arXiv: Soft Condensed Matter最新文献_第2页

Inverse Flexoelectret Effect: Bending Dielectrics by a Uniform Electric Field 反向挠性驻极体效应:均匀电场使电介质弯曲

arXiv: Soft Condensed Matter Pub Date : 2020-10-15 DOI: 10.1103/PHYSREVAPPLIED.15.014032

X. Wen, K. Tan, Q. Deng, S. Shen

引用次数: 7

Effect of transport mechanism on the coarsening of bicontinuous structures: A comparison between bulk and surface diffusion 输运机制对双连续结构粗化的影响:体扩散与表面扩散的比较

arXiv: Soft Condensed Matter Pub Date : 2020-10-14 DOI: 10.1103/physrevmaterials.4.103401

W. Andrews, K. Elder, P. Voorhees, K. Thornton

{"title":"Effect of transport mechanism on the coarsening of bicontinuous structures: A comparison between bulk and surface diffusion","authors":"W. Andrews, K. Elder, P. Voorhees, K. Thornton","doi":"10.1103/physrevmaterials.4.103401","DOIUrl":"https://doi.org/10.1103/physrevmaterials.4.103401","url":null,"abstract":"Coarsening of bicontinuous microstructures is observed in a variety of systems, such as nanoporous metals and mixtures that have undergone spinodal decomposition. To better understand the morphological evolution of these structures during coarsening, we compare the morphologies resulting from two different coarsening mechanisms, surface and bulk diffusion. We perform phase-field simulations of coarsening via each mechanism in a two-phase mixture at nominal volume fractions of 50%-50% and 36%-64%, and the simulated structures are characterized in terms of topology (genus density), the interfacial shape distribution, structure factor, and autocorrelations of phase and mean curvature. We observe self-similar evolution of morphology and topology and agreement with the expected power laws for dynamic scaling, in which the characteristic length scale increases over time proportionally to $t^{1/4}$ for surface diffusion and $t^{1/3}$ for bulk diffusion. While we observe the expected difference in the coarsening kinetics, we find that differences in self-similar morphology due to coarsening mechanism are relatively small, although typically they are larger at 36% volume fraction than at 50% volume fraction. In particular, we find that bicontinuous structures coarsened via surface diffusion have lower scaled genus densities than structures coarsened via bulk diffusion. We also compare the self-similar morphologies to those in literature and to two model bicontinuous structures, namely, constant-mean-curvature surfaces based on the Schoen G minimal surface and random leveled-wave structures. The average scaled mean curvatures of these model structures agree reasonably with those of the coarsened structures at both 36% and 50%, but we find substantial disagreements in the scaled genus densities and the standard deviations of mean curvature.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75579307","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

Navier–Stokes transport coefficients for a model of a confined quasi-two-dimensional granular binary mixture 受限准二维颗粒二元混合物模型的Navier-Stokes输运系数

arXiv: Soft Condensed Matter Pub Date : 2020-10-12 DOI: 10.1063/5.0032919

V. Garz'o, R. Brito, R. Soto

{"title":"Navier–Stokes transport coefficients for a model of a confined quasi-two-dimensional granular binary mixture","authors":"V. Garz'o, R. Brito, R. Soto","doi":"10.1063/5.0032919","DOIUrl":"https://doi.org/10.1063/5.0032919","url":null,"abstract":"The Navier--Stokes transport coefficients for a model of a confined quasi-two-dimensional granular binary mixture of inelastic hard spheres are determined from the Boltzmann kinetic equation. A normal or hydrodynamic solution to the Boltzmann equation is obtained via the Chapman--Enskog method for states near the local version of the homogeneous time-dependent state. The mass, momentum, and heat fluxes are determined to first order in the spatial gradients of the hydrodynamic fields, and the associated transport coefficients are identified. As expected, they are given in terms of the solutions of a set of coupled linear integral equations. In addition, in contrast to previous results obtained for low-density granular mixtures, there are also nonzero contributions to the first-order approximations to the partial temperatures $T_i^{(1)}$ and the cooling rate $zeta^{(1)}$. Explicit forms for the diffusion transport coefficients, the shear viscosity coefficient, and the quantities $T_i^{(1)}$ and $zeta^{(1)}$ are obtained by assuming the steady-state conditions and by considering the leading terms in a Sonine polynomial expansion. The above transport coefficients are given in terms of the coefficients of restitution, concentration, and the masses and diameters of the components of the mixture. The results apply in principle for arbitrary degree of inelasticity and are not limited to specific values of concentration, mass and/or size ratios. As a simple application of these results, the violation of the Onsager reciprocal relations for a confined granular mixture is quantified in terms of the parameter space of the problem.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72901603","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: 5

Ionically Charged Topological Defects in Nematic Fluids 向列流体中的离子带电拓扑缺陷

arXiv: Soft Condensed Matter Pub Date : 2020-10-01 DOI: 10.1103/PHYSREVX.11.011054

J. Everts, M. Ravnik

{"title":"Ionically Charged Topological Defects in Nematic Fluids","authors":"J. Everts, M. Ravnik","doi":"10.1103/PHYSREVX.11.011054","DOIUrl":"https://doi.org/10.1103/PHYSREVX.11.011054","url":null,"abstract":"Charge profiles in liquid electrolytes are of crucial importance for applications, such as supercapacitors, fuel cells, batteries, or the self-assembly of particles in colloidal or biological settings. However, creating localised (screened) charge profiles in the bulk of such electrolytes, generally requires presence of surfaces -for example provided by colloidal particles or outer surfaces of the material, - which poses a fundamental constraint on the material design. Here, we show that topological defects in nematic electrolytes can perform as regions for local charge separation, forming charged defect cores and in some geometries even electric multilayers, as opposed to the electric double layers found in isotropic electrolytes. Using a Landau-de Gennes-Poisson-Boltzmann theoretical framework, we show that ions highly effectively couple with the topological defect cores via ion solvability, and with the local director-field distortions of the defects via flexoelectricity. The defect charging is shown for different defect types -- lines, points and walls -- using geometries of ionically screened flat IN interfaces, radial hedgehog point defects and half-integer wedge disclinations in the bulk and as stabilised by (charged) colloidal particles. More generally, our findings are relevant for possible applications where topological defects act as diffuse ionic capacitors or as ionic charge carriers.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89208322","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: 5

What is the stiffness of a bent book? 一本弯曲的书的硬度是多少?

arXiv: Soft Condensed Matter Pub Date : 2020-09-18 DOI: 10.26226/morressier.5f5f8e69aa777f8ba5bd6086

Samuel Poincloux, Tian Chen, B. Audoly, P. Reis

引用次数: 0

Kosterlitz-Thouless-type caging-uncaging transition in a quasi-one-dimensional hard disk system 准一维硬盘系统的kosterlitz - thoulless型笼-开笼跃迁

arXiv: Soft Condensed Matter Pub Date : 2020-09-02 DOI: 10.1103/PHYSREVRESEARCH.2.033351

A. Huerta, T. Bryk, V. Pergamenshchik, A. Trokhymchuk

引用次数: 12

Self-assembly in rod/coil block copolymers: Degenerate behavior under nonconfinement 棒/线圈嵌段共聚物的自组装:非约束下的简并行为

arXiv: Soft Condensed Matter Pub Date : 2020-09-01 DOI: 10.5488/CMP.23.33603

X.-G. Han, N. Liang, H. Zhang

{"title":"Self-assembly in rod/coil block copolymers: Degenerate behavior under nonconfinement","authors":"X.-G. Han, N. Liang, H. Zhang","doi":"10.5488/CMP.23.33603","DOIUrl":"https://doi.org/10.5488/CMP.23.33603","url":null,"abstract":"The self-assembly of block copolymers containing rigid blocks have received abiding attention due to its rich phase behavior and potential for use in a variety of applications. In this work, under asymmetric interactions between rod/coil components, the self-assembly of coil/coil/rod ABC triblock copolymers is studied using self-consistent field of lattice model. In addition to micelles, centrosymmetric lamellae (CSLM), lamellae, perforated lamellae, strips and gyroids, non-centrosymmetric (NCSLM) lamellae and wavy morphologies are observed as stable phases. The phase diagram of interaction between rod and coil components versus the rod fraction is constructed given a fixed interaction between coil components. For intermediate rod fraction, degenerate behavior is observed. NCSLM and CSLM are degenerate structures. It is found that the entropy of chain conformation plays an important role for this rich behavior. A mechanism of the degenerate behavior is proposed in coil/rod block copolymers under noncofinement. This study provides some new insights into the degenerate behavior of block compolymers, which can offer a theoretical reference for related experiments.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84994985","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: 3

Smecticlike rheology and pseudolayer compression elastic constant of a twist-bend nematic liquid crystal 扭弯向列液晶的微晶流变性和伪层压缩弹性常数

arXiv: Soft Condensed Matter Pub Date : 2020-08-24 DOI: 10.1103/PHYSREVMATERIALS.4.115601

M. P. Kumar, P. Kula, S. Dhara

{"title":"Smecticlike rheology and pseudolayer compression elastic constant of a twist-bend nematic liquid crystal","authors":"M. P. Kumar, P. Kula, S. Dhara","doi":"10.1103/PHYSREVMATERIALS.4.115601","DOIUrl":"https://doi.org/10.1103/PHYSREVMATERIALS.4.115601","url":null,"abstract":"In twist-bend nematic (Ntextsubscript{TB}) liquid crystals (LCs), the mean molecular orientation exhibits heliconical structure with nanoscale periodicity. On the mesoscopic scale, Ntextsubscript{TB} resembles layered systems (like smectics), where the helical pitch is equivalent to \"pseudo-layers\" without a true mass density wave. We study rheological properties of a Ntextsubscript{TB} phase and compare the results with those of an usual SmA phase. Analysing the shear response and adapting a simplified physical model for rheology of defect mediated lamellar systems we measure the pseudo-layer compression elastic constant $B_{eff}$ of Ntextsubscript{TB} phase from the measurements of dynamic modulus $G^{*}(omega)$. We find that $B_{eff}$ of the Ntextsubscript{TB} phase is in the range of $10^{3}-10^{6}$ Pa and it follows a temperature dependence, $B_{eff}sim (T_{TB}-T)^{2}$ as predicted by the recent coarse-grained elastic theory. Our results show that the structural rheology of Ntextsubscript{TB} is strikingly similar to that of the usual smectic LCs although the temperature dependence of $B_{eff}$ is much faster than smectic LCs as predicted by the coarse-grained models.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80641509","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: 3

Structural and mechanical characteristics of sphere packings near the jamming transition: From fully amorphous to quasiordered structures 接近干扰转变的球形填料的结构和力学特性:从完全非晶到准有序结构

arXiv: Soft Condensed Matter Pub Date : 2020-08-22 DOI: 10.1103/physrevmaterials.4.115602

H. Mizuno, Kuniyasu Saitoh, L. Silbert

{"title":"Structural and mechanical characteristics of sphere packings near the jamming transition: From fully amorphous to quasiordered structures","authors":"H. Mizuno, Kuniyasu Saitoh, L. Silbert","doi":"10.1103/physrevmaterials.4.115602","DOIUrl":"https://doi.org/10.1103/physrevmaterials.4.115602","url":null,"abstract":"Mechanically stable sphere packings are generated in three-dimensional space using the discrete element method, which span a wide range in structural order, ranging from fully amorphous to quasi-ordered structures, as characterized by the bond orientational order parameter. As the packing pressure, $p$, varies from the marginally rigid limit at the jamming transition ($p approx 0$) to that of more robust systems ($p gg 0$), the coordination number, $z$, follows a familiar scaling relation with pressure, namely, $Delta z = z - z_c sim p^{1/2}$, where $z_c = 2d = 6$ ($d=3$ is the spatial dimension). While it has previously been noted that $Delta z$ does indeed remain the control parameter for determining the packing properties, here we show how the packing structure plays an influential role on the mechanical properties of the packings. Specifically, we find that the elastic (bulk $K$ and shear $G$) moduli, generically referred to as $M$, become functions of both $Delta z$ and the structure, to the extent that $M-M_c sim Delta z$. Here, $M_c$ are values of the elastic moduli at the jamming transition, which depend on the structure of the packings. In particular, the zero shear modulus, $G_c=0$, is a special feature of fully amorphous packings, whereas more ordered packings take larger, positive values, $G_c > 0$.","PeriodicalId":8472,"journal":{"name":"arXiv: Soft Condensed Matter","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73514073","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: 1

Level statistics and Anderson delocalization in two-dimensional granular materials 二维颗粒材料中的水平统计和安德森离域

arXiv: Soft Condensed Matter Pub Date : 2020-08-17 DOI: 10.1103/PHYSREVB.103.104201

L. Zhang, Yinqiao Wang, Jie Zheng, Aile Sun, Xulai Sun, Yujie Wang, W. Schirmacher, Jie Zhang

引用次数: 1