Soft Matter最新文献

{"title":"Progressive colloidal clogging mechanism by dendritic build-up in porous media†","authors":"Walid Okaybi, Sophie Roman and Cyprien Soulaine","doi":"10.1039/D5SM00285K","DOIUrl":"10.1039/D5SM00285K","url":null,"abstract":"<p >Colloidal transport in porous media governs deposition and clogging mechanisms that critically influence flow behavior and impact the efficiency of both natural and industrial systems. However, the role of dendritic structures, a distinct deposition morphology, in this process remains unclear. Understanding the formation and growth of dendrites is essential for advancing clogging dynamics and assessing their impact on permeability. To address this, we perform microfluidic flow experiments and computational fluid analysis to observe and characterize dendrite formation in a heterogeneous tortuous porous domain. Our results reveal a novel clogging mechanism – dendrite clogging – where a single deposition site initiates a structure that extends across the pore space, bridging grains and causing complete clogging. Unlike previously described aggregation-based clogging, which involves multiple deposition sites, dendrite clogging evolves from a single-site deposition. We establish a flow-dependent criterion for dendrite formation by combining hydrodynamic-adhesive torque balance analysis with experimental deposition patterns. Our findings show that dendrites form when front cone stagnation regions are large enough to accommodate multilayer deposition. Moderate flow rates promote dendrite growth, leading to abrupt permeability loss. In contrast, higher flow rates suppress dendrite formation, resulting in a more gradual decline, as captured by the Verma–Pruess permeability–porosity model. Our results provide a predictive model for flow-induced colloidal deposition, with implications for improving filtration systems, groundwater flow, and biomedical microfluidics. Insights into dendrite-driven clogging could lead to methods for reducing clogging in porous systems and optimizing flow performance in diverse applications.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 28","pages":" 5687-5698"},"PeriodicalIF":2.9,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144473396","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":"Influence of polymer architecture, ionization, and salt annealing on the stiffness of weak polyelectrolyte multilayers†","authors":"Jordan Brito, Annie Luse, Aliaksei Aliakseyeu and Svetlana A. Sukhishvili","doi":"10.1039/D5SM00298B","DOIUrl":"10.1039/D5SM00298B","url":null,"abstract":"<p >The layer-by-layer deposition of polyelectrolyte multilayers (PEMs) is a versatile and widely used technique of forming nanoscale polymer films with controlled properties. Yet, the influence of polymer architecture and assembly conditions on the mechanical properties of PEM films is not well understood. In this paper, we compare the growth and mechanical properties of all-linear PEM films <em>versus</em> all-star (8-arm) PEM films assembled at varied assembly pH. The properties of these PEM systems, composed of linear and 8-arm weak polyelectrolytes poly(2-aminoethyl methacrylate) (PAMA) and poly(methacrylic acid) (PMAA), are affected by the assembly pH, leading to differences in internal ionization, film growth rates, swelling, and Young's modulus. For films assembled using either linear or star polyelectrolytes in acidic conditions – where PMAA has low ionization – we show slow, linear growth with reduced swelling and similar Young's moduli of the as-deposited PEM films. However, a striking difference in the mechanical behavior of dry PEM films made from linear and star polymers was found for the films showing nonlinear growth (<em>i.e.</em>, assembled at neutral and slightly alkaline conditions). Specifically, while all-star films demonstrated relatively high, thickness-independent Young's moduli, the stiffness of all-linear PEM films strongly decreased with film thickness, reflecting the overall weakening of the network of ionic connections. Finally, we show that the ductility of all-star films was more affected by salt annealing than all-linear films, which agrees with previous reports of faster salt-induced diffusion of polyelectrolytes in PEM films composed of star polymers.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 29","pages":" 5883-5893"},"PeriodicalIF":2.9,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00298b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144525553","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}

{"title":"Unravelling the self-assembly of a novel cationic pseudo-gemini surfactant and its monomeric counterpart: interactions with DNA and BSA in aqueous medium at neutral pH†","authors":"Homen Dahal, Sachin Soren, Shashi Kumar and Joykrishna Dey","doi":"10.1039/D5SM00075K","DOIUrl":"10.1039/D5SM00075K","url":null,"abstract":"<p >The demand for sustainable, efficient, and easily tunable cationic surfactants is growing rapidly due to their pivotal role in gene therapy, drug delivery, and biotechnology. However, conventional gemini surfactants often require laborious synthesis and lack design flexibility. Here, we introduce a novel pseudo-gemini surfactant system, innovatively constructed through simple non-covalent electrostatic interactions between a hydrophobic tertiary amine and a dibasic acid. This minimalist design approach bypasses traditional synthetic complexity, offering a rapid, modular pathway to functional surfactants. Our findings demonstrate that this new surfactant not only self-assembles into thermodynamically stable structures but also exhibits superior binding affinity to key biomacromolecules like DNA and BSA, as validated by spectroscopy and docking studies. The strong and specific interactions underscore its potential for high-impact applications in biomedicine. This work redefines the design paradigm for cationic surfactants and addresses an urgent need for accessible yet high-performance agents in therapeutic and industrial settings.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 27","pages":" 5515-5528"},"PeriodicalIF":2.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144332110","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":"Co-assembly of nanometer- and submicrometer-sized colloidal particles into multi-component ordered superstructures†","authors":"Javier Fonseca, Li Jiao, Anna Broto-Ribas, Gurvinder Singh and Angang Dong","doi":"10.1039/D5SM00247H","DOIUrl":"10.1039/D5SM00247H","url":null,"abstract":"<p >Despite advances in computational chemistry and modeling, the discovery of new materials still remains largely empirical, often resembling an art rather than a precise science. A promising approach is to prepare superstructures from building blocks with intrinsic useful properties. Monodisperse nanometer- and submicrometer-sized colloidal particles, in particular, serve as versatile building blocks for this purpose. Their assembly has become a popular “bottom-up” method for creating superstructures. When two or more types of colloidal particles co-assemble, they form multi-component superstructures—often referred to as metamaterials—with diverse ordered arrangements and new properties emerging from synergistic interactions between the different particles. This review aims to systematically explore the co-assembly of two or more types of uniform nanometer- and submicrometer-sized colloidal particles into these multi-component superstructures. We also cover the fundamentals of particle assembly, including the development of uniform particles, maintaining their colloidal stability, and controlling the interparticle forces. Additionally, we discuss the kinetics of particle assembly, summarize the methods used to prepare particle superstructures, address defects that may occur, and provide an overview of their characterization techniques. Finally, we outline the challenges and opportunities in designing multi-component superstructures with ordered arrangements.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 28","pages":" 5583-5654"},"PeriodicalIF":2.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00247h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144525551","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}

{"title":"Double symmetry breaking in filamentous colloidal tactoids†","authors":"Madina Almukambetova, Hamed Almohammadi, Florine Schleiffer and Raffaele Mezzenga","doi":"10.1039/D5SM00236B","DOIUrl":"10.1039/D5SM00236B","url":null,"abstract":"<p >Understanding the dynamics of liquid crystalline tactoids under external forces is of great importance due to their potential applications in optics, medical devices, and displays. However, only recently have tactoids started to be studied systematically under external forces, particularly under extensional flow. Here, we subject tactoids to a shear flow field and study their deformation dynamics under varying conditions of shear and time scales. Using amyloids and nanocellulose to form tactoids from model filamentous colloids with opposite sequences of chirality amplification (left-handed mesoscopic → right-handed cholesteric for amyloids; right-handed mesoscopic → left-handed cholesteric for nanocellulose), we show a complex deformation mechanism in their shape and internal structure under shear flow. When tactoids deform perpendicularly to their long axis, a double symmetry breaking occurs in both their contour shape, with the emergence of a kink, and the orientation of their nematic field. We further show that the mesoscopic chirality of the building blocks directs the position of the kink, with the macroscopic tactoid asymmetry being mirrored when inverting the mesoscopic chirality of the constitutive filamentous colloids, <em>e.g.</em>, from the left-handed amyloids to the right-handed nanocellulose.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 30","pages":" 6039-6046"},"PeriodicalIF":2.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00236b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144537509","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}

{"title":"Unraveling molecular mechanisms of aging dynamics in the Kob–Andersen model: the role of free volume†","authors":"Yifan Yang, Yuyuan Lu, Yaozhang Yang, Xia Wang and Lijia An","doi":"10.1039/D5SM00447K","DOIUrl":"10.1039/D5SM00447K","url":null,"abstract":"<p >This study elucidates the role of free volume in the aging dynamics of the Kob–Andersen (KA) model through temperature cycling experiments. By examining the relationship between free volume and key phenomena such as aging, rejuvenation, and memory effects, we clarify how free volume influences the aging process in this system. Our results reveal a strong correlation between local free volume and the fraction of fast-moving particles, both of which significantly affect the dynamic susceptibility. This indicates that aging dynamics are largely governed by rapidly relaxing particles residing in regions of larger local free volume. Notably, we find no evidence of rejuvenation effects, in contrast to previous reports on the Weeks–Chandler–Andersen (WCA) system; however, memory effects are observed and attributed to minimal local structural rearrangements during aging. Taken together, these findings contribute to a more detailed molecular-level understanding of aging dynamics and provide valuable perspectives on the complex behavior of glassy systems.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 27","pages":" 5542-5552"},"PeriodicalIF":2.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144332106","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":"Liquid drop impact on granular beds: the influence of drop inertia and grain size","authors":"Alexandre Pontier, Sarah Blosse, Sylvain Viroulet and Laurent Lacaze","doi":"10.1039/D4SM00917G","DOIUrl":"10.1039/D4SM00917G","url":null,"abstract":"<p >This paper explores crater formation resulting from the impact of a liquid drop on a densely packed granular bed composed of lightweight polystyrene beads. Several regimes based on the drop impact velocity <em>v</em> and diameter <em>D</em>, and the grain diameter <em>d</em><small>_g</small> are identified. These regimes are discussed in terms of several dimensionless numbers, including a Froude number Fr, which compares the droplet's kinetic energy to its potential energy at impact, the Weber number We, which compares the inertial to capillary forces, and the size ratio <em>d</em><small>_g</small>/<em>D</em>. At low We, Fr, and <em>d</em><small>_g</small>/<em>D</em>, the dimensionless crater diameter <em>D</em><small>_max</small>/<em>D</em> follows a power-law scaling as We<small>^1/4</small>, consistent with previous studies on droplet impacts on granular surfaces, where the crater size reflects the maximum droplet spreading observed on a solid surface. This situation is thus analysed using a so-called signature approach. In this situation, the crater size is also shown to quantitatively depend on <em>d</em><small>_g</small>/<em>D</em>. When We exceeds a critical value We<small>_c</small>(<em>d</em><small>_g</small>/<em>D</em>), the scaling deviates from We<small>^1/4</small> and the crater size depends mainly on <em>d</em><small>_g</small>/<em>D</em>. This transition is discussed in connection with the onset of droplet splashing. For larger <em>d</em><small>_g</small>/<em>D</em>, a different power-law scaling emerges with an exponent smaller than 1/4, regardless of the value of Fr or We, and the splash transition no longer occurs under these conditions. This is consistent with other studies, highlighting the significant amount of energy transfer in crater formation, therefore referred to as the energetic approach. Overall, the final crater size is found to depend strongly on <em>d</em><small>_g</small>/<em>D</em> among the droplet impact characteristics. To unify part of these observations, the role of local dissipation due to grain contact friction during crater formation is incorporated. This leads to the definition of a new dimensionless number <img>, which combines the effects of grain-to-drop size ratio <em>d</em><small>_g</small>/<em>D</em> and droplet inertia (<em>via</em> Fr). This parameter enables the collapse of <em>D</em><small>_max</small>/<em>D</em> data onto a single curve for the range of parameters investigated in this study.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 29","pages":" 5935-5946"},"PeriodicalIF":2.9,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d4sm00917g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144537510","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}

{"title":"Hacktive matter: data-driven discovery through hackathon-based cross-disciplinary coding†","authors":"Megan T. Valentine and Rae M. Robertson-Anderson","doi":"10.1039/D5SM00401B","DOIUrl":"10.1039/D5SM00401B","url":null,"abstract":"<p >The past decade has seen unprecedented growth in active matter and autonomous biomaterials research, yielding diverse classes of materials capable of flowing, contracting, bundling, de-mixing, and coalescing. These innovations promise revolutionary applications such as self-healing infrastructure, dynamic prosthetics, and self-sensing tissue implants. However, inconsistencies in metrics, definitions, and analysis algorithms across research groups, as well as the high-dimensionality of experimental data streams, has hindered the identification of performance intersections among such dynamic systems. Progress in this arena demands multi-disciplinary team approaches to discovery, with scaffolded training and cross-pollination of ideas, and requires new methods for learning and collaboration. To address this challenge, we have developed a hackathon platform to train future scientists and engineers in ‘big data’, interdisciplinary collaboration, and community coding; and to design and beta-test high-throughput (HTP) biomaterials analysis software and workflows. We enforce a flat hierarchy, pairing participants ranging from high school students to faculty with varied experiences and skills to collectively contribute to data acquisition and processing, ideation, coding, testing and dissemination. With clearly-defined goals and deliverables, participants achieve success through a series of tutorials, small group coding sessions, facilitated breakouts, and large group report-outs and discussions. These modules facilitate efficient iterative algorithm development and optimization; strengthen community and collaboration skills; and establish teams, benchmarks, and community standards for continued productive work. Our hackathons provide a powerful model for the soft matter community to educate and train students and collaborators in cutting edge data-driven analysis, which is critical for future innovation in complex materials research.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 27","pages":" 5381-5392"},"PeriodicalIF":2.9,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482627","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":"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":"<p >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.</p>","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}

{"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":"<p >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.</p>","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}