1
|
Janzen G, Matoz-Fernandez DA. Density and inertia effects on two-dimensional active semiflexible filament suspensions. SOFT MATTER 2024; 20:6618-6626. [PMID: 39108173 DOI: 10.1039/d4sm00572d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
We examine the influence of density on the transition between chain and spiral structures in planar assemblies of active semiflexible filaments, utilizing detailed numerical simulations. We focus on how increased density, and higher Péclet numbers, affect the activity-induced transition spiral state in a semiflexible, self-avoiding active chain. Our findings show that increasing the density causes the spiral state to break up, reverting to a motile chain-like shape. This results in a density-dependent reentrant phase transition from spirals back to open chains. We attribute this phenomenon to an inertial effect observed at the single polymer level, where increased persistence length due to inertia has been shown in recent three-dimensional studies to cause polymers to open up. Our two-dimensional simulations further reveal that a reduction in the damping coefficient leads to partial unwinding of the spirals, forming longer arms. In suspension, interactions among these extended arms can trigger a complete unwinding of the spirals, driven by the combined effects of density and inertia.
Collapse
Affiliation(s)
- Giulia Janzen
- Department of Theoretical Physics, Complutense University of Madrid, 28040 Madrid, Spain.
| | - D A Matoz-Fernandez
- Department of Theoretical Physics, Complutense University of Madrid, 28040 Madrid, Spain.
| |
Collapse
|
2
|
Siddiqui J, Codina J, Pagonabarraga I, Dobnikar J. The impact of viscosity asymmetry on phase separating binary mixtures with suspended colloids. SOFT MATTER 2024; 20:5564-5571. [PMID: 38963425 DOI: 10.1039/d3sm00955f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The introduction of neutrally wetting colloidal particles into coarsening binary fluids is known to arrest the dynamics of the phase separation, as the colloids tend to be captured by the growing interfaces to reduce the free energy of the system. This phenomenon has often been studied in systems with symmetric fluid viscosities. In this study, we investigate the behavior of colloidal particles introduced into asymmetric binary fluids with a viscosity contrast. Our results show that due to the broken symmetry the colloidal particles more easily escape from the interface towards the more viscous fluid, which reduces the lifetime of the jammed phase. Moreover, the presence of colloidal particles near the interfaces promotes the formation of micro-droplets with typical sizes comparable to the colloids.
Collapse
Affiliation(s)
- Javeria Siddiqui
- CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
| | - Joan Codina
- CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- Wenzhou Institute of the University of Chinese Academy of Sciences, Wenzhou, Zhejiang, China.
| | - Ignacio Pagonabarraga
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona, Spain.
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
| | - Jure Dobnikar
- CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| |
Collapse
|
3
|
Thijssen K, Liverpool TB, Royall CP, Jack RL. Necking and failure of a particulate gel strand: signatures of yielding on different length scales. SOFT MATTER 2023; 19:7412-7428. [PMID: 37743690 DOI: 10.1039/d3sm00681f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
"Sticky" spheres with a short-ranged attraction are a basic model of a wide range of materials from the atomic to the granular length scale. Among the complex phenomena exhibited by sticky spheres is the formation of far-from-equilibrium dynamically arrested networks which comprise "strands" of densely packed particles. The aging and failure of such gels under load is a remarkably challenging problem, given the simplicity of the model, as it involves multiple length- and time-scales, making a single approach ineffective. Here we tackle this challenge by addressing the failure of a single strand with a combination of methods. We study the mechanical response of a single strand of a model gel-former to deformation, both numerically and analytically. Under elongation, the strand breaks by a necking instability. We analyse this behaviour at three different length scales: a rheological continuum model of the whole strand; a microscopic analysis of the particle structure and dynamics; and the local stress tensor. Combining these different approaches gives a coherent picture of the necking and failure. The strand has an amorphous local structure and has large residual stresses from its initialisation. We find that neck formation is associated with increased plastic flow, a reduction in the stability of the local structure, and a reduction in the residual stresses; this indicates that the system loses its solid character and starts to behave more like a viscous fluid. These results will inform the development of more detailed models that incorporate the heterogeneous network structure of particulate gels.
Collapse
Affiliation(s)
- Kristian Thijssen
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen 2100, Denmark
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | | | - C Patrick Royall
- H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, UK
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
- Gulliver UMR CNRS 7083, ESPCI Paris, Université PSL, 75005 Paris, France
| | - Robert L Jack
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
- DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK.
| |
Collapse
|
4
|
Yuan J, Tateno M, Tanaka H. Mechanical Slowing Down of Network-Forming Phase Separation of Polymer Solutions. ACS NANO 2023; 17:18025-18036. [PMID: 37675940 DOI: 10.1021/acsnano.3c04657] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Phase separation is a fundamental phenomenon leading to spatially heterogeneous material distribution, which is critical in nature, biology, material science, and industry. In ordinary phase separation, the minority phase always forms droplets. Contrary to this common belief, even the minority phase can form a network structure in viscoelastic phase separation (VPS). VPS can occur in any mixture with significant mobility differences between their components and is highly relevant to soft matter and biomatter. In contrast to classical phase separation, experiments have shown that VPS in polymer solutions lacks self-similar coarsening, resulting in the absence of a domain-coarsening scaling law. However, the underlying microscopic mechanism of this behavior remains unknown. To this end, we perform fluid particle dynamics simulations of bead-spring polymers, incorporating many-body hydrodynamic interactions between polymers through a solvent. We discover that polymers in the dense-network-forming phase are stretched and store elastic energy when the deformation speed exceeds the polymer dynamics. This self-generated viscoelastic stress mechanically interferes with phase separation and slows its dynamics, disrupting self-similar growth. We also highlight the essential role of many-body hydrodynamic interactions in VPS. The implications of our findings may hold importance in areas such as biological phase separation, porous material formation, and other fields where network structures play a pivotal role.
Collapse
Affiliation(s)
- Jiaxing Yuan
- Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Michio Tateno
- Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hajime Tanaka
- Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| |
Collapse
|
5
|
Herrero C, Scalliet C, Ediger MD, Berthier L. Two-step devitrification of ultrastable glasses. Proc Natl Acad Sci U S A 2023; 120:e2220824120. [PMID: 37040403 PMCID: PMC10120036 DOI: 10.1073/pnas.2220824120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 03/11/2023] [Indexed: 04/12/2023] Open
Abstract
The discovery of ultrastable glasses raises novel challenges about glassy systems. Recent experiments studied the macroscopic devitrification of ultrastable glasses into liquids upon heating but lacked microscopic resolution. We use molecular dynamics simulations to analyze the kinetics of this transformation. In the most stable systems, devitrification occurs after a very large time, but the liquid emerges in two steps. At short times, we observe the rare nucleation and slow growth of isolated droplets containing a liquid maintained under pressure by the rigidity of the surrounding glass. At large times, pressure is released after the droplets coalesce into large domains, which accelerates devitrification. This two-step process produces pronounced deviations from the classical Avrami kinetics and explains the emergence of a giant lengthscale characterizing the devitrification of bulk ultrastable glasses. Our study elucidates the nonequilibrium kinetics of glasses following a large temperature jump, which differs from both equilibrium relaxation and aging dynamics, and will guide future experimental studies.
Collapse
Affiliation(s)
- Cecilia Herrero
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier34095, France
| | - Camille Scalliet
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, CambridgeCB3 0WA, United Kingdom
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin–Madison, Madison, WI53706
| | - Ludovic Berthier
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, CNRS, Montpellier34095, France
- Yusuf Hamied Department of Chemistry, University of Cambridge, CambridgeCB2 1EW, United Kingdom
| |
Collapse
|
6
|
Fadda F, Matoz-Fernandez DA, van Roij R, Jabbari-Farouji S. The interplay between chemo-phoretic interactions and crowding in active colloids. SOFT MATTER 2023; 19:2297-2310. [PMID: 36857712 PMCID: PMC10053041 DOI: 10.1039/d2sm00957a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Many motile microorganisms communicate with each other and their environments via chemical signaling which leads to long-range interactions mediated by self-generated chemical gradients. However, consequences of the interplay between crowding and chemotactic interactions on their collective behavior remain poorly understood. In this work, we use Brownian dynamics simulations to investigate the effect of packing fraction on the formation of non-equilibrium structures in a monolayer of diffusiophoretic self-propelled colloids as a model for chemically active particles. Focusing on the case when a chemical field induces attractive positional and repulsive orientational interactions, we explore dynamical steady-states of active colloids of varying packing fractions and degrees of motility. In addition to collapsed, active gas, and dynamical clustering steady-states reported earlier for low packing fractions, a new phase-separated state emerges. The phase separation results from a competition between long-range diffusiophoretic interactions and motility and is observed at moderate activities and a wide range of packing fractions. Our analysis suggests that the fraction of particles in the largest cluster is a suitable order parameter for capturing the transition from an active gas and dynamical clustering states to a phase-separated state.
Collapse
Affiliation(s)
- Federico Fadda
- Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
| | - Daniel A Matoz-Fernandez
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland.
| | - René van Roij
- Institute for Theoretical Physics, Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, Utrecht 3584 CC, The Netherlands.
| | - Sara Jabbari-Farouji
- Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands.
| |
Collapse
|
7
|
Structure and Mechanical Properties of a Porous Polymer Material via Molecular Dynamics Simulations. Polymers (Basel) 2023; 15:polym15020358. [PMID: 36679239 PMCID: PMC9867006 DOI: 10.3390/polym15020358] [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: 12/02/2022] [Revised: 12/29/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023] Open
Abstract
We characterize, using molecular dynamics simulations, the structure and mechanical response of a porous glassy system, obtained via arrested phase separation of a model polymer melt. In the absence of external driving, coarsening dynamics, with power-law time dependence, controls the slow structural evolution, in agreement with what was reported for other phase-separating systems. The mechanical response was investigated in athermal quasi-static conditions. In the elastic regime, low values for the Young's and shear modulus were found, as compared to dense glassy systems, which originate from the porous structure. For large deformations, stress-strain curves show a highly intermittent behavior, with avalanches of plastic events. The stress-drop distribution is characterized exploring a large set of parameters. This work goes beyond the previous numerical studies on atomic porous materials, as it first examines the role of chain connectivity in the elastic and plastic responses of materials of this type.
Collapse
|
8
|
Shimada M, Oyama N. Gas-liquid phase separation at zero temperature: mechanical interpretation and implications for gelation. SOFT MATTER 2022; 18:8406-8417. [PMID: 36285640 DOI: 10.1039/d2sm00628f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The relationship between glasses and gels has been intensely debated for decades; however, the transition between these two phases remains elusive. To investigate a gel formation process in the zero-temperature limit and its relation to the glass phase, we conducted numerical experiments on athermal quasistatic decompression. During decompression, the system experiences a cavitation event similar to phase separation and this is a gelation process at zero temperature. A normal mode analysis revealed that the phase separation is signaled by the vanishing of the lowest eigenenergy, similar to plastic events of glasses under shear. One primary difference from the shear-induced plasticity is that the vanishing mode experiences a qualitative change in its spatial energy distribution at the phase separation point. These findings enable us to define the glass-gel phase boundary based on mechanics.
Collapse
Affiliation(s)
- Masanari Shimada
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
- Department of Physics, Toronto Metropolitan University, M5B 2K3, Toronto, Canada.
| | - Norihiro Oyama
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
- Mathematics for Advanced Materials-OIL, AIST, Sendai 980-8577, Japan
| |
Collapse
|
9
|
Chandrasekaran A, Giniger E, Papoian GA. Nucleation causes an actin network to fragment into multiple high-density domains. Biophys J 2022; 121:3200-3212. [PMID: 35927959 PMCID: PMC9463697 DOI: 10.1016/j.bpj.2022.07.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/20/2021] [Accepted: 07/28/2022] [Indexed: 11/02/2022] Open
Abstract
Actin networks rely on nucleation mechanisms to generate new filaments because spontaneous nucleation is kinetically disfavored. Branching nucleation of actin filaments by actin-related protein (Arp2/3), in particular, is critical for actin self-organization. In this study, we use the simulation platform for active matter MEDYAN to generate 2000 s long stochastic trajectories of actin networks, under varying Arp2/3 concentrations, in reaction volumes of biologically meaningful size (>20 μm3). We find that the dynamics of Arp2/3 increase the abundance of short filaments and increases network treadmilling rate. By analyzing the density fields of F-actin, we find that at low Arp2/3 concentrations, F-actin is organized into a single connected and contractile domain, while at elevated Arp2/3 levels (10 nM and above), such high-density actin domains fragment into smaller domains spanning a wide range of volumes. These fragmented domains are extremely dynamic, continuously merging and splitting, owing to the high treadmilling rate of the underlying actin network. Treating the domain dynamics as a drift-diffusion process, we find that the fragmented state is stochastically favored, and the network state slowly drifts toward the fragmented state with considerable diffusion (variability) in the number of domains. We suggest that tuning the Arp2/3 concentration enables cells to transition from a globally coherent cytoskeleton, whose response involves the entire cytoplasmic network, to a fragmented cytoskeleton, where domains can respond independently to locally varying signals.
Collapse
Affiliation(s)
- Aravind Chandrasekaran
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland; National Institutes of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Edward Giniger
- National Institutes of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland
| | - Garegin A Papoian
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland; Institute for Physical Science and Technology, University of Maryland, College Park, Maryland.
| |
Collapse
|
10
|
Moron M, Al-Masoodi A, Lovato C, Reiser M, Randolph L, Surmeier G, Bolle J, Westermeier F, Sprung M, Winter R, Paulus M, Gutt C. Gelation Dynamics upon Pressure-Induced Liquid-Liquid Phase Separation in a Water-Lysozyme Solution. J Phys Chem B 2022; 126:4160-4167. [PMID: 35594491 DOI: 10.1021/acs.jpcb.2c01947] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Employing X-ray photon correlation spectroscopy, we measure the kinetics and dynamics of a pressure-induced liquid-liquid phase separation (LLPS) in a water-lysozyme solution. Scattering invariants and kinetic information provide evidence that the system reaches the phase boundary upon pressure-induced LLPS with no sign of arrest. The coarsening slows down with increasing quench depths. The g2 functions display a two-step decay with a gradually increasing nonergodicity parameter typical for gelation. We observe fast superdiffusive (γ ≥ 3/2) and slow subdiffusive (γ < 0.6) motion associated with fast viscoelastic fluctuations of the network and a slow viscous coarsening process, respectively. The dynamics age linearly with time τ ∝ tw, and we observe the onset of viscoelastic relaxation for deeper quenches. Our results suggest that the protein solution gels upon reaching the phase boundary.
Collapse
Affiliation(s)
- M Moron
- Fakultät Physik/DELTA, TU Dortmund, 44221 Dortmund, Germany
| | - A Al-Masoodi
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - C Lovato
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - M Reiser
- Department of Physics, Stockholm University, 10691 Stockholm, Sweden
| | - L Randolph
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - G Surmeier
- Fakultät Physik/DELTA, TU Dortmund, 44221 Dortmund, Germany
| | - J Bolle
- Fakultät Physik/DELTA, TU Dortmund, 44221 Dortmund, Germany
| | - F Westermeier
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - M Sprung
- Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany
| | - R Winter
- Fakultät Chemie und Chemische Biologie, Physikalische Chemie, TU Dortmund, 44227 Dortmund, Germany
| | - M Paulus
- Fakultät Physik/DELTA, TU Dortmund, 44221 Dortmund, Germany
| | - C Gutt
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| |
Collapse
|
11
|
Mizuno H, Hachiya M, Ikeda A. Phonon transport properties of particulate physical gels. J Chem Phys 2022; 156:204505. [DOI: 10.1063/5.0090233] [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
Particulate physical gels are sparse, low-density amorphous materials in which clusters of glasses are connected to form a heterogeneous network structure. This structure is characterized by two length scales, ξ s and ξ G: ξ s measures the length of heterogeneities in the network structure and ξ G is the size of glassy clusters. Accordingly, the vibrational states (eigenmodes) of such a material also exhibit a multiscale nature with two characteristic frequencies, [Formula: see text] and ω G, which are associated with ξ s and ξ G, respectively: (i) phonon-like vibrations in the homogeneous medium at [Formula: see text], (ii) phonon-like vibrations in the heterogeneous medium at [Formula: see text], and (iii) disordered vibrations in the glassy clusters at ω > ω G. Here, we demonstrate that the multiscale characteristics seen in the static structures and vibrational states also extend to the phonon transport properties. Phonon transport exhibits two distinct crossovers at frequencies ω* and ω G (or at wavenumbers of [Formula: see text] and [Formula: see text]). In particular, both transverse and longitudinal phonons cross over between Rayleigh scattering at [Formula: see text] and diffusive damping at [Formula: see text]. Remarkably, the Ioffe–Regel limit is located at the very low frequency of ω*. Thus, phonon transport is localized above ω*, even where phonon-like vibrational states persist. This markedly strong scattering behavior is caused by the sparse, porous structure of the gel.
Collapse
Affiliation(s)
- Hideyuki Mizuno
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
| | - Makoto Hachiya
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
| | - Atsushi Ikeda
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
- Research Center for Complex Systems Biology, Universal Biology Institute, The University of Tokyo, Tokyo 153-8902, Japan
| |
Collapse
|
12
|
Tateno M, Yanagishima T, Tanaka H. Microscopic structural origin behind slowing down of colloidal phase separation approaching gelation. J Chem Phys 2022; 156:084904. [DOI: 10.1063/5.0080403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The gelation of colloidal particles interacting through a short-range attraction is widely recognized as a consequence of the dynamic arrest of phase separation into colloid-rich and solvent-rich phases. However, the microscopic origin behind the slowing down and dynamic arrest of phase separation remains elusive. In order to access microscopic structural changes through the entire process of gelation in a continuous fashion, we used core–shell fluorescent colloidal particles, laser scanning confocal microscopy, and a unique experimental protocol that allows us to initiate phase separation instantaneously and gently. Combining these enables us to track the trajectories of individual particles seamlessly during the whole phase-separation process from the early stage to the late arresting stage. We reveal that the enhancement of local packing and the resulting formation of locally stable rigid structures slow down the phase-separation process and arrest it to form a gel with an average coordination number of z = 6–7. This result supports a mechanical perspective on the dynamic arrest of sticky-sphere systems based on the microstructure, replacing conventional explanations based on the macroscopic vitrification of the colloid-rich phase. Our findings illuminate the microscopic mechanisms behind the dynamic arrest of colloidal phase separation, the emergence of mechanical rigidity, and the stability of colloidal gels.
Collapse
Affiliation(s)
- Michio Tateno
- Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Taiki Yanagishima
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hajime Tanaka
- Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| |
Collapse
|
13
|
Mizuno H, Hachiya M, Ikeda A. Structural, mechanical, and vibrational properties of particulate physical gels. J Chem Phys 2021; 155:234502. [PMID: 34937359 DOI: 10.1063/5.0072863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Our lives are surrounded by a rich assortment of disordered materials. In particular, glasses are well known as dense, amorphous materials, whereas gels exist in low-density, disordered states. Recent progress has provided a significant step forward in understanding the material properties of glasses, such as mechanical, vibrational, and transport properties. In contrast, our understanding of particulate physical gels is still highly limited. Here, using molecular dynamics simulations, we study a simple model of particulate physical gels, the Lennard-Jones (LJ) gels, and provide a comprehensive understanding of their structural, mechanical, and vibrational properties, all of which are markedly different from those of LJ glasses. First, the LJ gels show sparse, heterogeneous structures, and the length scale ξs of the structures grows as the density is lowered. Second, the LJ gels are extremely soft, with both shear G and bulk K moduli being orders of magnitude smaller than those of LJ glasses. Third, many low-frequency vibrational modes are excited, which form a characteristic plateau with the onset frequency ω* in the vibrational density of states. Structural, mechanical, and vibrational properties, characterized by ξs, G, K, and ω*, respectively, show power-law scaling behaviors with the density, which establishes a close relationship between them. Throughout this work, we also reveal that LJ gels are multiscale, solid-state materials: (i) homogeneous elastic bodies at long lengths, (ii) heterogeneous elastic bodies with fractal structures at intermediate lengths, and (iii) amorphous structural bodies at short lengths.
Collapse
Affiliation(s)
- Hideyuki Mizuno
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
| | - Makoto Hachiya
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
| | - Atsushi Ikeda
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo 153-8902, Japan
| |
Collapse
|
14
|
Niyogi S, Sen Gupta B. Mechanical properties and pore size distribution in athermal porous glasses. SOFT MATTER 2021; 17:9716-9724. [PMID: 34642732 DOI: 10.1039/d1sm01223a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We study the mechanical properties and pore structure in a three-dimensional molecular dynamics model of porous glass under athermal quasistatic shear. The vitreous samples are prepared by rapid thermal quenching from a high-temperature molten state. The pore structures form via solid-gas phase separation. The quiescent samples exhibit a wide range of pore topography, from inter-connected pore networks to randomly distributed compact pores depending on the material density. We find that the shear modulus strongly depends on the density and porosity. Under mechanical loading, the pore structure rearranges which is reflected in the pore size distribution function. Our results show that with increase in strain the distribution widens as the adjacent pores coalesce and form larger pores. We also propose a universal scaling law for the pore size distribution function which offers excellent data collapse for highly porous materials in the undeformed case. From the data scaling, we identify a critical density that can be attributed to the transition point from a porous-type to bulk-type material. The validity of the scaling law under finite deformation is also analyzed.
Collapse
Affiliation(s)
- Sucharita Niyogi
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India.
| | - Bhaskar Sen Gupta
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu 632014, India.
| |
Collapse
|
15
|
Zepeda-López JB, Medina-Noyola M. Waiting-time dependent non-equilibrium phase diagram of simple glass- and gel-forming liquids. J Chem Phys 2021; 154:174901. [PMID: 34241066 DOI: 10.1063/5.0039524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Under numerous circumstances, many soft and hard materials are present in a puzzling wealth of non-equilibrium amorphous states, whose properties are not stationary and depend on preparation. They are often summarized in unconventional "phase diagrams" that exhibit new "phases" and/or "transitions" in which time, however, is an essential variable. This work proposes a solution to the problem of theoretically defining and predicting these non-equilibrium phases and their time-evolving phase diagrams, given the underlying molecular interactions. We demonstrate that these non-equilibrium phases and the corresponding non-stationary (i.e., aging) phase diagrams can indeed be defined and predicted using the kinetic perspective of a novel non-equilibrium statistical mechanical theory of irreversible processes. This is illustrated with the theoretical description of the transient process of dynamic arrest into non-equilibrium amorphous solid phases of an instantaneously quenched simple model fluid involving repulsive hard-sphere plus attractive square well pair interactions.
Collapse
Affiliation(s)
- Jesús Benigno Zepeda-López
- Instituto de Física "Manuel Sandoval Vallarta," Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000, San Luis Potosí, SLP, Mexico
| | - Magdaleno Medina-Noyola
- Instituto de Física "Manuel Sandoval Vallarta," Universidad Autónoma de San Luis Potosí, Álvaro Obregón 64, 78000, San Luis Potosí, SLP, Mexico
| |
Collapse
|
16
|
Tateno M, Tanaka H. Power-law coarsening in network-forming phase separation governed by mechanical relaxation. Nat Commun 2021; 12:912. [PMID: 33568666 PMCID: PMC7875975 DOI: 10.1038/s41467-020-20734-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022] Open
Abstract
A space-spanning network structure is a basic morphology in phase separation of soft and biomatter, alongside a droplet one. Despite its fundamental and industrial importance, the physical principle underlying such network-forming phase separation remains elusive. Here, we study the network coarsening during gas-liquid-type phase separation of colloidal suspensions and pure fluids, by hydrodynamic and molecular dynamics simulations, respectively. For both, the detailed analyses of the pore sizes and strain field reveal the self-similar network coarsening and the unconventional power-law growth more than a decade according to ℓ ∝ t1/2, where ℓ is the characteristic pore size and t is the elapsed time. We find that phase-separation dynamics is controlled by mechanical relaxation of the network-forming dense phase, whose limiting process is permeation flow of the solvent for colloidal suspensions and heat transport for pure fluids. This universal coarsening law would contribute to the fundamental physical understanding of network-forming phase separation.
Collapse
Affiliation(s)
- Michio Tateno
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
- Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan
| | - Hajime Tanaka
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan.
| |
Collapse
|
17
|
Da Vela S, Begam N, Dyachok D, Schäufele RS, Matsarskaia O, Braun MK, Girelli A, Ragulskaya A, Mariani A, Zhang F, Schreiber F. Interplay between Glass Formation and Liquid-Liquid Phase Separation Revealed by the Scattering Invariant. J Phys Chem Lett 2020; 11:7273-7278. [PMID: 32787309 DOI: 10.1021/acs.jpclett.0c02110] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The interplay of the glass transition with liquid-liquid phase separation (LLPS) is a subject of intense debate. We use the scattering invariant Q to probe how approaching the glass transition affects the shape of LLPS boundaries in the temperature/volume fraction plane. Two protein systems featuring kinetic arrest with a lower and an upper critical solution temperature phase behavior, respectively, are studied varying the quench depth. Using Q we noninvasively identify system-dependent differences for the effect of glass formation on the LLPS boundary. The glassy dense phase appears to enter the coexistence region for the albumin-YCl3 system, whereas it follows the equilibrium binodal for the γ-globulin-PEG system.
Collapse
Affiliation(s)
- Stefano Da Vela
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Nafisa Begam
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Danylo Dyachok
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | | | - Olga Matsarskaia
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Michal K Braun
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Anita Girelli
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | | | - Alessandro Mariani
- European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble Cedex 9, France
| | - Fajun Zhang
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, 72076 Tübingen, Germany
| |
Collapse
|
18
|
Chakraborty S, Das SK. Relaxation in a phase-separating two-dimensional active matter system with alignment interaction. J Chem Phys 2020; 153:044905. [PMID: 32752724 DOI: 10.1063/5.0010043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Via computer simulations, we study kinetics of pattern formation in a two-dimensional active matter system. Self-propulsion in our model is incorporated via the Vicsek-like activity, i.e., particles have the tendency of aligning their velocities with the average directions of motion of their neighbors. In addition to this dynamic or active interaction, there exists passive inter-particle interaction in the model for which we have chosen the standard Lennard-Jones form. Following quenches of homogeneous configurations to a point deep inside the region of coexistence between high and low density phases, as the systems exhibit formation and evolution of particle-rich clusters, we investigate properties related to the morphology, growth, and aging. A focus of our study is on the understanding of the effects of structure on growth and aging. To quantify the latter, we use the two-time order-parameter autocorrelation function. This correlation, as well as the growth, is observed to follow power-law time dependence, qualitatively similar to the scaling behavior reported for passive systems. The values of the exponents have been estimated and discussed by comparing with the previously obtained numbers for other dimensions as well as with the new results for the passive limit of the considered model. We have also presented results on the effects of temperature on the activity mediated phase separation.
Collapse
Affiliation(s)
- Saikat Chakraborty
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064, India
| | - Subir K Das
- Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064, India
| |
Collapse
|
19
|
Paciolla M, Arismendi-Arrieta DJ, Moreno AJ. Coarsening Kinetics of Complex Macromolecular Architectures in Bad Solvent. Polymers (Basel) 2020; 12:E531. [PMID: 32121665 PMCID: PMC7182883 DOI: 10.3390/polym12030531] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 02/04/2020] [Accepted: 02/20/2020] [Indexed: 11/16/2022] Open
Abstract
This study reports a general scenario for the out-of-equilibrium features of collapsing polymeric architectures. We use molecular dynamics simulations to characterize the coarsening kinetics, in bad solvent, for several macromolecular systems with an increasing degree of structural complexity. In particular, we focus on: flexible and semiflexible polymer chains, star polymers with 3 and 12 arms, and microgels with both ordered and disordered networks. Starting from a powerful analogy with critical phenomena, we construct a density field representation that removes fast fluctuations and provides a consistent characterization of the domain growth. Our results indicate that the coarsening kinetics presents a scaling behaviour that is independent of the solvent quality parameter, in analogy to the time-temperature superposition principle. Interestingly, the domain growth in time follows a power-law behaviour that is approximately independent of the architecture for all the flexible systems; while it is steeper for the semiflexible chains. Nevertheless, the fractal nature of the dense regions emerging during the collapse exhibits the same scaling behaviour for all the macromolecules. This suggests that the faster growing length scale in the semiflexible chains originates just from a faster mass diffusion along the chain contour, induced by the local stiffness. The decay of the dynamic correlations displays scaling behavior with the growing length scale of the system, which is a characteristic signature in coarsening phenomena.
Collapse
Affiliation(s)
- Mariarita Paciolla
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain;
| | | | - Angel J. Moreno
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain;
- Donostia International Physics Center, Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain;
| |
Collapse
|
20
|
Ferreiro-Córdova C, Royall CP, van Duijneveldt JS. Anisotropic viscoelastic phase separation in polydisperse hard rods leads to nonsticky gelation. Proc Natl Acad Sci U S A 2020; 117:3415-3420. [PMID: 32005711 PMCID: PMC7035602 DOI: 10.1073/pnas.1909357117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spinodal demixing into two phases having very different viscosities leads to viscoelastic networks-i.e., gels-usually as a result of attractive particle interactions. Here, however, we demonstrate demixing in a colloidal system of polydisperse, rod-like clay particles that is driven by particle repulsions instead. One of the phases is a nematic liquid crystal with a highly anisotropic viscosity, allowing flow along the director, but suppressing it in other directions. This phase coexists with a dilute isotropic phase. Real-space analysis and molecular-dynamics simulations both reveal a long-lived network structure that is locally anisotropic, yet macroscopically isotropic. We show that our system exhibits the characteristics of colloidal gelation, leading to nonsticky gels.
Collapse
Affiliation(s)
- Claudia Ferreiro-Córdova
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
- Centre for Nanoscience and Quantum Information, University of Bristol, Bristol BS8 1FD, United Kingdom
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - C Patrick Royall
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom;
- Centre for Nanoscience and Quantum Information, University of Bristol, Bristol BS8 1FD, United Kingdom
- H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, United Kingdom
| | | |
Collapse
|
21
|
Elizondo-Aguilera LF, Cortés-Morales EC, Zubieta Rico PF, Medina-Noyola M, Castañeda-Priego R, Voigtmann T, Pérez-Ángel G. Arrested dynamics of the dipolar hard sphere model. SOFT MATTER 2020; 16:170-190. [PMID: 31774110 DOI: 10.1039/c9sm00687g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the combined results of molecular dynamics simulations and theoretical calculations concerning various dynamical arrest transitions in a model system representing a dipolar fluid, namely, N (soft core) rigid spheres interacting through a truncated dipole-dipole potential. By exploring different regimes of concentration and temperature, we find three distinct scenarios for the slowing down of the dynamics of the translational and orientational degrees of freedom: at low (η = 0.2) and intermediate (η = 0.4) volume fractions, both dynamics are strongly coupled and become simultaneously arrested upon cooling. At high concentrations (η≥ 0.6), the translational dynamics shows the features of an ordinary glass transition, either by compressing or cooling down the system, but with the orientations remaining ergodic, thus indicating the existence of partially arrested states. In this density regime, but at lower temperatures, the relaxation of the orientational dynamics also freezes. The physical scenario provided by the simulations is discussed and compared against results obtained with the self-consistent generalized Langevin equation theory, and both provide a consistent description of the dynamical arrest transitions in the system. Our results are summarized in an arrested states diagram which qualitatively organizes the simulation data and provides a generic picture of the glass transitions of a dipolar fluid.
Collapse
Affiliation(s)
- Luis F Elizondo-Aguilera
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft-und Raumfahrt (DLR), 51170 Köln, Germany.
| | - Ernesto C Cortés-Morales
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava 6, Zona Universitaria, 78290 San Luis Potosí, Mexico
| | - Pablo F Zubieta Rico
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava 6, Zona Universitaria, 78290 San Luis Potosí, Mexico
| | - Magdaleno Medina-Noyola
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava 6, Zona Universitaria, 78290 San Luis Potosí, Mexico
| | - Ramón Castañeda-Priego
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato, Loma del Bosque 103, 37150 León, Mexico
| | - Thomas Voigtmann
- Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft-und Raumfahrt (DLR), 51170 Köln, Germany. and Department of Physics, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Gabriel Pérez-Ángel
- Departamento de Física Aplicada, CINVESTAV del IPN, A. P. 73 "Cordemex", 97310 Mérida, Yucatán, Mexico
| |
Collapse
|
22
|
Roy S, Bera A, Majumder S, Das SK. Aging phenomena during phase separation in fluids: decay of autocorrelation for vapor-liquid transitions. SOFT MATTER 2019; 15:4743-4750. [PMID: 31149698 DOI: 10.1039/c9sm00366e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We performed molecular dynamics simulations to study relaxation phenomena during vapor-liquid transitions in a single component Lennard-Jones system. Results from two different overall densities are presented: one in the neighborhood of the vapor branch of the coexistence curve and the other being close to the critical density. The nonequilibrium morphologies, growth mechanisms and growth laws in the two cases are vastly different. In the low density case growth occurs via diffusive coalescence of droplets in a disconnected morphology. On the other hand, the elongated structure in the higher density case grows via advective transport of particles inside the tube-like liquid domains. The objective in this work has been to identify how the decay of the order-parameter autocorrelation, an important quantity to understand aging dynamics, differs in the two cases. In the case of the disconnected morphology, we observe a very robust power-law decay, as a function of the ratio of the characteristic lengths at the observation time and at the age of the system, whereas the results for the percolating structure appear rather complex. To quantify the decay in the latter case, unlike the standard method followed in a previous study, here we have performed a finite-size scaling analysis. The outcome of this analysis shows the presence of a strong preasymptotic correction, while revealing that in this case also, albeit in the asymptotic limit, the decay follows a power-law. Even though the corresponding exponents in the two cases differ drastically, this study, combined with a few recent ones, suggests that power-law behavior of this correlation function is rather universal in coarsening dynamics.
Collapse
Affiliation(s)
- Sutapa Roy
- Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany.
| | | | | | | |
Collapse
|
23
|
Tsurusawa H, Leocmach M, Russo J, Tanaka H. Direct link between mechanical stability in gels and percolation of isostatic particles. SCIENCE ADVANCES 2019; 5:eaav6090. [PMID: 31172025 PMCID: PMC6544450 DOI: 10.1126/sciadv.aav6090] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Accepted: 04/23/2019] [Indexed: 05/28/2023]
Abstract
Colloidal gels have unique mechanical and transport properties that stem from their bicontinuous nature, in which a colloidal network is intertwined with a viscous solvent, and have found numerous applications in foods, cosmetics, and construction materials and for medical applications, such as cartilage replacements. So far, our understanding of the process of colloidal gelation is limited to long-time dynamical effects, where gelation is viewed as a phase separation process interrupted by the glass transition. However, this purely out-of-equilibrium thermodynamic picture does not address the emergence of mechanical stability. With confocal microscopy experiments, we reveal that mechanical metastability is reached only after isotropic percolation of locally isostatic environments, establishing a direct link between the load-bearing ability of gels and the isostaticity condition. Our work suggests an operative description of gels based on mechanical equilibrium and isostaticity, providing the physical basis for the stability and rheology of these materials.
Collapse
Affiliation(s)
- Hideyo Tsurusawa
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| | - Mathieu Leocmach
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - John Russo
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- School of Mathematics, University of Bristol, Bristol BS8 1TW, UK
| | - Hajime Tanaka
- Department of Fundamental Engineering, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| |
Collapse
|
24
|
Rovigatti L, Gnan N, Tavagnacco L, Moreno AJ, Zaccarelli E. Numerical modelling of non-ionic microgels: an overview. SOFT MATTER 2019; 15:1108-1119. [PMID: 30543246 PMCID: PMC6371763 DOI: 10.1039/c8sm02089b] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/26/2018] [Indexed: 05/03/2023]
Abstract
Microgels are complex macromolecules. These colloid-sized polymer networks possess internal degrees of freedom and, depending on the polymer(s) they are made of, can acquire a responsiveness to variations of the environment (temperature, pH, salt concentration, etc.). Besides being valuable for many practical applications, microgels are also extremely important to tackle fundamental physics problems. As a result, these last years have seen a rapid development of protocols for the synthesis of microgels, and more and more research has been devoted to the investigation of their bulk properties. However, from a numerical standpoint the picture is more fragmented, as the inherently multi-scale nature of microgels, whose bulk behaviour crucially depends on the microscopic details, cannot be handled at a single level of coarse-graining. Here we present an overview of the methods and models that have been proposed to describe non-ionic microgels at different length-scales, from the atomistic to the single-particle level. We especially focus on monomer-resolved models, as these have the right level of details to capture the most important properties of microgels, responsiveness and softness. We suggest that these microscopic descriptions, if realistic enough, can be employed as starting points to develop the more coarse-grained representations required to investigate the behaviour of bulk suspensions.
Collapse
Affiliation(s)
- Lorenzo Rovigatti
- Dipartimento di Fisica
, Sapienza Università di Roma
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
- CNR-ISC
, Uos Sapienza
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
| | - Nicoletta Gnan
- Dipartimento di Fisica
, Sapienza Università di Roma
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
- CNR-ISC
, Uos Sapienza
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
| | - Letizia Tavagnacco
- Dipartimento di Fisica
, Sapienza Università di Roma
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
- CNR-ISC
, Uos Sapienza
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
| | - Angel J. Moreno
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC
,
Paseo Manuel de Lardizabal 5
, 20018 San Sebastián
, Spain
- Donostia International Physics Center
,
Paseo Manuel de Lardizabal 4
, 20018 San Sebastian
, Spain
| | - Emanuela Zaccarelli
- Dipartimento di Fisica
, Sapienza Università di Roma
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
- CNR-ISC
, Uos Sapienza
,
Piazzale A. Moro 2
, 00185 Roma
, Italy
.
| |
Collapse
|
25
|
Royall CP, Turci F, Tatsumi S, Russo J, Robinson J. The race to the bottom: approaching the ideal glass? JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:363001. [PMID: 29972145 DOI: 10.1088/1361-648x/aad10a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Key to resolving the scientific challenge of the glass transition is to understand the origin of the massive increase in viscosity of liquids cooled below their melting temperature (avoiding crystallisation). A number of competing and often mutually exclusive theoretical approaches have been advanced to describe this phenomenon. Some posit a bona fide thermodynamic phase to an 'ideal glass', an amorphous state with exceptionally low entropy. Other approaches are built around the concept of the glass transition as a primarily dynamic phenomenon. These fundamentally different interpretations give equally good descriptions of the data available, so it is hard to determine which-if any-is correct. Recently however this situation has begun to change. A consensus has emerged that one powerful means to resolve this longstanding question is to approach the putative thermodynamic transition sufficiently closely, and a number of techniques have emerged to meet this challenge. Here we review the results of some of these new techniques and discuss the implications for the existence-or otherwise-of the thermodynamic transition to an ideal glass.
Collapse
Affiliation(s)
- C Patrick Royall
- HH Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom. School of Chemistry, University of Bristol, Cantock Close, Bristol, BS8 1TS, United Kingdom. Centre for Nanoscience and Quantum Information, Tyndall Avenue, Bristol, BS8 1FD, United Kingdom
| | | | | | | | | |
Collapse
|
26
|
Moreno AJ, Lo Verso F. Computational investigation of microgels: synthesis and effect of the microstructure on the deswelling behavior. SOFT MATTER 2018; 14:7083-7096. [PMID: 30118116 DOI: 10.1039/c8sm01407h] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We present computer simulations of a realistic model of microgels. Unlike the regular network frameworks usually assumed in the simulation literature, we model and simulate a realistic and efficient synthesis route, mimicking cross-linking of functionalized chains inside a cavity. This model is inspired, e.g., by microfluidic fabrication of microgels from macromolecular precursors and is different from standard polymerization routes. The assembly of the chains is mediated by a low fraction of interchain crosslinks. The microgels are polydisperse in size and shape but globally spherical objects. In order to deeply understand the microgel structure and eventually improve the synthesis protocol we characterize their conformational properties and deswelling kinetics, and compare them with the results found for microgels obtained via underlying regular (diamond-like) structures. For the same molecular weight, monomer concentration and effective degree of cross-linking, the specific microstructure of the microgel has no significant effect on the locus of the volume phase transition (VPT). However, it strongly affects the deswelling kinetics, as revealed by a consistent analysis of the domain growth during the microgel collapse. Though both the disordered and the regular networks exhibit a similar early growth of the domains, an acceleration is observed in the regular network at the late stage of the collapse. Similar trends are found for the dynamic correlations coupled to the domain growth. As a consequence, the fast late processes for the domain growth and the dynamic correlations in the regular network are compensated, and the dynamic correlations follow a power-law dependence on the growing length scale that is independent of the microgel microstructure.
Collapse
Affiliation(s)
- Angel J Moreno
- Centro de Física de Materiales (CSIC, UPV/EHU) and Materials Physics Center MPC, Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain.
| | | |
Collapse
|
27
|
Sorichetti V, Hugouvieux V, Kob W. Structure and Dynamics of a Polymer–Nanoparticle Composite: Effect of Nanoparticle Size and Volume Fraction. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b00840] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Valerio Sorichetti
- Laboratoire Charles Coulomb (L2C), CNRS, Univ Montpellier, Montpellier, France
- SPO, Univ Montpellier, INRA, Montpellier SupAgro, Montpellier, France
| | | | - Walter Kob
- Laboratoire Charles Coulomb (L2C), CNRS, Univ Montpellier, Montpellier, France
| |
Collapse
|
28
|
Affiliation(s)
- C. Patrick Royall
- H.H. Wills Physics Laboratory, Bristol, UK
- School of Chemistry, University of Bristol, Bristol, UK
- Centre for Nanoscience and Quantum Information, Bristol, UK
| |
Collapse
|
29
|
Makeev MA, Priezjev NV. Distributions of pore sizes and atomic densities in binary mixtures revealed by molecular dynamics simulations. Phys Rev E 2018; 97:023002. [PMID: 29548136 DOI: 10.1103/physreve.97.023002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Indexed: 11/07/2022]
Abstract
We report on the results of a molecular dynamics simulation study of porous glassy media, formed in the process of isochoric rapid quenching from a high-temperature liquid state. The transition to a porous solid occurs due to the concurrent processes of phase separation and material solidification. The study is focused on topographies of the model porous structures and their dependence on temperature and average density. To quantify the pore-size distributions, we put forth a scaling relation that provides a satisfactory data collapse in systems with high porosity. We also find that the local density of the solid domains in the porous structures is broadly distributed, and, with increasing average density, a distinct peak in the local density distribution is displaced toward higher values.
Collapse
Affiliation(s)
- Maxim A Makeev
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| | - Nikolai V Priezjev
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435, USA
| |
Collapse
|
30
|
Priezjev NV, Makeev MA. Evolution of the pore size distribution in sheared binary glasses. Phys Rev E 2018; 96:053004. [PMID: 29347757 DOI: 10.1103/physreve.96.053004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Indexed: 11/07/2022]
Abstract
Molecular dynamics simulations are carried out to investigate mechanical properties and porous structure of binary glasses subjected to steady shear. The model vitreous systems were prepared via thermal quench at constant volume to a temperature well below the glass transition. The quiescent samples are characterized by a relatively narrow pore size distribution whose mean size is larger at lower glass densities. We find that in the linear regime of deformation, the shear modulus is a strong function of porosity, and the individual pores become slightly stretched while their structural topology remains unaffected. By contrast, with further increasing strain, the shear stress saturates to a density-dependent plateau value, which is accompanied by pore coalescence and a gradual development of a broader pore size distribution with a discrete set of peaks at large length scales.
Collapse
Affiliation(s)
- Nikolai V Priezjev
- Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435, USA
| | - Maxim A Makeev
- Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211, USA
| |
Collapse
|
31
|
Da Vela S, Exner C, Schäufele RS, Möller J, Fu Z, Zhang F, Schreiber F. Arrested and temporarily arrested states in a protein-polymer mixture studied by USAXS and VSANS. SOFT MATTER 2017; 13:8756-8765. [PMID: 29130090 DOI: 10.1039/c7sm01434a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigate the transition of the phase separation kinetics from a complete to an arrested liquid-liquid phase separation (LLPS) in mixtures of bovine γ-globulin with polyethylene glycol (PEG). The solutions feature LLPS with upper critical solution temperature phase behavior. At higher PEG concentrations or low temperatures, non-equilibrium, gel-like states are found. The kinetics is followed during off-critical quenches by ultra-small angle X-ray scattering (USAXS) and very-small angle neutron scattering (VSANS). For shallow quenches a kinetics consistent with classical spinodal decomposition is found, with the characteristic length (ξ) growing with time as ξ ∼ t1/3. For deep quenches, ξ grows only very slowly with a growth exponent smaller than 0.05 during the observation time, indicating an arrested phase separation. For intermediate quench depths, a novel growth kinetics featuring a three-stage coarsening is observed, with an initial classical coarsening, a subsequent slowdown of the growth, and a later resumption of coarsening approaching again ξ ∼ t1/3. Samples featuring the three-stage coarsening undergo a temporarily arrested state. We hypothesize that, while intermittent coarsening and collapse might contribute to the temporary nature of the arrested state, migration-coalescence of the minority liquid phase through the majority glassy phase may be the main mechanism underlying this kinetics, which is also consistent with earlier simulation results.
Collapse
Affiliation(s)
- Stefano Da Vela
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | | | | | | | | | | | | |
Collapse
|
32
|
Affiliation(s)
- Adrian-Marie Philippe
- Laboratoire
Charles Coulomb, UMR 5221, Université de Montpellier and CNRS, 34095 Montpellier, France
| | - Luca Cipelletti
- Laboratoire
Charles Coulomb, UMR 5221, Université de Montpellier and CNRS, 34095 Montpellier, France
| | - Domenico Larobina
- Institute
for Polymers, Composites and Biomaterials, National Research Council of Italy, P.le E. Fermi 1, Naples, 80055 Portici, Italy
| |
Collapse
|
33
|
Mahmoudi N, Stradner A. Structural arrest and dynamic localization in biocolloidal gels. SOFT MATTER 2017; 13:4629-4635. [PMID: 28613330 DOI: 10.1039/c7sm00496f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Casein micelles interacting via an entropic intermediate-ranged depletion attraction exhibit a fluid-to-gel transition due to arrested spinodal decomposition. The bicontinuous networked structure of the gel freezes shortly after formation. We determine the timescales of structural arrest from the build-up of network rigidity after pre-shear rejuvenation, and find that the arrest time as well as the plateau elastic modulus of the gel diverge as a function of the volume fraction and interaction potential. Moreover, we show using scaling from naïve mode coupling theory that their mechanical properties are dictated by their microscopic dynamics rather than their heterogeneous large scale structure.
Collapse
Affiliation(s)
- N Mahmoudi
- Adolphe Merkle Institute, University of Fribourg, Route de l'ancienne Papeterie 1, Marly, Switzerland. and Physical Chemistry, Lund University, Getingevägen 60, Lund, Sweden.
| | - A Stradner
- Physical Chemistry, Lund University, Getingevägen 60, Lund, Sweden.
| |
Collapse
|
34
|
Chaudhuri P, Berthier L. Ultra-long-range dynamic correlations in a microscopic model for aging gels. Phys Rev E 2017; 95:060601. [PMID: 28709225 DOI: 10.1103/physreve.95.060601] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Indexed: 06/07/2023]
Abstract
We use large-scale computer simulations to explore the nonequilibrium aging dynamics in a microscopic model for colloidal gels. We find that gelation resulting from a kinetically arrested phase separation is accompanied by "anomalous" particle dynamics revealed by superdiffusive particle motion and compressed exponential relaxation of time correlation functions. Spatiotemporal analysis of the dynamics reveals intermittent heterogeneities producing spatial correlations over extremely large length scales. Our study is a microscopically resolved model reproducing all features of the spontaneous aging dynamics observed experimentally in soft materials.
Collapse
Affiliation(s)
- Pinaki Chaudhuri
- The Institute of Mathematical Sciences, C.I.T. Campus, Taramani, Chennai 600 113, India
| | - Ludovic Berthier
- Laboratoire Charles Coulomb, UMR 5221, Université Montpellier and CNRS, 34095 Montpellier, France
| |
Collapse
|
35
|
Matoz-Fernandez DA, Martens K, Sknepnek R, Barrat JL, Henkes S. Cell division and death inhibit glassy behaviour of confluent tissues. SOFT MATTER 2017; 13:3205-3212. [PMID: 28398448 DOI: 10.1039/c6sm02580c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigate the effects of cell division and apoptosis on collective dynamics in two-dimensional epithelial tissues. Our model includes three key ingredients observed across many epithelia, namely cell-cell adhesion, cell death and a cell division process that depends on the surrounding environment. We show a rich non-equilibrium phase diagram depending on the ratio of cell death to cell division and on the adhesion strength. For large apoptosis rates, cells die out and the tissue disintegrates. As the death rate decreases, however, we show, consecutively, the existence of a gas-like phase, a gel-like phase, and a dense confluent (tissue) phase. Most striking is the observation that the tissue is self-melting through its own internal activity, ruling out the existence of any glassy phase.
Collapse
|
36
|
Razali A, Fullerton CJ, Turci F, Hallett JE, Jack RL, Royall CP. Effects of vertical confinement on gelation and sedimentation of colloids. SOFT MATTER 2017; 13:3230-3239. [PMID: 28401216 DOI: 10.1039/c6sm02221a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We consider the sedimentation of a colloidal gel under confinement in the direction of gravity. The confinement allows us to compare directly experiments and computer simulations, for the same system size in the vertical direction. The confinement also leads to qualitatively different behaviour compared to bulk systems: in large systems gelation suppresses sedimentation, but for small systems sedimentation is enhanced relative to non-gelling suspensions, although the rate of sedimentation is reduced when the strength of the attraction between the colloids is strong. We map interaction parameters between a model experimental system (observed in real space) and computer simulations. Remarkably, we find that when simulating the system using Brownian dynamics in which hydrodynamic interactions between the particles are neglected, we find that sedimentation occurs on the same timescale as the experiments. An analysis of local structure in the simulations showed similar behaviour to gelation in the absence of gravity.
Collapse
Affiliation(s)
- Azaima Razali
- H.H. Wills Physics Laboratory, University of Bristol, Bristol, BS8 1TL, UK.
| | | | | | | | | | | |
Collapse
|
37
|
Da Vela S, Braun MK, Dörr A, Greco A, Möller J, Fu Z, Zhang F, Schreiber F. Kinetics of liquid-liquid phase separation in protein solutions exhibiting LCST phase behavior studied by time-resolved USAXS and VSANS. SOFT MATTER 2016; 12:9334-9341. [PMID: 27830221 DOI: 10.1039/c6sm01837h] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We study the kinetics of the liquid-liquid phase separation (LLPS) and its arrest in protein solutions exhibiting a lower critical solution temperature (LCST) phase behavior using the combination of ultra-small angle X-ray scattering (USAXS) and very-small angle neutron scattering (VSANS). We employ a previously established model system consisting of bovine serum albumin (BSA) solutions with YCl3. We follow the phase transition from sub-second to 104 s upon an off-critical temperature jump. After a temperature jump, the USAXS profiles exhibit a peak that grows in intensity and shifts to lower q values with time. Below 45 °C, the characteristic length scale (ξ) obtained from this scattering peak increases with time with a power of about 1/3 for different sample compositions. This is in good agreement with the theoretical prediction for the intermediate stage of spinodal decomposition where the growth is driven by interface tension. Above 45 °C, ξ follows initially the 1/3 power law growth, then undergoes a significant slowdown, and an arrested state is reached below the denaturation temperature of the protein. This growth kinetics may indicate that the final composition of the protein-rich phase is located close to the high density branch of the LLPS binodal when a kinetically arrested state is reached.
Collapse
Affiliation(s)
- Stefano Da Vela
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Michal K Braun
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Andreas Dörr
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Alessandro Greco
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Johannes Möller
- European Synchrotron Radiation Facility, 71 avenue des Martyrs, 38043 Grenoble Cedex 9, France
| | - Zhendong Fu
- Forschungszentrum Jülich GmbH, JCNS@MLZ, Lichtenbergstrasse 1, 85747, Garching, Germany
| | - Fajun Zhang
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| | - Frank Schreiber
- Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
| |
Collapse
|
38
|
Sabin J, Bailey AE, Frisken BJ. Exploring the dynamics of phase separation in colloid-polymer mixtures with long range attraction. SOFT MATTER 2016; 12:5325-5333. [PMID: 27242183 DOI: 10.1039/c6sm00224b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We have studied the kinetics of phase separation and gel formation in a low-dispersity colloid - non-adsorbing polymer system with long range attraction using small-angle light scattering. This system exhibits two-phase and three-phase coexistence of gas, liquid and crystal phases when the strength of attraction is between 2 and 4kBT and gel phases when the strength of attraction is increased. For those samples that undergo macroscopic phase separation, whether to gas-crystal, gas-liquid or gas-liquid-crystal coexistence, we observe dynamic scaling of the structure factor and growth of a characteristic length scale that behaves as expected for phase separation in fluids. In samples that gel, the power law associated with the growth of the dominant length scale is not equal to 1/3, but appears to depend mainly on the strength of attraction, decreasing from 1/3 for samples near the coexistence region to 1/27 at 8kBT, over a wide range of colloid and polymer concentrations.
Collapse
Affiliation(s)
- Juan Sabin
- Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
| | | | | |
Collapse
|
39
|
Ruff Z, Nathan SH, Unwin RR, Zupkauskas M, Joshi D, Salmond GPC, Grey CP, Eiser E. Designing disordered materials using DNA-coated colloids of bacteriophage fd and gold. Faraday Discuss 2016; 186:473-88. [PMID: 26864018 DOI: 10.1039/c5fd00120j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DNA has emerged as an exciting binding agent for programmable colloidal self-assembly. Its popularity derives from its unique properties: it provides highly specific short-ranged interactions and at the same time it acts as a steric stabilizer against non-specific van der Waals and Coulomb interactions. Because complementary DNA strands are linked only via hydrogen bonds, DNA-mediated binding is thermally reversible: it provides an effective attraction that can be switched off by raising the temperature only by a few degrees. In this article we introduce a new binary system made of DNA-functionalized filamentous fd viruses of ∼880 nm length with an aspect ratio of ∼100, and 50 nm gold nanoparticles (gold NPs) coated with the complementary DNA strands. When quenching mixtures below the melt temperature Tm, at which the attraction is switched on, we observe aggregation. Conversely, above Tm the system melts into a homogenous particulate 'gas'. We present the aggregation behavior of three different gold NP to virus ratios and compare them to a gel made solely of gold NPs. In particular, we have investigated the aggregate structures as a function of cooling rate and determine how they evolve as function of time for given quench depths, employing fluorescence microscopy. Structural information was extracted in the form of an effective structure factor and chord length distributions. Rapid cooling rates lead to open aggregates, while slower controlled cooling rates closer to equilibrium DNA hybridization lead to more fine-stranded gels. Despite the different structures we find that for both cooling rates the quench into the two-phase region leads to initial spinodal decomposition, which becomes arrested. Surprisingly, although the fine-stranded gel is disordered, the overall structure and the corresponding length scale distributions in the system are remarkably reproducible. Such highly porous systems can be developed into new functional materials.
Collapse
Affiliation(s)
- Z Ruff
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
| | - S H Nathan
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
| | - R R Unwin
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
| | - M Zupkauskas
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
| | - D Joshi
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge, CB3 0HE, UK.
| | - G P C Salmond
- Department of Biochemistry, University of Cambridge, Tennis Court Rd, Cambridge, CB2 1QW, UK
| | - C P Grey
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - E Eiser
- Cavendish Laboratory, University of Cambridge, JJ Thomson Ave, Cambridge, CB3 0HE, UK. and BP Institute, Bullard Laboratories, Madingley Rd, CB3 0EZ Cambridge, UK
| |
Collapse
|
40
|
Marzi D, Capone B, Marakis J, Merola MC, Truzzolillo D, Cipelletti L, Moingeon F, Gauthier M, Vlassopoulos D, Likos CN, Camargo M. Depletion, melting and reentrant solidification in mixtures of soft and hard colloids. SOFT MATTER 2015; 11:8296-8312. [PMID: 26356800 DOI: 10.1039/c5sm01551k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present extensive experimental and theoretical investigations on the structure, phase behavior, dynamics and rheology of model soft-hard colloidal mixtures realized with large, multiarm star polymers as the soft component and smaller, compact stars as the hard one. The number and length of the arms in star polymers control their softness, whereas the size ratio, the overall density and the composition are additional parameters varied for the mixtures. A coarse-grained theoretical strategy is employed to predict the structure of the systems as well as their ergodicity properties on the basis of mode coupling theory, for comparison with rheological measurements on the samples. We discovered that dynamically arrested star-polymer solutions recover their ergodicity upon addition of colloidal additives. At the same time the system displays demixing instability, and the binodal of the latter meets the glass line in a way that leads, upon addition of a sufficient amount of colloidal particles, to an arrested phase separation and reentrant solidification. We present evidence for a subsequent solid-to-solid transition well within the region of arrested phase separation, attributed to a hard-sphere-mixture type of glass, due to osmotic shrinkage of the stars at high colloidal particle concentrations. We systematically investigated the interplay of star functionality and size ratio with glass melting and demixing, and rationalized our findings by the depletion of the big stars due to the smaller colloids. This new depletion potential in which, contrary to the classic colloid-polymer case, the hard component depletes the soft one, has unique and novel characteristics and allows the calculation of phase diagrams for such mixtures. This work covers a broad range of soft-hard colloidal mixture compositions in which the soft component exceeds the hard one in size and provides general guidelines for controlling the properties of such complex mixtures.
Collapse
Affiliation(s)
- Daniela Marzi
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
| | - Barbara Capone
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
| | - John Marakis
- FORTH, Institute of Electronic Structure and Laser, Heraklion, Crete 70013, Greece and Department of Materials Science and Technology, University of Crete, Heraklion, Crete 71003, Greece
| | - Maria Consiglia Merola
- FORTH, Institute of Electronic Structure and Laser, Heraklion, Crete 70013, Greece and Dipartimento di Ingegneria Industriale e dell' Informazione, Seconda Università di Napoli, Via Roma 21, 81031 Aversa, Caserta, Italy
| | - Domenico Truzzolillo
- FORTH, Institute of Electronic Structure and Laser, Heraklion, Crete 70013, Greece and Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, Montpellier, France
| | - Luca Cipelletti
- Laboratoire Charles Coulomb (L2C), UMR 5221 CNRS-Université de Montpellier, Montpellier, France
| | - Firmin Moingeon
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Mario Gauthier
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Dimitris Vlassopoulos
- FORTH, Institute of Electronic Structure and Laser, Heraklion, Crete 70013, Greece and Department of Materials Science and Technology, University of Crete, Heraklion, Crete 71003, Greece
| | - Christos N Likos
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
| | - Manuel Camargo
- Centro de Investigaciones en Ciencias Básicas y Aplicadas, Universidad Antonio Nariño - Campus Farallones, Km 18 via Cali-Jamundí, 760030 Santiago de Cali, Colombia.
| |
Collapse
|
41
|
Olais-Govea JM, López-Flores L, Medina-Noyola M. Non-equilibrium theory of arrested spinodal decomposition. J Chem Phys 2015; 143:174505. [DOI: 10.1063/1.4935000] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
42
|
Růžička Š, Allen MP. Monte Carlo simulation of kinetically slowed down phase separation. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:68. [PMID: 26123773 DOI: 10.1140/epje/i2015-15068-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/24/2015] [Accepted: 06/02/2015] [Indexed: 06/04/2023]
Abstract
Supercooled colloidal or molecular systems at low densities are known to form liquid, crystalline or glassy drops, which may remain isolated for a long time before they aggregate. This paper analyses the properties of this large time window, and how it can be tackled by computer simulation. We use single-particle and virtual move Monte Carlo simulations of short-range attractive spheres which are undercooled to the temperature region, where the spinodal intersects the attractive glass line. We study two different systems and we report the following kinetic behavior. A low-density system is shown to exhibit universal linear growth regimes under single-particle Monte Carlo correlating the growth rate to the local structure. These regimes are suppressed under collective motion, where droplets aggregate into a single large disordered domain. It is shown that the aggregation can be avoided and linear regimes recovered, if long-range repulsion is added to the short-range attraction. The results provide an insight into the behavior of the virtual move algorithm generating cluster moves according to the local forcefields. We show that different choices of maximum Monte Carlo displacement affect the dynamical trajectories but lead to the same kinetically slowed down or arrested states.
Collapse
Affiliation(s)
- Štěpán Růžička
- Laboratoire de Physique des Solides, Université Paris-Sud & CNRS, UMR 8502, 91405, Orsay, France.
- Department of Physics, University of Warwick, CV4 7AL, Coventry, UK.
| | - Michael P Allen
- Department of Physics, University of Warwick, CV4 7AL, Coventry, UK
- H. H. Wills Physics Laboratory, Royal Fort, Tyndall Avenue, BS8 1TL, Bristol, UK
| |
Collapse
|
43
|
Kerasidou A, Mauboussin Y, Teboul V. A simple diatomic potential that prevents crystallization in supercooled liquids simulations. Chem Phys 2015. [DOI: 10.1016/j.chemphys.2015.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
44
|
Bouttes D, Gouillart E, Boller E, Dalmas D, Vandembroucq D. Fragmentation and limits to dynamical scaling in viscous coarsening: an interrupted in situ x-ray tomographic study. PHYSICAL REVIEW LETTERS 2014; 112:245701. [PMID: 24996094 DOI: 10.1103/physrevlett.112.245701] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Indexed: 06/03/2023]
Abstract
X-ray microtomography was used to follow the coarsening of the structure of a ternary silicate glass experiencing phase separation in the liquid state. The volumes, surfaces, mean, and Gaussian curvatures of the domains of minority phase were measured after reconstruction of the 3D images and segmentation. A linear growth law of the characteristic length scale ℓ∼t was observed. A detailed morphological study was performed. While dynamical scaling holds for most of the geometrical observables under study, a progressive departure from scaling invariance of the distributions of local curvatures was evidenced. The latter results from a gradual fragmentation of the structure in the less viscous phase that also leads to a power-law size distribution of isolated domains.
Collapse
Affiliation(s)
- David Bouttes
- Laboratoire PMMH, UMR 7636 CNRS/ESPCI/University Paris 6 UPMC/University Paris 7 Diderot, 10 rue Vauquelin, 75231 Paris Cedex 05, France
| | - Emmanuelle Gouillart
- Surface du Verre et Interfaces, UMR 125 CNRS/Saint-Gobain, 93303 Aubervilliers, France
| | - Elodie Boller
- European Synchrotron Radiation Facility (ESRF), BP 220, 38043 Grenoble, France
| | - Davy Dalmas
- Surface du Verre et Interfaces, UMR 125 CNRS/Saint-Gobain, 93303 Aubervilliers, France
| | - Damien Vandembroucq
- Laboratoire PMMH, UMR 7636 CNRS/ESPCI/University Paris 6 UPMC/University Paris 7 Diderot, 10 rue Vauquelin, 75231 Paris Cedex 05, France
| |
Collapse
|