Soft Matter最新文献

{"title":"Thermal effects on the lifetime of evaporating drops on fibers†","authors":"Marie Corpart, Frédéric Restagno and François Boulogne","doi":"10.1039/D4SM00480A","DOIUrl":"10.1039/D4SM00480A","url":null,"abstract":"<p >We present an experimental study on the evaporation of drops on fibers. More specifically, we focus on the droplet lifetime both in quiescent air and in an air flow of constant velocity. We propose a model to describe the evaporation rate and lifetime in a purely diffusive regime, which includes the liquid cooling associated with evaporation and the thermal conductivity of the atmosphere and the fiber. Our model effectively captures the primary physical behaviors, demonstrating a semi-quantitative agreement with our measurements across various liquids and fiber materials. Finally, the model is generalized to a convective air flow, which also rationalizes our experimental data.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 48","pages":" 9622-9630"},"PeriodicalIF":2.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714892","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":"Size dependent polarities in tribocharged dust aggregates","authors":"Christopher Grünebeck, Florence Chioma Onyeagusi, Jens Teiser and Gerhard Wurm","doi":"10.1039/D4SM01013B","DOIUrl":"10.1039/D4SM01013B","url":null,"abstract":"<p >It is long known that particles of the same material but with different sizes charge with different polarities in mutual collisions. In most cases, the smaller grains become negative. Here, we study tribocharging of (sub-)mm dust aggregates in the course of microgravity experiments by determining the charges of particles through their motion within an electric field. Similar experiments were already conducted with monolithic grains. Here, the constituent dust grains in an aggregate add complexity to the process of tribocharging in various ways. This ranges from the dust size scale, setting local surface curvatures, over shifting grains during collisions, altering the outer surfaces and potentially generating sub-surface tribocharging, to material-dependent tribocharging with a non-homogeneous dust composition. Nevertheless, in concert with the usual size dependence, the small aggregates predominantly charge negatively, the large population charges predominantly positively.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 48","pages":" 9572-9577"},"PeriodicalIF":2.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/sm/d4sm01013b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685428","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":"Divalent cation effects in the glass transition of poly(diallyldimethylammonium)–poly(styrene sulfonate) polyelectrolyte complexes†","authors":"Tamunoemi Braide, Suvesh Manoj Lalwani, Chikaodinaka I. Eneh and Jodie L. Lutkenhaus","doi":"10.1039/D4SM00856A","DOIUrl":"10.1039/D4SM00856A","url":null,"abstract":"<p >The assembly and dynamics of polyelectrolyte complexes (PECs) and polyelectrolyte multilayers (PEMs) are influenced by water content, pH, and salt concentration. However, the influence of divalent salts on the assembly of polyelectrolyte complexes remains unclear. This work showcases that divalent chloride salts directly impact the glass transition temperature and the ion–ion interactions within PECs. Here, poly(diallyldimethylammonium)–poly(styrene sulfonate) (PDADMA–PSS) PECs are assembled in solutions containing MgCl<small>₂</small> and CaCl<small>₂</small> (following the Hofmeister series). These PECs are studied for the cations’ influence on physicochemical properties (glass transition, polymer composition, ion pairing) at varying salt concentrations (0.03 M, 0.10 M, 0.15 M, and 0.20 M). Modulated differential scanning calorimetry (MDSC) experiments demonstrate that PECs assembled with CaCl<small>₂</small> have a significantly higher glass transition temperature when compared to PECs assembled with MgCl<small>₂</small>. Neutron activation analysis (NAA) and nuclear magnetic resonance (NMR) spectroscopy demonstrate that this difference is due to strong ion-specific effects influencing the ratio of intrinsic and extrinsic ion pairings in the system. Furthermore, this study demonstrates a universal linear relationship between the thermal transition and the number of water molecules surrounding oppositely charged polyelectrolyte–polyelectrolyte intrinsic ion pairs, even when the salt contains divalent cations. Ion-specific trends have implications on the glass transition and composition of PDADMA–PSS PECs. Divalent salts not only follow the trend of the Hofmeister series but also introduce bridging into the polyelectrolyte complex; however, the structural relaxation of the PEC remains the same. This study offers a bridge between divalent cation behavior on polymer assembly properties and its transition to industrial applications such as controlled drug delivery, sensors, and water purification.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 48","pages":" 9631-9641"},"PeriodicalIF":2.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/sm/d4sm00856a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714890","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":"Interpolyelectrolyte complexes of a biguanide cationic polyelectrolyte: formation of core/corona nanoparticles with double-hydrophilic diblock polyanion†","authors":"Patricia Montes, Tania Chopra, Rafał Konefał, Pavla Hájovská, Igor Lacík, Vladimír Raus, Miroslav Šlouf, Mariusz Uchman and Miroslav Štěpánek","doi":"10.1039/D4SM00851K","DOIUrl":"10.1039/D4SM00851K","url":null,"abstract":"<p >Biguanide-based cationic polyelectrolytes are used as key components of interpolyelectrolyte complexes bolstering alginate hydrogel microcapsules employed in cell therapies. Nevertheless, electrostatic complexation of these unique polycations has not been studied before. In this study, the interaction between biguanide condensates and anionic polyelectrolytes with carboxylate groups was studied on a model system of a metformin condensate (MFC) and an anionic diblock polyelectrolyte poly(methacrylic acid)-<em>block</em>-poly(ethylene oxide) (PMAA–PEO). The formation of MFC/PMAA–PEO core–corona nanoparticles was followed by static, dynamic and electrophoretic light scattering and by isothermal titration calorimetry and their internal structure was investigated by small angle neutron scattering and cryogenic transmission electron microscopy. It was found that the aggregation of PMAA–PEO chains induced by MFC occurred at much lower MFC/PMAA–PEO ratios that would correspond to the isoelectric point, thus yielding strongly negatively charged nanoparticles, suggesting the role of specific (non-electrostatic) interactions in the stabilization of the complex between PMAA and MFC.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 47","pages":" 9475-9482"},"PeriodicalIF":2.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/sm/d4sm00851k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680288","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":"Phase behavior of symmetric diblock copolymers under 3D soft confinement","authors":"Zhijuan He, Jin Huang, Kai Jiang and An-Chang Shi","doi":"10.1039/D4SM01020E","DOIUrl":"10.1039/D4SM01020E","url":null,"abstract":"<p >The phase behavior of symmetric diblock copolymers under three-dimensional (3D) soft confinement is investigated using self-consistent field theory. Soft confinement is realized in binary blends composed of AB diblock copolymers and C homopolymers, where the copolymers self-assemble to form a droplet embedded in a homopolymer matrix. The phase behavior of the confined block copolymers is regulated by the degree of confinement and the selectivity of the homopolymers, resulting in a rich variety of novel structures. When the C homopolymers are neutral to the A- and B-blocks, stacked lamellae (SL) are formed where the number of layers increases with the droplet volume, resulting in a morphological transition sequence from Janus particles to square SL. When the C homopolymers are strongly selective for the B-blocks, a series of non-lamellar morphologies, including onion-, hamburger-, cross-, ring-, and cookie-like structures, are observed. A detailed free energy analysis reveals a first-order reversible transformation between SL and onion-like (OL) structures when the selectivity of the homopolymers is changed. Our results provide a comprehensive understanding of how various factors, such as the copolymer concentration, homopolymer chain length, degree of confinement, and homopolymer selectivity, affect the self-assembled structures of diblock copolymers under soft 3D confinement.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 47","pages":" 9404-9412"},"PeriodicalIF":2.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646170","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":"Modeling collagen fibril degradation as a function of matrix microarchitecture†","authors":"Bhanjan Debnath, Badri Narayanan Narasimhan, Stephanie I. Fraley and Padmini Rangamani","doi":"10.1039/D4SM00971A","DOIUrl":"10.1039/D4SM00971A","url":null,"abstract":"<p >Collagenolytic degradation is a process fundamental to tissue remodeling. The microarchitecture of collagen fibril networks changes during development, aging, and disease. Such changes to microarchitecture are often accompanied by changes in matrix degradability. In a matrix, the pore size and fibril characteristics such as length, diameter, number, orientation, and curvature are the major variables that define the microarchitecture. <em>In vitro</em>, collagen matrices of the same concentration but different microarchitectures also vary in degradation rate. How do different microarchitectures affect matrix degradation? To answer this question, we developed a computational model of collagen degradation. We first developed a lattice model that describes collagen degradation at the scale of a single fibril. We then extended this model to investigate the role of microarchitecture using Brownian dynamics simulation of enzymes in a multi-fibril three dimensional matrix to predict its degradability. Our simulations predict that the distribution of enzymes around the fibrils is non-uniform and depends on the microarchitecture of the matrix. This non-uniformity in enzyme distribution can lead to different extents of degradability for matrices of different microarchitectures. Our simulations predict that for the same enzyme concentration and collagen concentration, a matrix with thicker fibrils degrades more than that with thinner fibrils. Our model predictions were tested using <em>in vitro</em> experiments with synthetic collagen gels of different microarchitectures. Experiments showed that indeed degradation of collagen depends on the matrix architecture and fibril thickness. In summary, our study shows that the microarchitecture of the collagen matrix is an important determinant of its degradability.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 46","pages":" 9286-9300"},"PeriodicalIF":2.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646168","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":"Finite element modelling of atomic force microscopy imaging on deformable surfaces","authors":"Joshua Giblin-Burnham, Yousef Javanmardi, Emad Moeendarbary and Bart W. Hoogenboom","doi":"10.1039/D4SM01084A","DOIUrl":"10.1039/D4SM01084A","url":null,"abstract":"<p >Atomic force microscopy (AFM) provides a three-dimensional topographic representation of a sample surface, at nanometre resolution. Computational simulations can aid the interpretation of such representations, but have mostly been limited to cases where both the AFM probe and the sample are hard and not compressible. In many applications, however, the sample is soft and therefore deformed due to the force exerted by the AFM tip. Here we use finite element modelling (FEM) to study how the measured AFM topography relates to the surface structures of soft and compressible materials. Consistent with previous analytical studies, the measured elastic modulus in AFM is generally found to deviate from the elastic modulus of the sample material. By the analysis of simple surface geometries, the FEM modelling shows how measured mechanical and topographic features in AFM images depend on a combination of tip-sample geometry and indentation of the tip into the sample. Importantly for the interpretation of AFM data, nanoparticles may appear larger or smaller by a factor of two depending on tip size and indentation force; and a higher spatial resolution in AFM images does not necessarily coincide with a more accurate representation of the sample surface. These observations on simple surface geometries also extend to molecular-resolution AFM, as illustrated by comparing FEM results with experimental data acquired on DNA. Taken together, the FEM results provide a framework that aids the interpretation of surface topography and local mechanics as measured by AFM.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 47","pages":" 9483-9492"},"PeriodicalIF":2.9,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11580413/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680287","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":"CO2-induced drastic decharging of dielectric surfaces in aqueous suspensions†","authors":"Peter Vogel, David Beyer, Christian Holm and Thomas Palberg","doi":"10.1039/D4SM00957F","DOIUrl":"10.1039/D4SM00957F","url":null,"abstract":"<p >We study the influence of airborne CO<small>₂</small> on the charge state of carboxylate stabilized polymer latex particles suspended in aqueous electrolytes. We combine conductometric experiments interpreted in terms of Hessinger's conductivity model with Poisson–Boltzmann cell (PBC) model calculations with charge regulation boundary conditions. Without CO<small>₂</small>, a minority of the weakly acidic surface groups are dissociated and only a fraction of the total number of counter-ions actually contribute to conductivity. The remaining counter-ions exchange freely with added other ions like Na<small>⁺</small>, K<small>⁺</small> or Cs<small>⁺</small>. From the PBC-calculations we infer a corresponding p<em>K</em><small>_a</small> of 4.26 as well as a renormalized charge in reasonably good agreement with the number of freely mobile counter-ions. Equilibration of salt- and CO<small>₂</small>-free suspensions against ambient air leads to a drastic de-charging, which exceeds by far the expected effects of to dissolved CO<small>₂</small> and its dissociation products. Further, no counter-ion-exchange is observed. To reproduce the experimental findings, we have to assume an effective p<em>K</em><small>_a</small> of 6.48. This direct influence of CO<small>₂</small> on the state of surface group dissociation explains our recent finding of a CO<small>₂</small>-induced decrease of the <em>ζ</em>-potential and supports the suggestion of an additional charge regulation caused by molecular CO<small>₂</small>. Given the importance of charged surfaces in contact with aqueous electrolytes, we anticipate that our observations bear substantial theoretical challenges and important implications for applications ranging from desalination to bio-membranes.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 46","pages":" 9261-9272"},"PeriodicalIF":2.9,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/sm/d4sm00957f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142612841","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":"Dynamics of polymers in coarse-grained nematic solvents.","authors":"Zahra K Valei, Karolina Wamsler, Alex J Parker, Therese A Obara, Alexander R Klotz, Tyler N Shendruk","doi":"10.1039/d4sm00968a","DOIUrl":"10.1039/d4sm00968a","url":null,"abstract":"<p><p>Polymers are a primary building block in many biomaterials, often interacting with anisotropic backgrounds. While previous studies have considered polymer dynamics within nematic solvents, rarely are the effects of anisotropic viscosity and polymer elongation differentiated. Here, we study polymers embedded in nematic liquid crystals with isotropic viscosity <i>via</i> numerical simulations to explicitly investigate the effect of nematicity on macromolecular conformation and how conformation alone can produce anisotropic dynamics. We employ a hybrid multi-particle collision dynamics and molecular dynamics technique that captures nematic orientation, thermal fluctuations and hydrodynamic interactions. The coupling of the polymer segments to the director field of the surrounding nematic elongates the polymer, producing anisotropic diffusion even in nematic solvents with isotropic viscosity. For intermediate coupling, the competition between background anisotropy and macromolecular entropy leads to hairpins - sudden kinks along the backbone of the polymer. Experiments of DNA embedded in a solution of rod-like fd viruses qualitatively support the role of hairpins in establishing characteristic conformational features that govern polymer dynamics. Hairpin diffusion along the backbone exponentially slows as coupling increases. Better understanding two-way coupling between polymers and their surroundings could allow the creation of more biomimetic composite materials.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11612746/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637947","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":"Self-assembly of active bifunctional Brownian particles†","authors":"Caterina Landi, John Russo, Francesco Sciortino and Chantal Valeriani","doi":"10.1039/D4SM00805G","DOIUrl":"10.1039/D4SM00805G","url":null,"abstract":"<p >In this work, with the intent of exploring the out-of-equilibrium polymerization of active patchy particles in linear chains, we study a suspension of active bifunctional Brownian particles (ABBPs). At all studied temperatures and densities, ABBPs self-assemble in aggregating chains, as opposed to the uniformly space-distributed chains observed in the corresponding passive systems. The main effect of activity, other than inducing chain aggregation, is to reduce the chain length and favour the alignment of the propulsion vectors in the bonding process. At low activities, attraction dominates over activity in the bonding process, causing self-assembly to occur randomly regardless of the particle orientations. Interestingly, we find that at the lowest temperature, as density increases, chains aggregate forming a novel state: MISP, <em>i.e.</em>, motility-induced spirals, where spirals are characterised by a finite angular velocity. In contrast, at the highest temperature, density and activity, chains aggregate forming a different novel state (a spinning crystalline cluster) characterised by a compact and hexagonally ordered structure, both translating and rotating. The rotation arises from an effective torque generated by the presence of competing domains where particles self-propel in the same direction.</p>","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" 1","pages":" 45-54"},"PeriodicalIF":2.9,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sm/d4sm00805g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142708615","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}