Soft Matter最新文献

{"title":"Coating-induced lubrication in granular media: from particle-scale tribology to bulk rheology.","authors":"F M Rocha, D Dumont, F Tapia, A Gans, V Bertin, M Nicolas, O Pouliquen","doi":"10.1039/d6sm00039h","DOIUrl":"https://doi.org/10.1039/d6sm00039h","url":null,"abstract":"<p><p>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 <i>μ</i>(<i>I</i>) 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 <i>μ</i>(<i>I</i>) 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.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147831226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rheology of MXene-reinforced dual-network hydrogels in swollen and unswollen states.","authors":"Jiaxin Wu, Ruihui Yun, Yue Liang, Lesen Ma, Mehdihasan I Shekh, Guangming Zhu, Florian J Stadler","doi":"10.1039/d5sm01278c","DOIUrl":"https://doi.org/10.1039/d5sm01278c","url":null,"abstract":"<p><p>We examine the rheological behavior of MXene (MX) reinforced dual network hydrogels based on methacrylated chitosan (CSMA), oxidized dextran (ODXT), and poly(<i>N</i>,<i>N</i>-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.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147830549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of \"antifreeze\" oligopeptides and electric fields on unidirectional ice growth in thin water layers.","authors":"Masato Katoh, Tomonori Waku, Yoshimichi Hagiwara","doi":"10.1039/d5sm01157d","DOIUrl":"https://doi.org/10.1039/d5sm01157d","url":null,"abstract":"<p><p>The suppression of ice crystal growth is an important issue in several fields, such as food preservation in the food industry and the preservation of cells, tissues, and organs in medicine. The use of non-toxic additives, such as antifreeze proteins, is effective for this suppression. Oligopeptides, which are antifreeze protein segments, have recently shown unsatisfactory suppression of ice growth in solution. This study aimed to examine whether the suppressive effect of oligopeptides could be augmented by applying direct- and alternating-current electric fields. We conducted experiments by freezing an aqueous solution of oligopeptides. Successive images of the ice/solution interface were captured using a video camera. The interface velocities were calculated from the images. In the case of water, the interface velocities around the electrodes were lower than those between the electrodes. The latter interface velocities depended on the electric fields. These findings indicate that changes in the orientation of water molecules may contribute to these variations in interface velocities. In the case of the oligopeptide solution, the dependence of the interface velocities in the middle between the electrodes on the strength of the electric field applied was inconsistent with that for water. The interface velocities around the electrodes were different when an alternating-current electric field was applied. This resulted in the migration of oligopeptides caused by the electric fields. We predicted the lateral migration of oligopeptide aggregates in cases with intermittent direct-current and alternating-current electric fields, in which the electrostatic and induced forces varied in space and time. The changes in the lateral positions of the aggregates over time were more noticeable near the electrodes than between the electrodes. This noticeable migration may disturb the local growth of crystalline ice adjacent to the aggregates.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147831243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistic insights into hydrophobicity-dependent antimicrobial selectivity of quaternary ammonium poly(oxanorborneneimide) polymers using coarse-grained simulations.","authors":"Joshua D Richardson, Vincent M Rotello, Reid C Van Lehn","doi":"10.1039/d6sm00170j","DOIUrl":"https://doi.org/10.1039/d6sm00170j","url":null,"abstract":"<p><p>The rapid rise of antibiotic resistance to small molecule drugs has driven the development of materials that directly target and disrupt bacterial cell membranes. Inspired by antimicrobial peptides (AMPs), synthetic polymers are gaining attention as promising antimicrobial materials because their molecular properties, such as hydrophobicity and charge, can be tuned to enhance selective killing of bacterial <i>versus</i> mammalian cells. Poly(oxanorborneneimide) (PONI) polymers, featuring rigid bicyclic monomer units to mimic the amphiphilicity of AMPs, have exhibited high selectivity against a broad spectrum of Gram-negative and Gram-positive bacteria over human cells depending upon their side chain functionalities. However, the mechanistic basis of this selectivity remains poorly understood, limiting the physiochemical insight needed to efficiently design new PONI polymers with enhanced selectivity. In this study, we present a molecular dynamics (MD) simulation framework to investigate PONI-membrane interactions and extract several mechanistically relevant descriptors correlated with experimentally determined activities. Building upon prior experimental studies, we model four PONI polymers with side chains of increasing hydrophobicity to understand interactions with model <i>E. coli</i>, methicillin-resistant <i>S. aureus</i> (MRSA), and human red blood cell (RBC) membranes. Central to this framework, we develop a generalizable coarse-grained parameterization strategy for PONI polymers within the MARTINI 3 force field to enable simulation of polymer-membrane interactions at experimentally relevant length and timescales. Our simulations reveal that experimental activities against different membranes can be related to the propensity for PONI polymers to insert into the membrane, driven by electrostatic and hydrophobic interactions. We find that differences in membrane lipid composition, particularly strong enrichment of cardiolipin in bacterial membranes, play a critical role in the highly selective interactions of moderately hydrophobic polymers with bacterial <i>versus</i> RBC membranes, in contrast with the non-selective toxicity toward both bacterial and human RBC membranes observed with highly hydrophobic polymers.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147831156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stress-aided thermal activation of crack propagation in multidentate hydrogen bonding adhesives.","authors":"Zachary D Lamberty, Ngon T Tran, Daniel B Knorr, Joelle Frechette","doi":"10.1039/d6sm00081a","DOIUrl":"https://doi.org/10.1039/d6sm00081a","url":null,"abstract":"<p><p>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^-20 J (or 35 ± 4<i>k</i>_B<i>T</i> 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.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147830793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of hydrostatic pressure on epithelial dome formation and stability.","authors":"Jianfeng Meng, Guangsong Xie, Yifei Zheng, Huaixuan Chen, Peng Xia, Pengfei Xu, Yingke Xu, Liangfei Tian, Qi Gao, Youhua Tan, Dechang Li, Baohua Ji","doi":"10.1039/d6sm00004e","DOIUrl":"https://doi.org/10.1039/d6sm00004e","url":null,"abstract":"<p><p>Hydrostatic pressure in living organisms is crucial for the formation and stability of hollow structures in tissues and organs. However, the underlying mechanisms governing the collective cell responses to pressure in these processes have not yet been fully understood. Here, we developed a hydrostatic pressure generator to produce various pressures of physiological magnitudes and explored their effects on dome structure formation in the epithelial monolayer. We found that the positive hydrostatic pressure promoted dome formation, while the negative one suppressed it. The positive pressure induced cell autophagy and thus increased transepithelial electrical resistance, which elevated osmotic pressures inside the dome. In addition, the positive pressure induced reorganization of the actin-cytoskeleton, which stabilized the cytoskeleton network and weakened cell-matrix adhesion. Interestingly, during dome expansion, the negative pressure promoted the expansion, which eventually led to dome rupture, while the positive pressure suppressed the expansion and subsequent rupture. Our numerical simulations revealed that the negative pressure produced larger intercellular normal stress within the dome wall, making the dome more prone to rupture. These findings revealed the biophysical mechanisms by which hydrostatic pressure regulates dome formation and stability and provided insights into the effect of external pressure on collective cell behaviors during tissue morphogenesis.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147808964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interfacial ion transport in cellulose nanocrystal-based ionogels with low ionic liquid content.","authors":"Yang Ge, Kyle Shultz, Joyce Sundo, Benjamin A Paren, Pinar Akcora","doi":"10.1039/d6sm00048g","DOIUrl":"https://doi.org/10.1039/d6sm00048g","url":null,"abstract":"<p><p>This study investigates the gel formation of cellulose nanocrystals (CNCs) in a hydrophobic ionic liquid, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIm-TFSI), with the addition of a co-solvent, dimethylformamide (DMF). CNC-based ionogels prepared with very low HMIm-TFSI contents (0.1-0.5 wt%) exhibit higher molar ionic conductivity than gels containing larger amounts of HMIm-TFSI. Application of electric fields to CNC mixtures containing 0.4 wt% HMIm-TFSI induces CNC alignment but does not enhance macroscopic ionic conductivity, indicating that conductivity is not governed by CNC orientation. The enhanced ion mobility and conductivity of CNC-HMIm-TFSI gels are attributed to structuring of HMIm-TFSI near CNC surfaces, which facilitates efficient interfacial ionic transport. Unlike the polymer-CNC networks that are capable of confining a high amount of ionic liquid (95 wt%), the CNC gels with a low HMIm-TFSI amount can order liquids at the interfacial layers and exhibit higher conductivity than the neat ionic liquid.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147757844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural aging of a cohesive and amorphous granular solid under cyclic loading.","authors":"William Hobson-Rhoades, Douglas J Durian, Yue Fan, Hongyi Xiao","doi":"10.1039/d6sm00108d","DOIUrl":"https://doi.org/10.1039/d6sm00108d","url":null,"abstract":"<p><p>We investigate how cyclic loading evolves the structure and deformation behavior of a granular raft composed of particles floating at an air-oil interface. The raft has a disordered particle packing structure and is cohesive due to capillary interactions between particles. Under uniaxial cyclic loading with a small strain amplitude, the raft's packing structure experiences an aging process characterized by logarithmically increasing packing fraction and decreasing structural heterogeneity. The observed structural change is due to particle dynamics that are organized around morphologically evolving voids in the raft. The raft is then subjected to quasi-static tension or compression tests until failure. In comparison with non-aged rafts, the rafts that experienced cyclic loading show a higher strength, higher stiffness, and lower ductility, along with qualitatively different features, such as a stress overshoot in the loading curve.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147757921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rod particle-like viscoelastic behavior of hydroxypropylmethyl cellulose samples with narrow molar mass distributions dissolved in aqueous solutions.","authors":"Misato Yoshida, Daiki Nakagawa, Kengo Arai, Yoshiki Horikawa, Toshiyuki Shikata","doi":"10.1039/d6sm00235h","DOIUrl":"https://doi.org/10.1039/d6sm00235h","url":null,"abstract":"<p><p>The viscoelastic behaviors of aqueous solutions of hydroxypropylmethyl cellulose (HpMC) samples with narrow molar mass distributions were investigated over a wide concentration (<i>c</i>) range. The degree of substitution by methyl groups and the molar substitution number by hydroxypropyl groups of the samples were 1.8 and 0.15. The weight average molar masses (<i>M</i>_w) were 210, 310 and 440 kg mol^-1, and the molar mass distribution indices were less than 1.3 for each sample. The zero-shear viscosity (<i>η</i>₀), the average relaxation time (<i>τ</i>_w), and the steady state compliance (<i>J</i>_e) determined in the <i>c</i> range for HpMC molecules to fully entangle were determined using the molecular number density (<i>ν</i> = <i>cN</i>_A/<i>M</i>_w, where <i>N</i>_A is the Avogadro constant) and the rod particle length (<i>L</i>) of HpMC molecules. The results were reasonably understood on the basis of entangled rod particle suspension rheology, in which <i>η</i>₀ and <i>τ</i>_w are described with <i>L</i>³<i>ν</i> and <i>J</i>_e^-1 is described with <i>ν</i>. Consequently, all the obtained viscoelastic data clearly revealed that the HpMC molecules behave as rod-like particles even in a fully entangled concentration range.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147757776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reconstitution of metabolic reactions within self-assembled, multi-compartment protein vesicles.","authors":"Jooyong Shin, Webley Woods, Yeongseon Jang","doi":"10.1039/d6sm00163g","DOIUrl":"https://doi.org/10.1039/d6sm00163g","url":null,"abstract":"<p><p>Artificial cells that reproduce the spatial organization of metabolism offer a powerful platform for understanding and controlling complex biochemical pathways. In this work, we engineer globular protein vesicles (GPVs) by exhibiting octopine dehydrogenase (ODH), a model monomeric enzyme, on vesicle membranes through the self-assembly of recombinant fusion proteins. The enzymatic GPVs are constructed from two complementary fusion protein building blocks: ODH fused with a glutamic acid-rich leucine zipper (ODH-Z_E) and an elastin-like polypeptide fused with an arginine-rich leucine zipper (Z_R-ELP). The oppositely charged leucine zipper pairs (Z_E and Z_R) form a heterodimer <i>via</i> electrostatic interactions, driving vesicle assembly. Because these interactions are sensitive to ionic strength and stoichiometry, we investigate the effects of salt concentration and molar ratio on self-assembly behavior and vesicle morphology. Enzymatic assays show that ODH displayed on GPVs exhibits enhanced stability and sustained catalytic activity compared to the free enzyme. To recapitulate a two-step enzyme cascade representing the terminal steps of glycolysis and anaerobic fermentation observed in marine invertebrates, we created a hierarchical multicompartment architecture consisting of nanoscale ODH-displaying vesicles (∼500 nm in diameter) encapsulated within giant GPVs (tens of micrometers). We further engineered co-encapsulation and nested configurations to control pyruvate generation and transport across compartments. Fluorescence-based monitoring of NADH consumption reveals that these architectures produce distinct reaction kinetics, underscoring the role of spatial organization in modulating enzymatic behavior. Together, these results highlight the potential of GPVs as customizable platforms for rebuilding metabolic processes within artificial cell-like compartments.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147757789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}