Macromolecular Theory and Simulations最新文献_第10页

Dynamics Responses of Graphene Nanoplatelets-Reinforced Polydimethylsiloxane Nanocomposites: A Molecular Dynamics Study 石墨烯纳米板增强聚二甲基硅氧烷纳米复合材料的动力学响应：分子动力学研究

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-31 DOI: 10.1002/mats.202300021

Zheng Li, Tong Li, Ke Zhang, Bo Wang

引用次数: 0

Dimerization of Polyglutamine within the PRIME20 Model using Stochastic Approximation Monte Carlo 聚谷氨酰胺二聚化在PRIME20模型中的随机逼近蒙特卡罗方法

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-30 DOI: 10.1002/mats.202200075

Christian Lauer, Wolfgang Paul

{"title":"Dimerization of Polyglutamine within the PRIME20 Model using Stochastic Approximation Monte Carlo","authors":"Christian Lauer, Wolfgang Paul","doi":"10.1002/mats.202200075","DOIUrl":"10.1002/mats.202200075","url":null,"abstract":"This study presents a numerical investigation of the dimerization of polyglutamine homo-peptides of varying length. It employs the PRIME20 intermediate resolution protein model and studies it with a flat-histogram type Monte Carlo simulation that gives access to the thermodynamic equilibrium of this model over the complete control parameter range (for the simulations this is temperature). For densities comparable to typical in vitro experimental conditions, this study finds that the aggregation and folding of the polyglutamine chains occur concurrently. However, as a function of chain length the sequence of establishment of intra- and intermolecular hydrogen bonding contacts changes. Chains longer than about N = 24 polyglutamine repeat units fold first and then aggregate. This agrees well with the experimental finding that, beyond N = 24 the single polyglutamine chain is the critical nucleus for the aggregation of amyloid fibrils. A finite size scaling of the ordering temperatures reveals that for this chain length (and longer chains) folding occurs at physiological (respectively larger) temperatures, whereas shorter chains are disordered at physiological conditions.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 5","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202200075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44370061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Brownian Dynamics Investigations of the Scattering Functions of Ideal and Excluded Volume Linear Polymers in Higher Dimensions 高维理想和排除体积线性聚合物散射函数的布朗动力学研究

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-25 DOI: 10.1002/mats.202300024

Khoa Dang Dinh, Marvin Bishop

引用次数: 0

Emergence and Stability of Hierarchical Structures under Cylindrical Confinement 圆柱约束下层次结构的产生与稳定性

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-18 DOI: 10.1002/mats.202370005

Tiancheng Chen, Yuci Xu

引用次数: 0

Masthead: Macromol. Theory Simul. 3/2023 刊头：Macromol。理论模拟。2023年3月

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-18 DOI: 10.1002/mats.202370006

引用次数: 0

Coalescence of Sessile Polymer Droplets: A Molecular Dynamics Study 固定式聚合物液滴的聚结:分子动力学研究

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-12 DOI: 10.1002/mats.202300017

Soheil Arbabi, Panagiotis E. Theodorakis

引用次数: 2

On the Effective Lifetime of Reversible Bonds in Transient Networks 暂态网络中可逆键的有效寿命

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-05 DOI: 10.1002/mats.202300002

Sachin Shanbhag, Ralm G. Ricarte

{"title":"On the Effective Lifetime of Reversible Bonds in Transient Networks","authors":"Sachin Shanbhag, Ralm G. Ricarte","doi":"10.1002/mats.202300002","DOIUrl":"10.1002/mats.202300002","url":null,"abstract":"The renormalized bond lifetime model (RBLM) is a popular scaling theory for the effective lifetime of reversible bonds in transient networks. It recognizes that stickers connected by a reversible bond undergo many (J) cycles of dissociation and reassociation. After finally separating, one of these stickers finds a new open partner in time τopen via a subdiffusive process whose mean-squared displacement is proportional to tα, where t is the time elapsed, and α is the subdiffusion exponent. The RBLM makes convenient mathematical approximations to obtain analytical expressions for J and τopen. The consequences of relaxing these approximations is investigated by performing fractional Brownian motion (FBM) simulations. It is found that the scaling relations developed in the RBLM hold surprisingly well. However, RBLM overestimates both τopen and J, especially at lower values of α. For α = 0.5, corresponding to the Rouse limit, it is found that τopen is overestimated by a factor of approximately 4x, while the approximation for J is nearly exact. The degree of overestimation worsens as α decreases, and increases to 1–2 orders of magnitude at α = 0.25, corresponding to the reptation limit. This has important ramifications for experimental studies that use RBLM to interpret rheology and dielectric spectroscopy observations.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 4","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45558555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Kelvin's Tetrakaidecahedron as a Wigner–Seitz Cell Found in Spherically Microphase-Separated BCC Lattice from AB Diblock Copolymer by Monte Carlo Simulation 用蒙特卡罗模拟在球形微相分离的BCC晶格和AB双嵌段共聚物中发现了维格纳-塞茨细胞的Kelvin四面体

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-05-04 DOI: 10.1002/mats.202300016

Jiro Suzuki, Yushu Matsushita

{"title":"Kelvin's Tetrakaidecahedron as a Wigner–Seitz Cell Found in Spherically Microphase-Separated BCC Lattice from AB Diblock Copolymer by Monte Carlo Simulation","authors":"Jiro Suzuki, Yushu Matsushita","doi":"10.1002/mats.202300016","DOIUrl":"10.1002/mats.202300016","url":null,"abstract":"Metropolis Monte–Carlo simulation is carried out for microphase-separated bulk state of AB diblock copolymers with various compositions. The distribution probability of end segments in long B-block chain are explored to determine the Wigner–Seitz(WS) cells as primitive cells for four known periodic structures, lamellar-, Gyroid-, cylindrical-, and spherical ones. The end segments are commonly turned to be localized at the several distinct far sites from the lattice points of WS cells for all morphologies investigated. Among them, when the fraction of A segments is 0.25, a hexagonal prism type column appears as a WS, while when the fraction is much lower at 0.1, body-centered cubic(BCC) lattice is formed and its end segments are found to be localized at hexagonal frames and also on the six square faces of truncated octahedron or Kelvin's Tetrakaidecahedron(KT), which has rarely been found in real soft material ever. This achievement is strongly pointing that each micelle formed by self-assembled diblock coplymers in bulk have essentially the framework of equivolume KT in real material systems.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 5","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202300016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43238022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Kinetic Monte Carlo Simulations as a Tool for Unraveling the Impact of Solvent and Temperature on Polymer Topology for Self-Initiated Butyl Acrylate Radical Polymerizations at High Temperatures 动力学蒙特卡罗模拟作为揭示溶剂和温度对高温下自引发丙烯酸丁酯自由基聚合聚合物拓扑影响的工具

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-04-18 DOI: 10.1002/mats.202300007

Jonas Mätzig, Marco Drache, Georg Drache, Sabine Beuermann

{"title":"Kinetic Monte Carlo Simulations as a Tool for Unraveling the Impact of Solvent and Temperature on Polymer Topology for Self-Initiated Butyl Acrylate Radical Polymerizations at High Temperatures","authors":"Jonas Mätzig, Marco Drache, Georg Drache, Sabine Beuermann","doi":"10.1002/mats.202300007","DOIUrl":"10.1002/mats.202300007","url":null,"abstract":"High-temperature butyl acrylate polymerizations in bulk and in solution are investigated experimentally and by kinetic Monte Carlo (kMC) simulations. The experimental data comprise conversion-time data, molar mass distributions, and branching levels per polymer chain derived from size-exclusion chromatography with a multiangle laser light scattering detector. A kMC model is established, which allows for the description of the impact of solvent and temperature on molar mass distribution as well as type and content of macromonomers. Within the study kinetic coefficients for transfer to solvent and the thermal self-initiation of the monomer are determined according to the Metropolis Hastings algorithm. The kMC simulations provide information, which are otherwise not accessible, for example, the number of branch points per molecule as a function of molar mass or the molar mass distribution of various macromonomer species. Moreover, molar ratios of mid-chain and chain-end radicals are at hand for temperatures up to 160°C, which are important for the interpretation of the experimentally and via simulation-derived polymer topology as a function of molar masses.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 4","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202300007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47951207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Dimensions of Network Polymers: Universal Relationship for the Ratio between Mean-Square Radius of Gyration and Graph Diameter 网络聚合物的尺寸：回转均方半径与图形直径之比的普遍关系

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2023-04-14 DOI: 10.1002/mats.202300012

Hidetaka Tobita

{"title":"Dimensions of Network Polymers: Universal Relationship for the Ratio between Mean-Square Radius of Gyration and Graph Diameter","authors":"Hidetaka Tobita","doi":"10.1002/mats.202300012","DOIUrl":"10.1002/mats.202300012","url":null,"abstract":"Mean-square radius of gyration Rg2 and the graph diameter D, which describe the dimensions of polymers, are investigated for the network polymers. Both for the random and nonrandom statistical networks whose cycle rank is r, a linear relationship Rg2 = ar D applies. The ratio ϕ of ar against the corresponding ring-free architecture a0, ϕr = ar/a0 has a universal relationship applicable both for the random and nonrandom networks with ϕr∝r−0.25 for large r’s, and an empirical relationship, ϕr = [(1 + r)−2/3 + r/2]−0.25 is proposed. For the polymer fraction having a given number of r, the nonrandom nature of crosslinking tends to make both Rg2 and D larger compared with the corresponding random networks, except for the limited cases with small values of r’s.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"32 4","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202300012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42805079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0