Soft Matter[JOURNAL]
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200 papers
Growth pathway of an AB-type colloidal alloy during colloidal heteroepitaxy.
Sato M, Nozawa J
Soft Matter · 2026 Jun · PMID 42300197 · Publisher ↗
Ideally, the final crystal structures are determined by the minimization of free energy. However, the actual growth pathway, which is governed by growth conditions, also influences the resulting structure. In our previou...
Ideally, the final crystal structures are determined by the minimization of free energy. However, the actual growth pathway, which is governed by growth conditions, also influences the resulting structure. In our previous experimental study [J. Nozawa , , 2025, , 7309-7316], we observed the formation of a binary colloidal alloy on a substrate during colloidal heteroepitaxy. We experimentally investigated how the growth pathway of an AB type colloidal alloy depends on the growth conditions, and demonstrated how the growth velocity and nucleation rate are influenced by the composition of two particle types with different sizes. Based on these experiments, we conducted simulations, using a short-range interaction potential, similar to the Asakura-Oosawa potential, to model the depletion force. We examined the combinations of particle sizes that efficiently produce the AB-type colloidal alloy on the substrate and how the growth process affects the final structure.
Suppression of anomalous dynamics by random pinning in three-dimensional confluent tissues.
Li J, Li YW
Soft Matter · 2026 Jul · PMID 42300181 · Publisher ↗
We numerically investigate the supercooled glassy dynamics of a three-dimensional Voronoi model for confluent cellular tissues, focusing on the effect of randomly pinning a fraction of cells. The dynamics are analyzed in...
We numerically investigate the supercooled glassy dynamics of a three-dimensional Voronoi model for confluent cellular tissues, focusing on the effect of randomly pinning a fraction of cells. The dynamics are analyzed in both rigid and floppy regimes, tuned by the shape index. Unpinned floppy systems exhibit anomalous sub-Arrhenius temperature dependence of the structural relaxation time, a sub-diffusive mean-squared-displacement regime, and the preservation of the Stokes-Einstein (SE) relation across all temperatures-signatures of mean-field-like dynamics. In contrast, rigid systems show conventional super-Arrhenius behavior and a breakdown of the SE relation at low temperatures. Introducing random pinning systematically alters these behaviors: it suppresses the anomalous sub-diffusive regime in floppy systems, shifts their relaxation from sub-Arrhenius toward nearly Arrhenius behavior, and induces a breakdown of the SE relation in the supercooled regime. In rigid systems, pinning enhances dynamic heterogeneity, making the relaxation more super-Arrhenius and reducing the SE breakdown exponent. Pinning also increases the mean string length of cooperative string-like motion, raises the T1-transition rate in floppy systems, and strengthens the exponential correlation between this rate and the population of very small cell-cell interfaces, bringing these measures close to the values seen in rigid systems. These results demonstrate that geometrical constraint imposed by random pinning suppresses the unique anomalous glassy dynamics of under-constrained floppy confluent tissues, restoring conventional glass-forming behavior by enhancing geometric constraints and modifying the underlying energy landscape.
Crowding-induced collapse and adsorption of polymers with nonuniform bending stiffness.
Cantrall GR, Chauhan G, Abel SM
Soft Matter · 2026 Jun · PMID 42300112 · Full text
Macromolecular crowding can significantly impact the behavior of biopolymers, with crowding-induced depletion interactions influencing both the conformations and surface adsorption of individual polymers. Although previo...
Macromolecular crowding can significantly impact the behavior of biopolymers, with crowding-induced depletion interactions influencing both the conformations and surface adsorption of individual polymers. Although previous studies have explored the influence of homogeneous polymer stiffness in crowded conditions, biomolecules such as DNA can exhibit sequence-dependent stiffness, and DNA origami nanoparticles can be designed with alternating stiff and flexible domains. In this work, we use Langevin dynamics simulations to characterize how nonuniform bending stiffness modulates the conformations and adsorption of polymers in crowded environments. By systematically varying the relative length and arrangement of flexible and semiflexible domains along a linear chain, we show that increasing osmotic pressure leads to a pattern-dependent collapse of the polymer, as revealed by a decrease in the radius of gyration. In general, large flexible regions promote polymer collapse, although flexible domains separating extended semiflexible regions can facilitate their contact, leading to stable folded conformations. When a surface is present, large semiflexible domains promote adsorption, and the pattern of stiffness can be used to control the adsorption threshold. Our findings provide insight into the impact of spatially varying stiffness on the behavior of polymers in crowded environments, highlighting mechanisms relevant to biopolymers and deformable nanoparticles in both cellular and cell-free contexts.
Aromatic/aliphatic residue balance regulates Cu(II)-induced supramolecular gel formation and drug release in histidine-containing tetrapeptides.
Fukumoto K, Inada A, Oshima T
Soft Matter · 2026 Jul · PMID 42300085 · Publisher ↗
In this study, the effect of the balance between aromatic and aliphatic residues in Cu(II)-responsive tetrapeptides on self-assembly and supramolecular metallogel formation was investigated systematically. Tetrapeptides...
In this study, the effect of the balance between aromatic and aliphatic residues in Cu(II)-responsive tetrapeptides on self-assembly and supramolecular metallogel formation was investigated systematically. Tetrapeptides with the general sequence His-X-X-X (X = Ile or Phe)-HIIF, HIFF, and HFFF-were designed to evaluate the cooperative contributions of metal coordination, hydrophobic interactions, and π-π stacking in the presence of Cu. Histidine-mediated Cu coordination promoted the formation of three-dimensional supramolecular networks, whereas network density and mechanical strength were modulated by the relative proportions of isoleucine and phenylalanine residues. Rheological analysis revealed that the storage modulus followed the order HIFF > HIIF > HFFF, indicating that HIFF, with an optimal aromatic/aliphatic balance, exhibited the highest mechanical robustness. All gels displayed reversible gel-sol transitions and pronounced thixotropy, confirming the dynamic and reconstructable nature of the supramolecular networks. Doxorubicin (DOX) encapsulation further demonstrated pH-responsive release behavior. Minimal release was observed under physiological conditions (pH 7.2), whereas sustained release occurred under mildly acidic conditions (pH 5.6). The release efficiency followed the order HIIF > HFFF > HIFF, suggesting that higher aromatic content and a more compact network enhance drug retention. Collectively, these findings identify the isoleucine/phenylalanine ratio as a key design parameter for tuning metallogel mechanics and drug-delivery performance.
Translational diffusion and isomerization reaction of a liquid crystal molecule at solid-liquid interface of ionic liquids studied by total internal reflection-transient grating spectroscopy.
Fujiwara M, Shirota H, Kasahara K … +2 more , Matubayasi N, Kimura Y
Soft Matter · 2026 Jun · PMID 42300084 · Publisher ↗
The translational diffusion coefficients and isomerization reaction rates of -(4-methoxybenzylidene)-4-butylaniline (MBBA) dissolved in ionic liquids (ILs) were measured at the sapphire interface using total internal ref...
The translational diffusion coefficients and isomerization reaction rates of -(4-methoxybenzylidene)-4-butylaniline (MBBA) dissolved in ionic liquids (ILs) were measured at the sapphire interface using total internal reflection-transient grating (TIR-TG) spectroscopy. 1-Alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amides ([Cmim][NTf]) were used as ILs with different alkyl chain lengths. The diffusion coefficient of MBBA in the bulk did not monotonically decrease with an increase in the solvent viscosity, and it was maximum in [Cmim][NTf]. Based on the radial distribution functions (RDFs) calculated from molecular dynamics (MD) simulations, we interpreted that the non-monotonicity of diffusion was due to the fact that MBBA behaves as an amphiphilic surfactant at the interfaces between the polar and nonpolar domains of the ILs and diffuses selectively along the surfaces of the nonpolar domains. At the sapphire interface, the diffusion coefficient of MBBA was almost the same as that in the bulk, whereas the isomerization reaction rate was significantly accelerated, irrespective of the alkyl chain length. The contact angle measurement revealed that MBBA was significantly concentrated near the sapphire interface. The above experimental results were discussed in relation to the bulk and interfacial structures of ionic-liquid solutions of a liquid crystal molecule.
A model of 3D confluent tissue behaves as an under-constrained glass.
Li C, Merkel M, Sussman DM
Soft Matter · 2026 Jun · PMID 42300077 · Publisher ↗
The dynamics of glassy materials slows down upon cooling, typically showing either Arrhenius or super-Arrhenius behavior. However, it was recently shown that 2D cell-based models for biological tissues can be continuousl...
The dynamics of glassy materials slows down upon cooling, typically showing either Arrhenius or super-Arrhenius behavior. However, it was recently shown that 2D cell-based models for biological tissues can be continuously tuned between Arrhenius and sub-Arrhenius dynamics. In previous work, using the 2D Voronoi model, we proposed that such atypical dynamical behavior could be a generic feature of the broad class of mechanically under-constrained materials. Yet, our earlier study had left two important points open: (1) many 2D systems are affected by long-wavelength fluctuations and the 2D melting scenario, and (2) the 2D Voronoi model sits exactly at the isostatic point, making it a marginal case rather than a strictly under-constrained one. Both points complicate the interpretation of our 2D Voronoi model results and their generalization to other systems; to remedy this, here we use large-scale simulations to study the glassy behavior of the 3D extension of the Voronoi model. We first show that the structural relaxation time τ of the 3D Voronoi model can be tuned between sub-Arrhenius and Arrhenius behavior, like the 2D Voronoi model. We then establish that the four-point susceptibility, the structure factor, and the model's mechanical properties all display trends consistent with the 2D Voronoi model. These results provide strong evidence that sub-Arrhenius glassy dynamics are a generic feature of under-constrained materials across dimensions. Our work thus broadens the class of disordered materials known to have highly unusual glassy phenomenology.
Competing roles of aggregation and interfacial interactions in sustainable protein/cellulose nanocrystal-reinforced soft composites.
Jin H, Goldberg W, Wang Z … +4 more , Li H, Huang Y, Foston M, Genin GM
Soft Matter · 2026 Jun · PMID 42300076 · Publisher ↗
Renewable protein matrix nanocomposites reinforced with high-aspect-ratio cellulose nanocrystals (CNCs) offer promising alternatives to petroleum-based plastics. However, they exhibit mechanical properties far below theo...
Renewable protein matrix nanocomposites reinforced with high-aspect-ratio cellulose nanocrystals (CNCs) offer promising alternatives to petroleum-based plastics. However, they exhibit mechanical properties far below theoretical predictions, often approaching the Hashin-Shtrikman lower bound despite filler geometries that should approach upper-bound behavior. This discrepancy suggests that microstructural features not captured in standard homogenization approaches dominate the mechanical response. We develop a hierarchical Mori-Tanaka framework that accounts for two competing effects: CNC agglomeration, which diminishes load transfer, and interphase stiffening at CNC-matrix interfaces, which enhances it. Applying this model to soy protein isolate (SPI) composites with unmodified and polydopamine-modified CNCs, we demonstrate attenuation of the high agglomeration inherent to SPI/CNC composites without diminishing favorable interfacial effects. Phase maps reveal conditions that could shift composite performance toward the upper bound, making SPI/CNC bio-nanocomposites a potential sustainable alternative to petroleum-based plastics.
The division of vesicles requires the fission of closed membrane necks but does not require active processes.
Lipowsky R
Soft Matter · 2026 Jun · PMID 42300069 · Publisher ↗
One important objective of soft matter science and synthetic biology is to construct synthetic systems and processes that mimic the division of cells and organelles. Such division processes have been achieved experimenta...
One important objective of soft matter science and synthetic biology is to construct synthetic systems and processes that mimic the division of cells and organelles. Such division processes have been achieved experimentally for giant vesicles and for nanovesicles. Here, we analyze recent studies of these division processes, focussing on results that have been obtained by our group, using a combination of theory, experiment, and simulation. We show that the division of vesicles requires the formation and fission of closed membrane necks but does not require chemomechanical coupling to active processes such as nucleotide hydrolysis. Closed membrane necks are formed when the vesicle volume is decreased or the membrane area is increased, provided the vesicle is enclosed by an asymmetric bilayer with a sufficiently large transbilayer asymmetry between its two leaflets. The membrane necks experience a constriction force that is controlled by the spontaneous curvature for giant vesicles and by the stress asymmetry for nanovesicles. A sufficiently large constriction force leads to neck fission and vesicle division as observed for vesicle membranes (i) with uniform lipid-protein composition, (ii) with intramembrane domains of distinct lipid-protein compositions, and (iii) in contact with condensate droplets. Most of these biomimetic division processes involve membrane proteins that act to increase the transbilayer asymmetry but none of them is coupled to an active process such as nucleotide hydrolysis.
Chemically triggered rapid degradation of tetraPEG gels cross-linked with a diacylhydrazine-containing cross-linker.
Sekiguchi S, Sakai T, Tsuchiya K
Soft Matter · 2026 Jun · PMID 42300064 · Publisher ↗
Controlling the degradability of cross-linked polymer materials is essential for designing soft materials that combine structural stability during use with on-demand disassembly at the desired time. Herein, we report a c...
Controlling the degradability of cross-linked polymer materials is essential for designing soft materials that combine structural stability during use with on-demand disassembly at the desired time. Herein, we report a chemically degradable tetra-armed poly(ethylene glycol) (tetraPEG) hydrogel cross-linked with a newly designed diacylhydrazine-containing cross-linker. The cross-linker incorporates cysteine residues as reactive sites and a diacylhydrazine moiety as a chemically cleavable unit that undergoes rapid scission in response to sodium hypochlorite (NaClO). The cross-linker exhibited efficient reactivity toward maleimide compounds through thiol-maleimide click chemistry, enabling the formation of a stable tetraPEG network from tetraPEG bearing maleimide end groups. Upon treatment with NaClO, the tetraPEG gel underwent rapid degradation in a concentration-dependent manner. Microscopic analysis further revealed that the squared diameter decreased nearly linearly with time, consistent with a diffusion-limited surface erosion process. The degraded polymer component was almost identical to the original tetraPEG precursor, indicating that network cleavage occurred selectively at the diacylhydrazine units to release soluble tetraPEG chains. These results demonstrate that diacylhydrazine-based cross-linking provides an effective strategy for constructing robust yet chemically degradable hydrogel networks with controllable degradation behavior.
Non-native square packing and structural arrangement of ultrahigh molecular weight diblock copolymer from one-step solvent vapor annealing.
Wang Y, Joy A, Hnatchuk N … +6 more , Pawale T, Ogunrinola T, Gurung V, Berman D, Bao Y, Li X
Soft Matter · 2026 Jun · PMID 42300008 · Publisher ↗
Block copolymer self-assembly provides a promising method of generating nanoscale periodic structures with long-range order, serving as a template for advanced nano-lithographic applications. However, their intrinsic ten...
Block copolymer self-assembly provides a promising method of generating nanoscale periodic structures with long-range order, serving as a template for advanced nano-lithographic applications. However, their intrinsic tendency towards free-energy minimization typically limits the accessible morphologies to thermodynamically preferred arrangements such as spheres on cubic lattices, hexagonally packed cylinders, or alternating lamellae. In this study, we demonstrate the formation of unconventional well-ordered square-packed arrays of vertical cylinders through one-step solvent annealing of ultrahigh molecular weight (UHMW) block copolymers (BCPs). The square-packed morphology observed in this study emerges from the interplay between low solvent vapor pressure, sluggish chain dynamics, and molecular polydispersity in UHMW BCPs, which collectively and kinetically trap the system in a metastable, nonequilibrium state favoring square symmetry. Furthermore, the introduction of a homopolymer facilitates defect healing, enhances structural stability, and enlarges the domain size by approximately 30%. These findings establish a pathway for generating square arrays as soft templates for advanced nanofabrication, offering direct compatibility with conventional integrated circuit design and fabrication.
Geometric control of motility-induced phase separation.
Webb TH, Ansell HS, Sussman DM
Soft Matter · 2026 Jun · PMID 42299970 · Publisher ↗
Curvature fundamentally alters the collective properties of soft, active, and biological materials. Here we study motility-induced phase separation (MIPS), a canonical non-equilibrium transition, and demonstrate that eve...
Curvature fundamentally alters the collective properties of soft, active, and biological materials. Here we study motility-induced phase separation (MIPS), a canonical non-equilibrium transition, and demonstrate that even weak and slowly varying curvature provides robust geometric control over the dense MIPS phase. This includes dictating both the location and morphology of the MIPS cluster, even in regimes where curvature has minimal effect on the overall phase boundaries. Focusing on active Brownian particles confined to the surface of a torus, we show that varying the aspect ratio drives a structural transition of the dense cluster from a disk localized at the outer equator to a band wrapping the minor circumference. We then discuss how the curved geometry provides a platform for comparing different theoretical frameworks for the MIPS phase: by analyzing the geometries of the cluster boundaries, we show that the dense phase shape is more consistent with a boundary-length-minimizing, thermodynamic picture than with the simplest kinetic picture in the large-particle-number limit. Our results establish curved space not only as a tool to shape and guide non-equilibrium dynamics, but as a uniquely sensitive arena for probing the fundamental mechanisms of active matter.
Measuring the elastic properties of granular hydrogels: effects of capillary interaction and ionic conditions.
Zhao J, Zhong H, Gan Y
Soft Matter · 2026 Jun · PMID 42299969 · Publisher ↗
The elastic properties of granular hydrogels are commonly characterised under wet conditions, yet the influence of capillary interactions remains unclear. In practical applications, hydrogels operate in aqueous environme...
The elastic properties of granular hydrogels are commonly characterised under wet conditions, yet the influence of capillary interactions remains unclear. In practical applications, hydrogels operate in aqueous environments containing dissolved ionic species, where swelling and elastic behaviour depend sensitively on ionic conditions. In this study, an experimental setup is developed to measure the elastic responses of granular hydrogels under wet conditions. This setup directly observes liquid-bridge formation and its evolution during compression. Our results show that neglecting capillary contributions leads to a systematic underestimation of Young's modulus of hydrogels. This underestimation due to the capillary interaction increases as the sample size or intrinsic stiffness decreases. In addition to the swelling ratio, the tested samples were also prepared under controlled salinity conditions. The experimentally observed dependence of stiffness on swelling and salinity conditions is well captured by a modified constitutive model. This study offers a robust testing protocol for measuring the elastic properties of hydrogels under various environmental conditions.
Drop volume effect on the advancing macroscopic contact angle.
Issa R, Benabdelhalim H, Medale M … +1 more , Brutin D
Eur Phys J E Soft Matter · 2026 Jun · PMID 42234346 · Publisher ↗
We investigate the influence of drop volume on partial wetting of sessile drops on a horizontal solid substrate for up to large Bond numbers, considering water on both polymethyl methacrylate (PMMA) and aluminum-coated s...
We investigate the influence of drop volume on partial wetting of sessile drops on a horizontal solid substrate for up to large Bond numbers, considering water on both polymethyl methacrylate (PMMA) and aluminum-coated substrates, as well as glycerol on PMMA. The horizontal orientation of the substrate, along with methods for creating sessile drops, facilitated the rotational symmetry of drops to perform controlled and reproducible experiments. In particular, we explore the manner in which the statistic macroscopic contact angle (MCA) depends on the sessile drop volume or related Bond numbers, whether the drop is injected via a syringe positioned above the substrate (DSA30 Krüss equipment) or from below the substrate through a tiny hole drilled in it. In both cases, experimental results exhibit that as the drop volume is increased spanning Bond numbers in the range [0.1-14], the contact line advances on the substrate and the MCA significantly decreases down to an asymptotic value.
Giant nonequilibrium fluctuations in dilute and semidilute polymer solutions subjected to large temperature gradients.
Kantelhardt J, Zapf D, Köhler W
Eur Phys J E Soft Matter · 2026 Jun · PMID 42230401 · Full text
Shadowgraph experiments have been performed on giant nonequilibrium fluctuations in solutions of polystyrene in toluene with polymer molar masses between 2.1 and 90.9 kg/mol and mass fractions ranging from 0.002 up to 0....
Shadowgraph experiments have been performed on giant nonequilibrium fluctuations in solutions of polystyrene in toluene with polymer molar masses between 2.1 and 90.9 kg/mol and mass fractions ranging from 0.002 up to 0.6. Due to the large Soret coefficient of the polymer and the applied temperature difference of 50 K, a linear model is not sufficient to describe the time-dependent and static structure functions. Nonlinearities stemming mainly from the highly nonlinear concentration profile, as well as from the temperature and concentration dependence of various thermophysical parameters, are taken into account using a previously developed layer model. This model enables a detailed analysis of the signal generation within the shadowgraph cell. The thermal structure function mainly emerges from the hot top plate. For short polymer chains and/or low concentrations, the solutal structure function is dominated by the cold side. However, due to the complicated interplay between the Soret effect, the viscosity, and the gravitational quench, this can change for long chains and high concentrations, with the strongest solutal signal emerging from the hot side. Situations involving a non-monotonous layer sequence are also possible. The simulated structure functions agree reasonably with experimental data.
Thermodiffusion and thermo-osmosis in thin membranes with slit pores.
Hafskjold B, Kjelstrup S
Eur Phys J E Soft Matter · 2026 Jun · PMID 42223849 · Full text
Waste heat sources are potentially useful for component separation in fluid mixtures. To better understand how thermal driving forces can contribute to separation, we have investigated the Soret balances of forces for th...
Waste heat sources are potentially useful for component separation in fluid mixtures. To better understand how thermal driving forces can contribute to separation, we have investigated the Soret balances of forces for thermodiffusion and thermo-osmosis. A set of two-component fluid isotope mixtures with mass ratio has been investigated in membranes with molecular-sized pores. Numerical support generated by molecular dynamics simulations is achieved for two models; one for the Soret coefficient, , and one for the thermo-osmotic coefficient, , where is a parameter for the fluid-membrane interactions, refers to a difference across the membrane, H is the bulk fluid enthalpy, and T is the temperature. In these formulas are system-specific constants. The results apply to Lennard-Jones/spline isotope mixtures of mass ratios , with thermally insulating membrane materials, and component-specific fluid-pore interactions. The results give information about how the Soret balances depend on membrane properties, which potentially can be used to tailor membranes for efficient separation.
A study of the interference colors of the microscopic textures simulated along the lyotropic phase sequence: cholesteric discotic-cholesteric biaxial-unwound cholesteric calamitic.
Lüders DD, Akpinar E, Delmanoco GE
Eur Phys J E Soft Matter · 2026 Jun · PMID 42223814 · Full text
The interference colors of the microscopic textures, observed under a polarized microscope for the oriented cholesteric discotic (Ch)-cholesteric biaxial (Ch)-unwound cholesteric calamitic (N) phases sequence in the pres...
The interference colors of the microscopic textures, observed under a polarized microscope for the oriented cholesteric discotic (Ch)-cholesteric biaxial (Ch)-unwound cholesteric calamitic (N) phases sequence in the presence of a magnetic field, were studied in this work. The referred textures were interpreted from both experimental and theoretical views. The lyotropic nematic host mixtures consisted of potassium laurate (KL), 1-undecanol (unDeOH), potassium sulphfate (KSO), and water (HO). The chiral guest molecule brucine was added to the host nematic mixture to induce the cholesteric phases. The refractive indices and birefringences of the lyotropic samples were measured along the nematic calamitic (N)-nematic biaxial (N)-nematic discotic (N) phases sequence as a function of temperature, and they were used to simulate the stripe textures of the oriented cholesteric phases, Ch and Ch, theoretically. It was shown that the experimental and simulated results are in good agreement with each other.
Particle sizing in milk by combined differential dynamic microscopy and cryo-FIB-SEM tomography.
Bradley JJ, Laidlaw FHJ, Pendry T … +7 more , Li NYD, Boggon AK, Glen T, Martinez VA, Arlt J, Thijssen JHJ, Poon WCK
Soft Matter · 2026 Jun · PMID 42210860 · Full text
Milk is a suspension with a multimodal size distribution of fat droplets and protein micelles, which most sizing methods do not distinguish. We demonstrate the use of differential dynamic microscopy (DDM) and cryo-FIB-SE...
Milk is a suspension with a multimodal size distribution of fat droplets and protein micelles, which most sizing methods do not distinguish. We demonstrate the use of differential dynamic microscopy (DDM) and cryo-FIB-SEM tomography to size both fat globules and casein micelles in homogenised milk without the need for prior physical separation. The two techniques are complimentary: cryo FIB-SEM tomography can directly identify the 2 distinct constituents and reveal their overlapping size distributions. DDM reliably detects a bi-modal size distribution for whole milk samples, providing a fast high-throughput method to estimate volume-averaged mean sizes. Our results highlight that different sizing techniques seldom, if ever, yield the same answer. Instead, they can provide complementary information and further insights not obtainable from using each technique in isolation.
Dynamical universality and vibrational divergence in 2D supercooled liquids, quasicrystals, and crystals.
Bedolla-Montiel EA, Dijkstra M
Soft Matter · 2026 Jun · PMID 42206667 · Full text
We investigate the dynamical behavior and vibrational properties of three structurally distinct two-dimensional systems: a supercooled binary liquid, a dodecagonal quasicrystal (DDQC), and a hexagonal crystal. Using mole...
We investigate the dynamical behavior and vibrational properties of three structurally distinct two-dimensional systems: a supercooled binary liquid, a dodecagonal quasicrystal (DDQC), and a hexagonal crystal. Using molecular dynamics simulations, we find that all three systems exhibit transient caging in the mean-squared displacement and non-Gaussian single-particle displacement statistics. However, the temperature dependence of the dynamics differs markedly among them. In the supercooled liquid, the peak of the non-Gaussian parameter increases upon cooling, reflecting the growth of dynamical heterogeneity. In contrast, in the DDQC, the peak decreases as temperature is lowered, consistent with the progressive suppression of thermally activated, localized rearrangements. For the DDQC, this behavior is confirmed by the cage-relative self part of the van Hove function, which shows a systematic suppression of large single-particle displacements upon cooling. At the same time, the DDQC exhibits a large dynamical susceptibility, indicating that many-body dynamical correlations remain strong despite the reduction of large particle displacements upon cooling. A real-space cluster analysis reveals that mobile particles remain organized into extended, spatially correlated, dynamical clusters, with temperature primarily affecting the cluster-size distribution rather than the intrinsic cluster morphology. The vibrational spectra further differentiate the three systems: the crystal exhibits van Hove singularities, the supercooled liquid shows a boson peak, and the DDQC displays additional low-frequency contributions associated with quasiperiodic order. These results establish the DDQC as an intermediate state, combining glass-like caging dynamics with vibrational signatures strongly influenced by quasiperiodic order.
Hydrodynamic scattering of a neutral squirmer by a near-wall curved obstacle: MPCD simulations and analytical theory.
Nagar PK, Chauhan D, Pandey H … +2 more , Babu SB, Pandey K
Soft Matter · 2026 Jun · PMID 42206632 · Publisher ↗
Microscopic swimming organisms exhibit a wide range of behaviours, including swarming, synchronized motion, and clustering, driven by hydrodynamic interactions with each other and the environment. Designing artificial mi...
Microscopic swimming organisms exhibit a wide range of behaviours, including swarming, synchronized motion, and clustering, driven by hydrodynamic interactions with each other and the environment. Designing artificial microswimmers requires understanding the flow in constrained environments, such as microchannels or between obstacles. In this article, we explore the dynamics of a circular neutral squirmer near a curved wall-mounted obstacle. Using a multiparticle collision dynamics simulation, it is observed that the neutral squirmer always scatters from the obstacle. We measured the scattering angle from simulation, which agrees with analytical calculations based on Faxén's law and the far-field approximation. Further investigation reveals similarities to classical scattering with a repulsive potential.
Equilibrium fluctuations of a quasi-spherical vesicle: role of the membrane dissipation.
Vlahovska PM, Granek R
Soft Matter · 2026 May · PMID 42201773 · Publisher ↗
We theoretically investigate the thermally-driven curvature and lipid density fluctuations of a quasi-spherical vesicle, accounting for the dissipation due to monolayer viscosity and intermonolayer friction. The theory p...
We theoretically investigate the thermally-driven curvature and lipid density fluctuations of a quasi-spherical vesicle, accounting for the dissipation due to monolayer viscosity and intermonolayer friction. The theory predicts that membrane curvature makes long-wavelength undulations sensitive to membrane viscosity and speeds up the relaxation of the lipid density fluctuations. Implications for the dynamic roughness and dynamic structure factor measurements of submicron liposomes on nano-second time scales are discussed. Specifically, a clear stretched-exponential relaxation regime may not exist, in contrast to the behavior of planar membranes for which an anomalous diffusion exponent of 2/3 has been predicted [A. G. Zilman and R. Granek, Undulations and dynamic structure factor of membranes, , 1996, , 4788-4791].
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