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Kawamoto T, Yanagi K, Nishizawa Y, Minato H, Suzuki D. The compression of deformed microgels at an air/water interface. Chem Commun (Camb) 2023; 59:13289-13292. [PMID: 37830179 DOI: 10.1039/d3cc03425a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
The compression of deformed hydrogel microspheres (microgels) at air/water interfaces was investigated using a Langmuir-Blodgett trough with simultaneous in situ visualization of the process using a fluorescent microscope. The relationship between the structure of the microgel arrays and the compression behavior was clarified using microgels with different degrees of crosslinking.
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Affiliation(s)
- Takahisa Kawamoto
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Kohei Yanagi
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Yuichiro Nishizawa
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Haruka Minato
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
- Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
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2
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Palkar V, Thakar D, Kuksenok O. Nanogel Degradation at Soft Interfaces and in Bulk: Tracking Shape Changes and Interfacial Spreading. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- Vaibhav Palkar
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Devanshu Thakar
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
- Department of Chemical Engineering, Indian Institute of Technology, Gandhinagar 382055, India
| | - Olga Kuksenok
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
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3
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Mesoscale Modeling of Agglomeration of Molecular Bottlebrushes: Focus on Conformations and Clustering Criteria. Polymers (Basel) 2022; 14:polym14122339. [PMID: 35745920 PMCID: PMC9227207 DOI: 10.3390/polym14122339] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 02/04/2023] Open
Abstract
Using dissipative particle dynamics, we characterize dynamics of aggregation of molecular bottlebrushes in solvents of various qualities by tracking the number of clusters, the size of the largest cluster, and an average aggregation number. We focus on a low volume fraction of bottlebrushes in a range of solvents and probe three different cutoff criteria to identify bottlebrushes belonging to the same cluster. We demonstrate that the cutoff criteria which depend on both the coordination number and the length of the side chain allows one to correlate the agglomeration status with the structural characteristics of bottlebrushes in solvents of various qualities. We characterize conformational changes of the bottlebrush within the agglomerates with respect to those of an isolated bottlebrush in the same solvents. The characterization of bottlebrush conformations within the agglomerates is an important step in understanding the relationship between the bottlebrush architecture and material properties. An analysis of three distinct cutoff criteria to identify bottlebrushes belonging to the same cluster introduces a framework to identify both short-lived transient and long-lived agglomerates; the same approach could be further extended to characterize agglomerates of various macromolecules with complex architectures beyond the specific bottlebrush architecture considered herein.
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4
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Liu P, Freeley M, Zarbakhsh A, Resmini M. Adsorption of soft NIPAM nanogels at hydrophobic and hydrophilic interfaces: Conformation of the interfacial layers determined by neutron reflectivity. J Colloid Interface Sci 2022; 623:337-347. [PMID: 35594592 DOI: 10.1016/j.jcis.2022.05.010] [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: 01/31/2022] [Revised: 03/18/2022] [Accepted: 05/02/2022] [Indexed: 11/25/2022]
Abstract
The application of stimuli-responsive microgels and nanogels in drug delivery, catalysis, sensing, and coatings is restricted currently by the limited understanding of the factors influencing their adsorption dynamics and structural changes at interfaces. We have used neutron reflectivity to resolve, on the Ångström scale, the structure of 5% crosslinked N-isopropylacrylamide nanogels at both hydrophobic and hydrophilic interfaces in situ, as a function of temperature and bulk nanogel concentration. Our results show that the higher flexibility given by the low crosslinker content allows for a more ordered structure and packing. The adsorption of the thermoresponsive nanogels is primarily driven by temperature, more specifically its proximity to its volume phase transition temperature, while concentration plays a secondary role. Hydrophobic interactions drive the conformation of the first layer at the interface, which plays a key role in influencing the overall nanogel structure. The mobility of the first layer at the air-water interface as opposed to the interfacial confinement at the solid (SiC8)-liquid interface, results in a different conformation, a more compact and less deformed packing structure, which ultimately drives the structure of the subsequent layers. The evidence for the different structural conformations determined by the degree of hydrophobicity of the interface provides new knowledge, which is essential for the development of further applications. The key role of hydrophobic interactions in driving adsorption and interfacial behavior was also confirmed by fluid AFM experiments which visualized adherence of the nanogels to SiC8 modified surfaces.
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Affiliation(s)
- Pengfei Liu
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Mark Freeley
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Ali Zarbakhsh
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - Marina Resmini
- Department of Chemistry, SPCS, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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5
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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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6
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Yang Y, Peng W, Zhang H, Wang H, He X. The oil/water interfacial behavior of microgels used for enhancing oil recovery: A comparative study on microgel powder and microgel emulsion. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2021.127731] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Palkar V, Kuksenok O. Controlling Degradation and Erosion of Polymer Networks: Insights from Mesoscale Modeling. J Phys Chem B 2021; 126:336-346. [PMID: 34964629 DOI: 10.1021/acs.jpcb.1c09570] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Understanding and controlling degradation of polymer networks on the mesoscale is critical for a range of applications. We utilize dissipative particle dynamics to capture photocontrolled degradation and erosion processes in hydrogels formed by end-linking of four-arm polyethylene glycol precursors. We demonstrate that the polydispersity and the fraction of broken-off fragments scale with the relative extent of reaction. The reverse gel point measured is close to the value predicted by the bond percolation theory on a diamond lattice. We characterize the erosion process via tracking the mass loss that accounts for the fragments remaining in contact with the percolated network. We quantify the dependence of the mass loss on the extent of reaction and on the properties of the film prior to degradation. These results elucidate the main features of degradation and erosion on the mesoscale and could provide guidelines for future design of degrading materials with dynamically controlled properties.
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Affiliation(s)
- Vaibhav Palkar
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Olga Kuksenok
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
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8
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Kravchenko VS, Abetz V, Potemkin II. Self-assembly of gradient copolymers in a selective solvent. New structures and comparison with diblock and statistical copolymers. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.124288] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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9
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Biglione C, Neumann‐Tran TMP, Kanwal S, Klinger D. Amphiphilic micro‐ and nanogels: Combining properties from internal hydrogel networks, solid particles, and micellar aggregates. JOURNAL OF POLYMER SCIENCE 2021. [DOI: 10.1002/pol.20210508] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Catalina Biglione
- Institute of Pharmacy (Pharmaceutical Chemistry) Freie Universität Berlin Berlin Germany
| | | | - Sidra Kanwal
- Institute of Pharmacy (Pharmaceutical Chemistry) Freie Universität Berlin Berlin Germany
| | - Daniel Klinger
- Institute of Pharmacy (Pharmaceutical Chemistry) Freie Universität Berlin Berlin Germany
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10
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Song X, Ma J, Long T, Xu X, Zhao S, Liu H. Mechanochemical Cellular Membrane Internalization of Nanohydrogels: A Large-Scale Mesoscopic Simulation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:123-134. [PMID: 33307670 DOI: 10.1021/acsami.0c16688] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
By combining large-scale dissipative particle dynamics and steered molecular dynamics simulations, we investigate the mechanochemical cellular internalization pathways of homogeneous and heterogeneous nanohydrogels and demonstrate that membrane internalization is determined by the crosslink density and encapsulation ability of nanohydrogels. The homogeneous nanohydrogels with a high crosslink density and low encapsulation ability behave as soft nanoparticles partially wrapped by the membrane, while those with a low crosslink density and high encapsulation ability permeate into the membrane. Regardless of the crosslink density, the homogeneous nanohydrogels undergo typical dual morphological deformations. The local lipid nanodomains are identified at the contacting region between the membrane and nanohydrogels because of different diffusion behaviors between lipid and receptor molecules during the internalization process. The yolk@shell heterogeneous nanohydrogels present a different mechanochemical cellular internalization pathway. The yolk with strong affinity is directly in contact with the membrane, resulting in partial membrane wrapping, and the contacting area is much reduced when compared to homogenous nanohydrogels, leading to a smaller lipid nanodomain and thus avoiding related cellular toxicity. Our findings provide a critical mechanism understanding of the biological pathways of nanohydrogels and may guide the molecular design of the hydrogel-based materials for controlled release drug delivery, tissue engineering, and cell culture.
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Affiliation(s)
- Xianyu Song
- Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir, School of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404100, China
| | - Jule Ma
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Ting Long
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaofei Xu
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Shuangliang Zhao
- State Key Laboratory of Chemical Engineering and School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, Guangxi University, Nanning 530004, China
| | - Honglai Liu
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
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11
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Hoppe Alvarez L, Rudov AA, Gumerov RA, Lenssen P, Simon U, Potemkin II, Wöll D. Controlling microgel deformation via deposition method and surface functionalization of solid supports. Phys Chem Chem Phys 2021; 23:4927-4934. [PMID: 33620358 DOI: 10.1039/d0cp06355j] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Soft matter at solid-liquid interfaces plays an important role in multiple scientific disciplines as well as in various technological fields. For microgels, representing highly interesting soft matter systems, we demonstrate that the preparation method, i.e. the way how the microgel is applied to the specific surface, plays a key role. Focusing on the three most common sample preparation methods (spin-coating, drop-casting and adsorption from solution), we performed a comparative study of the deformation behavior of microgels at the solid-liquid interface on three different surfaces with varying hydrophilicities. For in situ visualization of the deformation of pNIPMAM microgels, we conducted highly sensitive 3D super resolution fluorescence microscopy methods. We furthermore performed complementary molecular dynamics simulations to determine the driving force responsible for the deformation depending on the surface and the deposition method. The combination of experiments and simulations revealed that the simulated equilibrium structure obtained after simulation of the completely dry microgel after deposition is retained after rehydration and subsequent fluorescent imaging.
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Affiliation(s)
- Laura Hoppe Alvarez
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52056 Aachen, Germany.
| | - Andrey A Rudov
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation and DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstraße 50, D-52056 Aachen, Germany
| | - Rustam A Gumerov
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation and DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstraße 50, D-52056 Aachen, Germany
| | - Pia Lenssen
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52056 Aachen, Germany.
| | - Ulrich Simon
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1 a, D-52056 Aachen, Germany
| | - Igor I Potemkin
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation and DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstraße 50, D-52056 Aachen, Germany and National Research South Ural State University, Chelyabinsk 454080, Russian Federation
| | - Dominik Wöll
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52056 Aachen, Germany.
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12
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13
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Choudhury CK, Palkar V, Kuksenok O. Computational Design of Nanostructured Soft Interfaces: Focus on Shape Changes and Spreading of Cubic Nanogels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:7109-7123. [PMID: 31927898 DOI: 10.1021/acs.langmuir.9b03486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding the dynamics of gels at soft interfaces is vital for a range of applications, from biocatalysis and drug delivery to enhanced oil recovery applications. Herein, we use dissipative particle dynamics simulations to focus on the shape changes of a cubic nanogel as it adsorbs from the aqueous phase onto the oil-water interface, effectively acting as a compatibilizer. Upon adsorption at the interface, the hydrogel spreads over the interface, adopting various shapes depending on its size and cross-link density. We characterize these shapes by the shape anisotropy and an effective extent of spreading. We highlight the differences between these characteristics for cubic and spherical nanogels and show that the choice of the cubic shape over the spherical one results in a wider range of topographies that could be dynamically prescribed onto the soft interface due to the gels' adsorption. We first validate our model parameters with respect to the known experimental values for polyacrylamide (PAAm) gels and focus on spreading and shape changes of PAAm nanogels onto the oil-water interfaces. We then probe the behavior of active gels by changing an affinity of the polymer matrix for the solvent, which can be caused by the application of an external stimulus (light, temperature, or change in the chemical composition of solvent). Furthermore, we focus on the interactions between multiple gels placed at the liquid-liquid interface. We show that controlling the shapes and the clustering of the gels at the interfaces via variations in solvent quality result in tailoring the dynamics and topography of soft nanostructured interfaces. Hence, our findings provide insights into the design of soft active nanostructured interfaces with topographies controlled externally via solvent quality.
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Affiliation(s)
- Chandan Kumar Choudhury
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Vaibhav Palkar
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | - Olga Kuksenok
- Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States
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14
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Arismendi-Arrieta DJ, Moreno AJ. Deformability and solvent penetration in soft nanoparticles at liquid-liquid interfaces. J Colloid Interface Sci 2020; 570:212-222. [DOI: 10.1016/j.jcis.2020.02.102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 12/29/2022]
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15
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Rudyak VY, Kozhunova EY, Chertovich AV. Simulation of interpenetrating networks microgel synthesis. SOFT MATTER 2020; 16:4858-4865. [PMID: 32421134 DOI: 10.1039/d0sm00287a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this paper, we have implemented the sequential template synthesis of interpenetrating network (IPN) microgels in computer simulations and studied the behavior of such particles. We explored the influence of the interaction between the components of primary and secondary networks on the polymerization process and determined the necessary conditions for IPN particle formation. The interconnection between the parameters of synthesis and topological properties of the resulting microgels was investigated. We studied the morphologies of microgels in "good", "poor" and "selective" solvents. For the first time, we demonstrated the possibility of the formation of shell-corona structures in IPN microgels obtained by in silico synthesis from monomers and exposed to a selective solvent. These results allow for the better understanding of the required experimental conditions and data interpretation such as static structure factors.
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Affiliation(s)
- Vladimir Yu Rudyak
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, 1-2, Moscow 119991, Russia
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16
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Anakhov MV, Gumerov RA, Richtering W, Pich A, Potemkin II. Scavenging One of the Liquids versus Emulsion Stabilization by Microgels in a Mixture of Two Immiscible Liquids. ACS Macro Lett 2020; 9:736-742. [PMID: 35648562 DOI: 10.1021/acsmacrolett.0c00191] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It is known that microgels can serve as soft, permeable and stimuli-responsive alternative of solid colloidal particles to stabilize oil-water emulsions. The driving force for the adsorption of the microgels on interface of two immiscible liquids is a shielding of unfavorable oil-water contacts by adsorbed subchains, that is, the decrease of the surface tension between the liquids. Such phenomenon usually proceeds if volume fractions of the two liquids are comparable with each other and the microgel concentration is not high enough. The natural question arises: what is going on with the system in the opposite case of strongly asymmetric mixture (one of the liquids (oil) has a very small fraction) or high microgel concentration (the overall volume of the microgels exceeds the volume of the minor oil component)? Here we demonstrate that the microgels uptake the oil whose concentration within the microgels can be orders of magnitude higher than outside, leading to the additional microgel swelling (in comparison with the swelling in water). Thus, the microgels can serve as scavengers and concentrators of liquids dissolved in water. At first glance, this effect seems counterintuitive. However, it has a clear physical reason related to the incompatibility of oil and water. Absorption of the oil by microgels reduces unfavorable oil-water contacts by microgel segments: the microgels have a higher concentration of the segments at the periphery, forming a shell. The microgels with uptaken oil are stable toward aggregation at very small oil concentration in the mixture. However, an increase in the oil concentration can lead to aggregation of the microgels into dimers, trimers, and so on. The increasing concentration of oil mediates the attraction between the microgels: the oil in the aggregates appears to be localized in-between the microgels instead of their interior, which is accompanied by the release of the elastic stress of the microgels. A further increase in the oil concentration results in a growth of the size of the oil droplets between the microgels and the number of the microgels at the droplet's periphery, that is, the emulsion is formed.
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Affiliation(s)
- Mikhail V. Anakhov
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
| | - Rustam A. Gumerov
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen 52056, Germany
| | - Andrij Pich
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
- Aachen Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD Geleen, The Netherlands
| | - Igor I. Potemkin
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
- DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany
- National Research South Ural State University, Chelyabinsk 454080, Russian Federation
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17
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Bushuev NV, Gumerov RA, Bochenek S, Pich A, Richtering W, Potemkin II. Compression and Ordering of Microgels in Monolayers Formed at Liquid-Liquid Interfaces: Computer Simulation Studies. ACS APPLIED MATERIALS & INTERFACES 2020; 12:19903-19915. [PMID: 32248678 DOI: 10.1021/acsami.0c01600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Monolayers of polymer microgels adsorbed at the liquid interfaces were studied by dissipative particle dynamics simulations. The results demonstrated that the compressibility of the monolayers can be widely tuned by varying the cross-linking density of the microgels and their (in)compatibility with the immiscible liquids. In particular, the compression of the monolayers (increase of 2D concentration of the microgels) leads to the decrease of their lateral size. Herewith, the shape of the individual soft particles gradually changes from oblate (diluted 2D system) to nearly spherical (compressed monolayer). The polymer concentration profiles plotted along the normal to the interface reveal a nonmonotonous shape with a sharp maximum at the interface. This is a consequence of the shielding effect: saturation of the interface by monomer units of the subchains is driven by minimization of unfavorable contacts between the immiscible liquids and is opposed by elasticity of the network. The decrease of the interfacial tension upon concentration (compression) of the monolayer is quantified. It has been demonstrated that the interfacial tension significantly differs if the solubility of the polymer chains of the microgel network in the liquids changes. These results correlate well with experimental data. The examination of the microgels' crystalline ordering in monolayers demonstrated a nonmonotonous dependency on the compression degree (microgel concentration). Finally, the worsening of the solvent quality leads to the collapse of the microgels in monolayer and nonmonotonous behavior of the interfacial tension.
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Affiliation(s)
- Nikita V Bushuev
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
| | - Rustam A Gumerov
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany
| | - Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen 52056, Germany
| | - Andrij Pich
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany
- Aachen Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, Geleen 6167 RD, The Netherlands
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen 52056, Germany
| | - Igor I Potemkin
- Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation
- DWI-Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany
- National Research South Ural State University, Chelyabinsk 454080, Russian Federation
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Enhanced catalyst performance through compartmentalization exemplified by colloidal l-proline modified microgel catalysts. J Colloid Interface Sci 2020; 559:76-87. [DOI: 10.1016/j.jcis.2019.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/29/2019] [Accepted: 10/03/2019] [Indexed: 01/28/2023]
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Hoppe Alvarez L, Eisold S, Gumerov RA, Strauch M, Rudov AA, Lenssen P, Merhof D, Potemkin II, Simon U, Wöll D. Deformation of Microgels at Solid-Liquid Interfaces Visualized in Three-Dimension. NANO LETTERS 2019; 19:8862-8867. [PMID: 31642321 DOI: 10.1021/acs.nanolett.9b03688] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Solid-liquid interfaces play an important role for functional devices. Hence, a detailed understanding of the interaction of soft matter objects with solid supports and of the often concomitant structural deformations is of great importance. We address this topic in a combined experimental and simulation approach. We investigated thermoresponsive poly(N-isopropylmethacrylamide) microgels (μGs) at different surfaces in an aqueous environment. As super-resolution fluorescence imaging method, three-dimensional direct stochastical optical reconstruction microscopy (dSTORM) allowed for visualizing μGs in their three-dimensional (3D) shape, for example, in a "fried-egg" conformation depending on the hydrophilicity of the surface (strength of adsorption). The 3D shape, as defined by point clouds obtained from single-molecule localizations, was analyzed. A new fitting algorithm yielded an isosurface of constant density which defines the deformation of μGs at the different surfaces. The presented methodology quantifies deformation of objects with fuzzy surfaces and allows for comparison of their structures, whereby it is completely independent from the data acquisition method. Finally, the experimental data are complemented with mesoscopic computer simulations in order to (i) rationalize the experimental results and (ii) to track the evolution of the shape with changing surface hydrophilicity; a good correlation of the shapes obtained experimentally and with computer simulations was found.
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Affiliation(s)
- Laura Hoppe Alvarez
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , D-52056 Aachen , Germany
| | - Sabine Eisold
- Institute of Inorganic Chemistry , RWTH Aachen University , Landoltweg 1 a , D-52056 Aachen , Germany
| | - Rustam A Gumerov
- Physics Department , Lomonosov Moscow State University , Leninskie Gory 1-2 , Moscow 119991 , Russian Federation
- DWI - Leibniz-Institute for Interactive Materials , Forckenbeckstraße 50 , D-52056 Aachen , Germany
| | - Martin Strauch
- Institute of Imaging and Computer Vision , RWTH Aachen University , Kopernikusstraße 16 , 52074 Aachen , Germany
| | - Andrey A Rudov
- Physics Department , Lomonosov Moscow State University , Leninskie Gory 1-2 , Moscow 119991 , Russian Federation
- DWI - Leibniz-Institute for Interactive Materials , Forckenbeckstraße 50 , D-52056 Aachen , Germany
| | - Pia Lenssen
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , D-52056 Aachen , Germany
| | - Dorit Merhof
- Institute of Imaging and Computer Vision , RWTH Aachen University , Kopernikusstraße 16 , 52074 Aachen , Germany
| | - Igor I Potemkin
- Physics Department , Lomonosov Moscow State University , Leninskie Gory 1-2 , Moscow 119991 , Russian Federation
- DWI - Leibniz-Institute for Interactive Materials , Forckenbeckstraße 50 , D-52056 Aachen , Germany
- National Research South Ural State University , Chelyabinsk 454080 , Russian Federation
| | - Ulrich Simon
- Institute of Inorganic Chemistry , RWTH Aachen University , Landoltweg 1 a , D-52056 Aachen , Germany
| | - Dominik Wöll
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , D-52056 Aachen , Germany
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