Macromolecular Theory and Simulations最新文献_第3页

Masthead: Macromol. Theory Simul. 3/2024 刊头：Macromol.理论模拟3/2024

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-05-17 DOI: 10.1002/mats.202470006

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Modeling the Interface Between Phases in Dense Polymer-Carbon Black Nanoparticle Composites by Dielectric Spectroscopy: Where Are We Now and What are the Opportunities? 通过介电光谱学模拟致密聚合物-碳黑纳米粒子复合材料中的相间界面：我们的现状和机遇是什么？

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-05-17 DOI: 10.1002/mats.202470005

Christian Brosseau

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Do Entangled Polymer Chains Reptate? 纠缠在一起的聚合物链会重复吗？

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-05-02 DOI: 10.1002/mats.202400024

Kia L. Ngai

{"title":"Do Entangled Polymer Chains Reptate?","authors":"Kia L. Ngai","doi":"10.1002/mats.202400024","DOIUrl":"10.1002/mats.202400024","url":null,"abstract":"Neutron spin echo spectroscopy of entangled polymer melts [M. Zamponi, et al. J. Phys. Chem. B 2008, 112, 16220], and of tracer diffusion of short polymer chains in highly entangled polymer melt [M. Zamponi et al. Phys. Rev. Lett. 2021, 126, 187801.] and [M. Kruteva et al. Macromolecules 2021, 54, 11384] found the center-of-mass mean-square displacements at shorter times are subdiffusive, heterogeneous, non-Gaussian, and cooperative. These properties contradict the assumption of reptation within the tube in the tube-reptation (TR) model, but are in accord with the predictions from the many-chain cooperative dynamics in the theory of Guenza. The inadequacy of the TR model revealed by the microscopic experiments and theory motivates the author to reexamine previously published data of diffusion of entangled polymer chains from experiments and simulations used to test the TR model. The results reported in this study lead to the conclusion that the key predictions of the TR model are at variance with experimental and simulation data. The cause lies in the reptation hypothesis contradicting the cooperative nature of entangled chain diffusion proven by its dynamics being isomorphic to cooperative diffusion in other materials. The Coupling Model has predictions consistent with the cooperative diffusion properties in interacting materials [Prog. Mater. Sci., 2023, 139, 101130.]. Applied to the entangled polymers, the predictions successfully explain the data, especially those contradicting the TR model. Thus, diffusion of entangled polymer chains is a cooperative many-chain process in having the universal properties of many-body cooperative diffusion established in many other interacting materials, and the reptation hypothesis is unwarranted.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830706","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}

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Numerical Modeling and Simulation of the Nonisothermal Double Quench Phase Separation Process for the Production of Polymeric Membranes Using Polystyrene-Cyclohexanol Polymer Solution 利用聚苯乙烯-环己醇聚合物溶液生产聚合物膜的非等温双淬火相分离过程的数值建模与模拟

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-04-29 DOI: 10.1002/mats.202400022

Samira Ranjbarrad, Philip K. Chan

{"title":"Numerical Modeling and Simulation of the Nonisothermal Double Quench Phase Separation Process for the Production of Polymeric Membranes Using Polystyrene-Cyclohexanol Polymer Solution","authors":"Samira Ranjbarrad, Philip K. Chan","doi":"10.1002/mats.202400022","DOIUrl":"10.1002/mats.202400022","url":null,"abstract":"The double quench phase separation is a simplified type of continuous cooling process that is widely seen in industrial processes for polymeric membrane formation. Uncommon quenching conditions can lead to the creation of novel membrane microstructures. This study aims to theoretically investigate the impact of nonisothermality on the morphology formation during the double-quench thermally-induced phase separation process. First, quench is employed during different stages of phase separation to observe the possibility of secondary morphology formation. Next, two initial quench temperatures are selected, one shallow and the other deep. The initial solution temperature and the secondary quench temperature are kept constant to inspect the impact of the initial quench temperature on the structure formation. Lastly, the results of the secondary quench are compared with and without employing the enthalpy of demixing. Results verified that the stage of phase separation, the initial and secondary quench temperatures, cooling rate, and the secondary quench composition are the most important parameters in the the nonisothermal double quench phase separation process. The morphology should be well-developed in order for the secondary structure formation. In addition, it is shown that heat generation during demixing in the primary and secondary quenches significantly influences the secondary morphology formation.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 5","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202400022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140830704","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

Swelling Behaviors of Natural Rubber/Solvent Systems Based on the Extended Modified Double Lattice Model 基于扩展修正双晶格模型的天然橡胶/溶剂体系的溶胀行为

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-04-18 DOI: 10.1002/mats.202400015

Sung Jin Pai, Eung Jun Kang, Won Min Ahn, Jae Sung Kim, Young Chan Bae, Ji Won Kwon, Jeong Seok Oh

{"title":"Swelling Behaviors of Natural Rubber/Solvent Systems Based on the Extended Modified Double Lattice Model","authors":"Sung Jin Pai, Eung Jun Kang, Won Min Ahn, Jae Sung Kim, Young Chan Bae, Ji Won Kwon, Jeong Seok Oh","doi":"10.1002/mats.202400015","DOIUrl":"10.1002/mats.202400015","url":null,"abstract":"Swelling experiments are conducted on nonfiller natural rubber using four solvents (toluene, cyclohexane, tetrahydrofuran (THF), and methylethylketone (MEK)) over temperatures from 10 to 70 °C. Toluene, cyclohexane, and THF, classified as effective solvents, show swelling ratios between 3 and 7, influenced by the crosslink density of the rubber. MEK, however, has a lower ratio of 1.5 to 2. Temperature has a minor impact on swelling compared to the crosslink density. The study evaluates the Extended Modified Double Lattice (EMDL) model for its mixing contribution in polymer network swelling, aiming to improve the Flory–Hüggins (FH) model. The superiority of EMDL above FH is in the boundary condition at the unvulcanized state, the former aligning its interaction energy with values from solvent activities in primary linear polymer/solvent solutions, unlike the FH model. The EMDL model also accounts for oriented interactions in polar solvents through a secondary lattice, linking specific interaction energy with solvent dipole moments. The study observes a nonlinear correlation between crosslinking density and sulfur amount, proposing a nonrandom mixing at lower sulfur concentrations. This model shows strong alignment with experimental data, suggesting that replacing the FH model's mixing contribution with the EMDL model could improve results with minimal additional complexity.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202400015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140625072","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

Numerical Analysis of the Blade Coating Process Using Non-Newtonian Nanofluid with Magnetohydrodynamic (MHD) and Slip Effects 使用具有磁流体动力（MHD）和滑移效应的非牛顿纳米流体对叶片涂层工艺进行数值分析

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-04-17 DOI: 10.1002/mats.202400017

Muhammad Asif Javed, Abuzar Ghaffari, Sami Ullah Khan, Ehab Elattar

{"title":"Numerical Analysis of the Blade Coating Process Using Non-Newtonian Nanofluid with Magnetohydrodynamic (MHD) and Slip Effects","authors":"Muhammad Asif Javed, Abuzar Ghaffari, Sami Ullah Khan, Ehab Elattar","doi":"10.1002/mats.202400017","DOIUrl":"10.1002/mats.202400017","url":null,"abstract":"The coating process is widely used in various industries to enhance the production quality and efficiency. This study gives a comprehensive analysis of non-isothermal blade coating of non-Newtonian nanofluid incorporating magnetic, thermophoresis, and Brownian effects. The mathematical equations derived from mass, momentum, and energy conservation laws are initially streamlined by means of lubrication approximation theory (LAT). Subsequently, these dimensionless equations are solved in dimensionless form numerically using fourth order Runge–Kutta and Newton–Raphson methods. This study includes the effects of the slip parameter, magnetohydrodynamic (MHD) and other material parameters on the coating thickness (<math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>h</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 <annotation>${{h}_1}$</annotation>\u0000 </semantics></math>), blade load, velocity, temperature, concentration, and pressure profiles through graphs and tables. The velocity of molten polymer increases near the substrate while it decreases near the blade surface as the slip parameter increases. The temperature distribution increases as the Brinkman number rises, with the maximum temperature occurring in the nip region of the flow. The coating thickness and load-carrying force for both plane and exponential coater increase with higher values of the magnetohydrodynamic (MHD) parameter.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140611288","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: 0

Quantitative Structure-Property Relations for Polyester Materials via Statistical Learning 通过统计学习确定聚酯材料的定量结构-性能关系

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-04-12 DOI: 10.1002/mats.202400008

Stephen McCoy, Damilola Ojedeji, Brendan Abolins, Cameron Brown, Manolis Doxastakis, Ioannis Sgouralis

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An Alternative Explanation of the Microscopic Dynamics of Cyclic Polymers 循环聚合物微观动力学的另一种解释

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-04-03 DOI: 10.1002/mats.202400021

Kia L. Ngai

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Effect of Highly Crosslinked Domains on the Dimensions of Network Polymers 高交联域对网络聚合物尺寸的影响

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-03-21 DOI: 10.1002/mats.202300068

Hidetaka Tobita

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Dissipative Particle Dynamics Study on the Phase Region of Spatial Gradient Materials Produced by Photoinduced Isomerization 关于光诱导异构化产生的空间梯度材料相区的耗散粒子动力学研究

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-03-14 DOI: 10.1002/mats.202400006

Hui Li, Kaiming Gao, Haitao Zhao, Zijian Xue, Zhenbin Chen, Xuefeng Lu, Hong Liu

{"title":"Dissipative Particle Dynamics Study on the Phase Region of Spatial Gradient Materials Produced by Photoinduced Isomerization","authors":"Hui Li, Kaiming Gao, Haitao Zhao, Zijian Xue, Zhenbin Chen, Xuefeng Lu, Hong Liu","doi":"10.1002/mats.202400006","DOIUrl":"10.1002/mats.202400006","url":null,"abstract":"Spatial gradient materials occupy an important research position in the field of functional materials with their unique porous structure. Gradient changes in pore size and density distribution have received extensive attention in the fields of biomimetic and smart materials. The gradient transition law is mathematically related to the driving force of isomerization reaction and component phase separation. In this study, a dissipative particle dynamics simulation is used to introduce photoisomerization reactions into the system. Lambert's law is used to construct a reaction model for the variation of light intensity with irradiation depth, and a gradient structure with a spatial transition law is obtained. The effects of the extinction coefficient ε, the initial reaction probability Pr0, and the interactions α(A,B) between the isomerized molecules as well as the viscosity on the formation of the gradient structure are investigated in detail. Furthermore, the mathematical proportionality between the size of the phase region and interfacial energy of the two phases is elucidated. This study provides preliminary computational insights into the factors affecting the photoinduced phase separation process of polymeric gradient materials. It may help to develop effective strategies to improve the phase separation and properties of polymer gradient materials in subsequent studies.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140128613","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: 0