Soft Matter最新文献_第9页

X-ray fluorescence standing wave study of the interaction of the antimicrobial peptide indolicidin with a supported model membrane† 抗菌肽吲哚啶与支撑模型膜相互作用的x射线荧光驻波研究。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-17 DOI: 10.1039/D5SM00257E

Gobind Basnet, Jonathan Maloney, Jyotsana Lal, Elizabeth Gaillard, Denis T. Keane, Evguenia A. Karapetrova, Raymond Conley and Laurence Lurio

引用次数: 0

Long-range order in two-dimensional systems with fluctuating active stresses† 具有波动主动应力的二维系统的长程阶。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-17 DOI: 10.1039/D5SM00208G

Yann-Edwin Keta and Silke Henkes

{"title":"Long-range order in two-dimensional systems with fluctuating active stresses†","authors":"Yann-Edwin Keta and Silke Henkes","doi":"10.1039/D5SM00208G","DOIUrl":"10.1039/D5SM00208G","url":null,"abstract":"In two-dimensional tissues, such as developing germ layers, pair-wise forces (or active stresses) arise from the contractile activity of the cytoskeleton, with dissipation provided by the three-dimensional surroundings. We show analytically how these pair-wise stochastic forces, unlike the particle-wise independent fluctuating forces usually considered in active matter systems, produce conserved centre-of-mass dynamics and so are able to damp large-wavelength displacement fluctuations in elastic systems. A consequence of this is the stabilisation of long-range translational order in two dimensions, in clear violation of the celebrated Mermin–Wagner theorem, and the emergence of hyperuniformity with a structure factor S(q) ∼ q2 in the q → 0 limit. We then introduce two numerical cell tissue models which feature these pair-wise active forces. First a vertex model, in which the cell tissue is represented by a tiling of polygons where the edges represent cell junctions and with activity provided by stochastic junctional contractions. Second an active disk model, derived from active Brownian particles, but with pairs of equal and opposite stochastic forces between particles. We study the melting transition of these models and find a first-order phase transition between an ordered and a disordered phase in the disk model with active stresses. We confirm our analytical prediction of long-range order in both numerical models and show that hyperuniformity survives in the disordered phase, thus constituting a hidden order in our model tissue. Owing to the generality of this mechanism, we expect our results to be testable in living organisms, and to also apply to artificial systems with the same symmetry.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 28","pages":" 5710-5719"},"PeriodicalIF":2.9,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00208g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Note on two-point mean square displacement 注意两点均方位移。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-16 DOI: 10.1039/D5SM00555H

Naoya Katayama and Takahiro Sakaue

引用次数: 0

Solvent-induced ion clusters generate long-ranged double-layer forces at high ionic strengths† 溶剂诱导的离子团簇在高离子强度下产生长距离的双层力。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-13 DOI: 10.1039/D5SM00027K

David Ribar, Clifford E. Woodward and Jan Forsman

{"title":"Solvent-induced ion clusters generate long-ranged double-layer forces at high ionic strengths†","authors":"David Ribar, Clifford E. Woodward and Jan Forsman","doi":"10.1039/D5SM00027K","DOIUrl":"10.1039/D5SM00027K","url":null,"abstract":"Recent experimental results by the surface force apparatus (SFA) have identified a dramatic deviation from previously established theories of simple electrolytes. This deviation, referred to as anomalous underscreening, suggests that the range of electrostatic interactions increase upon a further addition of salt, beyond some threshold concentration (usually about 1 M). In this theoretical work, we explore an extension of the restricted primitive model (RPM) wherein a short-ranged pair potential of mean force (sPMF) is added to the usual Coulombic interactions so as to mimic changes of the hydration as two ions approach one another. The strength of this potential is adjusted so that the modified RPM saturates at a realistic concentration level (within a range 4–7 M, typical to aqueous 1 : 1 salts). We utilise grand canonical simulations to establish surface forces predicted by the model and compare them directly with SFA data. We explore different sPMF models, which in all cases display significant clustering at concentrations above about 1 M. In these models, we find significant double-layer repulsion at separations that significantly exceed those expected from standard RPM predictions. We do not, however, observe an increase of the screening length with salt concentration, but rather that this screening length seemingly saturates at a (rather high) value. The simulated long-ranged interactions are shown to correlate with ion cluster formation, implicating the important role of accompanying cluster–cluster interactions. In particular, steric interactions between clusters (manifested in density–density correlations) are quite relevant in these systems.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 27","pages":" 5562-5572"},"PeriodicalIF":2.9,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00027k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correction: Evolution of shear zones in granular packings under pressure 修正：压力下颗粒填料中剪切带的演化。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-13 DOI: 10.1039/D5SM90107C

Mahnoush Madani, Maniya Maleki, János Török and M. Reza Shaebani

引用次数: 0

Micromechanical modelling of cellulose hydrogel composites based on coarse-grained molecular dynamics 基于粗粒度分子动力学的纤维素水凝胶复合材料微观力学建模。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-13 DOI: 10.1039/D4SM01488J

Mauricio R. Bonilla, Sridhar K. Kannam, Matthew T. Downton, Monika S. Doblin, Antony Bacic, Michael J. Gidley and Jason R. Stokes

{"title":"Micromechanical modelling of cellulose hydrogel composites based on coarse-grained molecular dynamics","authors":"Mauricio R. Bonilla, Sridhar K. Kannam, Matthew T. Downton, Monika S. Doblin, Antony Bacic, Michael J. Gidley and Jason R. Stokes","doi":"10.1039/D4SM01488J","DOIUrl":"10.1039/D4SM01488J","url":null,"abstract":"The mechanical response and structure of cellulose hydrogel composites (CHCs) are modelled as cellulose microfibrils using a bead-spring coarse-graining approach. Our results demonstrate that varying the adhesive contact energy between the flexible chains, as well as the number of contacts and structural anisotropy, significantly impacts the mechanical response of the network structure under tensile forces. Specifically, decreasing the contact energy and increasing its range is sufficient to increase the network's extensibility while decreasing its overall modulus. This key finding aligns qualitatively with experiments where the inclusion of polysaccharides in bacterial cellulose-based CHCs had an analogous effect. We hypothesise that polysaccharides, including hemicelluloses, facilitate alignment under strain by increasing the range (“softening”) of the contact forces between microfibrils. Conversely, their absence results in “hard” contacts between microfibrils that are more energetic and can only act over short distances. In contrast to finite element models for CHCs, this coarse-grained approach incorporates non-permanent contacts between flexible microfibrils that permits structural rearrangement of the network in response to deformation, whereby controlling the density and proportion of long- and short- range contact forces suffice to qualitatively describe experiments. Controlling interactions between microfibrils thus provides a lever for designing CHCs with specific mechanical properties for various applications. Additionally, we suggest that plants naturally tune these variables in plant cell development to balance wall rigidity and extensibility.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 27","pages":" 5480-5493"},"PeriodicalIF":2.9,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309228","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}

引用次数: 0

Low-profile folding mechanism for multi-DoF feedback control. 低轮廓折叠机构多自由度反馈控制。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-13 DOI: 10.1039/d5sm00143a

Hwayeong Jeong, Jung Kim, Jamie Paik

{"title":"Low-profile folding mechanism for multi-DoF feedback control.","authors":"Hwayeong Jeong, Jung Kim, Jamie Paik","doi":"10.1039/d5sm00143a","DOIUrl":"https://doi.org/10.1039/d5sm00143a","url":null,"abstract":"Soft structures gain their adaptability from a high number of distributed degrees of freedom (DoF). Integrating reconfigurable robotic systems into these soft structures enables efficient transmission of forces and torques, supporting a wide range of tasks. However, implementing actuation, sensing, and transmission components remains challenging, particularly in optimizing their spatial distribution to achieve effective control over the target structure. In this study, we present an embeddable pneumatic system featuring ultra-thin actuators, with integrable sensors and modular transmissions. The system's ultra-thin profile enables seamless and space-efficient integration onto various surfaces, while its modular design enables flexible reconfiguration to suit different mechanical and control needs. The rolling diaphragm mechanism reduces friction and stress on the joints which are more prone to occur in flat structures. The proposed diaphragm has an aspect ratio of approximately 10 (15 mm 1.4 mm cross-section) and achieves a stroke length up to five times its thickness, extendable through modular connection. An optical sensor module is also introduced to provide precise, low-profile feedback without affecting the mechanical characteristics or flatness of the overall system. We demonstrate the control of folding sequence and angle through feedback control, using compactly embedded components within an origami-inspired surface. This approach leverages the geometric principles of folding to enable complex and reconfigurable structures. The proposed integrable actuator, transmission, and sensor module provides a scalable and customizable foundation for developing large-scale robotic systems with intricate geometries and distributed control, supporting seamless deployment and adaptability.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281752","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}

引用次数: 0

Freedericksz transitions in the nematic and smectic ZA phases of DIO† DIO向列相和近晶ZA相的fredericksz跃迁。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-12 DOI: 10.1039/D5SM00238A

J. T. Gleeson, S. N. Sprunt, A. Jákli, P. Guragain and R. J. Twieg

{"title":"Freedericksz transitions in the nematic and smectic ZA phases of DIO†","authors":"J. T. Gleeson, S. N. Sprunt, A. Jákli, P. Guragain and R. J. Twieg","doi":"10.1039/D5SM00238A","DOIUrl":"10.1039/D5SM00238A","url":null,"abstract":"The remarkable material DIO presents fascinating behaviors. It has been extensively studied as one of the first materials exhibiting a ferroelectric nematic phase. However, at higher temperatures it exhibits what has been termed the smectic ZA: identified as an orientationally ordered, antiferroelectric phase with a density modulation in direction perpendicular to the optic axis. At even higher temperatures, this transitions to an apparently normal nematic phase. We have studied the splay-bend Freedericksz transition in the nematic and SmZA phases of the material DIO. Both the magnetic and electric field transitions were utilized. We observed the transitions by measuring effective birefringence and capacitance as well as with polarizing light microscopy. In both the nematic and the SmZA states the field induced transitions resemble (in numerous aspects) the classical Freedericksz transition. These enable determinations of several fundamental material parameters and also reveal intriguing aspects of the SmZA phase, including the surprising behavior of the elastic constants and the dielectric anisotropy. Detailed comparison with Frank elastic theory of the Freedericksz transition shows that the N phase behaves largely as expected, but the transition in the SmZA phase differs significantly. Two specific examples of this are the onset of striations in the Freedericksz distorted state, and the presence of optical biaxiality. The former may be related to the periodic Freedericksz transition as it coincides with a large increase in the splay elastic constant. The latter has been predicted for the SmZA phase, but not previously observed.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 29","pages":" 5862-5870"},"PeriodicalIF":2.9,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00238a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144504245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigating glass transition in a PA6T/66 copolymer through molecular dynamics simulations† 通过分子动力学模拟研究PA6T/66共聚物的玻璃化转变。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-12 DOI: 10.1039/D5SM00165J

Lele Wei, Liping Zhu, Jin Wen and Meifang Zhu

{"title":"Investigating glass transition in a PA6T/66 copolymer through molecular dynamics simulations†","authors":"Lele Wei, Liping Zhu, Jin Wen and Meifang Zhu","doi":"10.1039/D5SM00165J","DOIUrl":"10.1039/D5SM00165J","url":null,"abstract":"Tailoring copolymer composition is a key strategy for enhancing the thermal and mechanical performance of semi-aromatic polyamides. In this work, we investigate the thermal behavior of poly(hexamethylene terephthalamide-co-hexamethylene adipamide) (PA6T/66) copolymers by probing their glass transition temperature (Tg), a critical parameter governing material stability. Classical molecular dynamics simulations reveal Tg trends across PA6T/66 systems with varying molar ratios of poly(terephthaloyl hexylenediamine) (PA6T), in alignment with experimental data obtained from temperature-dependent density analysis. Increasing PA6T content promotes interchain hydrogen bond (HB) formation, which enhances thermal stability by restricting segmental mobility. However, beyond 55% PA6T content, Tg decreases due to steric hindrance from stacked benzene rings and a shift in the interchain/intrachain HB equilibrium, which disrupts cohesive interactions. These findings reveal the thermal properties at the atomic scale by which PA6T content modulates Tg, providing a molecular-level understanding that offers valuable guidelines for designing PA6T/66 copolymers with enhanced thermal performance.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 27","pages":" 5553-5561"},"PeriodicalIF":2.9,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473394","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}

引用次数: 0

Topology effects on associative polymers† 结合聚合物的拓扑效应。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-12 DOI: 10.1039/D5SM00368G

John M. Bracewell, Rosita Sivaraj, Dvora Perahia and Gary S. Grest

{"title":"Topology effects on associative polymers†","authors":"John M. Bracewell, Rosita Sivaraj, Dvora Perahia and Gary S. Grest","doi":"10.1039/D5SM00368G","DOIUrl":"10.1039/D5SM00368G","url":null,"abstract":"Tailoring the topology of associative polymers offers a means to control macromolecular responses that in turn enables the design of new responsive soft materials. The current study probes the conformation and response of ring associative polymers in comparison with their entangled linear analogues using molecular dynamics simulations of a coarse-grained bead-spring model. The uniqueness of ring polymers lies in their topology where the chains have no free ends, resulting in considerably faster dynamics compared to their linear analogs, whereas the associative groups drive assembly that constrains the polymer motion. Here, polymers consisting of randomly distributed associative groups, with a fraction f = 0.02 to 0.1 and interaction strength varying from 2 to 8kBT, were studied. We find that with increasing f and association strength, larger clusters of associative groups are formed, where their size and dynamics are strongly affected by chain topology. While the associative groups do not impact the chain conformation, they slow stress relaxation, with a distinctively stronger effect on the linear chains. This is attributed to the lower number of unique chains associated with clusters of the same size in ring melts compared with linear ones. Overall, the coupling of associating groups with entanglements results in slower stress relaxation, where the distinctive topologies affect the association of the chains.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 29","pages":" 5823-5832"},"PeriodicalIF":2.9,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473398","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}

引用次数: 0