1
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Forg S, Guo X, von Klitzing R. Influence of Dopamine Methacrylamide on Swelling Behavior and Nanomechanical Properties of PNIPAM Microgels. ACS APPLIED MATERIALS & INTERFACES 2024; 16:1521-1534. [PMID: 38146181 DOI: 10.1021/acsami.3c15134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
The combination of the catechol-containing comonomer dopamine methacrylamide (DMA) with stimuli-responsive poly(N-isopropylacrylamide) (PNIPAM) microgels bears a huge potential in research and for applications due to the versatile properties of catechols. This research gives the first detailed insights into the influence of DMA on the swelling of PNIPAM microgels and their nanomechanical properties. Dynamic light scattering measurements showed that DMA decreases the volume phase transition temperature and completion temperature due to its higher hydrophobicity when compared to NIPAM, while sharpening the transition. The cross-linking ability of DMA decreases the swelling ratios and mesh sizes of the microgels. Microgels adsorbed at the solid surface are characterized by atomic force microscopy─as the DMA content increases, microgels protrude more from the surface. Force spectroscopy measurements below and above the volume phase transition temperature display a stiffening of the microgels with the incorporation of DMA and upon heating across its entire cross section as evidenced by an increase in the E modulus. This confirms the cross-linking ability of DMA. The affine network factor β, derived from the Flory-Rehner theory, is linearly correlated with the E moduli of both pure PNIPAM and P(NIPAM-co-DMA) microgels. However, large DMA amounts hinder the microgel shrinking while maintaining mechanical stiffness, possibly due to catechol interactions within the microgel network.
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Affiliation(s)
- Sandra Forg
- Soft Matter at Interfaces (SMI), Institute for Physics of Condensed Matter, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Xuhong Guo
- School of Chemical Engineering, East China University of Science and Technology, 200231 Shanghai, China
| | - Regine von Klitzing
- Soft Matter at Interfaces (SMI), Institute for Physics of Condensed Matter, Technical University of Darmstadt, 64289 Darmstadt, Germany
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2
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Akgonullu DZ, Murray BS, Connell SD, Fang Y, Linter B, Sarkar A. Synthetic and biopolymeric microgels: Review of similarities and difference in behaviour in bulk phases and at interfaces. Adv Colloid Interface Sci 2023; 320:102983. [PMID: 37690329 DOI: 10.1016/j.cis.2023.102983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023]
Abstract
This review discusses the current knowledge of interfacial and bulk interactions of biopolymeric microgels in relation to the well-established properties of synthetic microgels for applications as viscosity modifiers and Pickering stabilisers. We present a timeline showing the key milestones in designing microgels and their bulk/ interfacial performance. Poly(N-isopropylacrylamide) (pNIPAM) microgels have remained as the protagonist in the synthetic microgel domain whilst proteins or polysaccharides have been primarily used to fabricate biopolymeric microgels. Bulk properties of microgel dispersions are dominated by the volume fraction (ϕ) of the microgel particles, but ϕ is difficult to pinpoint, as addressed by many theoretical models. By evaluating recent experimental studies over the last five years, we find an increasing focus on the analysis of microgel elasticity as a key parameter in modulating their packing at the interfaces, within the provinces of both synthetic and biopolymeric systems. Production methods and physiochemical factors shown to influence microgel swelling in the aqueous phase can have a significant impact on their bulk as well as interfacial performance. Compared to synthetic microgels, biopolymer microgels show a greater tendency for polydispersity and aggregation and do not appear to have a core-corona structure. Comprehensive studies of biopolymeric microgels are still lacking, for example, to accurately determine their inter- and intra- particle interactions, whilst a wider variety of techniques need to be applied in order to allow comparisons to real systems of practical usage.
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Affiliation(s)
- Daisy Z Akgonullu
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK
| | - Brent S Murray
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, UK
| | - Yuan Fang
- PepsiCo, Valhalla, New York, NY, USA
| | | | - Anwesha Sarkar
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
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3
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Kew B, Holmes M, Liamas E, Ettelaie R, Connell SD, Dini D, Sarkar A. Transforming sustainable plant proteins into high performance lubricating microgels. Nat Commun 2023; 14:4743. [PMID: 37550321 PMCID: PMC10406910 DOI: 10.1038/s41467-023-40414-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 07/26/2023] [Indexed: 08/09/2023] Open
Abstract
With the resource-intensive meat industry accounting for over 50% of food-linked emissions, plant protein consumption is an inevitable need of the hour. Despite its significance, the key barrier to adoption of plant proteins is their astringent off-sensation, typically associated with high friction and consequently poor lubrication performance. Herein, we demonstrate that by transforming plant proteins into physically cross-linked microgels, it is possible to improve their lubricity remarkably, dependent on their volume fractions, as evidenced by combining tribology using biomimetic tongue-like surface with atomic force microscopy, dynamic light scattering, rheology and adsorption measurements. Experimental findings which are fully supported by numerical modelling reveal that these non-lipidic microgels not only decrease boundary friction by an order of magnitude as compared to native protein but also replicate the lubrication performance of a 20:80 oil/water emulsion. These plant protein microgels offer a much-needed platform to design the next-generation of healthy, palatable and sustainable foods.
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Affiliation(s)
- Ben Kew
- Food Colloids and Processing Group, School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Melvin Holmes
- Food Colloids and Processing Group, School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK.
| | - Evangelos Liamas
- Food Colloids and Processing Group, School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
- Unilever Research & Development Port Sunlight, Quarry Road East, Bebington, Merseyside, CH63 3JW, UK
| | - Rammile Ettelaie
- Food Colloids and Processing Group, School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Simon D Connell
- Molecular and Nanoscale Physics Group, School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK.
| | - Daniele Dini
- Department of Mechanical Engineering, Imperial College London, London, SW7 2AZ, UK
| | - Anwesha Sarkar
- Food Colloids and Processing Group, School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK.
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4
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Hagemans F, Camerin F, Hazra N, Lammertz J, Dux F, Del Monte G, Laukkanen OV, Crassous JJ, Zaccarelli E, Richtering W. Buckling and Interfacial Deformation of Fluorescent Poly( N-isopropylacrylamide) Microgel Capsules. ACS NANO 2023; 17:7257-7271. [PMID: 37053566 DOI: 10.1021/acsnano.2c10164] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Hollow microgels are fascinating model systems at the crossover between polymer vesicles, emulsions, and colloids as they deform, interpenetrate, and eventually shrink at higher volume fraction or when subjected to an external stress. Here, we introduce a system consisting of microgels with a micrometer-sized cavity enabling a straightforward characterization in situ using fluorescence microscopy techniques. Similarly to elastic capsules, these systems are found to reversibly buckle above a critical osmotic pressure, conversely to smaller hollow microgels, which were previously reported to deswell at high volume fraction. Simulations performed on monomer-resolved in silico hollow microgels confirm the buckling transition and show that the presented microgels can be described with a thin shell model theory. When brought to an interface, these microgels, that we define as microgel capsules, strongly deform and we thus propose to utilize them to locally probe interfacial properties within a theoretical framework adapted from the Johnson-Kendall-Roberts (JKR) theory. Besides their capability to sense their environment and to address fundamental questions on the elasticity and permeability of microgel systems, microgel capsules can be further envisioned as model systems mimicking anisotropic responsive biological systems such as red blood and epithelial cells thanks to the possibility offered by microgels to be synthesized with custom-designed properties.
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Affiliation(s)
- Fabian Hagemans
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
| | - Fabrizio Camerin
- CNR-ISC, Sapienza University of Rome, p.le A. Moro 2, 00185 Roma, Italy
- Department of Physics, Sapienza University of Rome, p.le A. Moro 2 00185 Roma, Italy
| | - Nabanita Hazra
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
| | - Janik Lammertz
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
| | - Frédéric Dux
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
| | - Giovanni Del Monte
- CNR-ISC, Sapienza University of Rome, p.le A. Moro 2, 00185 Roma, Italy
- Department of Physics, Sapienza University of Rome, p.le A. Moro 2 00185 Roma, Italy
| | - Olli-Ville Laukkanen
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
- VTT Technical Research Centre of Finland Ltd, Koivurannantie 1, 40400 Jyväskylä, Finland
| | - Jérôme J Crassous
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
| | - Emanuela Zaccarelli
- CNR-ISC, Sapienza University of Rome, p.le A. Moro 2, 00185 Roma, Italy
- Department of Physics, Sapienza University of Rome, p.le A. Moro 2 00185 Roma, Italy
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany
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5
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Jose M, Singh R, Satapathy DK. Triple-line dynamics of a soft colloid-laden drop on a hydrophobic surface. SOFT MATTER 2023; 19:1803-1812. [PMID: 36789683 DOI: 10.1039/d2sm01486f] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Evaporation of fluid from a pinned drop placed on solid surface proceeds via constant contact radius (CCR) mode, with a continuous reduction in the contact angle. The reduction of contact angle leads to an imbalance of interfacial tensions at the three-phase contact line. When the unbalanced force is sufficiently strong, the drop slips from the pinned contact line and slides inward. Depinning of the drop alters the mode of evaporation to constant contact angle (CCA) mode till it repins onto the surface. The change in evaporation mode from CCR to CCA is usually achieved by tuning the pinning energy barrier by controlling the surface properties of the substrate. Here, we demonstrate that the evaporation mode can be controlled by solely tailoring the surface tension of the drop, which is achieved in microgel particle-laden sessile drops that show spontaneous adsorption of microgels to the air/water interface, leading to a decrease in the interfacial tension. We show that droplets containing a sufficient number of microgels evaporate predominantly in CCR mode even on a hydrophobic surface, and the contact line remains pinned throughout the evaporation of the drop. Interestingly, the contact line dynamics can be controlled by tuning the softness of the microgels and the particle concentration in the drops.
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Affiliation(s)
- Merin Jose
- Department of Physics, Indian Institute of Technology Madras, Chennai - 600036, India.
| | - Rajesh Singh
- Department of Physics, Indian Institute of Technology Madras, Chennai - 600036, India.
| | - Dillip K Satapathy
- Department of Physics, Indian Institute of Technology Madras, Chennai - 600036, India.
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6
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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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7
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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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8
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Sui J. Osmotic release of drugs via deswelling dynamics of microgels: modeling of collaborative flow and diffusions. Phys Chem Chem Phys 2022; 25:410-418. [PMID: 36477299 DOI: 10.1039/d2cp02668f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hydrogel colloids, i.e., micro- or nano-gels, are increasingly engineered as promising vehicles for polymer-based drug delivery systems. We report a continuum theory of deswelling dynamics of nanocomposite microgels driven by external osmotic shocks and further develop a universal framework, by introducing a buffer release domain, to quantitatively characterize a continuous drug release from deswollen microgels towards surroundings. The drug release is shown to proceed accompanied by an active outward solvent flow created by the elastically shrunken gel network. We further find that a declining trend in the cumulative release plateau with the drug size is followed by an apparent increase again as the drug size increases above a threshold. These findings highlight a nontrivial behavior that the resulting hydrodynamic interactions coexist collaboratively with the passive diffusions to facilitate a desired drug release. We show that deswelling of a stiffer microgel (the mesh size reduces slowly) or loading the larger drugs could bring a control-like release type, otherwise a burst-like release type emerges. Compared with a uniform microgel, the fuzzy-corona-like microgel enables a more productive drug release before reaching deswelling equilibrium. Our model not only predicts well the existing experiments, but also serves as a versatile paradigm to help understand the reciprocal roles of the solvent flow, the gel dynamics, and the diffusions in the polymer-based drug delivery systems.
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Affiliation(s)
- Jize Sui
- State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
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9
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Vialetto J, Ramakrishna SN, Isa L. In situ imaging of the three-dimensional shape of soft responsive particles at fluid interfaces by atomic force microscopy. SCIENCE ADVANCES 2022; 8:eabq2019. [PMID: 36351021 PMCID: PMC9645722 DOI: 10.1126/sciadv.abq2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The reconfiguration of individual soft and deformable particles upon adsorption at a fluid interface underpins many aspects of their dynamics and interactions, ultimately regulating the properties of monolayers of relevance for applications. In this work, we demonstrate that atomic force microscopy can be used for the in situ reconstruction of the three-dimensional conformation of model poly(N-isopropylacrylamide) microgels adsorbed at an oil-water interface. We image the particle topography from both sides of the interface to characterize its in-plane deformation and to visualize the occurrence of asymmetric swelling in the two fluids. In addition, the technique enables investigating different fluid phases and particle architectures, as well as studying the effect of temperature variations on particle conformation in situ. We envisage that these results open up an exciting range of possibilities to provide microscopic insights into the single-particle behavior of soft objects at fluid interfaces and into the resulting macroscopic material properties.
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Affiliation(s)
| | | | - Lucio Isa
- Corresponding author. (J.V.); (S.N.R.); (L.I.)
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10
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Temperature triggered aggregation toward nanoparticles formation from tri-arm poly(HEAAm-b-NIPAAm) in aqueous solutions. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04477-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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11
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Schlattmann D, Schönhoff M. Interplay of the Influence of Crosslinker Content and Model Drugs on the Phase Transition of Thermoresponsive PNiPAM-BIS Microgels. Gels 2022; 8:gels8090571. [PMID: 36135283 PMCID: PMC9498534 DOI: 10.3390/gels8090571] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 11/16/2022] Open
Abstract
The phase transition behavior of differently crosslinked poly(N-isopropylacrylamide)/N,N’-methylenebisacrylamide (PNiPAM/BIS) microgels with varying crosslinker content is investigated in presence of aromatic additives. The influence of meta-hydroxybenzaldehyde (m-HBA) and 2,4-dihydroxybenzaldehyde (2,4-DHBA), chosen as model drugs, on the volume phase transition temperature (VPTT) is analyzed by dynamic light scattering (DLS), differential scanning calorimetry (DSC), and 1H-NMR, monitoring and comparing the structural, calorimetric, and dynamic phase transition, respectively. Generally, the VPTT is found to increase with crosslinker content, accompanied by a drastic decrease of transition enthalpy. The presence of an additive generally decreases the VPTT, but with distinct differences concerning the crosslinker content. While the structural transition is most affected at lowest crosslinker content, the calorimetric and dynamic transitions are most affected for an intermediate crosslinker content. Additive uptake of the collapsed gel is largest for low crosslinked microgels and in case of large additive-induced temperature shifts. Furthermore, as temperature is successively raised, 1H NMR data, aided by spin relaxation rates, reveal an interesting uptake behavior, as the microgels act in a sponge-like fashion including a large initial uptake and a squeeze-out phase above VPTT.
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12
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Dhand AP, Davidson MD, Galarraga JH, Qazi TH, Locke RC, Mauck RL, Burdick JA. Simultaneous One-Pot Interpenetrating Network Formation to Expand 3D Processing Capabilities. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202261. [PMID: 35510317 PMCID: PMC9283285 DOI: 10.1002/adma.202202261] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/28/2022] [Indexed: 05/31/2023]
Abstract
The incorporation of a secondary network into traditional single-network hydrogels can enhance mechanical properties, such as toughness and loading to failure. These features are important for many applications, including as biomedical materials; however, the processing of interpenetrating polymer network (IPN) hydrogels is often limited by their multistep fabrication procedures. Here, a one-pot scheme for the synthesis of biopolymer IPN hydrogels mediated by the simultaneous crosslinking of two independent networks with light, namely: i) free-radical crosslinking of methacrylate-modified hyaluronic acid (HA) to form the primary network and ii) thiol-ene crosslinking of norbornene-modified HA with thiolated guest-host assemblies of adamantane and β-cyclodextrin to form the secondary network, is reported. The mechanical properties of the IPN hydrogels are tuned by changing the network composition, with high water content (≈94%) hydrogels exhibiting excellent work of fracture, tensile strength, and low hysteresis. As proof-of-concept, the IPN hydrogels are implemented as low-viscosity Digital Light Processing resins to fabricate complex structures that recover shape upon loading, as well as in microfluidic devices to form deformable microparticles. Further, the IPNs are cytocompatible with cell adhesion dependent on the inclusion of adhesive peptides. Overall, the enhanced processing of these IPN hydrogels will expand their utility across applications.
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Affiliation(s)
- Abhishek P Dhand
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Matthew D Davidson
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
- BioFrontiers Institute and Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Jonathan H Galarraga
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Taimoor H Qazi
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ryan C Locke
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Robert L Mauck
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jason A Burdick
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, 19104, USA
- BioFrontiers Institute and Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, 19104, USA
- Department of Orthopaedic Surgery, McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia, PA, 19104, USA
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13
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Scotti A, Schulte MF, Lopez CG, Crassous JJ, Bochenek S, Richtering W. How Softness Matters in Soft Nanogels and Nanogel Assemblies. Chem Rev 2022; 122:11675-11700. [PMID: 35671377 DOI: 10.1021/acs.chemrev.2c00035] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Softness plays a key role in determining the macroscopic properties of colloidal systems, from synthetic nanogels to biological macromolecules, from viruses to star polymers. However, we are missing a way to quantify what the term "softness" means in nanoscience. Having quantitative parameters is fundamental to compare different systems and understand what the consequences of softness on the macroscopic properties are. Here, we propose different quantities that can be measured using scattering methods and microscopy experiments. On the basis of these quantities, we review the recent literature on micro- and nanogels, i.e. cross-linked polymer networks swollen in water, a widely used model system for soft colloids. Applying our criteria, we address the question what makes a nanomaterial soft? We discuss and introduce general criteria to quantify the different definitions of softness for an individual compressible colloid. This is done in terms of the energetic cost associated with the deformation and the capability of the colloid to isotropically deswell. Then, concentrated solutions of soft colloids are considered. New definitions of softness and new parameters, which depend on the particle-to-particle interactions, are introduced in terms of faceting and interpenetration. The influence of the different synthetic routes on the softness of nanogels is discussed. Concentrated solutions of nanogels are considered and we review the recent results in the literature concerning the phase behavior and flow properties of nanogels both in three and two dimensions, in the light of the different parameters we defined. The aim of this review is to look at the results on micro- and nanogels in a more quantitative way that allow us to explain the reported properties in terms of differences in colloidal softness. Furthermore, this review can give researchers dealing with soft colloids quantitative methods to define unambiguously which softness matters in their compound.
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Affiliation(s)
- Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - M Friederike Schulte
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - Carlos G Lopez
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - Jérôme J Crassous
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany, European Union
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany, European Union
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14
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Izak‐Nau E, Braun S, Pich A, Göstl R. Mechanically Resistant Poly(N-vinylcaprolactam) Microgels with Sacrificial Supramolecular Catechin Hydrogen Bonds. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104004. [PMID: 35187862 PMCID: PMC9036020 DOI: 10.1002/advs.202104004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/10/2022] [Indexed: 06/14/2023]
Abstract
Microgels (μgels) swiftly undergo structural and functional degradation when they are exposed to shear forces, which potentially limit their applicability in, e.g., biomedicine and engineering. Here, poly(N-vinylcaprolactam) μgels that resist mechanical disruption through supramolecular hydrogen bonds provided by (+)-catechin hydrate (+C) are synthesized. When +C is added to the microgel structure, an increased resistance against shear force exerted by ultrasonication is observed compared to μgels crosslinked by covalent bonds. While covalently crosslinked μgels degrade already after a few seconds, it is found that μgels having both supramolecular interchain interactions and covalent crosslinks show the highest mechanical durability. By the incorporation of optical force probes, it is found that the covalent bonds of the μgels are not stressed beyond their scission threshold and mechanical energy is dissipated by the force-induced reversible dissociation of the sacrificial +C bonds for at least 20 min of ultrasonication. Additionally, +C renders the μgels pH-sensitive and introduces multiresponsivity. The μgels are extensively characterized using Fourier-transform infrared, Raman and quantitative nuclear magnetic resonance spectroscopy, dynamic light scattering, and cryogenic transmission electron microscopy. These results may serve as blueprint for the preparation of many mechanically durable μgels.
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Affiliation(s)
- Emilia Izak‐Nau
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
| | - Susanne Braun
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 1Aachen52074Germany
| | - Andrij Pich
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
- Institute of Technical and Macromolecular ChemistryRWTH Aachen UniversityWorringerweg 1Aachen52074Germany
- Aachen Maastricht Institute for Biobased Materials (AMIBM) Maastricht UniversityBrightlands Chemelot CampusGeleen6167 RDThe Netherlands
| | - Robert Göstl
- DWI – Leibniz Institute for Interactive MaterialsForckenbeckstr. 50Aachen52056Germany
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15
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Schulte MF, Izak-Nau E, Braun S, Pich A, Richtering W, Göstl R. Microgels react to force: mechanical properties, syntheses, and force-activated functions. Chem Soc Rev 2022; 51:2939-2956. [PMID: 35319064 DOI: 10.1039/d2cs00011c] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microgels are colloidal polymer networks with high molar mass and properties between rigid particles, flexible macromolecules, and micellar aggregates. Their unique stimuli-responsiveness in conjunction with their colloidal phase behavior render them useful for many applications ranging from engineering to biomedicine. In many scenarios either the microgel's mechanical properties or its interactions with mechanical force play an important role. Here, we firstly explain microgel mechanical properties and how these are measured by atomic force microscopy (AFM), then we equip the reader with the synthetic background to understand how specific architectures and chemical functionalities enable these mechanical properties, and eventually we elucidate how the interaction of force with microgels can lead to the activation of latent functionality. Since the interaction of microgels with force is a multiscale and multidisciplinary subject, we introduce and interconnect the different research areas that contribute to the understanding of this emerging field in this Tutorial Review.
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Affiliation(s)
- M Friederike Schulte
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany.
| | - Emilia Izak-Nau
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
| | - Susanne Braun
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany. .,Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Andrij Pich
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany. .,Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.,Maastricht University, Aachen Maastricht Institute for Biobased Materials (AMIBM), Brightlands Chemelot Campus, 6167 RD Geleen, The Netherlands
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52056 Aachen, Germany.
| | - Robert Göstl
- DWI - Leibniz Institute for Interactive Materials, Forckenbeckstr. 50, 52056 Aachen, Germany.
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16
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Kittel Y, Kuehne AJC, De Laporte L. Translating Therapeutic Microgels into Clinical Applications. Adv Healthc Mater 2022; 11:e2101989. [PMID: 34826201 DOI: 10.1002/adhm.202101989] [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: 09/17/2021] [Revised: 11/17/2021] [Indexed: 12/14/2022]
Abstract
Microgels are crosslinked, water-swollen networks with a 10 nm to 100 µm diameter and can be modified chemically or biologically to render them biocompatible for advanced clinical applications. Depending on their intended use, microgels require different mechanical and structural properties, which can be engineered on demand by altering the biochemical composition, crosslink density of the polymer network, and the fabrication method. Here, the fundamental aspects of microgel research and development, as well as their specific applications for theranostics and therapy in the clinic, are discussed. A detailed overview of microgel fabrication techniques with regards to their intended clinical application is presented, while focusing on how microgels can be employed as local drug delivery materials, scavengers, and contrast agents. Moreover, microgels can act as scaffolds for tissue engineering and regeneration application. Finally, an overview of microgels is given, which already made it into pre-clinical and clinical trials, while future challenges and chances are discussed. This review presents an instructive guideline for chemists, material scientists, and researchers in the biomedical field to introduce them to the fundamental physicochemical properties of microgels and guide them from fabrication methods via characterization techniques and functionalization of microgels toward specific applications in the clinic.
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Affiliation(s)
- Yonca Kittel
- DWI – Leibniz Institute for Interactive Materials Forckenbeckstrasse 50 52074 Aachen Germany
| | - Alexander J. C. Kuehne
- DWI – Leibniz Institute for Interactive Materials Forckenbeckstrasse 50 52074 Aachen Germany
- Institute of Organic and Macromolecular Chemistry Ulm University Albert‐Einstein‐Allee 11 89081 Ulm Germany
- Institute of Technical and Macromolecular Chemistry (ITMC) Polymeric Biomaterials RWTH University Aachen Worringerweg 2 52074 Aachen Germany
| | - Laura De Laporte
- DWI – Leibniz Institute for Interactive Materials Forckenbeckstrasse 50 52074 Aachen Germany
- Max Planck School‐Matter to Life (MtL) Jahnstraße 29 69120 Heidelberg Germany
- Advanced Materials for Biomedicine (AMB) Institute of Applied Medical Engineering (AME) Center for Biohybrid Medical Systems (CBMS) University Hospital RWTH 52074 Aachen Germany
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17
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Gruber A, Joshi AA, Graff P, Cuéllar-Camacho JL, Hedtrich S, Klinger D. Influence of Nanogel Amphiphilicity on Dermal Delivery: Balancing Surface Hydrophobicity and Network Rigidity. Biomacromolecules 2021; 23:112-127. [PMID: 34874701 DOI: 10.1021/acs.biomac.1c01100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Polymeric nanogels are promising nonirritating nanocarriers for topical delivery applications. However, conventional hydrophilic networks limit encapsulation of hydrophobic therapeutics and hinder tailored interactions with the amphiphilic skin barrier. To address these limitations, we present amphiphilic nanogels containing hydrophilic networks with hydrophobic domains. Two competing factors determine favorable nanogel-skin interactions and need to be balanced through network composition: suitable surface hydrophobicity and low network rigidity (through physical hydrophobic cross-links). To ensure comparability in such investigations, we prepared a library of nanogels with increasing hydrophobic cholesteryl amounts but similar colloidal features. By combining mechanical and surface hydrophobicity tests (atomic force microscopy (AFM)) with dermal delivery experiments on excised human skin, we can correlate an increased delivery efficacy of Nile red to the viable epidermis with a specific network composition, i.e., 20-30 mol % cholesterol. Thus, our nanogel library identifies a specific balance between surface amphiphilicity and network rigidity to guide developments of advanced dermal delivery vehicles.
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Affiliation(s)
- Alexandra Gruber
- Institute of Pharmacy (Pharmaceutical Chemistry), Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany
| | - Aaroh Anand Joshi
- Institute of Pharmacy (Pharmacology and Toxicology), Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany
| | - Patrick Graff
- Institute of Pharmacy (Pharmacology and Toxicology), Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany
| | - José Luis Cuéllar-Camacho
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Sarah Hedtrich
- Institute of Pharmacy (Pharmacology and Toxicology), Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany.,Faculty of Pharmaceutical Sciences, University of British Columbia, Wesbrook Mall, Vancouver, British Columbia V6T1Z3, Canada
| | - Daniel Klinger
- Institute of Pharmacy (Pharmaceutical Chemistry), Freie Universität Berlin, Königin-Luise-Straße 2-4, 14195 Berlin, Germany
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18
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Shang L, Zhou X, Zhang J, Shi Y, Zhong L. Metal Nanoparticles for Photodynamic Therapy: A Potential Treatment for Breast Cancer. Molecules 2021; 26:molecules26216532. [PMID: 34770941 PMCID: PMC8588551 DOI: 10.3390/molecules26216532] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/13/2021] [Accepted: 10/26/2021] [Indexed: 12/12/2022] Open
Abstract
Breast cancer (BC) is the most common malignant tumor in women worldwide, which seriously threatens women’s physical and mental health. In recent years, photodynamic therapy (PDT) has shown significant advantages in cancer treatment. PDT involves activating photosensitizers with appropriate wavelengths of light, producing transient levels of reactive oxygen species (ROS). Compared with free photosensitizers, the use of nanoparticles in PDT shows great advantages in terms of solubility, early degradation, and biodistribution, as well as more effective intercellular penetration and targeted cancer cell uptake. Under the current circumstances, researchers have made promising efforts to develop nanocarrier photosensitizers. Reasonably designed photosensitizer (PS) nanoparticles can be achieved through non-covalent (self-aggregation, interfacial deposition, interfacial polymerization or core-shell embedding and physical adsorption) or covalent (chemical immobilization or coupling) processes and accumulate in certain tumors through passive and/or active targeting. These PS loading methods provide chemical and physical stability to the PS payload. Among nanoparticles, metal nanoparticles have the advantages of high stability, adjustable size, optical properties, and easy surface functionalization, making them more biocompatible in biological applications. In this review, we summarize the current development and application status of photodynamic therapy for breast cancer, especially the latest developments in the application of metal nanocarriers in breast cancer PDT, and highlight some of the recent synergistic therapies, hopefully providing an accessible overview of the current knowledge that may act as a basis for new ideas or systematic evaluations of already promising results.
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Affiliation(s)
- Liang Shang
- Department of Breast Surgery, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; (L.S.); (J.Z.); or (Y.S.)
| | - Xinglu Zhou
- Department of PET/CT Center, Harbin Medical University Cancer Hospital, Harbin 150081, China;
| | - Jiarui Zhang
- Department of Breast Surgery, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; (L.S.); (J.Z.); or (Y.S.)
| | - Yujie Shi
- Department of Breast Surgery, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; (L.S.); (J.Z.); or (Y.S.)
| | - Lei Zhong
- Department of Breast Surgery, Second Affiliated Hospital of Harbin Medical University, Harbin 150086, China; (L.S.); (J.Z.); or (Y.S.)
- Department of Breast Surgery, Sixth Affiliated Hospital of Harbin Medical University, Harbin 150086, China
- Correspondence:
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19
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Li G, Varga I, Kardos A, Dobryden I, Claesson PM. Nanoscale Mechanical Properties of Core-Shell-like Poly-NIPAm Microgel Particles: Effect of Temperature and Cross-Linking Density. J Phys Chem B 2021; 125:9860-9869. [PMID: 34428041 DOI: 10.1021/acs.jpcb.1c04173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Poly-NIPAm microgel particles with two different cross-linking densities were prepared with the classical batch polymerization process. These particles were adsorbed onto modified silica surfaces, and their nanomechanical properties were measured by means of atomic force microscopy. It was found that these particles have a hard core-soft shell structure both below and above the volume transition temperature. The core-shell-like structure appears due to a higher reaction rate of the cross-linker compared to that of the monomer, leading to depletion of cross-linker in the shell region. The microgel beads with lower average cross-linking density were found to be less stiff below the volume transition temperature than the microgel with higher cross-linking density. Increasing the temperature further to just above the volume transition temperature led to lower stiffness of the more highly cross-linked microgel compared to its less cross-linked counterpart. This effect is explained with the more gradual deswelling with temperature for the more cross-linked microgel particles. This phenomenon was confirmed by dynamic light scattering measurements in the bulk phase, which showed that the larger cross-linking density microgel showed a more gradual collapse in aqueous solution as the temperature was increased.
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Affiliation(s)
- Gen Li
- Biotechnology and Health, Department of Chemistry, Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
| | - Imre Varga
- Institute of Chemistry, Eötvös Loránd University, Pázmány P. s. 1/A, 1117 Budapest, Hungary.,Department of Chemistry, University J. Selyeho, 945 01 Komarno, Slovakia
| | - Attila Kardos
- Institute of Chemistry, Eötvös Loránd University, Pázmány P. s. 1/A, 1117 Budapest, Hungary.,Department of Chemistry, University J. Selyeho, 945 01 Komarno, Slovakia
| | - Illia Dobryden
- Biotechnology and Health, Department of Chemistry, Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden.,Department of Engineering Sciences and Mathematics, Division of Materials Science, Luleå University of Technology, 97187 Luleå, Sweden
| | - Per M Claesson
- Biotechnology and Health, Department of Chemistry, Division of Surface and Corrosion Science, School of Engineering Sciences in Chemistry, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden.,Division of Bioscience and Materials, RISE Research Institutes of Sweden, Box 5607, SE 114 86 Stockholm, Sweden
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20
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Oevreeide IH, Szydlak R, Luty M, Ahmed H, Prot V, Skallerud BH, Zemła J, Lekka M, Stokke BT. On the Determination of Mechanical Properties of Aqueous Microgels-Towards High-Throughput Characterization. Gels 2021; 7:64. [PMID: 34072792 PMCID: PMC8261632 DOI: 10.3390/gels7020064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/15/2022] Open
Abstract
Aqueous microgels are distinct entities of soft matter with mechanical signatures that can be different from their macroscopic counterparts due to confinement effects in the preparation, inherently made to consist of more than one domain (Janus particles) or further processing by coating and change in the extent of crosslinking of the core. Motivated by the importance of the mechanical properties of such microgels from a fundamental point, but also related to numerous applications, we provide a perspective on the experimental strategies currently available and emerging tools being explored. Albeit all techniques in principle exploit enforcing stress and observing strain, the realization differs from directly, as, e.g., by atomic force microscope, to less evident in a fluid field combined with imaging by a high-speed camera in high-throughput strategies. Moreover, the accompanying analysis strategies also reflect such differences, and the level of detail that would be preferred for a comprehensive understanding of the microgel mechanical properties are not always implemented. Overall, the perspective is that current technologies have the capacity to provide detailed, nanoscopic mechanical characterization of microgels over an extended size range, to the high-throughput approaches providing distributions over the mechanical signatures, a feature not readily accessible by atomic force microscopy and micropipette aspiration.
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Affiliation(s)
- Ingrid Haga Oevreeide
- Biophysics and Medical Technology, Department of Physics, NTNU The Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (I.H.O.); (H.A.)
| | - Renata Szydlak
- Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland; (R.S.); (M.L.); (J.Z.)
| | - Marcin Luty
- Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland; (R.S.); (M.L.); (J.Z.)
| | - Husnain Ahmed
- Biophysics and Medical Technology, Department of Physics, NTNU The Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (I.H.O.); (H.A.)
| | - Victorien Prot
- Biomechanics, Department of Structural Engineering, NTNU The Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (V.P.); (B.H.S.)
| | - Bjørn Helge Skallerud
- Biomechanics, Department of Structural Engineering, NTNU The Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (V.P.); (B.H.S.)
| | - Joanna Zemła
- Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland; (R.S.); (M.L.); (J.Z.)
| | - Małgorzata Lekka
- Institute of Nuclear Physics, Polish Academy of Sciences, PL-31342 Krakow, Poland; (R.S.); (M.L.); (J.Z.)
| | - Bjørn Torger Stokke
- Biophysics and Medical Technology, Department of Physics, NTNU The Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; (I.H.O.); (H.A.)
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21
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Drozdov AD, deClaville Christiansen J. Equilibrium swelling of thermo‐responsive core‐shell microgels. J Appl Polym Sci 2021. [DOI: 10.1002/app.50354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Aleksey D. Drozdov
- Department of Materials and Production Aalborg University Aalborg Denmark
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22
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Abstract
Abstract
The review presents current research results for Carbopol-based microgels as yield-stress materials, covering three aspects: chemical, physical and rheological. Such a joint three-aspect study has no analog in the literature. The chemical aspects of Carbopol polymers are presented in terms of a cross-linking polymerization of acrylic acid, their molecular structure, microgel formulation, polyacid dissociation and neutralization, osmotic pressure and associated immense microgel swelling. The physical characterization is focused on models of the shear-induced solid-to-liquid transition of microgels, which are formed of mesoscopic particles typical for soft matter materials. Models that describe interparticle effects are presented to explain the energy states of microgel particles at the mesoscale of scrutiny. Typical representatives of the models utilize attributes of jamming dispersions, micromechanical and polyelectrolyte reactions. Selected relationships that result from the models, such as scaling rules and nondimensional flow characteristics are also presented. The rheological part presents the discussion of problems of yield stress in 2D and 3D deformations, appearance and magnitude of the wall slip. The theory and characteristics of Carbopol microgel deformation in rotational rheometers are presented with graphs for the steady-state measurements, stress-controlled oscillation and two types of transient shear deformation. The review is concluded with suggestions for future research.
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Affiliation(s)
- Zdzisław Jaworski
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
| | - Tadeusz Spychaj
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
| | - Anna Story
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
| | - Grzegorz Story
- Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology , Aleja Piastow 42 , 71-065 , Szczecin , Poland
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23
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Lee A, Septiadi D, Taladriz‐Blanco P, Almeida M, Haeni L, Spuch‐Calvar M, Abdussalam W, Rothen‐Rutishauser B, Petri‐Fink A. Particle Stiffness and Surface Topography Determine Macrophage-Mediated Removal of Surface Adsorbed Particles. Adv Healthc Mater 2021; 10:e2001667. [PMID: 33434386 DOI: 10.1002/adhm.202001667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 12/10/2020] [Indexed: 01/09/2023]
Abstract
Cellular surface recognition and behavior are driven by a host of physical and chemical features which have been exploited to influence particle-cell interactions. Mechanical and topographical cues define the physical milieu which plays an important role in defining a range of cellular activities such as material recognition, adhesion, and migration through cytoskeletal organization and signaling. In order to elucidate the effect of local mechanical and topographical features generated by the adsorption of particles to an underlying surface on primary human monocyte-derived macrophages (MDM), a series of poly(N-isopropylacrylamide) (pNIPAM) particles with differing rigidity are self-assembled to form a defined particle-decorated surface. Assembly of particle-decorated surfaces is facilitated by modification of the underlying glass to possess a positive charge through functionalization using 3-aminopropyltriethoxysilane (APTES) or coating with poly(L-lysine) (PLL). MDMs are noted to preferentially remove particles with higher degrees of crosslinking (stiffer) than those with lower degrees of crosslinking (softer). Alterations to the surface density of particles enabled a greater area of the particle-decorated surface to be cleared. Uniquely, the impact of particle adsorption is evinced to have a direct impact on topographical recognition of the surface, suggesting a novel approach for controllably affecting cell-surface recognition and response.
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Affiliation(s)
- Aaron Lee
- Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 Fribourg 1700 Switzerland
| | - Dedy Septiadi
- Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 Fribourg 1700 Switzerland
| | | | - Mauro Almeida
- Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 Fribourg 1700 Switzerland
| | - Laetitia Haeni
- Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 Fribourg 1700 Switzerland
| | - Miguel Spuch‐Calvar
- Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 Fribourg 1700 Switzerland
| | - Wildan Abdussalam
- Department of High Energy Density Helmholtz‐Zentrum Dresden‐Rossendorf Bautzner Landstraße 400 Dresden 01328 Germany
| | | | - Alke Petri‐Fink
- Adolphe Merkle Institute University of Fribourg Chemin des Verdiers 4 Fribourg 1700 Switzerland
- Department of Chemistry University of Fribourg Chemin du Musée 9 Fribourg 1700 Switzerland
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24
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Li G, Varga I, Kardos A, Dobryden I, Claesson PM. Temperature-Dependent Nanomechanical Properties of Adsorbed Poly-NIPAm Microgel Particles Immersed in Water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:1902-1912. [PMID: 33502872 PMCID: PMC7879429 DOI: 10.1021/acs.langmuir.0c03386] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/15/2021] [Indexed: 05/24/2023]
Abstract
The temperature dependence of nanomechanical properties of adsorbed poly-NIPAm microgel particles prepared by a semibatch polymerization process was investigated in an aqueous environment via indentation-based atomic force microscopy (AFM) methods. Poly-NIPAm microgel particles prepared by the classical batch process were also characterized for comparison. The local mechanical properties were measured between 26 and 35 °C, i.e., in the temperature range of the volume transition. Two different AFM tips with different shapes and end radii were utilized. The nanomechanical properties measured by the two kinds of tips showed a similar temperature dependence of the nanomechanical properties, but the actual values were found to depend on the size of the tip. The results suggest that the semibatch synthesis process results in the formation of more homogeneous microgel particles than the classical batch method. The methodological approach reported in this work is generally applicable to soft surface characterization in situ.
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Affiliation(s)
- Gen Li
- School
of Engineering Sciences in Chemistry, Biotechnology and Health, Department
of Chemistry, Division of Surface and Corrosion Science, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
| | - Imre Varga
- Institute
of Chemistry, Eötvös Loránd
University, Pázmány P. s. 1/A, 1117 Budapest, Hungary
- Department
of Chemistry, University J. Selyeho, 945 01 Komarno, Slovakia
| | - Attila Kardos
- Institute
of Chemistry, Eötvös Loránd
University, Pázmány P. s. 1/A, 1117 Budapest, Hungary
- Department
of Chemistry, University J. Selyeho, 945 01 Komarno, Slovakia
| | - Illia Dobryden
- School
of Engineering Sciences in Chemistry, Biotechnology and Health, Department
of Chemistry, Division of Surface and Corrosion Science, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
- Department
of Engineering Sciences and Mathematics, Division of Materials Science, Luleå University of Technology, 97187 Luleå, Sweden
| | - Per M. Claesson
- School
of Engineering Sciences in Chemistry, Biotechnology and Health, Department
of Chemistry, Division of Surface and Corrosion Science, KTH Royal Institute of Technology, Drottning Kristinas väg 51, SE-100 44 Stockholm, Sweden
- Division
of Bioscience and Materials, RISE Research
Institutes of Sweden, Box 5607, SE 114 86 Stockholm, Sweden
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25
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Schulte MF, Bochenek S, Brugnoni M, Scotti A, Mourran A, Richtering W. Stiffness Tomography of Ultra-Soft Nanogels by Atomic Force Microscopy. Angew Chem Int Ed Engl 2021; 60:2280-2287. [PMID: 33459462 PMCID: PMC7898630 DOI: 10.1002/anie.202011615] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Indexed: 01/02/2023]
Abstract
The softness of nanohydrogels results in unique properties and recently attracted tremendous interest due to the multi-functionalization of interfaces. Herein, we study extremely soft temperature-sensitive ultra-low cross-linked (ULC) nanogels adsorbed to the solid/water interface by atomic force microscopy (AFM). The ultra-soft nanogels seem to disappear in classical imaging modes since a sharp tip fully penetrates these porous networks with very low forces in the range of steric interactions (ca. 100 pN). However, the detailed evaluation of Force Volume mode measurements allows us to resolve their overall shape and at the same time their internal structure in all three dimensions. The nanogels exhibit an extraordinary disk-like and entirely homogeneous but extremely soft structure-even softer than polymer brushes. Moreover, the temperature-sensitive nanogels can be switched on demand between the ultra-soft and a very stiff state.
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Affiliation(s)
| | - Steffen Bochenek
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
| | - Monia Brugnoni
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
| | - Andrea Scotti
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
| | - Ahmed Mourran
- DWI—Leibniz Institute for Interactive MaterialsForckenbeckstr. 5052056AachenGermany
| | - Walter Richtering
- Institute of Physical ChemistryRWTH Aachen UniversityLandoltweg 252056AachenGermany
- DWI—Leibniz Institute for Interactive MaterialsForckenbeckstr. 5052056AachenGermany
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26
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Lenzi V, Ramos MMD, Marques LSA. Dissipative particle dynamics simulations of end-cross-linked nanogels. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1859111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Veniero Lenzi
- Center of Physics of Universities of Minho and Porto, University of Minho, Campus de Gualtar, Braga, Portugal
| | - Marta M. D. Ramos
- Center of Physics of Universities of Minho and Porto, University of Minho, Campus de Gualtar, Braga, Portugal
| | - Luís S. A. Marques
- Center of Physics of Universities of Minho and Porto, University of Minho, Campus de Gualtar, Braga, Portugal
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27
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Schulte MF, Bochenek S, Brugnoni M, Scotti A, Mourran A, Richtering W. Stiffness Tomography of Ultra‐Soft Nanogels by Atomic Force Microscopy. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011615] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- M. Friederike Schulte
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Steffen Bochenek
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Monia Brugnoni
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Andrea Scotti
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
| | - Ahmed Mourran
- DWI—Leibniz Institute for Interactive Materials Forckenbeckstr. 50 52056 Aachen Germany
| | - Walter Richtering
- Institute of Physical Chemistry RWTH Aachen University Landoltweg 2 52056 Aachen Germany
- DWI—Leibniz Institute for Interactive Materials Forckenbeckstr. 50 52056 Aachen Germany
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28
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Drozdov AD, Christiansen JD. Equilibrium swelling of thermo-responsive copolymer microgels. RSC Adv 2020; 10:42718-42732. [PMID: 35514931 PMCID: PMC9057954 DOI: 10.1039/d0ra08619c] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/17/2020] [Indexed: 01/31/2023] Open
Abstract
Thermo-responsive (TR) hydrogels with a lower critical solution temperature swell strongly at temperatures below their volume phase transition temperature Tc and collapse above Tc. Biomedical application of these materials requires tuning the critical temperature in a rather wide interval. A facile method for modulation of Tc is to polymerize the basic monomers with hydrophilic or hydrophobic comonomers. Although the effectiveness of this method has been confirmed by experimental data, molar fractions of comonomers necessary for fine tuning of Tc in macroscopic gels and microgels are unknown. A simple model is developed for the equilibrium swelling of TR copolymer gels. Its adjustable parameters are found by fitting swelling diagrams on several macro- and microgels with N-isopropylacrylamide as a basic monomer. Good agreement is demonstrated between the experimental swelling curves and results of numerical analysis. An explicit expression is derived for the volume phase transition temperature as a function of molar fraction of comonomers. The ability of this relation to predict the critical temperature is confirmed by comparison with observations. A model is developed for equilibrium swelling of thermo-responsive copolymer gels and is applied to predict the effect of molar fraction of comonomers on the volume phase transition temperature of macroscopic gels and microgels.![]()
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Affiliation(s)
- A D Drozdov
- Department of Materials and Production, Aalborg University Fibigerstraede 16 Aalborg 9220 Denmark
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29
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Scheffold F. Pathways and challenges towards a complete characterization of microgels. Nat Commun 2020; 11:4315. [PMID: 32887886 PMCID: PMC7473851 DOI: 10.1038/s41467-020-17774-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Accepted: 07/20/2020] [Indexed: 01/07/2023] Open
Abstract
Due to their controlled size, sensitivity to external stimuli, and ease-of-use, microgel colloids are unique building blocks for soft materials made by crosslinking polymers on the micrometer scale. Despite the plethora of work published, many questions about their internal structure, interactions, and phase behavior are still open. The reasons for this lack of understanding are the challenges arising from the small size of the microgel particles, complex pairwise interactions, and their solvent permeability. Here we describe pathways toward a complete understanding of microgel colloids based on recent experimental advances in nanoscale characterization, such as super-resolution microscopy, scattering methods, and modeling.
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Affiliation(s)
- Frank Scheffold
- Department of Physics, University of Fribourg, Chemin du Musée 3, 1700, Fribourg, Switzerland.
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30
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Minami S, Watanabe T, Sasaki Y, Minato H, Yamamoto A, Suzuki D, Urayama K. Two-step yielding behavior of densely packed microgel mixtures with chemically dissimilar surfaces and largely different sizes. SOFT MATTER 2020; 16:7400-7413. [PMID: 32699868 DOI: 10.1039/d0sm00366b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Steady-state flow and elastic behavior is investigated for the moderately concentrated binary suspensions of soft microgels (pastes) with chemically dissimilar surfaces, and various degrees of size- and stiffness disparities. The pastes of poly(N-isopropyl acrylamide) (N) and poly(N-isopropyl methacrylamide) (NM) microgels with different values of yield strain γc (γNc > γNMc) are employed as the components. For the single microgel pastes (φ ≈ 1 where φ is apparent volume fraction), the values of γc are governed by the chemical species of constituent polymer in microgel surface whereas γc is insensitive to cross-link density and particle size. We demonstrate that the binary N/NM pastes with large size disparity (RN/NM = DN/DNM < 0.26 where D is the microgel diameter) at low φN (φN: weight fraction of small N microgels) exhibit the peculiarities in several rheological aspects, i.e., the two-step yielding in steady-state flow, and their values of γc and equilibrium shear modulus (G0) being equivalent to those of the single large NM microgel paste. These peculiarities are attributed to the characteristic packing resulting from large size disparity in which all or almost of the small N microgels tend to be accommodated in the gap between the large NM microgels even in moderately concentrated state. This characteristic packing substantially masks the contribution of the small N microgels at low φN, explaining the φN-independent G0 and γc as well as the first yielding governed solely by the large NM microgels. The second yielding results from the emerged contribution of the small N microgels expelled out from the gap by the positional rearrangements after the first yielding. The binary homo-N/N pastes with the similarly large size disparity at low φsmall also exhibit the φsmall-independent values of G0, but they show one-step yielding, indicating that the two-step yielding requires not only sufficiently large size disparity but also chemical dissimilarity (different values of γc) between the two components.
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Affiliation(s)
- Saori Minami
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
| | - Takumi Watanabe
- Graduate School of Textile Science & Technology, Shinshu University, Ueda 386-8567, Japan.
| | - Yuma Sasaki
- Graduate School of Textile Science & Technology, Shinshu University, Ueda 386-8567, Japan.
| | - Haruka Minato
- Graduate School of Textile Science & Technology, Shinshu University, Ueda 386-8567, Japan.
| | - Atsushi Yamamoto
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, Ueda 386-8567, Japan. and Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Ueda 386-8567, Japan
| | - Kenji Urayama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan.
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31
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Liu Y, Sokolov I, Dokukin ME, Xiong Y, Peng P. Can AFM be used to measure absolute values of Young's modulus of nanocomposite materials down to the nanoscale? NANOSCALE 2020; 12:12432-12443. [PMID: 32495797 DOI: 10.1039/d0nr02314k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
At present, a technique potentially capable of measuring values of Young's modulus at the nanoscale is atomic force microscopy (AFM) working in the indentation mode. However, the question if AFM indentation data can be translated into absolute values of the modulus is not well-studied as yet, in particular, for the most interesting case of stiff nanocomposite materials. Here we investigate this question. A special sample of nanocomposite material, shale rock, was used, which is relatively homogeneous at the multi-micron scale. Two AFM modes, force-volume and PeakForce QNM were used in this study. The nanoindentation technique was used as a control benchmark for the measurement of effective Young's modulus of the shale sample. The indentation rate was carefully controlled. To ensure the self-consistency of the mechanical model used to analyze AFM data, the model was modified to take into account the presence of the surface roughness. We found excellent agreement between the average values of effective Young's modulus calculated within AFM and the nanoindenter benchmark method. At the same time, the softest and hardest areas of the sample were seen only with AFM.
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Affiliation(s)
- Yuke Liu
- Department of Mechanical Engineering, Tufts University, Medford, MA, USA.
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32
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Sakai A, Murayama Y, Yanagisawa M. Cyclic Micropipette Aspiration Reveals Viscoelastic Change of a Gelatin Microgel Prepared Inside a Lipid Droplet. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5186-5191. [PMID: 32347734 DOI: 10.1021/acs.langmuir.0c00428] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Gelatin microgels prepared inside lipid droplets have a much higher elasticity than that of bulk gels because of their differences in nanostructure. This nanostructural difference in gelatin microgels is expected to provide the microgels with unique viscoelastic properties that differ from the bulk gels. To clarify this hypothesis, here we evaluated the frequency-dependent viscoelasticity of gelatin gels by developing a cyclic micropipette aspiration. The frequency-dependent relationship between storage modulus E' (reflecting elasticity) and loss modulus E″ (reflecting viscosity) was compared between the microgels and the bulk gels. The microgels have a smaller E″/E' than that of the bulk gels. Because the ratio E″/E' of the bulk gels is constant regardless of the concentration, the microgel viscoelasticity cannot be achieved for the bulk gels with a different concentration. These findings mean that preparing biopolymer gels inside droplets is useful to change the viscoelasticity via nanostructural transition through the interaction with the droplet interface.
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Affiliation(s)
- Atsushi Sakai
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588, Japan
- Komaba Institute for Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan
| | - Yoshihiro Murayama
- Department of Applied Physics, Tokyo University of Agriculture and Technology, Naka-cho 2-24-16, Koganei, Tokyo 184-8588, Japan
| | - Miho Yanagisawa
- Komaba Institute for Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro, Tokyo 153-8902, Japan
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33
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Minami S, Yamamoto A, Oura S, Watanabe T, Suzuki D, Urayama K. Criteria for colloidal gelation of thermo-sensitive poly(N-isopropylacrylamide) based microgels. J Colloid Interface Sci 2020; 568:165-175. [DOI: 10.1016/j.jcis.2020.02.047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 11/24/2022]
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Affiliation(s)
- Kenechi A. Agbim
- Department of Mechanical Engineering, Rice University, Houston, Texas, USA
| | - Laura A. Schaefer
- Department of Mechanical Engineering, Rice University, Houston, Texas, USA
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35
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Visualization of the Stimuli-responsive Surface Behavior of Functionalized Wood Material by Chemical Force Microscopy. Sci Rep 2019; 9:18569. [PMID: 31811171 PMCID: PMC6898718 DOI: 10.1038/s41598-019-54664-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 11/15/2019] [Indexed: 01/04/2023] Open
Abstract
The hierarchical and porous wood structure provides a stable scaffold to design functionalized lignocellulosic materials with extended properties by chemical modification techniques. However, proper nanoscale characterization methods for these novel materials are needed to confirm the presence of the added functionality and to locate the introduced functional groups with high spatial resolution. Chemical force microscopy is a suitable characterization method to distinguish chemical surface characteristics by scanning the samples surface with a functionalized tip. We report the application of this nanotechnology method on both, unmodified and functionalized wood samples to confirm the thermo-responsive behavior of poly(N-isopropylacrylamide) (PNIPAM) modified spruce wood. By performing force measurements on ultra-microtomed surfaces, adhesion force differences on the analysed structure are monitored and reveal the location and functionality of introduced functional groups. The modified samples are scanned below and above their lower critical solution temperature with a hydrophobic tip in aqueous media to observe adhesion changes. Additionally, confocal Raman microscopy support the chemical force microscopy measurements by revealing the success of the modification and the distribution of PNIPAM across the sample cross-sections. The results show that PNIPAM is mainly located in wood cell wall areas close to the lumen in early- and transitionwood.
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36
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Andablo-Reyes E, Yerani D, Fu M, Liamas E, Connell S, Torres O, Sarkar A. Microgels as viscosity modifiers influence lubrication performance of continuum. SOFT MATTER 2019; 15:9614-9624. [PMID: 31603453 DOI: 10.1039/c9sm01802f] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Biocompatible microgels have been demonstrated to act as excellent lubricants, however, the influence of the continuum on their overall mechanical performance has been neglected so far. In this work, the mechanical performance of colloidal whey protein microgels (hydrodynamic diameter ∼100 nm measured using dynamic light scattering and atomic force microscopy) of different rigidity dispersed in Newtonian (buffer and corn syrup) or complex non-Newtonian fluids (xanthan gum) is investigated for the first time via rheology and soft tribology. Dispersions of both soft microgels (G' ∼ 100.0 Pa) and hard microgels (G' ∼ 10.0 kPa) were observed to act as thickeners in buffer as well as in low viscosity corn syrup and correspondingly reduced the friction, latter decreased as a function of the increased rigidity of the microgels. Differently, in high viscosity continuum, the microgels acted as thinning agents and increased the friction. In the lubrication limit, microgels in buffer or corn syrup behaved as Newtonian fluids with effective viscosity corresponding to their second Newtonian plateau value (η∞). However, the lubrication performance of the microgels dispersed in the complex fluid (xanthan gum) could not be described quantitatively by η∞. For the low viscosity xanthan gum, the microgels had no influence on friction. Nevertheless, for the high viscosity counterparts, the soft microgels acted as thinning agents whilst the hard microgels accelerated the onset of elastohydrodynamic regime. This study demonstrates that microgels act as viscosity modifiers directly influencing the tribological performance, depending upon a subtle interplay of rheological properties of the particles and continuum.
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Affiliation(s)
- Efren Andablo-Reyes
- Food Colloids and Bioprocessing Group, School of Food Science and Nutrition, University of Leeds, UK.
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37
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Schulte MF, Scotti A, Brugnoni M, Bochenek S, Mourran A, Richtering W. Tuning the Structure and Properties of Ultra-Low Cross-Linked Temperature-Sensitive Microgels at Interfaces via the Adsorption Pathway. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14769-14781. [PMID: 31638406 DOI: 10.1021/acs.langmuir.9b02478] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The structure of poly(N-isopropylacrylamide) (PNIPAM) microgels adsorbed onto a solid substrate is investigated in the dry and hydrated states by means of atomic force microscopy (AFM). We compare two different systems: a regularly cross-linked microgel containing 5 mol % cross-linker and ultra-low cross-linked microgels (ULC) prepared without a dedicated cross-linker. Furthermore, we compare three different adsorption processes: (i) in situ adsorption from solution, (ii) spin-coating, and (iii) Langmuir-Blodgett deposition from an oil-water interface. The results demonstrate that the morphology and the temperature-induced collapse of microgels adsorbed onto a solid substrate are very different for ultra-low cross-linked microgels as compared to regularly cross-linked microgels, despite the fact that their general behavior in solution is very similar. Furthermore, the morphology of ULC microgels can be controlled by the adsorption pathway onto the substrate. Absorbed ULC microgels are strongly deformed when being prepared either by spin-coating or by Langmuir-Blodgett deposition from an oil-water interface. After rehydration, the ULC microgels cannot collapse as entire objects, instead small globules are formed. Such a strong deformation can be avoided by in situ adsorption onto the substrate. Then, the ULC microgels exhibit half-ellipsoidal shapes with a smooth surface in the collapsed state similar to the more cross-linked microgels. As ULC microgels can be selectively trapped either in a more particle-like or in a more polymer-like behavior, coatings with strongly different topographies and properties can be prepared by one and the same ultra-low cross-linked microgel. This provides new opportunities for the development of smart polymeric coatings.
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Affiliation(s)
- M Friederike Schulte
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , 52056 Aachen , Germany
| | - Andrea Scotti
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Monia Brugnoni
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Steffen Bochenek
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
| | - Ahmed Mourran
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , 52056 Aachen , Germany
| | - Walter Richtering
- Institute of Physical Chemistry , RWTH Aachen University , Landoltweg 2 , 52056 Aachen , Germany
- DWI-Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , 52056 Aachen , Germany
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38
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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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39
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Rovigatti L, Gnan N, Ninarello A, Zaccarelli E. Connecting Elasticity and Effective Interactions of Neutral Microgels: The Validity of the Hertzian Model. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00099] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Lorenzo Rovigatti
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy
- CNR-ISC, Uos Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy
| | - Nicoletta Gnan
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy
- CNR-ISC, Uos Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy
| | - Andrea Ninarello
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy
- CNR-ISC, Uos Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy
| | - Emanuela Zaccarelli
- Dipartimento di Fisica, Sapienza Università di Roma, Piazzale A. Moro 2, 00185 Roma, Italy
- CNR-ISC, Uos Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy
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40
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Song X, Qiao C, Tao J, Bao B, Han X, Zhao S. Interfacial Engineering of Thermoresponsive Microgel Capsules: Polymeric Wetting vs Colloidal Adhesion. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b02323] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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41
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Camerin F, Fernández-Rodríguez MÁ, Rovigatti L, Antonopoulou MN, Gnan N, Ninarello A, Isa L, Zaccarelli E. Microgels Adsorbed at Liquid-Liquid Interfaces: A Joint Numerical and Experimental Study. ACS NANO 2019; 13:4548-4559. [PMID: 30865829 DOI: 10.1021/acsnano.9b00390] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Soft particles display highly versatile properties with respect to hard colloids and even more so at fluid-fluid interfaces. In particular, microgels, consisting of a cross-linked polymer network, are able to deform and flatten upon adsorption at the interface due to the balance between surface tension and internal elasticity. Despite the existence of experimental results, a detailed theoretical understanding of this phenomenon is still lacking due to the absence of appropriate microscopic models. In this work, we propose an advanced modeling of microgels at a flat water/oil interface. The model builds on a realistic description of the internal polymeric architecture and single-particle properties of the microgel and is able to reproduce its experimentally observed shape at the interface. Complementing molecular dynamics simulations with in situ cryo-electron microscopy experiments and atomic force microscopy imaging after Langmuir-Blodgett deposition, we compare the morphology of the microgels for different values of the cross-linking ratios. Our model allows for a systematic microscopic investigation of soft particles at fluid interfaces, which is essential to develop predictive power for the use of microgels in a broad range of applications, including the stabilization of smart emulsions and the versatile patterning of surfaces.
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Affiliation(s)
- Fabrizio Camerin
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Basic and Applied Sciences for Engineering , Sapienza University of Rome , Via Antonio Scarpa 14 , 00161 Roma , Italy
| | - Miguel Ángel Fernández-Rodríguez
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Lorenzo Rovigatti
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
| | - Maria-Nefeli Antonopoulou
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Nicoletta Gnan
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
| | - Andrea Ninarello
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
| | - Lucio Isa
- Laboratory for Interfaces, Soft Matter and Assembly, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland
| | - Emanuela Zaccarelli
- CNR Institute for Complex Systems, Uos Sapienza , Piazzale Aldo Moro 2 , 00185 Roma , Italy
- Department of Physics , Sapienza University of Rome , Piazzale Aldo Moro 2 , 00185 Roma , Italy
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42
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Nakaishi A, Minami S, Oura S, Watanabe T, Suzuki D, Urayama K. Elastic and Flow Properties of Densely Packed Binary Microgel Mixtures with Size and Stiffness Disparities. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01625] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ayaki Nakaishi
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | - Saori Minami
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | | | | | | | - Kenji Urayama
- Department of Macromolecular Science and Engineering, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
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