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Walkowiak JJ, Litzen I, Michalska-Walkowiak J, Förster B, Stouten J, Bernaerts KV, Demco DE, Pich A. Microgels with controlled network topologies by photocrosslinking-assisted continuous precipitation polymerization. J Colloid Interface Sci 2024; 675:614-619. [PMID: 38991275 DOI: 10.1016/j.jcis.2024.07.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2024] [Revised: 07/03/2024] [Accepted: 07/06/2024] [Indexed: 07/13/2024]
Abstract
In this study, we present a new synthesis methodology based on photo-crosslinking-assisted continuous precipitation polymerization which allows controlling the distribution of crosslinks in microgels. In our approach we substituted conventional crosslinking agent by a comonomer carrying photo-crosslinkable 4-oxocyclopent-2-en-1-yl group. Microgel size, morphology, distribution of crosslinks and packing density of the polymer chains are studied as a function of retention time (Rt) in the flow reactor. Dynamic and static light scattering (DLS and SLS) as well as small angle X-ray scattering (SAXS) proved an excellent level of control over the distribution of crosslinks in microgels during the polymerization process. These results were confirmed by atomic force microscopy (AFM), indicating a difference in microgel stiffness and arrangement of the polymer network as resulting from increased Rt.
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Affiliation(s)
- Jacek J Walkowiak
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany; DWI - Leibniz-Institute for Interactive Materials e.V, Forckenbeckstraße 50, 52074 Aachen, Germany; Sustainable Polymer Synthesis Group, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD Geleen, the Netherlands
| | - Inga Litzen
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany; DWI - Leibniz-Institute for Interactive Materials e.V, Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Joanna Michalska-Walkowiak
- CNRS, UMR 8232 - IPCM - Institut Parisien de Chimie Moléculaire - Polymer Chemistry Team, Sorbonne Université, 4 Pl. Jussieu, 75005 Paris, France
| | - Beate Förster
- Ernst Ruska Centre (ER-C 1) Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Jules Stouten
- Sustainable Polymer Synthesis Group, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD Geleen, the Netherlands
| | - Katrien V Bernaerts
- Sustainable Polymer Synthesis Group, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD Geleen, the Netherlands
| | - Dan E Demco
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany; DWI - Leibniz-Institute for Interactive Materials e.V, Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Andrij Pich
- Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Worringerweg 2, 52074 Aachen, Germany; DWI - Leibniz-Institute for Interactive Materials e.V, Forckenbeckstraße 50, 52074 Aachen, Germany; Sustainable Polymer Synthesis Group, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167 RD Geleen, the Netherlands.
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2
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Petrunin AV, Höfken T, Schneider S, Mota-Santiago P, Houston JE, Scotti A. Phase behavior of binary mixtures of hollow and regular microgels. SOFT MATTER 2024. [PMID: 39364605 DOI: 10.1039/d4sm00862f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2024]
Abstract
Soft colloids are widely used to study glass transition, aging and jamming. A high size polydispersity is typically introduced in these systems to avoid crystal formation. Here, we use binary mixtures of hollow and regular microgels with comparable sizes to inhibit crystallization. The phase behavior of the mixture is probed as a function of the number fraction of hollow microgels and characterized by small-angle X-ray scattering. Molecular dynamic simulations are used to extract the particle-particle pair potential and obtain insight on their deformation. The results suggest that the high deformability of the hollow microgels offers an alternative route to maximize the entropy without crystal formation.
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Affiliation(s)
- Alexander V Petrunin
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, EU, Germany.
| | - Tom Höfken
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, EU, Germany.
| | - Stefanie Schneider
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, EU, Germany.
| | - Pablo Mota-Santiago
- Australian Synchrotron, ANSTO, Clayton, Victoria, Australia
- MAX IV Laboratory, Lund University, P.O. Box 118, 22100 Lund, EU, Sweden
| | - Judith E Houston
- European Spallation Source ERIC, Box 176, SE-221 00 Lund, EU, Sweden
| | - Andrea Scotti
- Division of Physical Chemistry, Lund University, SE-22100 Lund, Sweden.
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3
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Kumar S, Sarkar S, Bagchi B. Glassy dynamics in a liquid of anisotropic molecules: Bifurcation of relaxation spectrum. J Chem Phys 2024; 160:224501. [PMID: 38856065 DOI: 10.1063/5.0210699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 05/24/2024] [Indexed: 06/11/2024] Open
Abstract
In experimental and theoretical studies of glass transition phenomena, one often finds a sharp crossover in dynamical properties at a temperature Tcr. A bifurcation of a relaxation spectrum is also observed at a temperature TB≈Tcr; both lie significantly above the glass transition temperature. In order to better understand these phenomena, we introduce a new model of glass-forming liquids, a binary mixture of prolate and oblate ellipsoids. This model system exhibits sharp thermodynamic and dynamic anomalies, such as the specific heat jump during heating and a sharp variation in the thermal expansion coefficient around a temperature identified as the glass transition temperature, Tg. The same temperature is obtained from the fit of the calculated relaxation times to the Vogel-Fulcher-Tammann (VFT) form. As the temperature is lowered, the calculated single peak rotational relaxation spectrum splits into two peaks at TB above the estimated Tg. Similar bifurcation is also observed in the distribution of short-to-intermediate time translational diffusion. Interrogation of the two peaks reveals a lower extent of dynamic heterogeneity in the population of the faster mode. We observe an unexpected appearance of a sharp peak in the product of rotational relaxation time τ2 and diffusion constant D at a temperature Tcr, close to TB, but above the glass transition temperature. Additionally, we coarse-grain the system into cubic boxes, each containing, on average, ∼62 particles, to study the average dynamical properties. Clear evidence of large-scale sudden changes in the diffusion coefficient and rotational correlation time signals first-order transitions between low and high-mobility domains.
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Affiliation(s)
- Shubham Kumar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Sarmistha Sarkar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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4
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Xue B, Liufu W, Yin J, Yang J, Yin P. Particle topology-regulated relaxation dynamics in cluster-ordering. J Chem Phys 2024; 160:154902. [PMID: 38624128 DOI: 10.1063/5.0195905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 03/29/2024] [Indexed: 04/17/2024] Open
Abstract
The granular materials of soft particles (SPs) demonstrate unique viscoelasticity distinct from general colloidal and polymer systems. Exploiting dynamic light scattering measurements, together with molecular dynamics simulations, we study the diffusive dynamics of soft particle clusters (SPCs) with spherical and cylindrical brush topologies, respectively, in the melts of SPs. A topologically constrained relaxation theory is proposed by quantitatively correlating the relaxation time to the topologies of the SPCs, through the mean free space (Va) of tethered SPs in the cluster. The tethered SPs in SPCs are crowded by SPs of the melts to form the cage zones, and the cooperative diffusion of the tether SPs in the zones is required for the diffusive motion of SPCs. The cage zone serves as an entropic barrier for the diffusion of SP clusters, while its strength is determined by Va. Three characteristic modes can be confirmed: localized non-diffusive mode around critical Va, diffusive mode with Va deviating far from the critical value, and a sub-diffusive mode as an interlude between two limits. Our studies raise attention to the emergent physical properties of materials based on SPs via a topological design while opening new avenues for the design of soft structural materials.
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Affiliation(s)
- Binghui Xue
- State Key Laboratory of Luminescent Materials and Devices & South China Advanced Institute for Soft Matter Science and Technology, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Wei Liufu
- State Key Laboratory of Luminescent Materials and Devices & South China Advanced Institute for Soft Matter Science and Technology, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Jiafu Yin
- State Key Laboratory of Luminescent Materials and Devices & South China Advanced Institute for Soft Matter Science and Technology, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Junsheng Yang
- State Key Laboratory of Luminescent Materials and Devices & South China Advanced Institute for Soft Matter Science and Technology, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Panchao Yin
- State Key Laboratory of Luminescent Materials and Devices & South China Advanced Institute for Soft Matter Science and Technology, South China University of Technology, Guangzhou 510640, People's Republic of China
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5
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Minato H, Ushida S, Yokouchi K, Suzuki D. Multi-layer core/shell microgels with internal complexity and their nanocomposites. Chem Commun (Camb) 2024; 60:1630-1633. [PMID: 38234227 DOI: 10.1039/d3cc05579e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
In this study, we show that core/shell (CS) microgels with multiple layers can be created via a one-pot precipitation polymerization, in which monomers are added to the reaction flask multiple times once most of the previous monomer has been consumed. The complex internal structures of the microgels were examined using a combination of scattering and microscopy techniques.
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Affiliation(s)
- Haruka Minato
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
| | - Satoki Ushida
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
| | - Kentaro Yokouchi
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
- Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
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6
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Xie Z, Atherton TJ. Jamming on convex deformable surfaces. SOFT MATTER 2024; 20:1070-1078. [PMID: 38206105 DOI: 10.1039/d2sm01608g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Jamming is a fundamental transition that governs the behavior of particulate media, including sand, foams and dense suspensions. Upon compression, such media change from freely flowing to a disordered, marginally stable solid that exhibits non-Hookean elasticity. While the jamming process is well established for fixed geometries, the nature and dynamics of jamming for a diverse class of soft materials and deformable substrates, including emulsions and biological matter, remains unknown. Here we propose a new scenario, metric jamming, where rigidification occurs on a surface that has been deformed from its ground state. Unlike classical jamming processes that exhibit discrete mechanical transitions, surprisingly we find that metric jammed states possess mechanical properties continuously tunable between those of classically jammed and conventional elastic media. The compact and curved geometry significantly alters the vibrational spectra of the structures relative to jamming in flat Euclidean space, and metric jammed systems also possess new types of vibrational mode that couple particle and shape degrees of freedom. Our work provides a theoretical framework that unifies our understanding of solidification processes that take place on deformable media and lays the groundwork to exploit jamming for the control and stabilization of shape in self-assembly processes.
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Affiliation(s)
- Zhaoyu Xie
- Department of Physics & Astronomy, Tufts University, 574 Boston Ave, Medford, MA 02155, USA.
| | - Timothy J Atherton
- Department of Physics & Astronomy, Tufts University, 574 Boston Ave, Medford, MA 02155, USA.
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7
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Zavala-Martínez AB, Grelet E. M13-Phage-Based Star-Shaped Particles with Internal Flexibility. ACS NANO 2024; 18:281-287. [PMID: 38113352 DOI: 10.1021/acsnano.3c06134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
We report on the construction and the dynamics of monodisperse star-shaped particles, mimicking, at the mesoscale, star polymers. Such multiarm star-like particles result from the self-assembly of gold nanoparticles, forming the core, with tip-linked filamentous viruses (M13 bacteriophages) acting as spines in a sea urchin-like structure. By combining fluorescence and dark-field microscopy with dynamic light scattering, we investigate the diffusion of these hybrid spiny particles. We reveal the internal dynamics of the star particles by probing their central metallic core, which exhibits a hindered motion that can be described as a Brownian particle trapped in a harmonic potential. We therefore show that the filamentous viruses and specifically their tip proteins behave as entropic springs, extending the relevance of the study of such hybrid mesoscopic analogues of star polymers to phage biotechnology.
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Affiliation(s)
- Arantza B Zavala-Martínez
- Univ. Bordeaux, CNRS, Centre de Recherche Paul-Pascal, UMR 5031,115Avenue du Dr. Schweitzer, F-33600 Pessac, France
| | - Eric Grelet
- Univ. Bordeaux, CNRS, Centre de Recherche Paul-Pascal, UMR 5031,115Avenue du Dr. Schweitzer, F-33600 Pessac, France
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8
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Schmidt MM, Ruiz-Franco J, Bochenek S, Camerin F, Zaccarelli E, Scotti A. Interfacial Fluid Rheology of Soft Particles. PHYSICAL REVIEW LETTERS 2023; 131:258202. [PMID: 38181345 DOI: 10.1103/physrevlett.131.258202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/18/2023] [Accepted: 11/20/2023] [Indexed: 01/07/2024]
Abstract
In situ interfacial rheology and numerical simulations are used to investigate microgel monolayers in a wide range of packing fractions, ζ_{2D}. The heterogeneous particle compressibility determines two flow regimes characterized by distinct master curves. To mimic the microgel architecture and reproduce experiments, an interaction potential combining a soft shoulder with the Hertzian model is introduced. In contrast to bulk conditions, the elastic moduli vary nonmonotonically with ζ_{2D} at the interface, confirming long-sought predictions of reentrant behavior for Hertzian-like systems.
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Affiliation(s)
- Maximilian M Schmidt
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - José Ruiz-Franco
- Laboratory of Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Steffen Bochenek
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - Fabrizio Camerin
- Soft Condensed Matter & Biophysics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands
| | - Emanuela Zaccarelli
- Italian National Research Council-Institute for Complex Systems (CNR-ISC), Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Department of Physics, Sapienza University of Rome, Piazzale Aldo Moro 2, 00185 Rome, Italy
| | - Andrea Scotti
- Department of Biomedical Science, Faculty of Health and Society, Malmö University, SE-205 06 Malmö, Sweden
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9
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Sposini V, Likos CN, Camargo M. Glassy phases of the Gaussian core model. SOFT MATTER 2023. [PMID: 38050434 DOI: 10.1039/d3sm01314f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
We present results from molecular dynamics simulations exploring the supercooled dynamics of the Gaussian Core Model in the low- and intermediate-density regimes. In particular, we analyse the transition from the low-density hard-sphere-like glassy dynamics to the high-density one. The dynamics at low densities is well described by the caging mechanism, giving rise to intermittent dynamics. At high densities, the particles undergo a more continuous motion in which the concept of cage loses its meaning. We elaborate on the idea that these different supercooled dynamics are in fact the precursors of two different glass states.
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Affiliation(s)
- Vittoria Sposini
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
| | - Christos N Likos
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria.
| | - Manuel Camargo
- Facultad de Ciencias & CICBA, Universidad Antonio Nariño-Campus Farallones, Km 18 via Cali-Jamundí, 760030 Cali, Colombia
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10
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Svoboda R, Pakosta M, Doležel P. How the Presence of Crystalline Phase Affects Structural Relaxation in Molecular Liquids: The Case of Amorphous Indomethacin. Int J Mol Sci 2023; 24:16275. [PMID: 38003465 PMCID: PMC10671508 DOI: 10.3390/ijms242216275] [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: 10/30/2023] [Revised: 11/10/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
The influence of partial crystallinity on the structural relaxation behavior of low-molecular organic glasses is, contrary to, e.g., polymeric materials, a largely unexplored territory. In the present study, differential scanning calorimetry was used to prepare a series of amorphous indomethacin powders crystallized to various extents. The preparations stemmed from the two distinct particle size fractions: 50-125 µm and 300-500 µm. The structural relaxation data from the cyclic calorimetric measurements were described in terms of the phenomenological Tool-Narayanaswamy-Moynihan model. For the 300-500 µm powder, the crystalline phase forming dominantly on the surface led to a monotonous decrease in the glass transition by ~6 °C in the 0-70% crystallinity range. The activation energy of the relaxation motions and the degree of heterogeneity within the relaxing matrix were not influenced by the increasing crystallinity, while the interconnectivity slightly increased. This behavior was attributed to the release of the quenched-in stresses and to the consequent slight increase in the structural interconnectivity. For the 50-125 µm powder, distinctly different relaxation dynamics were observed. This leads to a conclusion that the crystalline phase grows throughout the bulk glassy matrix along the internal micro-cracks. At higher crystallinity, a sharp increase in Tg, an increase in interconnectivity, and an increase in the variability of structural units engaged in the relaxation motions were observed.
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Affiliation(s)
- Roman Svoboda
- Department of Physical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, 532 10 Pardubice, Czech Republic
| | - Marek Pakosta
- Faculty of Electrical Engineering and Informatics, University of Pardubice, nam. Cs. legii 565, 530 02 Pardubice, Czech Republic; (M.P.); (P.D.)
| | - Petr Doležel
- Faculty of Electrical Engineering and Informatics, University of Pardubice, nam. Cs. legii 565, 530 02 Pardubice, Czech Republic; (M.P.); (P.D.)
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11
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Kawamoto T, Yanagi K, Nishizawa Y, Minato H, Suzuki D. The compression of deformed microgels at an air/water interface. Chem Commun (Camb) 2023; 59:13289-13292. [PMID: 37830179 DOI: 10.1039/d3cc03425a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
The compression of deformed hydrogel microspheres (microgels) at air/water interfaces was investigated using a Langmuir-Blodgett trough with simultaneous in situ visualization of the process using a fluorescent microscope. The relationship between the structure of the microgel arrays and the compression behavior was clarified using microgels with different degrees of crosslinking.
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Affiliation(s)
- Takahisa Kawamoto
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Kohei Yanagi
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Yuichiro Nishizawa
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Haruka Minato
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
- Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan.
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12
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Li X, Li X, Xia T, Chen W, Shea KJ, Lu X. Remarkable sol-gel transition of PNIPAm-based nanogels via large steric hindrance of side-chains. MATERIALS HORIZONS 2023; 10:4452-4462. [PMID: 37503733 DOI: 10.1039/d3mh00892d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
While the block/graft/branched structures are widely studied to favor the reversible physical gelation, there are no reports regarding the steric hindrance-induced sol-gel transition of PNIPAm-based nanogels above their phase transition temperature (Tp). Generally, the introduction of hydrophobic components into poly (N-isopropylacrylamide) (PNIPAm)-based nanogels only led to collapse and lower viscosity instead of the sol-gel transition upon heating above the Tp. Herein, the results of temperature-variable 1HNMR and FTIR confirm that the introduction of hydrophobic N-tert-butylacrylamide (TBA) with the large steric hindrance of side groups of N-tert-butyl to form NIPAm/TBA copolymer nanogels can dramatically slow down the dehydration of all the hydrophobic alkyl groups, thus resulting in the formation of thermally induced sol-gel transition above the Tp. Furthermore, the N-acrylamido-L-phenylalanine (APhe) monomer composed of a strongly water absorbing carboxyl group and a phenyl group with larger steric hindrance is studied to form P(NIPAm/TBA/APhe) terpolymer nanogels which can self-assemble into colorful colloidal crystals. Surprisingly, owing to the synergistic effect between the water absorbing carboxyl group and the steric hindrance group on the same side group, these colloidal crystals can achieve sol-gel transition above Tp, forming a physically crosslinked colorful hydrogel. This work is expected to greatly advance the design, synthesis, and application of the sol-gel transition of PNIPAm-based nanogel systems.
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Affiliation(s)
- Xiaoxiao Li
- College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, People's Republic of China.
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, People's Republic of China
| | - Xueting Li
- College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, People's Republic of China.
- Fujian Nano-Micro Advanced Materials Sci. & Tech. Co. Ltd., Three Creation Park, Jinjiang, Fujian 362200, People's Republic of China
- Anhui Microdelivery Smart Microcapsule Sci. & Tech. Co. Ltd., Tongling, Anhui 244000, People's Republic of China
| | - Tingting Xia
- College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, People's Republic of China.
| | - Wei Chen
- College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, People's Republic of China.
| | - Kenneth J Shea
- Department of Chemistry, University of California, Irvine, California 92697, USA
| | - Xihua Lu
- College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, People's Republic of China.
- Fujian Nano-Micro Advanced Materials Sci. & Tech. Co. Ltd., Three Creation Park, Jinjiang, Fujian 362200, People's Republic of China
- Anhui Microdelivery Smart Microcapsule Sci. & Tech. Co. Ltd., Tongling, Anhui 244000, People's Republic of China
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13
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Chen N. Embedded 3D printing and pressurized thermo-curing of PMMA for medical implants. J Mech Behav Biomed Mater 2023; 146:106083. [PMID: 37678106 DOI: 10.1016/j.jmbbm.2023.106083] [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: 06/07/2023] [Revised: 08/15/2023] [Accepted: 08/20/2023] [Indexed: 09/09/2023]
Abstract
Poly (methyl methacrylate) (PMMA) is a synthetic polymer commonly used for medical implants in cranioplasty and orthopedic surgery owing to its excellent mechanical properties, optical transparency, and minimal inflammatory responses. Recently, the development of 3D printing opens new avenues in the fabrication of patient-specific PMMA implants for personalized medicine. However, challenges are confronted when adapting medical-grade PMMA to the 3D printing process due to its dynamic viscosity and nonself-supporting characteristics before cured. In addition, the intrinsically exothermic polymerization of MMA brings about bubble generation issues that reduce its mechanical performance harshly. Therefore, in this study, an embedded 3D printing methodology followed by pressurized thermo-curing is proposed and developed: a granular alginate microgel is designed for serving as a supporting matrix when jamming formed between the granules to structurally support the extruded precursor filaments of PMMA-MMA ink during both 3D printing and post-curing; moreover, the autoclave reactor enclosing the alginate matrix and as-sculpted PMMA structures is utilized to generate temperature-dependent pressure, which serves for suppressing the bubbles and solidifying the polymerized MMA during the post-curing process. The 3D printed PMMA is comparably matchable to traditional PMMA castings in terms of their microstructures, density, thermal properties, mechanical performance and biocompatibility. In the future, the proposed embedded 3D printing platform combined with the special post-curing method has great potential for a customized and cost-effective fabrication of patient-specific, complex and functional PMMA implants.
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Affiliation(s)
- Na Chen
- Xi'an Children's Hospital, Xi'an, Shaanxi, China.
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14
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Petrunin AV, Schmidt MM, Schweins R, Houston JE, Scotti A. Self-Healing of Charged Microgels in Neutral and Charged Environments. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37220302 DOI: 10.1021/acs.langmuir.2c03054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The softness of microgels depends on many aspects, such as particle characteristic lengths, sample concentration, chemical composition of the sample, and elastic moduli of the particle. Here, the response to crowding of ionic microgels is studied. Charged and uncharged ionic microgels are studied in concentrated suspensions of both neutral and ionic microgels with the same swollen size. The combination of small-angle X-ray and neutron scattering with contrast variation allows us to probe both the particle-to-particle arrangement and the response of individual ionic microgels to crowding. When the ionic microgels are uncharged, initial isotropic deswelling followed by faceting is observed. Therefore, the ionizable groups in the polymeric network do not affect the response of the ionic microgel to crowding, which is similar to what has been reported for neutral microgels. In contrast, the kind of microgels composing the matrix plays a key role once the ionic microgels are charged. If the matrix is composed of neutral microgels, a pronounced faceting and negligible deswelling is observed. When only charged ionic microgels are present in the suspension, isotropic deswelling without faceting is dominant.
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Affiliation(s)
- Alexander V Petrunin
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - Maximilian M Schmidt
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
| | - Ralf Schweins
- Institut Laue-Langevin ILL, DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - Judith E Houston
- European Spallation Source ERIC, Box 176, SE-221 00 Lund, Sweden
| | - Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, 52074 Aachen, Germany
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15
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Saisavadas MV, Dhara S, Joshi RG, Tata BVR. Large amplitude oscillatory shear studies on dense PNIPAM microgel colloidal glasses. Colloid Polym Sci 2023. [DOI: 10.1007/s00396-023-05096-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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16
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Zhang Q, Li W, Qiao K, Han Y. Surface premelting and melting of colloidal glasses. SCIENCE ADVANCES 2023; 9:eadf1101. [PMID: 36930717 PMCID: PMC10022898 DOI: 10.1126/sciadv.adf1101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
The nature of liquid-to-glass transition is a major puzzle in science. A similar challenge exists in glass-to-liquid transition, i.e., glass melting, especially for the poorly investigated surface effects. Here, we assemble colloidal glasses by vapor deposition and melt them by tuning particle attractions. The structural and dynamic parameters saturate at different depths, which define a surface liquid layer and an intermediate glassy layer. The power-law growth of both layers and melting front behaviors at different heating rates are similar to crystal premelting and melting, suggesting that premelting and melting can be generalized to amorphous solids. The measured single-particle kinetics reveal various features and confirm theoretical predictions for glass surface layer.
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Affiliation(s)
- Qi Zhang
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Wei Li
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Kaiyao Qiao
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
| | - Yilong Han
- Department of Physics, Hong Kong University of Science and Technology, Hong Kong, China
- Hong Kong University of Science and Technology, Shenzhen Research Institute, Shenzhen 518057, China
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17
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Single Hydrogel Particle Mechanics and Dynamics Studied by Combining Capillary Micromechanics with Osmotic Compression. Gels 2023; 9:gels9030194. [PMID: 36975643 PMCID: PMC10048562 DOI: 10.3390/gels9030194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/21/2023] [Accepted: 02/24/2023] [Indexed: 03/08/2023] Open
Abstract
Hydrogels can exhibit a remarkably complex response to external stimuli and show rich mechanical behavior. Previous studies of the mechanics of hydrogel particles have generally focused on their static, rather than dynamic, response, as traditional methods for measuring single particle response at the microscopic scale cannot readily measure time-dependent mechanics. Here, we study both the static and the time-dependent response of a single batch of polyacrylamide (PAAm) particles by combining direct contact forces, applied by using Capillary Micromechanics, a method where particles are deformed in a tapered capillary, and osmotic forces are applied by a high molecular weight dextran solution. We found higher values of the static compressive and shear elastic moduli for particles exposed to dextran, as compared to water (KDex≈63 kPa vs. Kwater≈36 kPa, and GDex≈16 kPa vs. Gwater≈7 kPa), which we accounted for, theoretically, as being the result of the increased internal polymer concentration. For the dynamic response, we observed surprising behavior, not readily explained by poroelastic theories. The particles exposed to dextran solutions deformed more slowly under applied external forces than did those suspended in water (τDex≈90 s vs. τwater≈15 s). The theoretical expectation was the opposite. However, we could account for this behaviour by considering the diffusion of dextran molecules in the surrounding solution, which we found to dominate the compression dynamics of our hydrogel particles suspended in dextran solutions.
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18
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Analysis of the glass effect and Trommsdorff effect during bulk polymerization of methyl methacrylate, ethyl methacrylate, and butyl methacrylate. Polym J 2023. [DOI: 10.1038/s41428-022-00746-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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19
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Revealing the relationship between liquid fragility and medium-range order in silicate glasses. Nat Commun 2023; 14:13. [PMID: 36596825 PMCID: PMC9810649 DOI: 10.1038/s41467-022-35711-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 12/21/2022] [Indexed: 01/04/2023] Open
Abstract
Despite decades of studies, the nature of the glass transition remains elusive. In particular, the sharpness of the dynamical arrest of a melt at the glass transition is captured by its fragility. Here, we reveal that fragility is governed by the medium-range order structure. Based on neutron-diffraction data for a series of aluminosilicate glasses, we propose a measurable structural parameter that features a strong inverse correlation with fragility, namely, the average medium-range distance (MRD). We use in-situ high-temperature neutron-scattering data to discuss the physical origin of this correlation. We argue that glasses exhibiting low MRD values present an excess of small network rings. Such rings are unstable and deform more readily with changes in temperature, which tends to increase fragility. These results reveal that the sharpness of the dynamical arrest experienced by a silicate glass at the glass transition is surprisingly encoded into the stability of rings in its network.
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20
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Singh A, Singh Y. Structure ordering and glass transition in size-asymmetric ternary mixtures of hard spheres: Variation from fragile to strong glasses. Phys Rev E 2023; 107:014119. [PMID: 36797956 DOI: 10.1103/physreve.107.014119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 12/21/2022] [Indexed: 01/15/2023]
Abstract
We investigate the structure and activated dynamics of a binary mixture of colloidal particles dispersed in a solvent of much smaller-sized particles. The solvent degrees of freedom are traced out from the grand partition function of the colloid-solvent mixture which reduces the system from ternary to effective binary mixture of colloidal particles. In the effective binary mixture colloidal particles interact via effective potential that consists of bare potential plus the solvent-induced interaction. Expressions for the effective potentials and pair correlation functions are derived. We used the result of pair correlation functions to determine the number of particles in a cooperatively reorganizing cluster (CRC) in which localized particles form "long-lived" nonchemical bonds with the central particle. For an event of relaxation to take place these bonds have to reorganize irreversibly, the energy involved in the processes is the effective activation energy of relaxation. Results are reported for hard sphere colloidal particles dispersed in a solvent of hard sphere particles. Our results show that the concentration of solvent can be used as a control parameter to fine-tune the microscopic structural ordering and the size of CRC that governs the glassy dynamics. We show that a small variation in the concentration of solvent creates a bigger change in the kinetic fragility which highlights a wide variation in behavior, ranging from fragile to strong glasses. We conclude that the CRC which is determined from the static pair correlation function and the fluctuations embedded in the system is probably the sole player in the physics of glass transition.
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Affiliation(s)
- Ankit Singh
- Department of Physics, Banaras Hindu University, Varanasi 221 005, India
| | - Yashwant Singh
- Department of Physics, Banaras Hindu University, Varanasi 221 005, India
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21
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Emiroglu DB, Bekcic A, Dranseikiene D, Zhang X, Zambelli T, deMello AJ, Tibbitt MW. Building block properties govern granular hydrogel mechanics through contact deformations. SCIENCE ADVANCES 2022; 8:eadd8570. [PMID: 36525484 PMCID: PMC9757745 DOI: 10.1126/sciadv.add8570] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Granular hydrogels have been increasingly exploited in biomedical applications, including wound healing and cardiac repair. Despite their utility, design guidelines for engineering their macroscale properties remain limited, as we do not understand how the properties of granular hydrogels emerge from collective interactions of their microgel building blocks. In this work, we related building block features (stiffness and size) to the macroscale properties of granular hydrogels using contact mechanics. We investigated the mechanics of the microgel packings through dynamic oscillatory rheology. In addition, we modeled the system as a collection of two-body interactions and applied the Zwanzig and Mountain formula to calculate the plateau modulus and viscosity of the granular hydrogels. The calculations agreed with the dynamic mechanical measurements and described how microgel properties and contact deformations define the rheology of granular hydrogels. These results support a rational design framework for improved engineering of this fascinating class of materials.
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Affiliation(s)
- Dilara Börte Emiroglu
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Aleksandar Bekcic
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Dalia Dranseikiene
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Xinyu Zhang
- Laboratory of Biosensors and Bioelectronics, Department of Information Technology and Electrical Engineering, ETHZurich, 8093 Zurich, Switzerland
| | - Tomaso Zambelli
- Laboratory of Biosensors and Bioelectronics, Department of Information Technology and Electrical Engineering, ETHZurich, 8093 Zurich, Switzerland
| | - Andrew J. deMello
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland
| | - Mark W. Tibbitt
- Macromolecular Engineering Laboratory, Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland
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22
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Zhang DM, Sun DY, Gong XG. Angell plot from the potential energy landscape perspective. Phys Rev E 2022; 106:064129. [PMID: 36671189 DOI: 10.1103/physreve.106.064129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
Within the scenario of the potential energy landscape (PEL), a thermodynamic model has been developed to uncover the physics behind the Angell plot. In our model, by separating the barrier distribution in PELs into a Gaussian-like and a power-law form, we obtain a general relationship between the relaxation time and the temperature. The wide range of the experimental data in the Angell plot, as well as the molecular-dynamics data, can be excellently fitted by two characteristic parameters, the effective barrier (ω) and the effective width (σ) of a Gaussian-like distribution. More importantly, the fitted ω and σ^{2} for all glasses are found to have a simple linear relationship within a very narrow band, and fragile and strong glasses are well separated in the ω-σ^{2} plot, which indicates that glassy states appear only in a specific region of the PEL.
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Affiliation(s)
- D M Zhang
- Key Laboratory for Computational Physical Sciences (MOE), Institute of Computational Physics, Fudan University, Shanghai 200433, China
| | - D Y Sun
- Engineering Research Center for Nanophotonics & Advanced Instrument (MOE), School of Physics and Electronic Science, East China Normal University, 200241 Shanghai, China.,Shanghai Qi Zhi Institution, Shanghai 200030, China
| | - X G Gong
- Key Laboratory for Computational Physical Sciences (MOE), Institute of Computational Physics, Fudan University, Shanghai 200433, China.,Shanghai Qi Zhi Institution, Shanghai 200030, China
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23
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Ferreira RMS. From generalized Langevin stochastic dynamics to anomalous diffusion. Phys Rev E 2022; 106:054157. [PMID: 36559457 DOI: 10.1103/physreve.106.054157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 11/08/2022] [Indexed: 06/17/2023]
Abstract
Scaling methods are fundamental in all branches of physics. In stochastic process, we usually try to describe the long time behavior of a given time correlation function. In this work we investigate a scaling method for anomalous diffusion in systems with memory that produces good results for long and intermediate times. We will initially present a generalization of the diffusion exponent. Then, we present an asymptotic method to obtain an analytical expression for the diffusion coefficient by introducing a time scale factor λ(t). We found an exact expression for the function λ(t), which allows us to describe the diffusive process. For large times, λ(t) becomes a universal parameter determined by the diffusion exponent. In turn, the analytical results are then compared to the numerical results, with a good matching. Then, we'll show the practical effects of scaling. An important first result is that λ(t) quickly converges to a constant. Another very important point was the classification of new forms of diffusion due to the generalized exponent. In previous works, we verified the existence of ergodic ballistic diffusion with diffusion exponent α=2^{-}. Here, we verify the existence of the nonergodic ballistic diffusion type with the obtainment of the diffusion coefficient α=2. Finally, we show that the scaling works. This method is general and can be applied to various types of stochastic problems.
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Affiliation(s)
- Rogelma M S Ferreira
- Centro de Ciências Exatas e Tecnológicas, Universidade Federal do Recôncavo da Bahia, 44.380-000, Cruz das Almas, Bahia, Brasil
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24
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Vargas-Lara F, Starr FW, Douglas JF. Solution properties of spherical gold nanoparticles with grafted DNA chains from simulation and theory. NANOSCALE ADVANCES 2022; 4:4144-4161. [PMID: 36285224 PMCID: PMC9514572 DOI: 10.1039/d2na00377e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 07/30/2022] [Indexed: 06/16/2023]
Abstract
There has been a rapidly growing interest in the use of functionalized Au nanoparticles (NPs) as platforms in multiple applications in medicine and manufacturing. The sensing and targeting characteristics of these NPs, and the realization of precisely organized structures in manufacturing applications using such NPs, depend on the control of their surface functionalization. NP functionalization typically takes the form of polymer grafted layers, and a detailed knowledge of the chemical and structural properties of these layers is required to molecularly engineer the particle characteristics for specific applications. However, the prediction and experimental determination of these properties to enable the rational engineering of these particles is a persistent problem in the development of this class of materials. To address this situation, molecular dynamic simulations were performed based on a previously established coarse-grained single-stranded DNA (ssDNA) model to determine basic solution properties of model ssDNA-grafted NP-layers under a wide range of conditions. In particular, we emphasize the calculation of the hydrodynamic radius for ssDNA-grafted Au NPs as a function of structural parameters such as ssDNA length, NP core size, and surface coverage. We also numerically estimate the radius of gyration and the intrinsic viscosity of these NPs, which in combination with hydrodynamic radius estimates, provide valuable information about the fluctuating structure of the grafted polymer layers. We may then understand the origin of the commonly reported variation in effective NP "size" by different measurement methods, and then exploit this information in connection to material design and characterization in connection with the ever-growing number of applications utilizing polymer-grafted NPs.
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Affiliation(s)
- Fernando Vargas-Lara
- Departments of Physics & Molecular Biology & Biochemistry, Wesleyan University Middletown CT 06459 USA
| | - Francis W Starr
- Departments of Physics & Molecular Biology & Biochemistry, Wesleyan University Middletown CT 06459 USA
| | - Jack F Douglas
- Materials Science & Engineering Division, National Institute of Standards and Technology Gaithersburg Maryland 20899 USA
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25
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Cao X, Sun M. Influence of the interatomic repulsive hardness on the microstructure and dynamics of CuZr metallic glasses. J Mol Model 2022; 28:265. [DOI: 10.1007/s00894-022-05269-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 08/12/2022] [Indexed: 11/24/2022]
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26
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Elancheliyan R, Del Monte G, Chauveau E, Sennato S, Zaccarelli E, Truzzolillo D. Role of Charge Content in the Two-Step Deswelling of Poly( N-isopropylacrylamide)-Based Microgels. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rajam Elancheliyan
- Laboratoire Charles Coulomb, UMR 5221, CNRS−Université de Montpellier, F-34095 Montpellier, France
| | - Giovanni Del Monte
- National Research Council−Institute for Complex Systems (CNR-ISC), Sapienza University of Rome, 00185 Rome, Italy
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - Edouard Chauveau
- Laboratoire Charles Coulomb, UMR 5221, CNRS−Université de Montpellier, F-34095 Montpellier, France
| | - Simona Sennato
- National Research Council−Institute for Complex Systems (CNR-ISC), Sapienza University of Rome, 00185 Rome, Italy
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - Emanuela Zaccarelli
- National Research Council−Institute for Complex Systems (CNR-ISC), Sapienza University of Rome, 00185 Rome, Italy
- Department of Physics, Sapienza University of Rome, 00185 Rome, Italy
| | - Domenico Truzzolillo
- Laboratoire Charles Coulomb, UMR 5221, CNRS−Université de Montpellier, F-34095 Montpellier, France
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27
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Scotti A, Gasser U, Petrunin AV, Fruhner L, Richtering W, Houston JE. Experimental determination of the bulk moduli of hollow nanogels. SOFT MATTER 2022; 18:5750-5758. [PMID: 35899831 DOI: 10.1039/d2sm00680d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The softness of an object can be quantified by one of the fundamental elastic moduli. The bulk modulus of the particle is most appropriate in the presence of isotropic compressions. Here, we use small-angle neutron scattering with contrast variation to directly access the bulk modulus of polymeric nanocapsules - pNIPAM-based hollow nanogels. We show that the size of the cavity is the most important quantity that determines the softness of hollow nanogels. During initial compression, the polymer collapses into the cavity and leads to a large change in the particle volume, resulting in a very small initial bulk modulus. Once the cavity is partially occupied by the polymer, the hollow nanogels become significantly stiffer since now the highly crosslinked network has to be compressed. Furthermore, we show that the larger the cavity, the softer the nanogel.
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Affiliation(s)
- Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
| | - Urs Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | | | - Lisa Fruhner
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information processing (IBI-8), 52425 Jülich, Germany
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany.
| | - Judith E Houston
- European Spallation Source ERIC, Box 176, SE-221 00 Lund, Sweden
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28
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Stubley SJ, Cayre OJ, Murray BS, Celigueta Torres I. Pectin-based microgels for rheological modification in the dilute to concentrated regimes. J Colloid Interface Sci 2022; 628:684-695. [DOI: 10.1016/j.jcis.2022.07.147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 06/14/2022] [Accepted: 07/23/2022] [Indexed: 11/25/2022]
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29
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Houston JE, Fruhner L, de la Cotte A, Rojo González J, Petrunin AV, Gasser U, Schweins R, Allgaier J, Richtering W, Fernandez-Nieves A, Scotti A. Resolving the different bulk moduli within individual soft nanogels using small-angle neutron scattering. SCIENCE ADVANCES 2022; 8:eabn6129. [PMID: 35776796 PMCID: PMC10883365 DOI: 10.1126/sciadv.abn6129] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The bulk modulus, K, quantifies the elastic response of an object to an isotropic compression. For soft compressible colloids, knowing K is essential to accurately predict the suspension response to crowding. Most colloids have complex architectures characterized by different softness, which additionally depends on compression. Here, we determine the different values of K for the various morphological parts of individual nanogels and probe the changes of K with compression. Our method uses a partially deuterated polymer, which exerts the required isotropic stress, and small-angle neutron scattering with contrast matching to determine the form factor of the particles without any scattering contribution from the polymer. We show a clear difference in softness, compressibility, and evolution of K between the shell of the nanogel and the rest of the particle, depending on the amount of cross-linker used in their synthesis.
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Affiliation(s)
| | - Lisa Fruhner
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), 52425 Jülich, Germany
| | - Alexis de la Cotte
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
| | - Javier Rojo González
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
| | | | - Urs Gasser
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Ralf Schweins
- Institut Laue-Langevin ILL DS/LSS, 71 Avenue des Martyrs, F-38000 Grenoble, France
| | - Jürgen Allgaier
- Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science (JCNS-1) and Institute for Biological Information Processing (IBI-8), 52425 Jülich, Germany
| | - Walter Richtering
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
- JARA-SOFT, 52056 Aachen, Germany
| | - Alberto Fernandez-Nieves
- Department of Condensed Matter Physics, University of Barcelona, 08028 Barcelona, Spain
- ICREA-Institucio Catalana de Recerca i Estudis Avancats, 08010 Barcelona, Spain
| | - Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056 Aachen, Germany
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30
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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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31
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Buoso S, Belletti G, Ragno D, Castelvetro V, Bertoldo M. Rheological Response of Polylactic Acid Dispersions in Water with Xanthan Gum. ACS OMEGA 2022; 7:12536-12548. [PMID: 35474836 PMCID: PMC9026014 DOI: 10.1021/acsomega.1c05382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
In this work, the rheological behavior of stable poly(lactic acid) (PLA) dispersions in water, intended for coating applications, was investigated. The newly prepared dispersion consists of PLA particles with an average diameter of 222 ± 2 nm based on dynamic light scattering (DLS) and scanning electron microscopy (SEM) analyses, at concentrations varying in the 5-22 wt % range. Xanthan gum (XG), a bacterial polysaccharide, was used as a thickening agent to modulate the viscosity of the formulations. The rheological properties of the PLA dispersions with different XG and PLA contents were studied in steady shear, amplitude sweep, and frequency sweep experiments. Under steady shear conditions, the viscosity of all the formulations showed a shear-thinning behavior similar to XG solutions in the whole investigated 1-1000 s-1 range, with values dependent on both PLA particles and XG concentrations. Amplitude and frequency sweep data revealed a weak-gel behavior except in the case of the most diluted sample, with moduli dependent on both PLA and XG contents. A unified scaling parameter was identified in the volume fraction (ϕ) of the PLA particles, calculated by considering the dependence of the continuous phase density on the XG concentration. Accordingly, a master curve at different volume fractions was built using the time-concentration-superposition approach. The master curve describes the rheological response of the system over a wider frequency window than the experimentally accessible one and reveals the presence of a superimposed β relaxation process in the high-frequency region.
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Affiliation(s)
- Sara Buoso
- Institute
of Organic Synthesis and Photoreactivity−Italian National Research
Council, via P. Gobetti,
101, Bologna 40129, Italy
| | - Giada Belletti
- Institute
of Organic Synthesis and Photoreactivity−Italian National Research
Council, via P. Gobetti,
101, Bologna 40129, Italy
- Department
of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, via. L. Borsari, 46, Ferrara 44121, Italy
| | - Daniele Ragno
- Department
of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, via. L. Borsari, 46, Ferrara 44121, Italy
| | - Valter Castelvetro
- Department
of Chemistry and Industrial Chemistry, University
of Pisa, via G. Moruzzi,
2, Pisa 56124, Italy
| | - Monica Bertoldo
- Institute
of Organic Synthesis and Photoreactivity−Italian National Research
Council, via P. Gobetti,
101, Bologna 40129, Italy
- Department
of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, via. L. Borsari, 46, Ferrara 44121, Italy
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32
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Behra JS, Thiriez A, Truzzolillo D, Ramos L, Cipelletti L. Controlling the volume fraction of glass-forming colloidal suspensions using thermosensitive host "mesogels". J Chem Phys 2022; 156:134901. [PMID: 35395903 DOI: 10.1063/5.0086822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The key parameter controlling the glass transition of colloidal suspensions is φ, the fraction of the sample volume occupied by the particles. Unfortunately, changing φ by varying an external parameter, e.g., temperature T as in molecular glass formers, is not possible, unless one uses thermosensitive colloidal particles, such as the popular poly(N-isopropylacrylamide) (PNiPAM) microgels. These, however, have several drawbacks, including high deformability, osmotic deswelling, and interpenetration, which complicate their use as a model system to study the colloidal glass transition. Here, we propose a new system consisting of a colloidal suspension of non-deformable spherical silica nanoparticles, in which PNiPAM hydrogel spheres of ∼100-200μm size are suspended. These non-colloidal "mesogels" allow for controlling the sample volume effectively available to the silica nanoparticles and hence their φ, thanks to the T-induced change in mesogels' volume. Using optical microscopy, we first show that the mesogels retain their ability to change size with T when suspended in Ludox suspensions, similarly as in water. We then show that their size is independent of the sample thermal history such that a well-defined, reversible relationship between T and φ may be established. Finally, we use space-resolved dynamic light scattering to demonstrate that, upon varying T, our system exhibits a broad range of dynamical behaviors across the glass transition and beyond, comparable with those exhibited by a series of distinct silica nanoparticle suspensions of various φ.
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Affiliation(s)
- J S Behra
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, Montpellier, France
| | - A Thiriez
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, Montpellier, France
| | - D Truzzolillo
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, Montpellier, France
| | - L Ramos
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, Montpellier, France
| | - L Cipelletti
- Laboratoire Charles Coulomb (L2C), Université Montpellier, CNRS, Montpellier, France
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33
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Shamana H, Dutcher JR. Transition in the Glassy Dynamics of Melts of Acid-Hydrolyzed Phytoglycogen Nanoparticles. Biomacromolecules 2022; 23:2040-2050. [PMID: 35390260 DOI: 10.1021/acs.biomac.2c00046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The deformability, responsiveness, and tunability of soft nanoparticles (NPs) offer unique opportunities to learn about their complex properties and the interactions between particles. In the present study, we provide new insights into the physical properties of phytoglycogen (PG) NPs, which are soft, compact particles with a dendritic architecture that are produced in the kernels of sweet corn. In particular, we study PG NPs modified using acid hydrolysis, which not only reduces their diameter but also alters their stiffness, internal structure, and the interactions between particles in aqueous dispersions. We used steady shear rheology to determine the dependence of the relative zero-shear viscosity ηr of aqueous dispersions of acid-hydrolyzed PG NPs on the effective volume fraction ϕeff, which indicated a reduction in stiffness of the particles relative to that of native PG NPs. We quantified this difference by analyzing the nature of the colloidal glasses formed at high ϕeff. We measured a smaller value of the fragility index m for acid-hydrolyzed PG NP glasses than that for native PG NP glasses, indicating that acid-hydrolyzed PG NPs form stronger glasses and are therefore softer than native PG NPs. Unlike the native PG NPs, we observed a distinctive change in the character of the glass transition of the acid-hydrolyzed PG NPs as ϕeff was increased above ϕeff∼1: a crossover in the dependence of ηr on ϕeff from Vogel-Fulcher-Tammann behavior to a more gradual, Arrhenius-like behavior. By expressing the steady shear and oscillatory rheology data in terms of generalized Péclet numbers, we obtained collapse of the data onto master curves. We interpret this result in terms of the acid-hydrolyzed PG NPs predominantly interpenetrating neighboring particles at large ϕeff, for which fluctuations of the outer chains enhance the mobility of the particles and make α-relaxation times τα experimentally accessible.
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Affiliation(s)
- Hurmiz Shamana
- Department of Physics, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - John R Dutcher
- Department of Physics, University of Guelph, Guelph, ON N1G 2W1, Canada
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34
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Echeverría C, Mijangos C. Rheology Applied to Microgels: Brief (Revision of the) State of the Art. Polymers (Basel) 2022; 14:1279. [PMID: 35406152 PMCID: PMC9003433 DOI: 10.3390/polym14071279] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/18/2022] [Accepted: 03/18/2022] [Indexed: 12/10/2022] Open
Abstract
The ability of polymer microgels to rapidly respond to external stimuli is of great interest in sensors, lubricants, and biomedical applications, among others. In most of their uses, microgels are subjected to shear, deformation, and compression forces or a combination of them, leading to variations in their rheological properties. This review article mainly refers to the rheology of microgels, from the hard sphere versus soft particles' model. It clearly describes the scaling theories and fractal structure formation, in particular, the Shih et al. and Wu and Morbidelli models as a tool to determine the interactions among microgel particles and, thus, the viscoelastic properties. Additionally, the most recent advances on the characterization of microgels' single-particle interactions are also described. The review starts with the definition of microgels, and a brief introduction addresses the preparation and applications of microgels and hybrid microgels.
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Affiliation(s)
- Coro Echeverría
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain;
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35
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Lapkin D, Mukharamova N, Assalauova D, Dubinina S, Stellhorn J, Westermeier F, Lazarev S, Sprung M, Karg M, Vartanyants IA, Meijer JM. In situ characterization of crystallization and melting of soft, thermoresponsive microgels by small-angle X-ray scattering. SOFT MATTER 2022; 18:1591-1602. [PMID: 34994372 PMCID: PMC8864529 DOI: 10.1039/d1sm01537k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/16/2021] [Indexed: 05/05/2023]
Abstract
Depending on the volume fraction and interparticle interactions, colloidal suspensions can form different phases, ranging from fluids, crystals, and glasses to gels. For soft microgels that are made from thermoresponsive polymers, the volume fraction can be tuned by temperature, making them excellent systems to experimentally study phase transitions in dense colloidal suspensions. However, investigations of phase transitions at high particle concentration and across the volume phase transition temperature in particular, are challenging due to the deformability and possibility for interpenetration between microgels. Here, we investigate the dense phases of composite core-shell microgels that have a small gold core and a thermoresponsive microgel shell. Employing Ultra Small-Angle X-ray Scattering, we make use of the strong scattering signal from the gold cores with respect to the almost negligible signal from the shells. By changing the temperature we study the freezing and melting transitions of the system in situ. Using Bragg peak analysis and the Williamson-Hall method, we characterize the phase transitions in detail. We show that the system crystallizes into an rhcp structure with different degrees of in-plane and out-of-plane stacking disorder that increase upon particle swelling. We further find that the melting process is distinctly different, where the system separates into two different crystal phases with different melting temperatures and interparticle interactions.
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Affiliation(s)
- Dmitry Lapkin
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | | | - Dameli Assalauova
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Svetlana Dubinina
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- Moscow Institute of Physics and Technology (State University), Institutskiy Per. 9, 141701 Dolgoprudny, Moscow Region, Russia
| | - Jens Stellhorn
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- Department of Applied Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashihiroshima 739-8527, Japan
| | - Fabian Westermeier
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Sergey Lazarev
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- National Research Tomsk Polytechnic University (TPU), Lenin Avenue 30, 634050 Tomsk, Russia
| | - Michael Sprung
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
| | - Matthias Karg
- Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Ivan A Vartanyants
- Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe shosse 31, 115409 Moscow, Russia.
| | - Janne-Mieke Meijer
- Department of Applied Physics and Institute for Complex Molecular Systems, Eindhoven University of Technology, Groene Loper 19, 5612 AP Eindhoven, The Netherlands.
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36
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Zhu Y, Luo J, Zou Q, Ouyang X, Ruan Y, Liu Y, Liu G. Glassy feature in melts of 3-dimensional architectured polymer blends. POLYMER 2022. [DOI: 10.1016/j.polymer.2021.124336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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37
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Jiang H, Zhang S, Sun G, Li Y, Guan X, Yang C, Ngai T. Engineering hybrid microgels as particulate emulsifiers for reversible Pickering emulsions. Chem Sci 2021; 13:39-43. [PMID: 35059148 PMCID: PMC8694365 DOI: 10.1039/d1sc05398a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 10/29/2021] [Indexed: 12/24/2022] Open
Abstract
Thermo-responsive microgels are unique stabilizers for stimuli-sensitive Pickering emulsions that can be switched between the state of emulsification and demulsification by changing the temperature. However, directly temperature-triggering the phase inversion of microgel-stabilized emulsions remains a great challenge. Here, a hybrid poly(N-isopropylacrylamide)-based microgel has now been successfully fabricated with tunable wettability from hydrophilicity to hydrophobicity in a controlled manner. Engineered microgels are synthesized from an inverse emulsion stabilized with hydrophobic silica nanoparticles, and the swelling-induced feature can make the resultant microgel behave like either hydrophilic or hydrophobic colloids. Remarkably, the phase inversion of such microgel-stabilized Pickering emulsions can be in situ regulated by temperature change. Moreover, the engineered microgels were capable of stabilizing water-in-oil Pickering emulsions and encapsulation of enzymes for interfacial bio-catalysis, as well as rapid cargo release triggered by phase inversion.
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Affiliation(s)
- Hang Jiang
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education & School of Chemical and Material Engineering, Jiangnan University Wuxi 214122 P. R. China
| | - Shengwei Zhang
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education & School of Chemical and Material Engineering, Jiangnan University Wuxi 214122 P. R. China
| | - Guanqing Sun
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education & School of Chemical and Material Engineering, Jiangnan University Wuxi 214122 P. R. China
| | - Yunxing Li
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education & School of Chemical and Material Engineering, Jiangnan University Wuxi 214122 P. R. China
| | - Xin Guan
- Department of Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong P. R. China
| | - Cheng Yang
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education & School of Chemical and Material Engineering, Jiangnan University Wuxi 214122 P. R. China
| | - To Ngai
- The Key Laboratory of Synthetic and Biological Colloids, Ministry of Education & School of Chemical and Material Engineering, Jiangnan University Wuxi 214122 P. R. China
- Department of Chemistry, The Chinese University of Hong Kong Shatin, N. T. Hong Kong P. R. China
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38
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Atia L, Fredberg JJ, Gov NS, Pegoraro AF. Are cell jamming and unjamming essential in tissue development? Cells Dev 2021; 168:203727. [PMID: 34363993 PMCID: PMC8935248 DOI: 10.1016/j.cdev.2021.203727] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/07/2021] [Accepted: 07/28/2021] [Indexed: 11/25/2022]
Abstract
The last decade has seen a surge of evidence supporting the existence of the transition of the multicellular tissue from a collective material phase that is regarded as being jammed to a collective material phase that is regarded as being unjammed. The jammed phase is solid-like and effectively 'frozen', and therefore is associated with tissue homeostasis, rigidity, and mechanical stability. The unjammed phase, by contrast, is fluid-like and effectively 'melted', and therefore is associated with mechanical fluidity, plasticity and malleability that are required in dynamic multicellular processes that sculpt organ microstructure. Such multicellular sculpturing, for example, occurs during embryogenesis, growth and remodeling. Although unjamming and jamming events in the multicellular collective are reminiscent of those that occur in the inert granular collective, such as grain in a hopper that can flow or clog, the analogy is instructive but limited, and the implications for cell biology remain unclear. Here we ask, are the cellular jamming transition and its inverse --the unjamming transition-- mere epiphenomena? That is, are they dispensable downstream events that accompany but neither cause nor quench these core multicellular processes? Drawing from selected examples in developmental biology, here we suggest the hypothesis that, to the contrary, the graded departure from a jammed phase enables controlled degrees of malleability as might be required in developmental dynamics. We further suggest that the coordinated approach to a jammed phase progressively slows those dynamics and ultimately enables long-term mechanical stability as might be required in the mature homeostatic multicellular tissue.
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Affiliation(s)
- Lior Atia
- Department of Mechanical Engineering, Ben Gurion University, Beer-Sheva, Israel
| | - Jeffrey J Fredberg
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Nir S Gov
- Department of Chemical and Biological Physics, Weizmann Institute, Israel
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39
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Debets VE, Luo C, Ciarella S, Janssen LMC. Generalized mode-coupling theory for mixtures of Brownian particles. Phys Rev E 2021; 104:065302. [PMID: 35030832 DOI: 10.1103/physreve.104.065302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 11/29/2021] [Indexed: 11/07/2022]
Abstract
Generalized mode-coupling theory (GMCT) has recently emerged as a promising first-principles theory to study the poorly understood dynamics of glass-forming materials. Formulated as a hierarchical extension of standard mode-coupling theory (MCT), it is able to systematically improve its predictions by including the exact dynamics of higher-order correlation functions into its hierarchy. However, in contrast to Newtonian dynamics, a fully generalized version of the theory based on Brownian dynamics is still lacking. To close this gap, we provide a detailed derivation of GMCT for colloidal mixtures obeying a many-body Smoluchowski equation. We demonstrate that a hierarchy of coupled equations can again be established and show that these, consistent with standard MCT, are identical to the ones obtained from Newtonian GMCT when taking the overdamped limit. Consequently, the nontrivial similarity between Brownian and Newtonian MCT is maintained for our multicomponent GMCT. As a proof of principle, we also solve the generalized mode-coupling equations for the binary Kob-Andersen Lennard-Jones mixture undergoing Brownian dynamics and confirm the improved predictive power of the theory upon using more levels of the GMCT hierarchy of equations.
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Affiliation(s)
- Vincent E Debets
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Chengjie Luo
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Simone Ciarella
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.,Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, F-75005 Paris, France
| | - Liesbeth M C Janssen
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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40
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Luo J, Zhu Y, Ruan Y, Wu W, Ouyang X, Du Z, Liu G. Diameter and Elasticity Governing the Relaxation of Soft-Nanoparticle Melts. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jintian Luo
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yihui Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yifu Ruan
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
| | - Weiwei Wu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
| | - Xikai Ouyang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
| | - Zhukang Du
- South China Advanced Institute for Soft Matter Science and Technology, School of Molecular Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - GengXin Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620, China
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41
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Frenzel L, Dartsch M, Balaguer GM, Westermeier F, Grübel G, Lehmkühler F. Glass-liquid and glass-gel transitions of soft-shell particles. Phys Rev E 2021; 104:L012602. [PMID: 34412357 DOI: 10.1103/physreve.104.l012602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/23/2021] [Indexed: 12/12/2022]
Abstract
We study the structure and dynamics of colloidal particles with a spherical hard core and a thermo-responsive soft shell over the whole phase diagram by means of small-angle x-ray scattering and x-ray photon correlation spectroscopy. By changing the effective volume fraction by temperature and particle concentration, liquid, repulsive glass. and attractive gel phases are observed. The dynamics slow down with increasing volume fraction in the liquid phase and reflect a Vogel-Fulcher-Tamann behavior known for fragile glass formers. We find a liquid-glass transition above 50 vol.% that is independent of the particles' concentration and temperature. In an overpacked state at effective volume fractions above 1, the dispersion does not show a liquid phase but undergoes a gel-glass transition at an effective volume fraction of 34 vol.%. At the same concentration, extrema of subdiffusive dynamics are found in the liquid phase at lower weight fractions. We interpret this as dynamic precursors of the glass-gel transition.
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Affiliation(s)
- Lara Frenzel
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Michael Dartsch
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | | | - Fabian Westermeier
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Gerhard Grübel
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Felix Lehmkühler
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany
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42
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Li Q, Peng X, Chen D, McKenna GB. Softness mapping of the concentration dependence of the dynamics in model soft colloidal systems. J Colloid Interface Sci 2021; 605:398-409. [PMID: 34332413 DOI: 10.1016/j.jcis.2021.07.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 07/06/2021] [Accepted: 07/16/2021] [Indexed: 11/28/2022]
Abstract
The dynamics of a series of soft colloids comprised of polystyrene cores with poly(N-isopropylacrylamide) (PNIPAM) coronas was investigated by diffusing wave spectroscopy (DWS). The modulus of the coronas was varied by changing the cross-link density and we were able to interpret the results within a hard-soft mapping framework. The soft, swellable particle properties were modeled using an extended Flory-Rehner theory and a Hertzian pair potential. Following volume fraction jumps, softness effects on the concentration dependence of dynamics were determined, with a 'soft colloids make strong glass-forming liquid'-type of behavior observed close to the nominal glass transition volume fraction, φg. Such behavior from the current systems cannot be fully explained by the osmotic deswelling model alone. However, inspired by the soft-hard mapping from Schmiedeberg et al, [Europhys. Lett. 2011, 96(3), 36010] we estimated effective hard-sphere diameters and achieved a successful mapping of the α-relaxation times to a master curve below φg. Above φg, the curves no longer collapse but show strong deviations from a Vogel-Fulcher type of divergence onto soft jamming plateaux. Our results provide evidence that osmotic deswelling itself cannot fully explain the observed dynamics. Softness also plays an important role in the dynamics of soft, concentrated colloids.
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Affiliation(s)
- Qi Li
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Xiaoguang Peng
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Dongjie Chen
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Gregory B McKenna
- Department of Chemical Engineering, Texas Tech University, Lubbock, TX 79409, United States.
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43
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Roullet M, Clegg PS, Frith WJ. Rheology of protein-stabilised emulsion gels envisioned as composite networks. 2 - Framework for the study of emulsion gels. J Colloid Interface Sci 2021; 594:92-100. [PMID: 33756372 DOI: 10.1016/j.jcis.2021.02.088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 11/30/2022]
Abstract
HYPOTHESIS The aggregation of protein-stabilised emulsions leads to the formation of emulsion gels. These soft solids may be envisioned as droplet-filled matrices. Here however, it is assumed that protein-coated sub-micron droplets contribute to the network formation in a similar way to proteins. Emulsion gels are thus envisioned as composite networks made of proteins and droplets. EXPERIMENTS Emulsion gels with a wide range of composition are prepared and their viscoelasticity and frequency dependence are measured. Their rheological behaviours are then analysed and compared with the properties of pure gels presented in the first part of this study. FINDINGS When the concentrations of droplets and protein are expressed as an effective volume fraction, the rheological behaviour of emulsion gels is shown to depend mostly on the total volume fraction, while the composition of the gel indicates its level of similarity with either pure droplet gels or pure protein gels. These results help to form an emerging picture of protein-stabilised emulsion gel as intermediate between droplet and protein gels. This justifies a posteriori the hypothesis of composite networks, and opens the road for the formulation of emulsion gels with fine-tuned rheology.
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Affiliation(s)
- Marion Roullet
- Unilever R& D Colworth, Sharnbrook, Bedford MK44 1LQ, UK; School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK.
| | - Paul S Clegg
- School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, Edinburgh EH9 3FD, UK.
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44
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Lauersdorf N, Kolb T, Moradi M, Nazockdast E, Klotsa D. Phase behavior and surface tension of soft active Brownian particles. SOFT MATTER 2021; 17:6337-6351. [PMID: 34128024 DOI: 10.1039/d1sm00350j] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We study quasi two-dimensional, monodisperse systems of active Brownian particles (ABPs) for a range of activities, stiffnesses, and densities. We develop a microscopic, analytical method for predicting the dense phase structure formed after motility-induced phase separation (MIPS) has occurred, including the dense cluster's area fraction, interparticle pressure, and radius. Our predictions are in good agreement with our Brownian dynamics simulations. We, then, derive a continuum model to investigate the relationship between the predicted interparticle pressure, the swim pressure, and the macroscopic pressure in the momentum equation. We find that formulating the point-wise macroscopic pressure as the interparticle pressure and modeling the particle activity through a spatially variant body force - as opposed to a volume-averaged swim pressure - results in consistent predictions of pressure in both the continuum model and the microscopic theory. This formulation of pressure also results in nearly zero surface tension for the phase separated domains, irrespective of activity, stiffness, and area fraction. Furthermore, using Brownian dynamics simulations and our continuum model, we showed that both the interface width and surface tension, are intrinsic characteristics of the system. On the other hand, if we were to exclude the body force induced by activity, we find that the resulting surface tension values are linearly dependent on the size of the simulation, in contrast to the statistical mechanical definition of surface tension.
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Affiliation(s)
- Nicholas Lauersdorf
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, USA.
| | - Thomas Kolb
- Department of Chemistry, University of North Carolina at Chapel Hill, USA
| | - Moslem Moradi
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, USA.
| | - Ehssan Nazockdast
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, USA.
| | - Daphne Klotsa
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, USA.
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45
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From Femtoseconds to Hours—Measuring Dynamics over 18 Orders of Magnitude with Coherent X-rays. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11136179] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources. In this article, we will introduce the XPCS concepts and review the latest developments of XPCS with special attention on the extension of accessible time scales to sub-μs and the application of XPCS at FELs. Furthermore, we will discuss future opportunities of XPCS and the related technique X-ray speckle visibility spectroscopy (XSVS) at new X-ray sources. Due to its particular signal-to-noise ratio, the time scales accessible by XPCS scale with the square of the coherent flux, allowing to dramatically extend its applications. This will soon enable studies over more than 18 orders of magnitude in time by XPCS and XSVS.
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Scotti A. Characterization of the volume fraction of soft deformable microgels by means of small-angle neutron scattering with contrast variation. SOFT MATTER 2021; 17:5548-5559. [PMID: 33978056 DOI: 10.1039/d1sm00277e] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The volume occupied by colloids in a suspension - namely the volume fraction - is the thermodynamic variable that determines the phase behavior of these systems. While for hard incompressible spheres this quantity is well defined, for soft compressible colloids such as microgels - polymeric crosslinked networks swollen in a good solvent - the determination of the real volume occupied by these particles in solution is particularly challenging. This fact depends on two aspects: first the surface and, therefore, the volume of the microgels is hard to define properly given their external fuzziness; second, microgels can osmotically deswell, deform or interpenetrate their neighbors, i.e. change their shape and size depending on the solution concentration. Here, the form factors of few hydrogenated microgels embedded in a matrix of deuterated but otherwise identical microgels are measured using small-angle neutron scattering with contrast variation. From the analysis of the scattering data, the variation of the volume of the microgels as a function of concentration is obtained and used to calculate the real microgel volume fraction in solution. Soft neutral microgels are shown to facet already at low concentrations while in contrast, harder microgels maintain their shape and change their volume.
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Affiliation(s)
- Andrea Scotti
- Institute of Physical Chemistry, RWTH Aachen University, 52056, Aachen, Germany.
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Affiliation(s)
- Yuichiro Nishizawa
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Kenshiro Honda
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
| | - Daisuke Suzuki
- Graduate School of Textile Science & Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
- Research Initiative for Supra-Materials, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, 3-15-1 Tokida, Ueda, Nagano 386-8567, Japan
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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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49
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Higham JE, Shahnam M, Vaidheeswaran A. Anomalous diffusion in a bench-scale pulsed fluidized bed. Phys Rev E 2021; 103:043103. [PMID: 34005865 DOI: 10.1103/physreve.103.043103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/23/2021] [Indexed: 11/07/2022]
Abstract
We present our analysis on microrheology of a bench-scale pulsed fluidized bed, which represents a weakly confined system. Nonlinear gas-particle and particle-particle interactions resulting from pulsed flow are associated with harmonic and subharmonic modes. While periodic structured bubble patterns are observed at the mesoscale, particle-scale measurements reveal anomalous diffusion in the driven granular medium. We use single-particle tracks to analyze ergodicity and ageing properties at two pulsing frequencies having remarkably different mesoscale features. The scaling of ensemble-averaged mean-squared displacement is not unique. The distribution of time-averaged mean-squared displacements is non-Gaussian, asymmetric, and has a finite trivial contribution from particles in crowded quasistatic surroundings. Results indicate weak ergodicity breaking, which along with ageing characterizes the nonstationary and out-of-equilibrium dynamics.
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Affiliation(s)
- Jonathan E Higham
- University of Liverpool, School of Environmental Sciences, Department of Geography and Planning, Roxby Building, Liverpool, L69 7ZT, United Kingdom
| | - Mehrdad Shahnam
- National Energy Technology Laboratory 3610 Collins Ferry Road, Morgantown, West Virginia 26505, USA
| | - Avinash Vaidheeswaran
- National Energy Technology Laboratory 3610 Collins Ferry Road, Morgantown, West Virginia 26505, USA
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50
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Dhand AP, Poling-Skutvik R, Osuji CO. Simple production of cellulose nanofibril microcapsules and the rheology of their suspensions. SOFT MATTER 2021; 17:4517-4524. [PMID: 33710229 DOI: 10.1039/d1sm00225b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microcapsules are commonly used in applications ranging from therapeutics to personal care products due to their ability to deliver encapsulated species through their porous shells. Here, we demonstrate a simple and scalable approach to fabricate microcapsules with porous shells by interfacial complexation of cellulose nanofibrils and oleylamine, and investigate the rheological properties of suspensions of the resulting microcapsules. The suspensions of neat capsules are viscous liquids whose viscosity increases with volume fraction according to a modified Kreiger-Dougherty relation with a maximum packing fraction of 0.74 and an intrinsic viscosity of 4.1. When polyacrylic acid (PAA) is added to the internal phase of the microcapsules, however, the suspensions become elastic and display yield stresses with power-law dependencies on capsule volume fraction and PAA concentration. The elasticity appears to originate from associative microcapsule interactions induced by PAA that is contained within and incorporated into the microcapsule shell. These results demonstrate that it is possible to tune the rheological properties of microcapsule suspensions by changing only the composition of the internal phase, thereby providing a novel method to tailor complex fluid rheology.
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Affiliation(s)
- Abhishek P Dhand
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Ryan Poling-Skutvik
- Department of Chemical Engineering, University of Rhode Island, Kingston, RI 02881, USA.
| | - Chinedum O Osuji
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
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