Soft Matter[JOURNAL]
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200 papers
Liquid crystalline order delays crystallisation in mixed surfactant systems.
Khodaparast S, Sharratt WN, Dalgliesh RM … +1 more , Cabral JT
Soft Matter · 2026 May · PMID 42149070 · Publisher ↗
Crystallisation in mixed surfactant systems is often preceded by the formation of intermediate self-assembled structures, whose influence on crystallisation pathways remains poorly understood. In particular, the emergenc...
Crystallisation in mixed surfactant systems is often preceded by the formation of intermediate self-assembled structures, whose influence on crystallisation pathways remains poorly understood. In particular, the emergence of liquid crystalline phases can impact both the onset and progression of crystallisation. Here, we investigate crystallisation upon cooling in aqueous mixtures of sodium dodecyl sulfate (SDS) and dimethyldodecylamine oxide (DDAO) at concentrations relevant to formulated systems, employing dynamic light scattering, cross-polarised optical microscopy, and small-angle neutron scattering. We find that addition of DDAO to 20% SDS promotes the formation of a hexagonal liquid crystalline phase, accompanied by a marked increase in viscosity and a pronounced change in crystallisation kinetics. While the apparent crystallisation temperature is only weakly affected beyond 3 wt% DDAO, the induction time for crystallisation increases by orders of magnitude for DDAO concentrations 5 wt%, indicating a strong retardation of crystallisation within the liquid crystalline regime. Time-resolved small-angle neutron scattering (SANS) reveals that crystallisation proceeds a delayed transformation of the hexagonal phase, with coexistence of liquid crystalline and crystalline structures over extended timescales. This kinetically hindered pathway associated to liquid crystalline order can be exploited to postpone crystallisation (and thus increase metastability) in surfactant formulations without significant changes to overall composition.
Droplet dynamics in textured flow-focusing microchannels: effects of surface texture on deformation and transport.
Kumar R, Eswari G, Bhattacharjee D … +1 more , Atta A
Soft Matter · 2026 Jun · PMID 42149044 · Publisher ↗
This study investigates the post-formation dynamics of water droplets dispersed in an oil continuous phase within a microfluidic flow-focusing channel incorporating lithographically fabricated surface grooves. The effect...
This study investigates the post-formation dynamics of water droplets dispersed in an oil continuous phase within a microfluidic flow-focusing channel incorporating lithographically fabricated surface grooves. The effects of continuous-phase flow rate, interfacial tension, and viscosity ratio on droplet deformation and transport are systematically examined. The role of surface topography is elucidated by quantifying droplet morphology upstream and downstream of the grooved section. At low flow rates, droplets conform closely to the groove geometry, while increasing flow rate promotes a partially suspended state above the oil-filled grooves due to enhanced shear and reduced interfacial residence time. Detailed visualisation of droplet morphologies reveals the coupled influence of hydrodynamics and surface texture. Compared to smooth microchannels, introducing surface texture alters droplet-wall interactions and interfacial behaviour even when the flow rate and fluid properties are unchanged.
Delamination and restructuring inside multilamellar lipid vesicles by a polycation: formation of multi-compartment vesicles.
Cao R, Jain R, Torres IK … +2 more , Oville C, Dinsmore AD
Soft Matter · 2026 Jun · PMID 42149042 · Publisher ↗
We describe experiments and analysis of delamination and reformation of multilamellar vesicles triggered by their interaction with highly charged polycations in the exterior solution. Above a threshold polymer concentrat...
We describe experiments and analysis of delamination and reformation of multilamellar vesicles triggered by their interaction with highly charged polycations in the exterior solution. Above a threshold polymer concentration, the vesicles reform their multilamellar outer membrane into close-packed interior membrane compartments. The process leads to a vesicle with a hierarchically ordered superstructure, , vesicular superparticles. Using giant multilamellar vesicles, we report time-lapse observations of the formation process and also of the breakup process after the polymer is diluted at constant osmotic stress. We show the results of a range of polymer molecular weights and concentrations. We present a simple model that predicts conditions of delamination owing to a competition between electrostatic repulsion among the polymers and the bending elasticity of the membranes. The results pave the way to a new kind of response mechanism in multilamellar vesicles that might lead to soft materials that can change their stiffness or topology on demand.
Lysine containing amphiphilic peptide-based non-cytotoxic soft materials with potential antifungal and antibacterial activities for 3D cell culture.
Banerjee S, Haldar S, Bose S … +5 more , Chatterjee S, Castelletto V, Hamley IW, Sinha DK, Banerjee A
Soft Matter · 2026 May · PMID 42149019 · Publisher ↗
Two amphiphilic peptides each with an N-terminal lysine residue have been designed and synthesized. These self-assembling peptide-based molecules form transparent hydrogels in Tris-HCl buffer at physiological pH. Transmi...
Two amphiphilic peptides each with an N-terminal lysine residue have been designed and synthesized. These self-assembling peptide-based molecules form transparent hydrogels in Tris-HCl buffer at physiological pH. Transmission electron microscopic (TEM) images of the peptide hydrogels reveal a nanofibrillar network. Rheological studies reveal high values of storage moduli for these two enantiomeric peptide hydrogels, demonstrating high mechanical strength. Interestingly, these peptide hydrogels exhibit potential antibacterial properties against multidrug-resistant bacterial strains and antifungal activities with great efficacy. The gelators are cytocompatible with NIH 3T3 and HEK 293 cells. The peptide gelator containing D-amino acid residues displayed excellent proteolytic stability against chymotrypsin, pepsin, and proteinase K. The peptide-based hydrogels were successfully used as a suitable platform for 3-dimensional cell culture, pointing to future applications in regenerative medicine, which, combined with their antimicrobial properties, holds promise for the discovery of new peptide based biomaterials in biomedicine.
Parallel micro- and mesophase transitions of thermoplastic polyurethane induced by thermal annealing.
Lee YC, Lin WC, Zhang YQ … +1 more , Hua CC
Soft Matter · 2026 Jun · PMID 42149002 · Publisher ↗
We report on the first rheology-morphology evidence revealing that, under short-term thermal annealing well below the melting temperature, thermoplastic polyurethanes (TPUs) can undergo parallel micro- and mesophase tran...
We report on the first rheology-morphology evidence revealing that, under short-term thermal annealing well below the melting temperature, thermoplastic polyurethanes (TPUs) can undergo parallel micro- and mesophase transitions. While thermal annealing is shown to promote the well-known microphase transition, characterized by promoted hard segment (HS) associations, we have identified another mesophase transition, characterized by an enhanced aggregation of micron-sized ellipsoidal clusters that harbor the microphase above. Upon increasing system temperature beyond the melting temperature, while the microphase transition eventually diminishes due to its enthalpic nature, the corresponding mesophase transition persists and, thereby, notably modifies the rheological features of the annealed TPUs. The last feature is proposed to arise from the thermal-induced soft segment (SS) entanglement between two proximate TPU clusters during the HS associations, while the inter-cluster SS entanglement remains intact beyond the melting temperature due to its entropic nature. The present findings point to the potential to manipulate the multiscale phase behaviors of TPUs and similar materials for various end applications using easily implementable physical treatments such as thermal annealing.
Modeling the heat of formation of indium telluride via graph entropy descriptors and curve fitting techniques.
Ahmed W, Farzeen A, Ali K … +2 more , Zaman S, Ullah A
Eur Phys J E Soft Matter · 2026 May · PMID 42141347 · Publisher ↗
This study presents an extensive graph-theoretic analysis of the thermodynamic properties of indium telluride (InTe). We analyze the significant relationship between the molecular structure of InTe and its macroscopic be...
This study presents an extensive graph-theoretic analysis of the thermodynamic properties of indium telluride (InTe). We analyze the significant relationship between the molecular structure of InTe and its macroscopic behavior through the application of graph entropy, a fundamental metric in information theory and statistical thermodynamics. In this framework, the chemical structure is depicted as a graph, with atoms as vertices and chemical bonds as edges. We calculate a set of topological indices for InTe, a material that is very useful in thermoelectrics, phase-change memory, and infrared optics. These indices encode the material's structural connectivity in numbers. These indices are used to figure out a range of graph entropies, which measure how complex and information-rich the molecular lattice is. The main part of this work shows strong quantitative links between these graph entropies and important thermodynamic properties, such as heat capacity and heat of formation. We use suitable quadratic surface-fitting models that show exactly how these thermodynamic responses depend on pairs of graph entropies in a nonlinear way. All computational modeling and analysis are conducted to enhance statistical fit, guaranteeing that the chosen models deliver the most dependable predictive capability for comprehending and anticipating the material's stability and thermal characteristics.
Entropy-weighted topological descriptors in QSPR modeling of antituberculosis drugs.
Li X, Kanwal S, Butt HA
Eur Phys J E Soft Matter · 2026 May · PMID 42141329 · Publisher ↗
In this study, we develop quantitative structure-property relationship (QSPR) model using entropy-weighted topological descriptors to predict the physicochemical properties of antituberculosis drugs. The molecular struct...
In this study, we develop quantitative structure-property relationship (QSPR) model using entropy-weighted topological descriptors to predict the physicochemical properties of antituberculosis drugs. The molecular structures of fifteen drugs used to treat tuberculosis were taken from PubChem, and their conventional degree-based descriptors were enhanced via Shannon entropy to account for both structural magnitude and distributional irregularity. These entropy-augmented indices were incorporated into quadratic, cubic, exponential, and logarithmic regression models to describe structure-property relationships. Model validation was performed using unsupervised (Entropy-Property Concordance Index, EPCI) and supervised (Local Regression Concordance, LRC) methods. The results demonstrate that entropy-weighted descriptors significantly improve interpretability, predictive accuracy, and structural validation in QSPR modeling. This approach offers a robust computational framework that can be extended to the rational design and property prediction of macrocyclic ligands and supramolecular assemblies, supporting advances in host-guest chemistry and targeted drug delivery systems.
Structural characterization of phosphatidylcholine lipid monolayers across the liquid-expanded/liquid-condensed phase transition.
Weber K, Reed J, Mueller B … +3 more , Shen C, Brezesinski G, Schneck E
Soft Matter · 2026 Jun · PMID 42132898 · Publisher ↗
Lipid layers are the foundational element of biological membranes and can exhibit heterogeneous structural ordering that impacts membrane function. However, important thermodynamic aspects of transitions between fluid an...
Lipid layers are the foundational element of biological membranes and can exhibit heterogeneous structural ordering that impacts membrane function. However, important thermodynamic aspects of transitions between fluid and ordered lipid phases are still not fully understood. Using state-of-the-art grazing-incidence X-ray diffraction, we are able to re-assess the structural transition between the fluid, liquid-expanded (LE) phase and the chain-crystalline, liquid condensed (LC) phase of Langmuir monolayers of a saturated double-chain phosphatidylcholine (1,2-dipentadecanoyl--3-phosphocholine, diCPC) at the air-water interface, induced by lateral compression. While the sharp diffraction peaks characteristic for the LC phase are seen at phase coexistence but not in the LE phase, the broad peak indicative of LE-like short-range correlations persists throughout the entire transition and beyond. The monolayer's structural parameters are found to depend on the transition progress. These observations indicate that lateral compression at typical speeds is not quasi-static and thereby shed some light on the non-horizontality of the transition plateau in pressure-area isotherms.
Confined labyrinthine pattern in chiral liquid crystal droplets.
Rubio-Saldías M, Fernandez-Gonzalez V, Clerc MG … +2 more , Hidalgo PI, Vergara J
Soft Matter · 2026 May · PMID 42132811 · Publisher ↗
Systems that continuously inject and dissipate energy tend to self-organize, resulting in complex spatial patterns. Labyrinthine patterns are characterized by an arrangement that exhibits local order while lacking global...
Systems that continuously inject and dissipate energy tend to self-organize, resulting in complex spatial patterns. Labyrinthine patterns are characterized by an arrangement that exhibits local order while lacking global order. We experimentally investigate the formation of confined textures in temperature-driven chiral liquid crystal droplets. The observed textures are mainly dominated by labyrinthine patterns. To describe the observed textures, we have theoretically examined the system near the winding/unwinding transition. In this region, we can use a simplified description based on an amplitude equation with inhomogeneous coefficients that account for the confinement imposed by the droplet geometry. Numerical simulations of this model show qualitative agreement with the experimental observations. Our findings offer a novel perspective on the confined textures under various geometric configurations.
Systematic error detection in the database of liquid crystals (LiqCryst) using predictive models.
Uchida Y, Kaji S, Nakano N
Soft Matter · 2026 Jun · PMID 42132795 · Publisher ↗
Experimental data often contain anomalies, which can be errors or previously unrecognised knowledge gaps. While errors undermine the reliability of reported findings, unknown gaps can sometimes point to opportunities for...
Experimental data often contain anomalies, which can be errors or previously unrecognised knowledge gaps. While errors undermine the reliability of reported findings, unknown gaps can sometimes point to opportunities for discoveries. Machine learning (ML) techniques offer a promising means of identifying such anomalies. In this study, we propose a human-in-the-loop approach that integrates domain expertise and an ML model trained on a comprehensive database of phase transition behaviours of liquid crystalline (LC) materials (LiqCryst 5.2) to scrutinise data integrity. The ML model uncovered multiple anomalies in reported chemical data on LC phase transition behaviours, which were subsequently re-examined by human experts to determine whether they were due to errors. Our results demonstrate that the ML model can effectively detect inconsistencies even within a large-scale database widely regarded as an industry standard. At the same time, anomalies that do not originate from errors may highlight unexplored phenomena and thereby stimulate future discoveries. The proposed methodology for systematically reassessing reported chemical data has the potential to be applied broadly across different materials systems and scientific domains.
Hybrid magnetic Janssen effect arising from percolating ferromagnetic grain networks.
Thorens L, Rodriguez S, Taberlet N … +3 more , Bourgoin M, Måløy KJ, Santucci S
Soft Matter · 2026 May · PMID 42132774 · Publisher ↗
When confining granular materials, vertical stresses are redirected toward the sidewalls, causing the pressure at the base of the granular column to saturate - a phenomenon called the "Janssen effect". This behaviour ori...
When confining granular materials, vertical stresses are redirected toward the sidewalls, causing the pressure at the base of the granular column to saturate - a phenomenon called the "Janssen effect". This behaviour originates from the heterogeneous force-chain network within the packing, constrained by geometry and friction. Using ferromagnetic grains under an external magnetic field, we recently demonstrated the remote control of this stress redirection, giving rise to a "magnetic Janssen effect". Here, we go further by showing that the apparent mass of granular columns can be precisely controlled by varying the fraction of ferromagnetic grains and their spatial arrangement within the packing. Combining experiments with discrete-element numerical simulations, we uncover a hybrid magnetic Janssen effect: the apparent mass at the base decreases once the fraction of magnetic grains exceeds a critical threshold. This transition corresponds to the percolation of magnetic clusters, which form a system-spanning network capable of channeling forces laterally. Our findings establish a straightforward pathway toward programmable granular materials, in which load distribution can be actively tuned using external fields.
Multiscale reorganisation of colloidal aggregation by percolating bacterial networks.
Stricker L, Charlton SGV, Secchi E
Soft Matter · 2026 Jun · PMID 42132752 · Full text
Self-assembly in colloidal suspensions emerges from the interplay of local ordering and constraints imposed by the surrounding medium. While motile bacteria are known to alter colloidal dynamics, the influence of non-mot...
Self-assembly in colloidal suspensions emerges from the interplay of local ordering and constraints imposed by the surrounding medium. While motile bacteria are known to alter colloidal dynamics, the influence of non-motile species remains largely unexplored. Here, we study suspensions of colloids and non-motile sedimenting near the wall and forming percolating networks. Using multiscale structural descriptors, we show that bacteria enhance colloidal aggregation into branch-like clusters. In turn, colloids reinforce bacterial networks by extending their elastic backbone. The analysis of mid-range ordering reveals that, unlike purely colloidal suspensions where ordering propagates across 3-4 neighbour shells, bacterial scaffolds suppress this propagation beyond the first shell. These findings highlight how non-motile bacteria reshape colloidal self-assembly across scales, while providing a quantitative framework for studying complex particle-network interactions. This approach opens pathways to understanding analogous processes in natural systems, including those involving microplastic contaminants.
NTA-Ni lipids affect membrane phase behavior and fluorescence of lipid-like dyes.
Mangiarotti A, Altamirano MJ, Dominguez MC … +1 more , Wilke N
Soft Matter · 2026 May · PMID 42132705 · Publisher ↗
The nitrilotriacetic acid group coordinated with nickel, NTA(Ni), is the standard chelator for purifying fusion proteins containing poly-histidine tags. The development of lipids with NTA(Ni) headgroups has enabled the s...
The nitrilotriacetic acid group coordinated with nickel, NTA(Ni), is the standard chelator for purifying fusion proteins containing poly-histidine tags. The development of lipids with NTA(Ni) headgroups has enabled the specific attachment of His-tagged peptides and proteins to model membranes. Recently, these lipids have become essential for the study of surface-mediated protein phase separation and membrane interaction with biomolecular condensates. While this approach is gaining popularity, the intrinsic effects of NTA(Ni) lipids on the properties of the host membrane have been very little studied. As the field begins to unveil the mechanisms driving membrane-condensate interactions, decoupling the effects of the anchor lipid from those of the condensate is critical to avoid misinterpretations. Here, we systematically characterize model membranes containing 18 : 1 DGS-NTA(Ni), one of the most widely used chelator lipids. We evaluate its impact on fundamental membrane properties, including lipid packing, compressibility, and stability. Using Brewster angle microscopy (BAM), we investigate how DGS-NTA(Ni) modulates lipid phase separation. Finally, using fluorescence spectroscopy, we address how nickel ion quenching influences the performance of lipid-like and solvatochromic dyes. Our results demonstrate that DGS-NTA(Ni) lipids show considerable effects on the membrane properties and fluorescence of lipophilic dyes, which must be accounted for when interpreting the effect of His-tagged proteins attached to the membrane or membrane anchored condensates.
Scaling dynamics of particles confined at fluid-fluid interfaces.
Oliveira EB, Correia EL, Winter HH … +1 more , Razavi S
Soft Matter · 2026 May · PMID 42132657 · Publisher ↗
Particle-laden fluid interfaces exhibit complex linear viscoelastic behavior resulting from collective particle dynamics confined to two dimensions. While interfacial rheology has been widely used to characterize such sy...
Particle-laden fluid interfaces exhibit complex linear viscoelastic behavior resulting from collective particle dynamics confined to two dimensions. While interfacial rheology has been widely used to characterize such systems, a consistent framework for comparing relaxation behavior across different particle-laden interfaces remains limited. In this work, we investigate the interfacial shear rheology of hydrophobically modified silica particle monolayers at air-water and oil-water interfaces small amplitude oscillatory shear measurements. Dynamic moduli obtained at different particle surface concentrations are combined into master curves time-surface concentration superposition, and the viscoelastic response is analyzed in terms of relaxation time spectra obtained using the parsimonious spectral approach. The resulting spectra are well described by a truncated double power-law form analogous to the Baumgärtel-Schausberger-Winter spectrum originally developed for bulk viscoelastic materials. We refer to this representation as a two-dimensional BSW (2dBSW) spectrum and demonstrate that it captures the dominant relaxation features of the interfacial networks studied here. To further examine the scope of this approach, published interfacial rheology data for particle-laden interfaces with varying particle attributes and subphase conditions are reanalyzed within the same framework. Despite wide variations in particle type and interfacial environment in these publications, the relaxation spectra collapse onto a common self-similar form consisting of two power law columns of relaxation modes, with the longest relaxation time reflecting the strength of interparticle attractions. This apparent universality suggests that the linear viscoelastic response of particle-laden interfaces is governed by generic network features, making 2dBSW a useful and transferable description of their linear viscoelasticity.
Effect of external salt solution concentration on carboxyl dissociation degree () and p of weak polyelectrolyte membranes for sustainable technologies.
Kim Y, Rahman CM, Shaqfeh MA … +5 more , Tierney KM, Lukaszewski AJ, Kanumuru NS, Kang DE, Oh HJ
Soft Matter · 2026 May · PMID 42132595 · Publisher ↗
Understanding the dissociation process of weakly charged polymers under varied external salt conditions is critical to develop innovative charged polymer membranes with desirable transport properties for sustainable tech...
Understanding the dissociation process of weakly charged polymers under varied external salt conditions is critical to develop innovative charged polymer membranes with desirable transport properties for sustainable technologies. We previously designed a series of weakly charged polymer membranes, , cross-linked acrylic acid (AA)-poly(ethylene glycol) diacrylate (PEGDA) (AA-PEGDA) random copolymer networks with a wide ion-exchange capacity (IEC = 0-4 mequiv. per g) range and limited water swelling. Here, we report the dissociation process in the representative chemical structure of AA-PEGDA series, , 10-2 AA-PEGDA network (PEGDA cross-linker length = 10, mIEC = 2 mequiv. per g) in different external salt concentration solutions (0-1 M NaCl (aq)). When titrated with a strong base (NaOH), both POT titration (detecting a solution phase) and ATR-FTIR analysis (probing a polymer phase) well describe the dissociation process and yield similar ranges of dissociation parameters (, p). The dissociation behavior follows the modified Henderson-Hasselbalch equation, showing lower p values with increasing external salt concentrations. The governing molecular factor for dissociation was determined by comparing four length scales (, , , and ) in the system, including (1) charged group distance in a polymer (), (2) distance between salt ions in an external solution (), the respective (3) Bjerrum length () and (4) Debye screening length (). At the lower external salt concentration (0 M ≤ ≤ 0.01 M), the relative standing of these length scales ( < ≪ < ) indicates that the enhanced electrostatic interaction in dilute conditions suppresses the dissociation in the network and thus increases p. At the higher salt concentration (0.1 M ≤ ≤ 1.0 M), the different order of these length scales ( ≪ ≲ ≲ ) represents that the screened electrostatic interaction the added external salts promotes the dissociation and thus decreases p. As the external salt concentration increases (0-1.0 M NaCl), water swelling in the network slightly decreases due to osmotic deswelling. However, the lower water swelling has very little effect on effectively decreasing the charged group distance in the polymer (), and thus, leads to little substantive influence on the electrostatic interaction (consequently, the dissociation). Therefore, the screened electrostatic interaction by the added external salts dictates the dissociation and p in our system. Our multiscale analysis of dissociation across varying external salt concentrations provides a pathway to tune the dissociation behavior of weakly charged polymers and achieve desired transport properties for target applications.
Macroscopic emulsion drops formed through limited coalescence.
Langevin D
Eur Phys J E Soft Matter · 2026 May · PMID 42118502 · Full text
This short paper is a perspective article related to the seminal paper: S. Arditty, C. P. Whitby, B. P. Binks, V. Schmitt & F. Leal-Calderon "Some general features of limited coalescence in solid-stabilized emulsions" pu...
This short paper is a perspective article related to the seminal paper: S. Arditty, C. P. Whitby, B. P. Binks, V. Schmitt & F. Leal-Calderon "Some general features of limited coalescence in solid-stabilized emulsions" published in 2003 (Arditty et al. in Eur. Phys. J. E 12:355, 2003). I will first briefly recall the work described in this paper and discuss some of the developments that followed its publication. This will include comparisons with different coalescence mechanisms, together with comparisons with surfactant-stabilized emulsions and with particle-stabilized foams. I will end with a few comments on the state of the field of research and on future directions.
Role of wing surface morphology of the Indian carpenter bee in self-cleaning and dew formation.
Narhe R
Eur Phys J E Soft Matter · 2026 May · PMID 42104038 · Publisher ↗
We studied the surface morphology (micro- plus nanostructure) of Indian carpenter bee wings. In comparison with the Stenocara beetle's surface morphology or the lotus leaf surface morphology, the Indian carpenter bee win...
We studied the surface morphology (micro- plus nanostructure) of Indian carpenter bee wings. In comparison with the Stenocara beetle's surface morphology or the lotus leaf surface morphology, the Indian carpenter bee wing shows a different type of surface morphology. It is observed that the two-tire surface morphology of the wings plays a key role in controlling wettability. The equilibrium contact angle (θ) and contact angle hysteresis (Δθ) measurement revealed that the carpenter bees' wings behave as superhydrophobic and self-cleaning for large water drops. Small drops formed by condensation nucleate in microchannels and ridges, grow through condensation and coalescence, and eventually become larger Wenzel or Wenzel-Cassie-Baxter type drops that lose their superhydrophobicity and self-cleaning property. Growth dynamics of condensed water drops on the wing surface show two distinguishing growth laws < R > ~ t, α = 0.41 ± 0.03 in the initial state and < R > ~ t, α = 0.99 ± 0.03 in the self-similar (coalescence-dominated) state with maximum surface coverage ≃ 0.45.
Coating-induced lubrication in granular media: from particle-scale tribology to bulk rheology.
Rocha FM, Dumont D, Tapia F … +4 more , Gans A, Bertin V, Nicolas M, Pouliquen O
Soft Matter · 2026 Jun · PMID 42093569 · Publisher ↗
Coated granular materials are involved in numerous industrial processes, including powder handling in pharmaceuticals, additive manufacturing, cement production, and food processing, where surface treatments control flow...
Coated granular materials are involved in numerous industrial processes, including powder handling in pharmaceuticals, additive manufacturing, cement production, and food processing, where surface treatments control flowability, prevent agglomeration, and improve product consistency. Despite their widespread use, the influence of coatings on the collective behavior of granular materials remains poorly understood. While dry granular flows are well described by the () rheology for frictional, noncohesive particles, many real-world systems involve additional interparticle interactions that fall outside this framework. Here, we investigate how polymer coatings on silica grains modify dry granular rheology by introducing non-Coulombic frictional behavior at the particle scale. Pressure-imposed rheological experiments reveal that coatings activate a low-friction regime in which the bulk friction coefficient and packing fraction approach values typical of frictionless grains. The transition from this lubricated state to a conventional frictional regime depends on both normal stress and shear rate, indicating stress- and velocity-dependent contact mechanics. Tribological measurements show that interparticle friction decreases with coating thickness and sliding velocity, but increases with normal load. Building on these findings, we develop a mean-field rheological model that extends the classical () framework to include coating-dependent, non-Coulombic friction. Discrete Element Method simulations incorporating the measured friction law capture the key qualitative features observed experimentally. These results demonstrate that controlled surface coatings provide a powerful route to engineer granular rheology and enhance flowability across various industrial applications.
Rheology of MXene-reinforced dual-network hydrogels in swollen and unswollen states.
Wu J, Yun R, Liang Y … +4 more , Ma L, Shekh MI, Zhu G, Stadler FJ
Soft Matter · 2026 Jun · PMID 42093505 · Publisher ↗
We examine the rheological behavior of MXene (MX) reinforced dual network hydrogels based on methacrylated chitosan (CSMA), oxidized dextran (ODXT), and poly(,-dimethylacrylamide) (PDMA). Structural characterization usin...
We examine the rheological behavior of MXene (MX) reinforced dual network hydrogels based on methacrylated chitosan (CSMA), oxidized dextran (ODXT), and poly(,-dimethylacrylamide) (PDMA). Structural characterization using FTIR, TGA, and SEM was performed to assess chemical connectivity, composition, and microstructure and to verify the presence and dispersion state of MX within the hydrogel matrix. Small amplitude oscillatory shear is employed to establish linear viscoelastic properties, while large amplitude oscillatory shear and cyclic strain time protocols are used to probe nonlinear softening, deformation induced damage, and mechanical recovery. Measurements are performed for multiple MX loadings in both unswollen and swollen states to separate interfacial reinforcement from concentration effects associated with hydration. MX addition increases elastic dominance, delays the onset of nonlinearity to higher strain, and improves post-deformation recovery, consistent with enhanced polymer filler coupling and transient interfacial constraints. Uniaxial extension further indicates increased resistance to tensile deformation. Swelling measurements reveal MX dependent changes in water uptake and pore morphology. Together, these shear and extensional data establish how the MX content and hydration state jointly regulate the viscoelastic function of multicomponent hydrogels and provide quantitative guidelines for tuning formulations in soft material applications.
Stress-aided thermal activation of crack propagation in multidentate hydrogen bonding adhesives.
Lamberty ZD, Tran NT, Knorr DB … +1 more , Frechette J
Soft Matter · 2026 Jun · PMID 42093409 · Publisher ↗
Adhesives containing multidentate hydrogen bonding moieties are gaining prominence for their ability to adhere strongly underwater. Previous studies attributed their remarkable underwater adhesion to the multiple adjacen...
Adhesives containing multidentate hydrogen bonding moieties are gaining prominence for their ability to adhere strongly underwater. Previous studies attributed their remarkable underwater adhesion to the multiple adjacent attachment points within a moiety stabilizing the bond, enabling cooperative hydrogen bonding. However, as adhesion involves multiple coupled phenomena, isolating the contribution of individual bonds to the adhesive strength remains challenging. Here we investigate the relationship between peeling velocity and adhesion over a range of temperatures to estimate the activation energy of the chemical bonds that fracture at the adhesive interface. We utilize a model epoxy modified by the addition of tridentate hydrogen bonding moieties (DGEBA-Tris). We report on the effect of curing, debonding temperature, and crack velocity on the adhesive strength at the DGEBA-Tris/mica interface. Adhesion is measured using self-arrested crack propagation to probe the threshold velocity above which the energy release rate transitions from velocity-independent to increasing sharply with crack velocity. We measure a shift by two orders of magnitude in the threshold velocity as the debonding temperature increases from 9 °C to 60 °C, consistent with a thermally activated process. The increase in threshold velocity with an increase in temperature follows an Arrhenius dependence revealing a bond activation energy of 14 ± 2 × 10 J (or 35 ± 4 at 20 °C). The bond energy and associated temperature dependence of the energy release rate suggest that adhesion is dominated by cooperative tridentate hydrogen bonds, and that adhesive fracture of these bonds proceeds through an activated process.
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