comprehensively summarized the development and the catalysis applications of Pickering emulsions since the pioneering work in 2010. The explicit mechanism for Pickering emulsions will be initially discussed and clarified. Then, summarization is given to the design strategy of amphiphilic emulsion catalysts in two categories of intrinsic and extrinsic amphiphilicity. The progress of the unconventional catalytic reactions in Pickering emulsion is further described, especially for the polarity/solubility difference-driven phase segregation, "smart" emulsion reaction system, continuous flow catalysis, and Pickering interfacial biocatalysis. Challenges and future trends for the development of Pickering emulsion catalysis are finally outlined.
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Affiliation(s)
- Lin Ni
- State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P.R. China
| | - Chang Yu
- State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P.R. China
| | - Qianbing Wei
- State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P.R. China
| | - Dongming Liu
- State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P.R. China
| | - Jieshan Qiu
- State Key Lab of Fine Chemicals, School of Chemical Engineering, Liaoning Key Lab for Energy Materials and Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P.R. China.,State Key Lab of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
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9
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Wu Y, Zeng M, Cheng Q, Huang C. Recent Progress toward Physical Stimuli-Responsive Emulsions. Macromol Rapid Commun 2022; 43:e2200193. [PMID: 35622941 DOI: 10.1002/marc.202200193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/30/2022] [Indexed: 11/11/2022]
Abstract
Emulsion as a fine dispersion of immiscible liquids has involved widespread applications in industry, pharmaceuticals, agriculture and personal care. Stimuli-responsive emulsions capable of on-demand demulsification or changing their properties are required in many cases such as controllable release cargo, oil recovery, emulsifiers recycle and product separation, great progress has been achieved in these areas. Among these various triggers, much effort has been made to develop physical stimuli, due to the noninvasive and environmentally friendly characteristics. Physical stimuli-responsive emulsions provide a plenty of valuable practical applications in the fields of sustainable industry, biomedical reaction, drug delivery. Here, we summarize the recent development in the field of emulsions in response to physical stimuli consisting of temperature, light, magnetic field, electrical field, etc. The preparation methods and mechanisms of physical stimuli-responsive emulsions and their applications of catalysis reaction, drug delivery, and oil recovery are highlighted in this review. The future directions and outstanding problems of the physical stimuli-responsive emulsions are also discussed. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yutian Wu
- School of chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430070, China
| | - Min Zeng
- School of chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430070, China
| | - Quanyong Cheng
- School of chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430070, China
| | - Caili Huang
- School of chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430070, China
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10
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Ni L, Yu C, Wei Q, Liu D, Qiu J. Pickering Emulsion Catalysis: Interfacial Chemistry, Catalyst Design, Challenges, and Perspectives. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lin Ni
- Dalian University of Technology School of Chemical Engineering CHINA
| | - Chang Yu
- Dalian University of Technology School of Chemical Engineering CHINA
| | - Qianbing Wei
- Dalian University of Technology School of Chemical Engineering CHINA
| | - Dongming Liu
- Dalian University of Technology School of Chemical Engineering CHINA
| | - Jieshan Qiu
- Dalian University of Technology School of Chemical Engineering High Technology Zone, No. 2 Ling Gong Road 116024 Dalian CHINA
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11
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Siebenmorgen C, Zu G, Keskin D, van Rijn P. Dynamic Covalent Cross-linked Nanogel-stabilized Pickering Emulsion for Responsive Microstructures. Macromol Rapid Commun 2022; 43:e2100766. [PMID: 35436017 DOI: 10.1002/marc.202100766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 03/15/2022] [Indexed: 11/09/2022]
Abstract
Designing new dynamic matrices in combination with a highly diverse material formation approach as Pickering emulsionsprovides us with the tools to engineer innovative dynamic porous microstructures in a highly controllable fashion. Here we make use of nanogels (nGels), which exhibits dynamic covalent cross-linking capabilities, as surface stabilizing agents in view of their highly controllable physiochemical properties. The method provides successful formation of dynamic covalent cross-linked hydrogel microstructures based on ketone and amine functionalized nGels using Pickering emulsions was shown. In this system we incorporated a pH-triggerable responsive behavior. The physiochemical properties of the resulting microstructure can be further tailored by modifying the intramolecular interactions at the interface, making this systems interesting for a wide range of applications. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Clio Siebenmorgen
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering-FB40, A. Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - Guangyue Zu
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering-FB40, A. Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - Damla Keskin
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering-FB40, A. Deusinglaan 1, Groningen, 9713 AV, The Netherlands
| | - Patrick van Rijn
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering-FB40, A. Deusinglaan 1, Groningen, 9713 AV, The Netherlands
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12
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Guzmán E, Maestro A. Soft Colloidal Particles at Fluid Interfaces. Polymers (Basel) 2022; 14:polym14061133. [PMID: 35335463 PMCID: PMC8956102 DOI: 10.3390/polym14061133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/08/2022] [Accepted: 03/10/2022] [Indexed: 02/01/2023] Open
Abstract
The assembly of soft colloidal particles at fluid interfaces is reviewed in the present paper, with emphasis on the particular case of microgels formed by cross-linked polymer networks. The dual polymer/colloid character as well as the stimulus responsiveness of microgel particles pose a challenge in their experimental characterization and theoretical description when adsorbed to fluid interfaces. This has led to a controversial and, in some cases, contradictory picture that cannot be rationalized by considering microgels as simple colloids. Therefore, it is necessary to take into consideration the microgel polymer/colloid duality for a physically reliable description of the behavior of the microgel-laden interface. In fact, different aspects related to the above-mentioned duality control the organization of microgels at the fluid interface, and the properties and responsiveness of the obtained microgel-laden interfaces. This works present a critical revision of different physicochemical aspects involving the behavior of individual microgels confined at fluid interfaces, as well as the collective behaviors emerging in dense microgel assemblies.
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Affiliation(s)
- Eduardo Guzmán
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain
- Instituto Pluridisciplinar, Universidad Complutense de Madrid, Paseo de Juan XXIII, 28040 Madrid, Spain
- Correspondence: (E.G.); (A.M.)
| | - Armando Maestro
- Centro de Física de Materiales (CSIC, UPV/EHU), Paseo Manuel de Lardizabal 5, 20018 San Sebastian, Spain
- IKERBASQUE—Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
- Correspondence: (E.G.); (A.M.)
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13
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Self-aggregate performance of hexyl alginate ester derivative synthesized via SN2 reaction for controlled release of λ-cyhalothrin. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04103-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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14
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Es Sayed J, Brummer H, Stuart MCA, Sanson N, Perrin P, Kamperman M. Responsive Pickering Emulsions Stabilized by Frozen Complex Coacervate Core Micelles. ACS Macro Lett 2022; 11:20-25. [PMID: 35574801 PMCID: PMC8772379 DOI: 10.1021/acsmacrolett.1c00647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/09/2021] [Indexed: 11/29/2022]
Abstract
Frozen complex coacervate core micelles (C3Ms) were developed as a class of particle stabilizers for Pickering emulsions. The C3Ms are composed of a core of electrostatically interacting weak polyelectrolytes, poly(acrylic acid) (pAA) and poly(dimethylaminopropylacrylamide) (pDMAPAA), surrounded by a corona of water-soluble and surface active poly(N-isopropylacrylamide) (pNiPAM). Mixing parameters of the two polymer solutions, including pH, mixing method, charge ratio, and salinity of the medium, were carefully controlled, leading to monodisperse, colloidally stable C3Ms. A combination of dynamic light scattering and proton nuclear magnetic resonance experiments showed that the C3Ms gradually disassembled from a dynamically frozen core state in pure water into free polyelectrolyte chains above 0.8 M NaCl. Upon formulation of dodecane-in-water emulsions, the frozen C3Ms adsorb as particles at the droplet interfaces in striking contrast with most of the conventional micelles made of amphiphilic block copolymers which fall apart at the interface. Eventually, increasing the salt concentration of the system triggered disassembly of the C3Ms, which led to emulsion destabilization.
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Affiliation(s)
- Julien Es Sayed
- Polymer
Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747 AG, The Netherlands
| | - Hugo Brummer
- Polymer
Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747 AG, The Netherlands
| | - Marc C. A. Stuart
- Groningen
Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, Groningen, 9747 AG, The Netherlands
| | - Nicolas Sanson
- Soft
Matter Sciences and Engineering, ESPCI,
PSL University, Sorbonne Université, CNRS, 10 rue Vauquelin, 75231 Cedex 05 Paris, France
| | - Patrick Perrin
- Soft
Matter Sciences and Engineering, ESPCI,
PSL University, Sorbonne Université, CNRS, 10 rue Vauquelin, 75231 Cedex 05 Paris, France
| | - Marleen Kamperman
- Polymer
Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747 AG, The Netherlands
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15
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Guan X, Liu Y, Wan Z, Steve Tse YL, Ngai T. Non-Covalent Reconfigurable Microgel Colloidosomes with a Well-Defined Bilayer Shell. Chem Sci 2022; 13:6205-6216. [PMID: 35733902 PMCID: PMC9159095 DOI: 10.1039/d2sc01082h] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/25/2022] [Indexed: 11/25/2022] Open
Abstract
Microgels are extremely interfacially active and are widely used to stabilize emulsions. However, they are commonly used to stabilize oil-in-water emulsions due to their intrinsic hydrophilicity and initially dispersed in water. In addition, there have been no attempts to control microgel structural layers that are formed at the interface and as a result it limits applications of microgel in advanced materials. Here, we show that by introducing octanol into poly(N-isopropylacrylamide-co-methacrylic acid) (PNIPAM-co-MAA) microgels, octanol-swollen microgels can rapidly diffuse from the initially dispersed oil phase onto the water droplet surface. This facilitates the formation of microgel-laden interfacial layers with strong elastic responses and also generates stable inverse water-in-oil Pickering emulsions. These emulsions can be used as templates to produce microgel colloidosomes, herein termed ‘microgelsomes’, with shells that can be fine-tuned from a particle monolayer to a well-defined bilayer. The microgelsomes can then be used to encapsulate and/or anchor nanoparticles, proteins, vitamin C, bio-based nanocrystals or enzymes. Moreover, the programmed release of these substances can be achieved by using ethanol as a trigger to mediate shell permeability. Thus, these reconfigurable microgelsomes with a microgel-bilayer shell can respond to external stimuli and demonstrate tailored properties, which offers novel insights into microgels and promise wider application of Pickering emulsions stabilized by soft colloids. Inverse W/O Pickering emulsions and reconfigurable microgelsomes with a well-defined bilayer structure are prepared from octanol-swollen PNIPAM-co-MAA microgels and the combination of binary microgels, which promise wider application of soft colloids.![]()
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Affiliation(s)
- Xin Guan
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
| | - Yang Liu
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
| | - Zhili Wan
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
- School of Food Science and Technology, South China University of Technology Guangzhou 510640 China
| | - Ying-Lung Steve Tse
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong Shatin N. T. Hong Kong China
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16
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Effect of pH on the mechanical, interfacial, and emulsification properties of chitosan microgels. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.106972] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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17
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Plant-based high internal phase emulsions stabilized by dual protein nanostructures with heat and freeze-thaw tolerance. Food Chem 2021; 373:131458. [PMID: 34731810 DOI: 10.1016/j.foodchem.2021.131458] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/28/2021] [Accepted: 10/20/2021] [Indexed: 01/20/2023]
Abstract
The formation of coherent, three-dimensional (3D) networks by particles either at the interface or in the bulk phase is vital for the stability of emulsions. In this study, nanoparticles of walnut proteins (WPs) were associated by unfolded fibrillar rice proteins (RPs), forming dual protein nanostructures (DPNs) characteristic of coherent 3D networks. The DPNs emulsified walnut oil and formed high internal phase emulsions (HIPEs), which were stable against 2-month storage and 30-min heating at 95 °C. Furthermore, the interfacial structures can be further reinforced by sodium chloride (50 mM and above), and became invulnerable to repeated freeze-thaw treatments. Based on the above results, a plant-based walnut sauce was developed with superior freeze-thaw stability to three arbitrary commercial mayonnaises. The HIPEs with tunable rheological properties in response to salt concentration and excellent stabilities against long-term storage, heating, and freeze-thaw may be potential surrogates of futuristic plant-based textural and sensory materials in foods.
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18
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Stock S, Jakob F, Röhl S, Gräff K, Kühnhammer M, Hondow N, Micklethwaite S, Kraume M, von Klitzing R. Exploring water in oil emulsions simultaneously stabilized by solid hydrophobic silica nanospheres and hydrophilic soft PNIPAM microgel. SOFT MATTER 2021; 17:8258-8268. [PMID: 34550151 DOI: 10.1039/d1sm00942g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A general drawback of microgels is that they do not stabilize water-in-oil (w/o) emulsions of non-polar oils. Simultaneous stabilization with solid hydrophobic nanoparticles and soft hydrophilic microgels overcomes this problem. For a fundamental understanding of this synergistic effect the use of well defined particle systems is crucial. Therefore, the present study investigates the stabilization of water droplets in a highly non-polar oil phase using temperature responsive, soft and hydrophilic PNIPAM microgel particles (MGs) and solid and hydrophobic silica nanospheres (SNs) simultaneously. The SNs are about 20 times smaller than the MGs. In a multiscale approach the resulting emulsions are studied from the nanoscale particle properties over microscale droplet sizes to macroscopic observations. The synergy of the particles allows the stabilization of water-in-oil (w/o) emulsions, which was not possible with MGs alone, and offers a larger internal interface than the stabilization with SNs alone. Furthermore, the incorporation of hydrophilic MGs into a hydrophobic particle layer accelerates the emulsions sedimentation speed. Nevertheless, the droplets are still sufficiently protected against coalescence even in the sediment and can be redispersed by gentle shaking. Based on droplet size measurements and cryo-SEM studies we elaborate a model, which explains the found phenomena.
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Affiliation(s)
- Sebastian Stock
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Franziska Jakob
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Susanne Röhl
- Chair of Chemical and Process Engineering, Technische Universität Berlin, Berlin, Germany
| | - Kevin Gräff
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Matthias Kühnhammer
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
| | - Nicole Hondow
- School of Chemical and Process Engineering, University of Leeds, Leeds, UK
| | | | - Matthias Kraume
- Chair of Chemical and Process Engineering, Technische Universität Berlin, Berlin, Germany
| | - Regine von Klitzing
- Institute for Condensed Matter Physics, Technische Universität Darmstadt, Darmstadt, Germany.
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19
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Saavedra Isusi GI, Weilandt M, Majollari I, Karbstein HP, van der Schaaf US. Emulsions stabilised with pectin-based microgels: investigations into the effect of pH and ionic strength on emulsion stability. Food Funct 2021; 12:7227-7238. [PMID: 34165131 DOI: 10.1039/d1fo00891a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Pectin-based microgel particles (MGPs) are encouraging sustainable emulsifying agents for food-applications. Based on polyelectrolytes, pectin-based MGPs are assumed to be pH and ionic strength sensitive, in a similar manner to MGPs of synthetic polymers. Besides building a barrier around oil droplets, charged MGPs repulse each other. Thus the stabilisation mechanisms of pectin-based MGPs should be both steric and electrostatic. To investigate this, emulsions were homogenised with MGP concentrations ranging from 0.5 to 2 wt% MGPs. After emulsification, the pH of the emulsions was adjusted to 4, 3, or 2; and the resulting droplet sizes were measured. We found out that the droplet size and the appearance of agglomerates increased with decreasing pH values. This was caused by the loss of the MGP surface charge, as stated by their ζ-potential, showing an increase from -33.71 ± 4.1 mV for samples with pH 4 to -17 ± 0.6 mV, and -3.4 ± 0.6 mV for pH 3 and 2, respectively. However, the degree of coalescence was dependent on the MGP concentration, as samples with 0.5 wt% coalesced more readily than samples with 2 wt% MGP. These results help understand the emulsion stabilisation mechanisms of pectin-based MGPs and what effect formulation parameters have on the long-term stability of MGP-stabilised emulsions.
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Affiliation(s)
- G I Saavedra Isusi
- Karlsruhe Institute of Technology, Institute of Process Engineering in Life Sciences - Chair of Food Process Engineering, Gotthard-Franz-Str. 3, Building 50.31, 76131 Karlsruhe, Germany.
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20
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Lu Y, Zhu Y, Yang F, Xu Z, Liu Q. Advanced Switchable Molecules and Materials for Oil Recovery and Oily Waste Cleanup. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2004082. [PMID: 34047073 PMCID: PMC8336505 DOI: 10.1002/advs.202004082] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 01/19/2021] [Indexed: 05/07/2023]
Abstract
Advanced switchable molecules and materials have shown great potential in numerous applications. These novel materials can express different states of physicochemical properties as controlled by a designated stimulus, such that the processing condition can always be maintained in an optimized manner for improved efficiency and sustainability throughout the whole process. Herein, the recent advances in switchable molecules/materials in oil recovery and oily waste cleanup are reviewed. Oil recovery and oily waste cleanup are of critical importance to the industry and environment. Switchable materials can be designed with various types of switchable properties, including i) switchable interfacial activity, ii) switchable viscosity, iii) switchable solvent, and iv) switchable wettability. The materials can then be deployed into the most suitable applications according to the process requirements. An in-depth discussion about the fundamental basis of the design considerations is provided for each type of switchable material, followed by details about their performances and challenges in the applications. Finally, an outlook for the development of next-generation switchable molecules/materials is discussed.
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Affiliation(s)
- Yi Lu
- Department of Chemical and Materials EngineeringUniversity of AlbertaEdmontonAlbertaT6G 1H9Canada
| | - Yeling Zhu
- Department of Chemical and Materials EngineeringUniversity of AlbertaEdmontonAlbertaT6G 1H9Canada
| | - Fan Yang
- College of New Materials and New EnergiesShenzhen Technology UniversityShenzhen518118P. R. China
| | - Zhenghe Xu
- Department of Chemical and Materials EngineeringUniversity of AlbertaEdmontonAlbertaT6G 1H9Canada
- Department of Materials Science and EngineeringSouthern University of Science and TechnologyShenzhen518055P. R. China
| | - Qingxia Liu
- Department of Chemical and Materials EngineeringUniversity of AlbertaEdmontonAlbertaT6G 1H9Canada
- College of New Materials and New EnergiesShenzhen Technology UniversityShenzhen518118P. R. China
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21
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Ahmed R, Wang M, Qi Z, Hira NUA, Jiang J, Zhang H, Iqbal S, Wang J, Stuart MA, Guo X. Pickering Emulsions Based on the pH-Responsive Assembly of Food-Grade Chitosan. ACS OMEGA 2021; 6:17915-17922. [PMID: 34308026 PMCID: PMC8295998 DOI: 10.1021/acsomega.1c01490] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/07/2021] [Indexed: 05/07/2023]
Abstract
Few natural, biocompatible, and inexpensive emulsifiers are available because such emulsifiers must satisfy severe requirements, be produced synthetically rather than naturally, be nontoxic, and require minimal effort to produce. Therefore, the synthesis of food-grade and biocompatible nanoparticles as an alternative to surfactants has recently received attention in the industry. However, many previous efforts involved chemical modification of materials or the introduction of secondary cocomponents for emulsion formation. To achieve the goal of simple preparation, we consider here chitosan nanoparticles to prepare Pickering emulsions of food-grade oil through the control of pH, without further chemical modification or extra additives. A mild process can prepare nanoparticles from chitosan by simply increasing the pH from 3.0 to 6.0. The results showed that the average radius of chitosan at pH 6.0 was 170 nm, while large aggregates were formed at pH 6.5. These nanoparticles were utilized to prepare the Pickering emulsion. The average size of emulsion droplets decreased upon increasing the pH from 3.0 to 6.0. Moreover, Pickering emulsions at different oil fractions and nanoparticle concentrations were stable and showed a low creaming index for 45 days. The emulsions were stable against coalescence and flocculation and behaved rheologically as gel-like, shear-thinning fluids (G' > G″). Pickering emulsion prevents the growth of the microorganism (Staphylococcus aureus) at different pH values and chitosan concentrations. These results demonstrate that chitosan nanoparticles could be a cost-effective and biocompatible emulsifier for the food or pharmaceutical industry for encapsulation and bioactive compounds, and Pickering emulsions have promising antibacterial effects for further applications.
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Affiliation(s)
- Rizwan Ahmed
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Mingwei Wang
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Zhiyao Qi
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Noor ul ain Hira
- State
Key Laboratory of Advanced Polymeric Material, School of Materials
Science and Engineering, East China University
of Science and Technology, Shanghai 200237, P. R. China
| | - Jiahui Jiang
- College
of Life Science, Henan Agricultural University, Zhengzhou 450002, P. R. China
| | - Hongsen Zhang
- College
of Life Science, Henan Agricultural University, Zhengzhou 450002, P. R. China
| | - Shahid Iqbal
- School
of Chemical and Environmental Engineering, College of Chemistry, Chemical
Engineering and Materials Science, Soochow
University, Suzhou, Jiangsu 215123, P.
R. China
| | - Junyou Wang
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Martien Abraham
Cohen Stuart
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Xuhong Guo
- State-Key
Laboratory of Chemical Engineering and Shanghai Key Laboratory of
Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
- International
Joint Research Center of Green Energy Chemical Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
- Engineering
Research Center of Materials Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Xinjiang 832000, P. R.
China
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22
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Dual-Responsive Micellar Microgels Matrixed with Surface-Engineered Lipids: a New Approach for Controlled Vaginal Drug Delivery. J Pharm Innov 2021. [DOI: 10.1007/s12247-021-09546-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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23
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Weng J, Lin R, Jiang C, Wei W, Wang X, Jin Q. O/W Emulsion Stabilized by Bovine Milk Phospholipid-Protein Nanoemulsions: Preparation, Stability, and In Vitro Digestion. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:5003-5012. [PMID: 33886291 DOI: 10.1021/acs.jafc.0c05617] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study aims to prepare a stable oil-in-water (O/W) emulsion with droplets of approximately 3-5 μm and a structured phospholipid (PL)-protein membrane that is similar to human milk fat globules. A nanoemulsion with an average droplet size of 200 nm prepared with bovine milk PL-protein, a milk fat globule membrane (MFGM)-rich ingredient, was used as an emulsifier to form an O/W emulsion with an average droplet size of 3.96 μm. Stable O/W emulsions were formed with a low concentration (1 wt %) of the MFGM-rich ingredient. The nanoemulsion was adsorbed at the oil-water interface. The O/W emulsions stored at 4 °C did not show structural damage upon 7 days of storage. The deformation or partial deformation of nanoemulsion droplets attached to lipid droplets may contribute to the physical stability of the emulsion. In vitro digestion of the O/W emulsion showed a low lipolysis degree in gastric digestion, and the final hydrolysis efficiency of the O/W emulsion was 62.74%, which is higher than that of traditional infant formula.
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Affiliation(s)
- Jiayu Weng
- State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Ruixue Lin
- State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Chenyu Jiang
- State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Wei Wei
- State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xingguo Wang
- State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Qingzhe Jin
- State Key Lab of Food Science and Technology, Jiangnan University, Wuxi 214122, China
- Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
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24
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Pickering emulsions stabilized by thermoresponsive oligo(ethylene glycol)-based microgels: Effect of temperature-sensitivity on emulsion stability. J Colloid Interface Sci 2021; 589:96-109. [DOI: 10.1016/j.jcis.2020.12.082] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 01/20/2023]
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25
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Saavedra Isusi G, Lohner N, Karbstein H, van der Schaaf U. Emulsions stabilised with pectin-based microgels: Investigations into the break-up of droplets in the presence of microgels. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2020.110421] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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26
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Pérez-Chávez NA, Albesa AG, Longo GS. Thermodynamic Theory of Multiresponsive Microgel Swelling. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02885] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Néstor A. Pérez-Chávez
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata 1900, Argentina
| | - Alberto G. Albesa
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata 1900, Argentina
| | - Gabriel S. Longo
- Instituto de Investigaciones Fisicoquímicas, Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata 1900, Argentina
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27
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Farias BV, Haeri F, Khan SA. Linking polymer hydrophobicity and molecular interactions to rheology and tribology in phospholipid-containing complex gels. J Colloid Interface Sci 2021; 584:134-144. [PMID: 33069013 DOI: 10.1016/j.jcis.2020.09.113] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/20/2020] [Accepted: 09/26/2020] [Indexed: 11/29/2022]
Abstract
HYPOTHESIS The rheological behavior and frictional properties (macroscopic level) of systems containing a hydrophobically modified polymer and phospholipids depend on the hydrophobic association that occur between the hydrophobic moiety of the polymer and the phospholipid tails (molecular level). The hydrophobicity of the polymer can thus be used to control its interactions with phospholipids, and manipulate complex gel macroscopic behavior. EXPERIMENTS By using systems composed of a crosslinked hydrophobically modified polyacrylic acid (HMPAA) or a crosslinked polyacrylic acid polymer (PAA) and phospholipids, we examine the underlying mechanisms through which the components interact using isothermal titration calorimetry (ITC) and their effect on rheological and tribological characteristics of complex gels. FINDINGS We find the systems containing HMPAA and phospholipid exhibit gel-like behavior with the elastic modulus increasing substantially upon phospholipid addition due to hydrophobic interactions that result in a more interconnected network formation, as evidenced by ITC measurements. Similar experiments with a crosslinked polyacrylic acid polymer (PAA) show no interactions, lending credence to our hypothesis. In addition, soft tribological behavior shows lower friction coefficients at low entrainment speeds with HMPAA concentration and the addition of phospholipid, while no change in friction coefficient was observed in the case of increasing PAA concentration, indicating HMPAA and phospholipids to be interacting with the soft PDMS contacts.
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Affiliation(s)
- Barbara V Farias
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Farrah Haeri
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States
| | - Saad A Khan
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, United States.
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28
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Fernandez-Rodriguez MA, Martín-Molina A, Maldonado-Valderrama J. Microgels at interfaces, from mickering emulsions to flat interfaces and back. Adv Colloid Interface Sci 2021; 288:102350. [PMID: 33418470 DOI: 10.1016/j.cis.2020.102350] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 12/22/2022]
Abstract
In this review, we cover the topic of p(NIPAM) based microgels at interfaces, revisiting classical studies in light of the newest ones. In particular, we focus on their use as emulsifiers in the so-called mickering emulsions, i.e. Pickering emulsion stabilized by soft particles. Given the complexity of the experimental characterization and simulation of these soft particles at interfaces, the review is structured in progressive complexity levels, until we reach the highly interesting and promising responsiveness to stimuli of mickering emulsions. We start from the lowest level of complexity, the current understanding of the behavior of single microgels confined at a flat interface. Then, we discuss their collective behavior upon crowding, their responsiveness at interfaces, and their macroscopic properties as microgel films. Once we have the necessary characterization tools, we proceed to discuss the complex and convoluted picture of responsive mickering emulsions. The way is rough, with current controversial and contradicting studies, but it holds promising results as well. We state open questions worth of being tackled by the Soft Matter community, and we conclude that it is worth the trouble of continuing after the master theory of microgel interfacial activity, as it will pave the way to widely adopt responsive mickering emulsions as the worthy Pickering emulsion successors.
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Affiliation(s)
| | - Alberto Martín-Molina
- Department of Applied Physics, University of Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain; Institute Carlos I for Theoretical and Computational Physics, University of Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain
| | - Julia Maldonado-Valderrama
- Department of Applied Physics, University of Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain; Excellence Unit "ModellingNature" (MNat), , University of Granada, Spain.
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29
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Bochenek S, Scotti A, Richtering W. Temperature-sensitive soft microgels at interfaces: air-water versus oil-water. SOFT MATTER 2021; 17:976-988. [PMID: 33284940 DOI: 10.1039/d0sm01774d] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The formation of smart emulsions or foams whose stability can be controlled on-demand by switching external parameters is of great interest for basic research and applications. An emerging group of smart stabilizers are microgels, which are nano- and micro-sized, three-dimensional polymer networks that are swollen by a good solvent. In the last decades, the influence of various external stimuli on the two-dimensional phase behavior of microgels at air- and oil-water interfaces has been studied. However, the impact of the top-phase itself has been barely considered. Here, we present data that directly address the influence of the top-phase on the microgel properties at interfaces. The dimensions of pNIPAM microgels are measured after deposition from two interfaces, i.e., air- and decane-water. While the total in-plane size of the microgel increases with increasing interfacial tension, the portions or fractions of the microgels situated in the aqueous phase are not affected. We correlate the area microgels occupy to the surface tensions of the interfaces, which allows to estimate an elastic modulus. In comparison to nanoindentation measurements, we observe a larger elastic modulus for the microgels. By combining compression, deposition, and visualization, we show that the two-dimensional phase behavior of the microgel monolayers is not altered, although the microgels have a larger total in-plane size at higher interfacial tension.
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Affiliation(s)
- Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany.
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30
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Zhang T, Ngai T. One-Step Formation of Double Emulsions Stabilized by PNIPAM-based Microgels: The Role of Co-monomer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1045-1053. [PMID: 33426887 DOI: 10.1021/acs.langmuir.0c02645] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microgels have been widely used as particulate emulsifiers to stabilize emulsions due to their multiresponsiveness and deformability. Generally, microgels stabilize oil-in-water (o/w) emulsions, whereas occasionally water-in-oil (w/o) emulsions are reported using oils like n-octanol in which microgels can swell. However, the use of microgels to stabilize double emulsions (DEs) remains scarce. In this work, we report a special poly(N-isopropylacrylamide)- (PNIPAM-) based microgel to obtain water-in-oil-in-water (w/o/w) DEs in one step with the introduction of 1-vinylimidazole (VIM) as comonomer and hydroxy silicone oil as the oily phase. By comparison, when methacrylic acid (MAA) is used, an o/w emulsion will be obtained. The same holds true even when we freeze-dry and redisperse the microgels in the oil. Compared with PNIPAM-co-MAA microgel, PNIPAM-co-VIM microgel achieves a lower interfacial tension (IFT) when dispersed in the aqueous phase. This interfacial affinity of PNIPAM-co-VIM is believed to result from acid-base interaction between VIM and hydroxyl groups of the silicone oil, the same interaction used for preparing silica-vinyl polymer composite particles. Increasing the particle concentrations from 0.05% to 0.9% (w/v), we observe the inversion from w/o to o/w/o and w/o/w emulsions. When the oil fraction is changed from 0.1 to 0.9, the emulsion morphology evolves from o/w and w/o/w to w/o emulsions. At last, we examine the emulsifying ability of PNIPAM-co-VIM microgel with other oils and find that w/o/w emulsions are obtained with edible oils as well. Considering the similarity between microgels and biopolymers, the discovery in this work will help in designing food-grade emulsifiers to form edible DEs.
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Affiliation(s)
- Tong Zhang
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
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31
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Microgels self-assembly at liquid/liquid interface as stabilizers of emulsion: Past, present & future. Adv Colloid Interface Sci 2021; 287:102333. [PMID: 33360120 DOI: 10.1016/j.cis.2020.102333] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 11/25/2020] [Accepted: 11/27/2020] [Indexed: 12/22/2022]
Abstract
The most recent developments on Pickering emulsions deal with the design of responsive emulsions able to undergo fast destabilization under the effect of an external stimulus. In this scenario, soft colloidal particles like microgels are considered novel class suitable emulsifiers. Microgels particles self-assemblies are highly deformable at interfaces covering higher surfaces than hard particles and their interfacial behavior strongly depends on external-stimuli. Microgels are very diverse owing to the large variety of them from the point of view of possible combinations of stimuli-responsiveness and different microstructures (crosslinking density and distribution). Herein, we illustrate the use of different types of responsive microgels not only from a structural point of view but also even from physical one. For that, the effect of different microgels parameters such as internal structure and charge density on mechanical properties of the interface will be discussed.
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Bochenek S, McNamee CE, Kappl M, Butt HJ, Richtering W. Interactions between a responsive microgel monolayer and a rigid colloid: from soft to hard interfaces. Phys Chem Chem Phys 2021; 23:16754-16766. [PMID: 34319323 DOI: 10.1039/d1cp01703a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Responsive poly-N-isopropylacrylamide-based microgels are commonly used as model colloids with soft repulsive interactions. It has been shown that the microgel-microgel interaction in solution can be easily adjusted by varying the environmental parameters, e.g., temperature, pH, or salt concentration. Furthermore, microgels readily adsorb to liquid-gas and liquid-liquid interfaces forming responsive foams and emulsions that can be broken on-demand. In this work, we explore the interactions between microgel monolayers at the air-water interface and a hard colloid in the water. Force-distance curves between the monolayer and a silica particle were measured with the Monolayer Particle Interaction Apparatus. The measurements were conducted at different temperatures and lateral compressions, i.e., different surface pressures. The force-distance approach curves display long-range repulsive forces below the volume phase transition temperature of the microgels. Temperature and lateral compression reduce the stiffness of the monolayer. The adhesion increases with temperature and decreases with a lateral compression of the monolayer. When compressed laterally, the interactions between the microgels are hardly affected by temperature, as the directly adsorbed microgel fractions are nearly insensitive to temperature. In contrast, our findings show that the temperature-dependent swelling of the microgel fractions in the aqueous phase strongly influences the interaction with the probe. This is explained by a change in the microgel monolayer from a soft to a hard repulsive interface.
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Affiliation(s)
- Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
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33
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Hunter SJ, Armes SP. Pickering Emulsifiers Based on Block Copolymer Nanoparticles Prepared by Polymerization-Induced Self-Assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:15463-15484. [PMID: 33325720 PMCID: PMC7884006 DOI: 10.1021/acs.langmuir.0c02595] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/27/2020] [Indexed: 05/28/2023]
Abstract
Block copolymer nanoparticles prepared via polymerization-induced self-assembly (PISA) represent an emerging class of organic Pickering emulsifiers. Such nanoparticles are readily prepared by chain-extending a soluble homopolymer precursor using a carefully selected second monomer that forms an insoluble block in the chosen solvent. As the second block grows, it undergoes phase separation that drives in situ self-assembly to form sterically stabilized nanoparticles. Conducting such PISA syntheses in aqueous solution leads to hydrophilic nanoparticles that enable the formation of oil-in-water emulsions. Alternatively, hydrophobic nanoparticles can be prepared in non-polar media (e.g., n-alkanes), which enables water-in-oil emulsions to be produced. In this review, the specific advantages of using PISA to prepare such bespoke Pickering emulsifiers are highlighted, which include fine control over particle size, copolymer morphology, and surface wettability. This has enabled various fundamental scientific questions regarding Pickering emulsions to be addressed. Moreover, block copolymer nanoparticles can be used to prepare Pickering emulsions over various length scales, with mean droplet diameters ranging from millimeters to less than 200 nm.
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Affiliation(s)
- Saul J. Hunter
- Department of Chemistry,
Dainton Building, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
| | - Steven P. Armes
- Department of Chemistry,
Dainton Building, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
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34
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Behrens SH. Oil-coated bubbles in particle suspensions, capillary foams, and related opportunities in colloidal multiphase systems. Curr Opin Colloid Interface Sci 2020. [DOI: 10.1016/j.cocis.2020.08.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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35
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Extraction of tetracycline in food samples using biochar microspheres prepared by a Pickering emulsion method. Food Chem 2020; 329:127162. [DOI: 10.1016/j.foodchem.2020.127162] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 05/10/2020] [Accepted: 05/25/2020] [Indexed: 11/18/2022]
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36
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Saavedra Isusi G, Madlindl L, Karbstein H, van der Schaaf U. Microstructures and conformational arrangement in emulsions caused by concentration ratios of pectin-based microgels and oil. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125166] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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37
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Mehrabian H, Snoeijer JH, Harting J. Desorption energy of soft particles from a fluid interface. SOFT MATTER 2020; 16:8655-8666. [PMID: 32857082 DOI: 10.1039/d0sm01122c] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The efficiency of soft particles to stabilize emulsions is examined by measuring their desorption free energy, i.e., the mechanical work required to detach the particle from a fluid interface. Here, we consider rubber-like elastic as well as microgel particles, using coarse-grained molecular dynamics simulations. The energy of desorption is computed for two and three-dimensional configurations by means of the mean thermodynamic integration method. It is shown that the softness affects the particle-interface binding in two opposing directions as compared to rigid particles. On the one hand, a soft particle spreads at the interface and thereby removes a larger unfavorable liquid-liquid contact area compared to rigid particles. On the other hand, softness provides the particle with an additional degree of freedom to get reshaped instead of deforming the interface, resulting in a smaller restoring force during the detachment. It is shown that the first effect prevails so that a soft spherical particle attaches to the fluid interface more strongly than rigid spheres. Finally, we consider microgel particles both in the swollen and in the collapsed state. Surprisingly, we find that the latter has a larger binding energy. All results are rationalised using thermodynamic arguments and thereby offer detailed insights into the desorption energy of soft particles from fluid interfaces.
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Affiliation(s)
- Hadi Mehrabian
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands and Physics of Fluids Group and J. M. Burgers Centre for Fluid Dynamics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands and Chemical Engineering Department, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jacco H Snoeijer
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands and Physics of Fluids Group and J. M. Burgers Centre for Fluid Dynamics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Jens Harting
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands and Physics of Fluids Group and J. M. Burgers Centre for Fluid Dynamics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands and Helmholtz-Institute Erlangen-Nürnberg for Renewable Energy, Forschungszentrum Jülich, Fürther Str. 248, 90429 Nürnberg, Germany. and Department of Chemical and Biological Engineering and Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fürther Straße 248, 90429 Nürnberg, Germany
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38
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Schmidt MM, Bochenek S, Gavrilov AA, Potemkin II, Richtering W. Influence of Charges on the Behavior of Polyelectrolyte Microgels Confined to Oil-Water Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11079-11093. [PMID: 32845643 DOI: 10.1021/acs.langmuir.0c02081] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The role of electrostatics on the interfacial properties of polyelectrolyte microgels has been discussed controversially in the literature. It is not yet clear if, or how, Coulomb interactions affect their behavior under interfacial confinement. In this work, we combine compression isotherms, atomic force microscopy imaging, and computer simulations to further investigate the behavior of pH-responsive microgels at oil-water interfaces. At low compression, charged microgels can be compressed more than uncharged microgels. The in-plane effective area of charged microgels is found to be smaller in comparison to uncharged ones. Thus, the compressibility is governed by in-plane interactions of the microgels with the interface. At high compression, however, charged microgels are less compressible than uncharged microgels. Microgel fractions located in the aqueous phase interact earlier for charged than for uncharged microgels because of their different swelling perpendicular to the interface. Therefore, the compressibility at high compression is controlled by out-of-plane interactions. In addition, the size of the investigated microgels plays a pivotal role. The charge-dependent difference in compressibility at low compression is only observed for small but not for large microgels, while the behavior at high compression does not depend on the size. Our results highlight the complex nature of soft polymer microgels as compared to rigid colloidal particles. We clearly demonstrate that electrostatic interactions affect the interfacial properties of polyelectrolyte microgels.
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Affiliation(s)
| | - Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, 52074 Aachen, Germany
| | - Alexey A Gavrilov
- Physics Department, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | - Igor I Potemkin
- Physics Department, Lomonosov Moscow State University, Moscow 119991, Russian Federation
- DWI - Leibniz Institute for Interactive Materials, 52074 Aachen, Germany
- National Research South Ural State University, Chelyabinsk 454080, Russian Federation
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52074 Aachen, Germany
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39
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Lian X, Liao S, Yang Y, Zhang X, Wang Y. Effect of pH or Metal Ions on the Oil/Water Interfacial Behavior of Humic Acid Based Surfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:10838-10845. [PMID: 32830504 DOI: 10.1021/acs.langmuir.0c01874] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Humic acid, a kind of widespread organic macromolecule on earth, is naturally formed through the microbial biodegradation of plant, animal, and microorganism residues. Because of the large number of active functional groups (phenolic hydroxyl and carboxyl), humic acid has been considered as a biocompatible, green, and low-cost biosurfactant recently. In this work, based on the sensitivity of humic acid to the external chemical environment, the oil/water interfacial behavior of sodium humate at different pH or in the presence of metal ions is closely investigated. Sodium humate is significantly enriched toward the oil/water interface at either low pH or high metal-ion concentration to adjust the properties of the prepared emulsion, but the mechanisms are proved to be different when considering the influence of pH and metal ions. Besides, to the best of our knowledge, humic acid based surfactant is proposed as a Pickering emulsifier for the first time, known as solid surfactant. This work promises the great potential of humic acid as a natural environment-responsive surfactant and has important implications for the application of humic acid based surfactant in industry and understanding of the role of humic acid in the natural environment.
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Affiliation(s)
- Xiaodong Lian
- Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Shenglong Liao
- Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Yipan Yang
- Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Xiaogang Zhang
- Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Yapei Wang
- Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
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40
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Polymer or microgel particle: Differences in emulsifying properties of pectin as microgel or as individual polymer chains. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.124793] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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41
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Es Sayed J, Meyer C, Sanson N, Perrin P. Oxidation-Responsive Emulsions Stabilized by Cleavable Metallo-Supramolecular Cross-Linked Microgels. ACS Macro Lett 2020; 9:1040-1045. [PMID: 35648615 DOI: 10.1021/acsmacrolett.0c00389] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
An original route to develop an advanced class of microgel emulsifiers containing stimulable metallo-supramolecular instead of frozen covalent cross-links is reported. The poly(N-isopropylmethacrylamide) (PNiPMAM) chains of the microgel are connected by iron(II)-bis(terpyridine) coordination supramolecular complexes that can be cleaved on demand, leading to unique properties both at interfaces and in volume. The microgel synthesis is not demanding, and the characterization of its supramolecular structure can be precisely achieved by standard methods. Singularly, interfaces of an oil-in-water emulsion stabilized by the supramolecular particles can be triggered at the molecular scale by oxidation of Fe(II) to Fe(III), leading to emulsion breaking. In bulk, we show that a microgel dispersion can indeed be transformed into a polymer solution upon oxidation. Our study paves the way to the discovery of unusual microgel properties as our proof-of-concept can be extended to different supramolecular chemistry and architecture.
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Affiliation(s)
- Julien Es Sayed
- Soft Matter Sciences and Engineering, ESPCI, PSL University, Sorbonne Université, CNRS, 10 rue Vauquelin, 75231 Cedex 05 Paris, France
| | - Christophe Meyer
- Molecular, Macromolecular Chemistry and Materials, ESPCI, PSL University, CNRS, 10 rue Vauquelin, 75231 Cedex 05 Paris, France
| | - Nicolas Sanson
- Soft Matter Sciences and Engineering, ESPCI, PSL University, Sorbonne Université, CNRS, 10 rue Vauquelin, 75231 Cedex 05 Paris, France
| | - Patrick Perrin
- Soft Matter Sciences and Engineering, ESPCI, PSL University, Sorbonne Université, CNRS, 10 rue Vauquelin, 75231 Cedex 05 Paris, France
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42
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Temperature and electrostatics effects on charged poly(N-isopropylacrylamide) microgels at the interface. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112678] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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43
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Oberdisse J, Hellweg T. Recent advances in stimuli-responsive core-shell microgel particles: synthesis, characterisation, and applications. Colloid Polym Sci 2020. [DOI: 10.1007/s00396-020-04629-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AbstractInspired by the path followed by Matthias Ballauff over the past 20 years, the development of thermosensitive core-shell microgel structures is reviewed. Different chemical structures, from hard nanoparticle cores to double stimuli-responsive microgels have been devised and successfully implemented by many different groups. Some of the rich variety of these systems is presented, as well as some recent progress in structural analysis of such microstructures by small-angle scattering of neutrons or X-rays, including modelling approaches. In the last part, again following early work by the group of Matthias Ballauff, applications with particular emphasis on incorporation of catalytic nanoparticles inside core-shell structures—stabilising the nanoparticles and granting external control over activity—will be discussed, as well as core-shell microgels at interfaces.
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44
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Månsson LK, Peng F, Crassous JJ, Schurtenberger P. A microgel-Pickering emulsion route to colloidal molecules with temperature-tunable interaction sites. SOFT MATTER 2020; 16:1908-1921. [PMID: 31995090 DOI: 10.1039/c9sm02401h] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A simple Pickering emulsion route has been developed for the assembly of temperature-responsive poly(N-isopropylacrylamide) (PNIPAM) microgel particles into colloidal molecules comprising a small number of discrete microgel interaction sites on a central oil emulsion droplet. Here, the surface activity of the microgels serves to drive their assembly through adsorption to growing polydimethylsiloxane (PDMS) emulsion oil droplets of high monodispersity, prepared in situ via ammonia-catalysed hydrolysis and condensation of dimethyldiethoxysilane (DMDES). A dialysis step is employed in order to limit further growth once the target assembly size has been reached, thus yielding narrowly size-distributed, colloidal molecule-like microgel-Pickering emulsion oil droplets with well-defined microgel interaction sites. The temperature-responsiveness of the PNIPAM interaction sites will allow for the directional interactions to be tuned in a facile manner with temperature, all the way from soft repulsive to short-range attractive as the their volume phase transition temperature (VPTT) is crossed. Finally, the microgel-Pickering emulsion approach is extended to a mixture of PNIPAM and poly(N-isopropylmethacrylamide) (PNIPMAM) microgels that differ with respect to their VPTT, this in order to prepare patchy colloidal molecules where the directional interactions will be more readily resolved.
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Affiliation(s)
- Linda K Månsson
- Division of Physical Chemistry, Lund University, POB 124, SE-22100 Lund, Sweden. and NanoLund, POB 118, SE-22100 Lund, Sweden
| | - Feifei Peng
- Division of Physical Chemistry, Lund University, POB 124, SE-22100 Lund, Sweden. and NanoLund, POB 118, SE-22100 Lund, Sweden
| | - Jérôme J Crassous
- Institute of Physical Chemistry, RWTH Aachen University, 52074 AAchen, Germany
| | - Peter Schurtenberger
- Division of Physical Chemistry, Lund University, POB 124, SE-22100 Lund, Sweden. and NanoLund, POB 118, SE-22100 Lund, Sweden and Lund Institute of Advanced Neutron and X-ray Science (LINXS), Scheelevägen 19, SE-22370 Lund, Sweden
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45
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Murray BS. Microgels at fluid-fluid interfaces for food and drinks. Adv Colloid Interface Sci 2019; 271:101990. [PMID: 31330395 DOI: 10.1016/j.cis.2019.101990] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/09/2019] [Accepted: 07/11/2019] [Indexed: 12/11/2022]
Abstract
Various aspects of microgel adsorption at fluid-fluid interfaces of relevance to emulsion and foam stabilization have been reviewed. The emphasis is on the wider non-food literature, with a view to highlighting how this understanding can be applied to food-based systems. The various different types of microgel, their methods of formation and their fundamental behavioral traits at interfaces are covered. The latter includes aspects of microgel deformation and packing at interfaces, their deformability, size, swelling and de-swelling and how this affects their surface activity and stabilizing properties. Experimental and theoretical methods for measuring and modelling their behaviour are surveyed, including interactions between microgels themselves at interfaces but also other surface active species. It is concluded that challenges still remain in translating all the possibilities synthetic microgels offer to microgels based on food-grade materials only, but Nature's rich tool box of biopolymers and biosurfactants suggests that this field will still open up important new avenues of food microstructure development and control.
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46
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Albert C, Beladjine M, Tsapis N, Fattal E, Agnely F, Huang N. Pickering emulsions: Preparation processes, key parameters governing their properties and potential for pharmaceutical applications. J Control Release 2019; 309:302-332. [DOI: 10.1016/j.jconrel.2019.07.003] [Citation(s) in RCA: 113] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 07/05/2019] [Accepted: 07/06/2019] [Indexed: 12/18/2022]
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47
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Ghosh SK, Böker A. Self‐Assembly of Nanoparticles in 2D and 3D: Recent Advances and Future Trends. MACROMOL CHEM PHYS 2019. [DOI: 10.1002/macp.201900196] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
| | - Alexander Böker
- Fraunhofer‐Institut für Angewandte Polymerforschung Geiselbergstraβe 69 14476 Potsdam‐Golm Germany
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48
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Harrer J, Rey M, Ciarella S, Löwen H, Janssen LMC, Vogel N. Stimuli-Responsive Behavior of PNiPAm Microgels under Interfacial Confinement. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10512-10521. [PMID: 31304759 DOI: 10.1021/acs.langmuir.9b01208] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The volume phase transition of microgels is one of the most paradigmatic examples of stimuli-responsiveness, enabling a collapse from a highly swollen microgel state into a densely coiled state by an external stimulus. Although well characterized in bulk, it remains unclear how the phase transition is affected by the presence of a confining interface. Here, we demonstrate that the temperature-induced volume phase transition of poly(N-isopropylacrylamide) microgels, conventionally considered an intrinsic molecular property of the polymer, is in fact largely suppressed when the microgel is adsorbed to an air/liquid interface. We further observe a hysteresis in the core morphology and interfacial pressure between heating and cooling cycles. Our results, supported by molecular dynamics simulations, reveal that the dangling polymer chains of microgel particles, spread at the interface under the influence of surface tension, do not undergo any volume phase transition. The balance in free energy responsible for the volume phase transition is fundamentally altered by interfacial confinement. These results imply that important technological properties of such systems, including the temperature-induced destabilization of emulsions, do not occur via a decrease in the interfacial coverage of the microgels.
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Affiliation(s)
- Johannes Harrer
- Institute of Particle Technology , Friedrich-Alexander University Erlangen-Nürnberg , Cauerstrasse 4 , 91058 Erlangen , Germany
| | - Marcel Rey
- Institute of Particle Technology , Friedrich-Alexander University Erlangen-Nürnberg , Cauerstrasse 4 , 91058 Erlangen , Germany
| | - Simone Ciarella
- Theory of Polymers and Soft Matter, Department of Applied Physics , Eindhoven University of Technology , P.O. Box 513, 5600MB Eindhoven , The Netherlands
| | - Hartmut Löwen
- Institut für Theoretische Physik II: Weiche Materie , Heinrich-Heine-Universität , D-40225 Düsseldorf , Germany
| | - Liesbeth M C Janssen
- Theory of Polymers and Soft Matter, Department of Applied Physics , Eindhoven University of Technology , P.O. Box 513, 5600MB Eindhoven , The Netherlands
| | - Nicolas Vogel
- Institute of Particle Technology , Friedrich-Alexander University Erlangen-Nürnberg , Cauerstrasse 4 , 91058 Erlangen , Germany
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49
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Zhai K, Pei X, Wang C, Deng Y, Tan Y, Bai Y, Zhang B, Xu K, Wang P. Water-in-oil Pickering emulsion polymerization of N-isopropyl acrylamide using starch-based nanoparticles as emulsifier. Int J Biol Macromol 2019; 131:1032-1037. [DOI: 10.1016/j.ijbiomac.2019.03.107] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 03/15/2019] [Accepted: 03/17/2019] [Indexed: 10/27/2022]
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50
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Kwok MH, Sun G, Ngai T. Microgel Particles at Interfaces: Phenomena, Principles, and Opportunities in Food Sciences. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:4205-4217. [PMID: 30836004 DOI: 10.1021/acs.langmuir.8b04009] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The use of soft microgel particles for stabilizing emulsions has captured increasing attention across a wide range of disciplines in the past decades. Being soft, the nanoparticles, which are spherical in solution, undergo a structure change when adsorbed at the oil-water interface. This morphology change leads to the special dynamic properties of interface layers and packing structures, which then alter the interfacial tension and rheological properties of the interface. In addition, emulsions stabilized by these particles, known as Pickering emulsions, can be triggered by changing a variety of environmental conditions, which is especially desirable in industrial applications such as oil transportation processes and biphasic catalysis, where the emulsions can be stabilized and destabilized on demand. Although many studies of the behavior of soft microgel nanoparticles at interfaces have been reported, there are still many challenges in gaining a full understanding of the structure, dynamics, and effective interactions between microgels at the interface. In this Feature Article, we address some of the most important findings and problems in the field. They include the adsorption kinetics of soft microgel particles, particle conformation at the interface, pH and thermal responsiveness, and the interfacial rheological properties of soft-particle-occupied interfaces. We also discuss some potential benefits of using emulsions stabilized by soft particles for food applications as an alternative to conventional surfactant-based systems. We hope to encourage further investigation of these problems, which would be very beneficial to extending this knowledge to all other related soft matter systems.
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Affiliation(s)
- Man-Hin Kwok
- Department of Chemistry , The Chinese University of Hong Kong , Shatin , NT 00852 , Hong Kong
| | - Guanqing Sun
- School of Chemical and Material Engineering , Jiangnan University , Wuxi 214122 , China
| | - To Ngai
- Department of Chemistry , The Chinese University of Hong Kong , Shatin , NT 00852 , Hong Kong
- School of Chemical and Material Engineering , Jiangnan University , Wuxi 214122 , China
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