Soft Matter最新文献

{"title":"A novel microscopic origin of co-nonsolvency†","authors":"Xingye Li, Zhiyuan Wang, Zheng Wang, Yuhua Yin, Run Jiang, Pengfei Zhang and Baohui Li","doi":"10.1039/D5SM00164A","DOIUrl":"10.1039/D5SM00164A","url":null,"abstract":"<p >Co-nonsolvency presents a fundamental paradox in polymer physics where macromolecules undergo collapse or precipitation in mixed good solvents. Through investigations combining simulations of various binary good solvent systems of polymers, including single-chain and multi-chain of homopolymers and block copolymers, and ternary Flory–Huggins theoretical validation, we reveal that the competition between the enthalpy of the system and the mixing entropy of binary solvents results in the liquid–liquid phase separation (LLPS) of the better solvent (S-solvent) and the co-nonsolvency phenomenon. To reduce the enthalpy, the polymer and S-solvent tend to mix together to maximize their contact, which, however, is entropically unfavorable due to the localization of the S-solvent in the polymer domain. The LLPS of the S-solvent, where different chain segments share the localized S-solvent molecules, simultaneously lowers the enthalpy and reduces the loss of the mixing entropy. This sharing leads the chain in single-chain systems to be in a locally folding conformation with a size being much smaller than that of the ideal chain. In multi-chain systems, however, the sharing can be among segments from different chains, which causes chain condensation and hence an average chain size larger than its ideal value. Our study provides a novel mechanism for co-nonsolvency and may provide insights into the LLPS in other soft matter systems.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 24","pages":" 4858-4868"},"PeriodicalIF":2.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148823","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":"Brillouin microscopy analysis of the fibroblast mechanical response to substrate's stiffness","authors":"Vsevolod Cheburkanov and Vladislav V. Yakovlev","doi":"10.1039/D5SM00315F","DOIUrl":"10.1039/D5SM00315F","url":null,"abstract":"<p >Cancer mechano-adaptation remains poorly understood due to the lack of imaging technologies capable of quantifying both mechanical and biochemical properties of cells and their microenvironment in 3D culture and <em>in vivo</em>. This challenge arises primarily due to the invasiveness of existing mechanical measurement techniques and their inability to assess mechanical properties in highly heterogeneous structures such as living tissues. Brillouin microscopy is an emerging, label-free technique that enables measurements of local mechanical properties with microscopic spatial resolution. In this study, we non-invasively imaged the elastic properties of monolayer 4T1 murine fibroblast cells using Brillouin microscopy and analyzed their response to variations in the mechanical properties of the external environment. Our findings demonstrate a significant correlation between the mechanical properties of the extracellular matrix and cancer cells, as assessed through Brillouin microspectroscopy in a non-invasive and safe manner. These results highlight the potential of Brillouin spectroscopy as a robust and effective technique for the characterization of biomechanical properties in cancer cells, offering valuable insights into their mechanical behavior.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 23","pages":" 4710-4718"},"PeriodicalIF":2.9,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12094280/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109182","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":"Intermediate scattering function of colloids in a periodic laser field†","authors":"Regina Rusch, Yasamin Mohebi Satalsari, Angel B. Zuccolotto-Bernez, Manuel A. Escobedo-Sánchez and Thomas Franosch","doi":"10.1039/D5SM00211G","DOIUrl":"10.1039/D5SM00211G","url":null,"abstract":"<p >We investigate the dynamics of individual colloidal particles in a one-dimensional periodic potential using the intermediate scattering function (ISF) as a key observable. We elaborate a theoretical framework and derive formally exact analytical expressions for the ISF. We introduce and analyze a generalized ISF with two wave numbers to capture correlations in a periodic potential beyond the standard ISF. Relying on Bloch's theorem for periodic systems and, by solving the Smoluchowski equation for an overdamped Brownian particle in a cosine potential, we evaluate the ISF by numerically solving for the eigenfunctions and eigenvalues of the expression. We apply time-dependent perturbation theory to expand the ISF and extract low-order moments, including the mean-square displacement, the time-dependent diffusivity, and the non-Gaussian parameter. Our analytical results are validated through Brownian-dynamics simulations and experiments on 2D colloidal systems exposed to a light-induced periodic potential generated by two interacting laser beams.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 24","pages":" 4908-4924"},"PeriodicalIF":2.9,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12127794/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144197829","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":"Experimental and FEM simulation study of compressive deformation of solder microballs and particle chains†","authors":"Y. Harkavyi, K. Giżyński and Z. Rozynek","doi":"10.1039/D4SM01499E","DOIUrl":"10.1039/D4SM01499E","url":null,"abstract":"<p >Beaded microstructures, formed by side-by-side alignment of spherical microparticles, offer a promising approach for creating micropaths with pre-determined electrical and thermal conductivity. Post-processing through mechanical compression effectively modulates the structural and conductive properties, enabling precise control over conductivity by applying defined compressive forces and calibrating strain levels. To investigate the mechanical properties of these beaded structures, this study begins with an in-depth analysis of the compressive response of unconstrained individual solder microballs, representative of malleable soft materials. The study examines the influence of particle size, engineering strain rate, and temperature on compressive force and deformation characteristics. Results from single-particle experiments are then systematically compared with those from beaded structures, revealing distinct mechanical responses. In particular, particle chains require higher compressive forces due to lateral constraints introduced by neighbouring particles, with differences in force values dependent on strain level and also on the number of microballs in the chain. FEM simulations were employed to model stress distributions, contact pressures, and deformation profiles, extending the analysis to deformation scenarios beyond experimental limits. The Johnson–Cook (J–C) model proved to be a robust predictor of compressive behaviour under varying strain rates and elevated temperatures, with temperature exerting a more significant influence than strain rate. Parameterization of the model allowed for accurate replication of empirical scaling behaviours, with strain rate and temperature dependencies from the J–C model closely matching experimental observations. These results expand our understanding of single solder microparticle deformation and offer valuable insights into the deformation of beaded structures, which could be beneficial for practical applications such as the fabrication of electronic components.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 22","pages":" 4393-4406"},"PeriodicalIF":2.9,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d4sm01499e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143953239","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":"Wave front propagation in the active coagulation model","authors":"Matteo Paoluzzi","doi":"10.1039/D5SM00129C","DOIUrl":"10.1039/D5SM00129C","url":null,"abstract":"<p >Spreading processes on top of active dynamics provide a novel theoretical framework for capturing emerging collective behavior in living systems. I consider run-and-tumble dynamics coupled with coagulation/decoagulation reactions that lead to an absorbing state phase transition. While the active dynamics does not change the location of the transition point, the relaxation toward the stationary state depends on motility parameters. Because of the competition between spreading dynamics and active motion, the system can support long-living currents whose typical time scale is a nontrivial function of motility and reaction rates. Because of this interplay between time-scales, the wave front propagation qualitatively changes from traveling to diffusive waves. Moving beyond the mean-field regime, instability at finite length scales regulates a crossover from periodic to diffusive modes. Finally, it is possible to individuate different mechanisms of pattern formation on a large time scale, ranging from the Fisher–Kolmogorov to the Kardar–Parisi–Zhang equation.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 22","pages":" 4533-4540"},"PeriodicalIF":2.9,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144075183","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":"Wrapping nonspherical vesicles at bio-membranes†","authors":"Ajit Kumar Sahu, Rajkumar Malik and Jiarul Midya","doi":"10.1039/D5SM00150A","DOIUrl":"10.1039/D5SM00150A","url":null,"abstract":"<p >The wrapping of particles and vesicles by lipid bilayer membranes is a fundamental process in cellular transport and targeted drug delivery. Here, we investigate the wrapping behavior of nonspherical vesicles, such as ellipsoidal, prolate, oblate, and stomatocytes, by systematically varying the bending rigidity of the vesicle membrane and the tension of the initially planar membrane. Using the Helfrich Hamiltonian, triangulated membrane models, and energy minimization techniques, we predict multiple stable-wrapped states and identify the conditions for their coexistence. Our results demonstrate that softer vesicles bind more easily to initially planar membranes; however, complete wrapping requires significantly higher adhesion strength than rigid vesicles. As membrane tension increases, deep-wrapped states disappear at a triple point where shallow-wrapped, deep-wrapped, and complete-wrapped states coexist. The coordinates of the triple point are highly sensitive to the vesicle shape and stiffness. For stomatocytes, increasing stiffness shifts the triple point to higher adhesion strengths and membrane tensions, while for oblates, it shifts to lower values, influenced by shape changes during wrapping. Oblate shapes are preferred in shallow-wrapped states and stomatocytes in deep-wrapped states. In contrast to hard particles, where optimal adhesion strength for complete wrapping occurs at tensionless membranes, complete wrapping of soft vesicles requires finite membrane tension for optimal adhesion strength. These findings provide insights into the interplay between vesicle deformability, shape, and membrane properties, advancing our understanding of endocytosis and the design of advanced biomimetic delivery systems.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 21","pages":" 4275-4287"},"PeriodicalIF":2.9,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00150a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956226","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":"Blockage effects in the chemotaxis of diffusiophoretic particles","authors":"Zehao Song, Matthew Farnese, Ahis Shresth and Monica Olvera de la Cruz","doi":"10.1039/D5SM00270B","DOIUrl":"10.1039/D5SM00270B","url":null,"abstract":"<p >Transport mechanisms at the micro- and nano-scale play an essential role in regulating intracellular organization. Recent work indicates that directed motion of constituents inside cells can emerge through diffusiophoretic transport, in which colloidal particles move under the influence of chemical gradients. Here, we examine how blockers—passive or actively consuming—reshape those gradients and thereby influence the motion of diffusiophoretic particles. By combining analytical solutions with finite element simulations, we first show that a single blocker can distort a background gradient enough to create or eliminate stagnation points, significantly modifying particle transport. We then introduce a second, explicitly sized blocker at one of these stagnation points and measure how its finite radius alters the diffusiophoretic velocity field for a test particle. Even moderate changes in the second blockers size can cause noticeable shifts in the substrate distribution, highlighting the importance of accounting for explicit particle radii under crowded or consumption-driven conditions. Our findings underscore that subtle geometric variations—such as the radii and positions of two or more blockers—can profoundly affect diffusiophoretic motion, providing a more complete picture of how blocking and crowding phenomena shape intracellular transport.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 23","pages":" 4692-4699"},"PeriodicalIF":2.9,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00270b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144109181","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":"Counter-intuitive photo-modulation of the aqueous phase behavior of azo dye-functionalized polyacrylamides†","authors":"René Steinbrecher, Peiran Zhang, Christine M. Papadakis, Peter Müller-Buschbaum, Andreas Taubert and André Laschewsky","doi":"10.1039/D5SM00200A","DOIUrl":"10.1039/D5SM00200A","url":null,"abstract":"<p >Three sets of water-soluble non-ionic polymers, which are thermo- as well as photo-responsive, are synthesized by statistical copolymerization of hydrophilic substituted acrylamides with varying amounts of a polymerizable azobenzene dye. Their coil-to-globule phase transition of the lower critical solution (LCST) type in aqueous solution is investigated with respect to the nature of the <em>N</em>-substituents and the content of azo dye. The phase transition temperatures <em>T</em><small>_CP</small> drop from &gt;100 °C to &lt;0 °C with increasing dye content. Irradiation of the copolymers with UV-vis light at 365 nm induces the <em>E</em>-to-<em>Z</em> (“<em>trans</em>–<em>cis</em>”) isomerization of the azobenzenes, reaching an <em>E </em>: <em>Z</em> ratio of 21 : 79 in the photo stationary state, while three isosbestic points in the spectra suggest a clean interconversion. The thermal back reaction to the <em>E</em>-isomer is relatively slow, with a half-life of the order of 12 h. For the copolymers with a small azo dye content, the <em>E</em>-to-<em>Z</em> photo-isomerization induces an increase of the phase transition temperature <em>T</em><small>_CP</small>, as it is expected due to the enhanced dipole moment of the <em>Z</em>-isomer. In contrast, the copolymers with higher azo dye contents behave counter-intuitively, <em>i.e.</em>, their <em>T</em><small>_CP</small> values markedly lower upon UV-irradiation. Possible reasons, <em>e.g.</em> chromophore aggregation, are discussed. In addition, DLS reveals that, at all temperatures and in both the <em>E</em>- and the <em>Z</em>-state, small clusters are formed by the polymer chains, probably mediated by the hydrophobic azobenzene side groups. These coexist with large associates.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 21","pages":" 4220-4232"},"PeriodicalIF":2.9,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143956613","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":"Ion specific effects on the rheology of cellulose nanofibrils in the presence of salts†","authors":"Ravisara Wattana, Daehwan Park and Chinedum O. Osuji","doi":"10.1039/D5SM00339C","DOIUrl":"10.1039/D5SM00339C","url":null,"abstract":"<p >Cellulose nanofibrils (CNFs) are high-aspect-ratio semiflexible filaments that can modify the rheology of fluids in which they are suspended. This work addresses the role of ionic strength in the rheology of CNF suspensions and the ion-specific nature of such rheology. Salt-free CNF suspensions exhibit viscoelastic, shear-thinning behavior. The concentration dependences of the storage modulus and specific viscosity exhibit similar power-law relationships in two regimes, <em>G</em>′ ∼ <em>η</em><small>_sp</small> ∼ <em>c</em><small>^<em>a</em></small>, with exponents of <em>a</em> ≈ 1 and <em>a</em> ≈ 5 below and above, respectively, a critical concentration of roughly 0.5 wt% that delineates “dilute” and “semi-dilute” characteristics. In the semi-dilute regime, salt addition increases the elastic modulus due to increased filament–filament association enabled by electrostatic screening of the repulsive interactions between weakly charged filaments. In the dilute regime, the intrinsic viscosity decreases with ionic strength, reflecting the adoption of more compact conformations at the single-filament level due to screened electrostatics. At a fixed ionic strength, both storage modulus and intrinsic viscosity show a marked dependence on ion identity, for which ion hydration enthalpy is used as a proxy. The storage modulus decreases with the enthalpy of hydration, whereas the intrinsic viscosity increases. Notably, the orderings of both parameters mimic the ion sequence of the Hofmeister series. This highlights a strong correlation between the ability of different ions to modify the hydrogen-bonding-network structure of water and their ability to screen inter- and intra-filament electrostatic interactions. This work provides new insight into ion-specific effects in CNF suspension rheology that can be used to rationally modify the properties of CNF-based complex fluids.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 23","pages":" 4719-4729"},"PeriodicalIF":2.9,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d5sm00339c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144118410","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":"Degradation mechanism of P3HT:PCBM-based bulk heterojunction solar cells.","authors":"Tirukoti Mounika, Manshi Singh, Inderpreet Singh, P Arun, Kuldeep Kumar","doi":"10.1039/d5sm00024f","DOIUrl":"https://doi.org/10.1039/d5sm00024f","url":null,"abstract":"<p><p>We have studied the degradation mechanism of P3HT:PCBM-based bulk heterojunction solar cells by developing the structure ITO/PEDOT:PSS/P3HT:PCBM/Al comprising different acceptor materials, namely, PC₆₀BM and PC₇₀BM. Both the devices have nearly the same photoconversion efficiency (PCE) of ≈3.8% immediately after fabrication. The PCE is observed to decrease in both the devices with the passage of time. While the degradation rate is found to be higher in PC₆₀BM based devices, its value is found to saturate after 100 minutes at a constant value of ≈2%. For PC₇₀BM based cells, the devices show a sudden change in the degradation rate from low to high as the time progresses beyond ≈170 minutes. The PCE in these devices fell to a very low value after 250 minutes. This rapid fall in PCE is attributed to the formation of trap states in the energy levels of PC₇₀BM molecules owing to their non-spherical structure.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143953193","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}