Soft Matter最新文献_第2页

Freedericksz transitions in the nematic and smectic Z_A 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 : 2025-06-27 DOI: 10.1039/d5sm00238a

J T Gleeson, S N Sprunt, A Jákli, P Guragain, 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, R J Twieg","doi":"10.1039/d5sm00238a","DOIUrl":"https://doi.org/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":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","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":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A motile rod in an active nematic medium: caging, orientational trapping, and anomalous diffusion. 活动向列介质中的活动棒：笼化、定向捕获和异常扩散。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-27 DOI: 10.1039/d5sm00573f

Abhishek Sharma, Harsh Soni

{"title":"A motile rod in an active nematic medium: caging, orientational trapping, and anomalous diffusion.","authors":"Abhishek Sharma, Harsh Soni","doi":"10.1039/d5sm00573f","DOIUrl":"https://doi.org/10.1039/d5sm00573f","url":null,"abstract":"We study the dynamical and statistical properties of a motile polar rod embedded in a vibrated granular medium composed of fore-aft symmetric rods using particle-based numerical simulations. Our study reveals phase-dependent memory effects and transport behaviors of the polar rod governed by the structural phase of the medium. In the isotropic phase, the rod behaves as an active Brownian particle, experiencing a noisy environment with increasing medium concentration that leads to short-lived directional memory, resulting in enhanced rotational diffusion and reduced translational diffusivity. In the nematic phase-determined by the medium's concentration and the polar rod's intrinsic rotational noise-the rod exhibits two distinct states: a rotationally trapped state, in which its orientation is locked along the nematic director, and a rotationally free state, in which it explores all orientations despite a tendency to align with the director. At high concentrations, the medium forms periodic layers in which the rods are slightly tilted in opposite directions across adjacent layers relative to the nematic director, as reported by Sharma et al. [Soft Matter, 2024, 20, 6608-6617]. In this regime, the motile rod is effectively caged in the direction perpendicular to the nematic alignment. We further study the diffusive behavior of the polar rod in both states, demonstrating that the phase of the medium strongly influences its diffusion dynamics and the MSD exponent values, revealing a wide range of behavior from normal to superdiffusive dynamics.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144504244","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

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 : 2025-06-27 DOI: 10.1039/d5sm00555h

Naoya Katayama, Takahiro Sakaue

引用次数: 0

Red blood cell partitioning and segregation through vascular bifurcations in a model of sickle cell disease. 镰状细胞病模型中通过血管分叉的红细胞分裂和分离。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-26 DOI: 10.1039/d4sm01519c

Xiaopo Cheng, Christina Caruso, Wilbur A Lam, Michael D Graham

{"title":"Red blood cell partitioning and segregation through vascular bifurcations in a model of sickle cell disease.","authors":"Xiaopo Cheng, Christina Caruso, Wilbur A Lam, Michael D Graham","doi":"10.1039/d4sm01519c","DOIUrl":"https://doi.org/10.1039/d4sm01519c","url":null,"abstract":"The impacts of cell segregation and margination in blood disorders on microcirculatory hemodynamics within bifurcated vessels are physiologically significant, yet poorly understood. This study presents a comprehensive computational investigation of red blood cell (RBC) suspension dynamics, with a focus on a model of sickle cell disease (SCD) as an example of a disorder associated with subpopulations of aberrant RBCs. The findings reveal how cell margination influences cellular partitioning and distributions as well as vessel wall shear stress (WSS) at vascular bifurcations. Normal RBCs, which migrate toward the channel center, exhibit the Zweifach-Fung effect, preferentially entering high-flow-rate branches. In contrast, sickle cells, which marginate near the vessel wall, demonstrate an anti-Zweifach-Fung effect, favoring lower-flow-rate branches due to their position within the cell-free layer (CFL). The upstream segregation of cells remains downstream through the bifurcation, where sickle cells accumulate along the outer branch walls. This accumulation of sickle cells increases the frequency of high WSS events via direct physical interactions, particularly on the outer side of high-velocity branches, potentially contributing to the vascular damage and endothelial disruption observed in many disorders that affect RBCs. In geometrically asymmetric bifurcations, cells preferentially enter branches with larger radii, underscoring the influence of geometric complexity on microcirculatory blood flow. These findings provide insights into microvascular hemodynamics in SCD and other blood disorders.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493186","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

Splay and bend deformations in cells near corners. 在角落附近的单元格中展开和弯曲变形。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-26 DOI: 10.1039/d5sm00093a

Aniruddh Murali, Prasoon Awasthi, Kirsten Endresen, Arkadiusz Goszczak, Francesca Serra

引用次数: 0

Precise detection of local relaxation of amorphous polymers at low temperatures via O₂ diffusion probed by a dual-luminescent imide compound. 用双发光亚胺化合物探测O2扩散在低温下精确检测非晶聚合物的局部弛豫。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-26 DOI: 10.1039/d5sm00394f

Rika Watanabe, Marina Doi, Haonan Liu, Masatoshi Tokita, Shinji Ando

引用次数: 0

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 : 2025-06-26 DOI: 10.1039/d5sm00257e

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

引用次数: 0

Dynamics of a bottom-heavy Janus particle near a wall under shear flow. 剪切流作用下靠近壁面的重底Janus颗粒动力学。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-26 DOI: 10.1039/d5sm00229j

Zohreh Jalilvand, Daniele Notarmuzi, Ubaldo M Córdova-Figueroa, Emanuela Bianchi, Ilona Kretzschmar

{"title":"Dynamics of a bottom-heavy Janus particle near a wall under shear flow.","authors":"Zohreh Jalilvand, Daniele Notarmuzi, Ubaldo M Córdova-Figueroa, Emanuela Bianchi, Ilona Kretzschmar","doi":"10.1039/d5sm00229j","DOIUrl":"10.1039/d5sm00229j","url":null,"abstract":"In this study, Brownian dynamics simulations are implemented to investigate the motion of a bottom-heavy Janus particle near a wall under varying shear flow conditions and at small Péclet (Pe) numbers. The stochastic motion of the Janus particle impacted by surface forces is described using a set of coupled Langevin equations that takes into account the Janus particle orientation. Interactions arising from surface potentials are found to depend on the separation distance between the Janus particle and the wall, the properties of the surfaces involved, and the thickness of the Janus particle cap. When shear flow is introduced in the system, the dynamical behavior of the Janus particle is also governed by the strain rate. Furthermore, the effect of friction on the dynamical behavior of the Janus particle under shear flow is investigated and reveals that the rotational motion of the Janus particle slows down slightly when the particle is close to the surface. In summary, we demonstrate the ability to utilize Brownian dynamics simulations to capture the rich dynamical behavior of a bottom-heavy Janus particle near a wall and under a range of shear flow conditions, cap thicknesses, and surface charges.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12198726/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144493184","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

Elastic, viscoelastic, dynamic, topological and structural properties of crosslinked SBR through atomistic molecular dynamics simulations. 通过原子分子动力学模拟交联SBR的弹性、粘弹性、动力学、拓扑和结构性质。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-25 DOI: 10.1039/d5sm00126a

Spyros V Kallivokas, Anthony Chazirakis, Rohit Ghanta, Anastassia Rissanou, Patrycja Polińska, Craig Burkhart, Manolis Doxastakis, Vagelis Harmandaris

{"title":"Elastic, viscoelastic, dynamic, topological and structural properties of crosslinked SBR through atomistic molecular dynamics simulations.","authors":"Spyros V Kallivokas, Anthony Chazirakis, Rohit Ghanta, Anastassia Rissanou, Patrycja Polińska, Craig Burkhart, Manolis Doxastakis, Vagelis Harmandaris","doi":"10.1039/d5sm00126a","DOIUrl":"https://doi.org/10.1039/d5sm00126a","url":null,"abstract":"In this research work, we provide a detailed investigation of the structural and viscoelastic properties of crosslinked styrene butadiene rubber (SBR) networks that are studied using atomistic molecular dynamics simulations. The composition of the system ratio is (styrene/trans/vinyl/cis): (15/33/26/26) by weight and a 4-atom sulfur chain was used as a hardener for the crosslinking process. The main goal of our work is to characterize a fully percolated SBR network, with a crosslinking density of 8%, at the molecular level, structurally, mechanically and topologically and compare its properties with a system with a lower crosslinking density (3%) and the non crosslinked SBR melt. SBR crosslinked systems are generated via a recently proposed crosslinking algorithm. The shear stress relaxation modulus and the mean square displacement (MSD) were calculated for all systems along with structural properties, such as the pair distribution function, angles and dihedral distributions, and statistical distributions of the atoms between the crosslinks, and finally the topology of these networks was investigated according to the number of clusters that are created during the different crosslink densities, the molecular weight fraction of the largest cluster in these networks, and finally the percolation threshold. The results indicate that the higher we crosslink the SBR, the stiffer our final rubber becomes according to the results of the dynamics and rheology. We further probe the dependence of the structural and viscoelastic properties of the SBS rubber on crosslinking density by comparing a fully percolated system with one having lower crosslinking density (3%) and the non crosslinked SBR melt.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482626","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

Co-assembly of amphiphilic triblock copolymers with DNA-polymer targeting ligands in solution. 两亲性三嵌段共聚物与dna -聚合物靶向配体在溶液中的共组装。

IF 2.9 3区化学

Soft Matter Pub Date : 2025-06-25 DOI: 10.1039/d5sm00107b

Junwei Zhou, Menghan Zou, Xiandeng Qiu, Rong Wang

{"title":"Co-assembly of amphiphilic triblock copolymers with DNA-polymer targeting ligands in solution.","authors":"Junwei Zhou, Menghan Zou, Xiandeng Qiu, Rong Wang","doi":"10.1039/d5sm00107b","DOIUrl":"https://doi.org/10.1039/d5sm00107b","url":null,"abstract":"The development of targeted drug delivery systems is highly valued, which not only improves the therapeutic effect of drugs, but also reduces the amount of drugs used and reduces side effects. By taking advantage of the excellent affinity and specificity of nucleic acid aptamers and co-assembly of targeting ligands with polymers, we used dissipative particle dynamics (DPD) simulations to explore the co-assembly behavior of amphiphilic ABA triblock copolymers and DNA-polymer targeting ligands in dilute solutions. By adjusting interaction parameters and concentrations of various components, we observed the formation of different targeting polymer nanostructures, such as targeting polymeric vesicles, sphere-like micelles, and disk-like micelles. The results show that the inclusion of targeting ligands prolongs the formation time of polymeric vesicles, and by modulating the interactions between DNA beads with hydrophilic beads and solvent beads, the localization of targeting ligands within the vesicles can be precisely controlled. When the interactions between DNA beads with hydrophilic beads aTS is high, the targeting ligands aggregate on the vesicle exterior, while at lower aTS values, they are uniformly distributed inside the vesicles. Additionally, the polymer and targeting ligand concentrations will influence the morphology of the aggregates, transitioning from sphere-like micelles to disk-like micelles and eventually to vesicles, including the mixture of multiple aggregate types under certain conditions. The findings provide theoretical support for the development of multi-targeted polymeric vesicles, advancing the field of precision therapy.","PeriodicalId":103,"journal":{"name":"Soft Matter","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482625","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