arXiv: Soft Condensed Matter最新文献_第9页

The van der Waals idea of pseudo associations and the critical compressibility factor 伪关联的范德华思想与临界压缩系数

arXiv: Soft Condensed Matter Pub Date : 2020-03-01 DOI: 10.5488/CMP.23.13603

O. Bakai

引用次数: 3

On generalization of Van der Waals approach for isotropic-nematic fluid phase equilibria of anisotropic fluids in disordered porous medium 无序多孔介质中各向异性流体各向同性相平衡Van der Waals方法的推广

arXiv: Soft Condensed Matter Pub Date : 2020-03-01 DOI: 10.5488/CMP.23.13601

M. Holovko, V. Shmotolokha

{"title":"On generalization of Van der Waals approach for isotropic-nematic fluid phase equilibria of anisotropic fluids in disordered porous medium","authors":"M. Holovko, V. Shmotolokha","doi":"10.5488/CMP.23.13601","DOIUrl":"https://doi.org/10.5488/CMP.23.13601","url":null,"abstract":"A generalized Van der Waals approach is developed for anisotropic fluids in disordered porous media. As the reference system a hard spherocylinder fluid in a disordered porous medium is considered and described in the framework of the scaled particle theory with the Carnahan-Starling and Parsons-Lee corrections. The attractive part of interaction is treated in the framework of the mean field approximation in which due to orientational dependence of the excluded volume of two spherocylinders, a coupling between attractive and repulsive contributions is found. We focus on spherocylinder fluids with sufficiently long particle lengths for which the nematic-nematic transition was established. It is shown that these two nematic phases have different densities and are characterized by different orientational ordering. Strong influence of the type of interparticle attraction on the phase behaviour of anisotropic fluids in disordered porous media is established. Three simple models for this purpose are considered, namely a model with the Lennard-Jones anisotropic attraction, a model with modified Lennard-Jones attraction and a model with anisotropic square-well potential. For all considered models, the phase diagram shifts to the region of lower densities and lower temperatures as the porosity decreases.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83320434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Discharging dynamics of topological batteries 拓扑电池的放电动力学

arXiv: Soft Condensed Matter Pub Date : 2020-02-26 DOI: 10.1103/physrevresearch.2.043196

Vishal P. Patil, Žiga Kos, M. Ravnik, J. Dunkel

引用次数: 6

Temperature dependence of bend elastic constant in oblique helicoidal cholesterics 斜螺旋胆甾体弯曲弹性常数的温度依赖性

arXiv: Soft Condensed Matter Pub Date : 2020-02-21 DOI: 10.1103/physrevresearch.2.013248

O. Iadlovska, Greta Babakhanova, G. Mehl, C. Welch, E. Cruickshank, Grant J. Strachan, J. Storey, C. Imrie, S. Shiyanovskii, O. Lavrentovich

{"title":"Temperature dependence of bend elastic constant in oblique helicoidal cholesterics","authors":"O. Iadlovska, Greta Babakhanova, G. Mehl, C. Welch, E. Cruickshank, Grant J. Strachan, J. Storey, C. Imrie, S. Shiyanovskii, O. Lavrentovich","doi":"10.1103/physrevresearch.2.013248","DOIUrl":"https://doi.org/10.1103/physrevresearch.2.013248","url":null,"abstract":"Elastic moduli of liquid crystals, known as Frank constants, are of quintessential importance for understanding fundamental properties of these materials and for the design of their applications. Although there are many methods to measure the Frank constants in the nematic phase, little is known about the elastic constants of the chiral version of the nematic, the so-called cholesteric liquid crystal, since the helicoidal structure of the cholesteric renders these methods inadequate. Here we present a technique to measure the bend modulus $K_{33}$ of cholesterics that is based on the electrically tunable reflection of light at an oblique helicoidal $Ch_{OH}$ cholesteric structure. $K_{33}$ is typically smaller than 0.6 pN, showing a non-monotonous temperature dependence with a slight increase near the transition to the twist-bend phase. $K_{33}$ depends strongly on the molecular composition. In particular, chiral mixtures that contain the flexible dimer 1'',7''-bis(4-cyanobiphenyl-4'-yl) heptane (CB7CB) and rod-like molecules such as pentylcyanobiphenyl (5CB) show a $K_{33}$ value that is 5 times smaller than $K_{33}$ of pure CB7CB or of mixtures of CB7CB with chiral dopants. Furthermore, $K_{33}$ in CB11CB doped with a chiral agent is noticeably smaller than $K_{33}$ in a similarly doped CB7CB which is explained by the longer flexible link in CB11CB. The proposed technique allows a direct in-situ determination of how the molecular composition, molecular structure and molecular chirality affect the elastic properties of chiral liquid crystals.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90609049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Boundary curvature effect on the wrinkling of thin suspended films 边界曲率对悬浮薄膜起皱的影响

arXiv: Soft Condensed Matter Pub Date : 2020-02-19 DOI: 10.1063/5.0006164

S. Janssens, Burhannudin Sutisna, A. Giussani, J. Kwiecinski, David V'azquez-Cort'es, E. Fried

引用次数: 9

The quantum character of buckling instabilities in thin rods 细棒屈曲不稳定性的量子特性

arXiv: Soft Condensed Matter Pub Date : 2020-02-13 DOI: 10.1119/10.0001684

T. Engstrom

引用次数: 2

Shear induced demixing in bidisperse and polydisperse polymer blends: Predictions from a multifluid model 双分散和多分散聚合物共混物中的剪切诱导脱混:来自多流体模型的预测

arXiv: Soft Condensed Matter Pub Date : 2020-02-11 DOI: 10.1122/8.0000036

J. Peterson, G. Fredrickson, L. Gary Leal

引用次数: 8

Kinematics of a simple reciprocal model swimmer at intermediate Reynolds numbers 中雷诺数下简单倒易模型游泳者的运动学

arXiv: Soft Condensed Matter Pub Date : 2020-02-06 DOI: 10.1103/PHYSREVFLUIDS.5.063103

Thomas Dombrowski, D. Klotsa

{"title":"Kinematics of a simple reciprocal model swimmer at intermediate Reynolds numbers","authors":"Thomas Dombrowski, D. Klotsa","doi":"10.1103/PHYSREVFLUIDS.5.063103","DOIUrl":"https://doi.org/10.1103/PHYSREVFLUIDS.5.063103","url":null,"abstract":"We computationally study the kinematics of a simple model reciprocal swimmer (asymmetric dumbbell) as a function of the Reynolds number (Re) and investigate how the onset and gradual increase of inertia impacts the swimming behavior: a reversal in the swim direction, flow directions, and the swim stroke. We divide the swim stroke into the expansion and compression of the two spheres and relate them to power and recovery strokes. We find that the switch in swim direction also corresponds to a switch in power and recovery strokes. We obtain expressions for the mean swimming velocity by collapsing the net displacement during expansion and compression under power law relationships with respect to Re, the swimmer's amplitude, and the distance between the two spheres. Analyzing the fluid flows, we see the averaged flow field during expansion always resembles a pusher and compression always a puller, but when averaged over the whole cycle, the flow that dominates is the one that occurs during the power stroke. We also relate the power and recovery strokes to the swimming efficiency during times of expansion and compression, and we find that the power stroke is, surprisingly, not always more efficient than the recovery stroke. Our results may have important implications for biology and ultimately the design of artificial swimmers.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85122530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Shape induced segregation and anomalous particle transport under spherical confinement 球形约束下的形状诱导偏析和异常粒子输运

arXiv: Soft Condensed Matter Pub Date : 2020-02-05 DOI: 10.1063/5.0002906

Abhinendra Singh, J. Hernandez-Ortiz, H. Jaeger, J. D. de Pablo

{"title":"Shape induced segregation and anomalous particle transport under spherical confinement","authors":"Abhinendra Singh, J. Hernandez-Ortiz, H. Jaeger, J. D. de Pablo","doi":"10.1063/5.0002906","DOIUrl":"https://doi.org/10.1063/5.0002906","url":null,"abstract":"Colloid or nanoparticle mobility under confinement is of central importance to a wide range of physical and biological processes. Here, we introduce a minimal model of particles in a hydrodynamic continuum to examine how particle shape and concentration affect the transport of particles in spherical confinement. Specifically, an immersed boundary-General geometry Ewald-like approach is adopted to simulate the dynamics of spheres and cylinders under the influence of short-and long-range fluctuating hydrodynamic interactions with appropriate non-slip conditions at the confining walls. An efficient $it{O(N)}$ parallel finite element algorithm is used, thereby allowing simulations at high concentrations, while a Chebyshev polynomial approximation is implemented in order to satisfy the fluctuation-dissipation theorem. A concentration-dependent anomalous diffusion is observed for suspended particles. It is found that introducing cylinders in a background of spheres, i.e. particles with a simple degree of anisotropy, has a pronounced influence on the structure and dynamics of the particles. First, increasing the fraction of cylinders induces a particle segregation effect, where spheres are pushed towards the wall and cylinders remain near the center of the cavity. This segregation leads to lower mobility for the spheres relative to that encountered in a system of pure spheres at the same volume fraction. Second, the diffusive-to-anomalous transition and the degree of anomaly--quantified by the power-law exponent in the mean square displacement vs. time relation-both increase as the fraction of cylinders becomes larger. These findings are of relevance for studies of diffusion in the cytoplasm, where proteins exhibit a distribution of size and shapes that could lead to some of the effects identified in the simulations reported here.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74456154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Elasticity of jammed packings of sticky disks 粘碟卡塞包装的弹性

arXiv: Soft Condensed Matter Pub Date : 2020-02-04 DOI: 10.1103/PHYSREVRESEARCH.2.032047

D. Koeze, Lingtjien Hong, Abhishek Kumar, B. Tighe

引用次数: 11