Macromolecular Theory and Simulations最新文献

Masthead: Macromol. Theory Simul. 6/2024 刊头：Macromol.理论模拟6/2024

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-11-18 DOI: 10.1002/mats.202470012

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The Logistic Function in Glass Transition Models of Amorphous Polymers: A Theoretical Framework for Isobaric Cooling Processes 无定形聚合物玻璃转化模型中的对数函数：等压冷却过程的理论框架

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-11-18 DOI: 10.1002/mats.202470011

Claudio Corbisieri

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The Logistic Function in Glass Transition Models of Amorphous Polymers: A Theoretical Framework for Isobaric Cooling Processes 无定形聚合物玻璃转化模型中的对数函数：等压冷却过程的理论框架

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-09-25 DOI: 10.1002/mats.202400052

Claudio Corbisieri

{"title":"The Logistic Function in Glass Transition Models of Amorphous Polymers: A Theoretical Framework for Isobaric Cooling Processes","authors":"Claudio Corbisieri","doi":"10.1002/mats.202400052","DOIUrl":"https://doi.org/10.1002/mats.202400052","url":null,"abstract":"Studying the macroscopic-phenomenological behavior of amorphous polymers at glass transition is often subject to limitations because the ordinary differential equations that describe the material behavior require numerical solution. To avoid these limitations, ad-hoc-formulated models of the glass transition have been proposed. However, their scope of application is expected to be limited due to insufficient theoretical foundation. This work establishes a theoretical framework for models that use the logistic function to approximate the macroscopic-phenomenological behavior of amorphous polymers at glass transition. For this purpose, an exactly-solvable Riccati equation is derived within thermodynamics with internal state variables. A closed-form expression in terms of mathematical functions for the temperature derivative of a single internal state variable is the result. This closed-form expression contains the logistic function thus featuring a continuous transition region centered around a pressure and cooling-rate dependent transition temperature. Based on comparison of existing models with the exact solution derived from the Riccati equation, generalized models that approximate the thermal expansion coefficient and heat capacity at glass transition are proposed. This work thus demonstrates the validity of the logistic function in glass transition models of amorphous polymers and provides suggestions as to how existing models can be extended in their applicability.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202400052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666085","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}

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Investigating the Effect of Rheological Parameter Ratios on the Mixing Properties of TPU Blends 研究流变参数比对热塑性聚氨酯混合物混合性能的影响

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-09-16 DOI: 10.1002/mats.202470009

Yiwen Zheng, Jiankang Wang, Chenyang Wang, Zhijun Li, Zuliang Yang

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Masthead: Macromol. Theory Simul. 5/2024 刊头：Macromol.理论模拟5/2024

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-09-16 DOI: 10.1002/mats.202470010

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Rheological Equivalent Circuit Model Using Electrochemical Impedance Analysis 利用电化学阻抗分析的流变等效电路模型

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-09-08 DOI: 10.1002/mats.202400069

Hwan Woo Choi, Young Seok Song

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Effect of Hydrolyzed Polyacrylamide on the Emulsion Stability by Multiple Light Scattering and Molecular Dynamics Simulation 通过多重光散射和分子动力学模拟研究水解聚丙烯酰胺对乳液稳定性的影响

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-09-05 DOI: 10.1002/mats.202400040

Jin Huang, Xiaorong Ma, Hongyao Li, Mengxue Liu, Qinghe Gao, Cuiqin Li

{"title":"Effect of Hydrolyzed Polyacrylamide on the Emulsion Stability by Multiple Light Scattering and Molecular Dynamics Simulation","authors":"Jin Huang, Xiaorong Ma, Hongyao Li, Mengxue Liu, Qinghe Gao, Cuiqin Li","doi":"10.1002/mats.202400040","DOIUrl":"10.1002/mats.202400040","url":null,"abstract":"Polymer flooding, using hydrolyzed polyacrylamide (HPAM), is crucial in enhanced oil recovery technology. The effect of the HPAM and NaCl concentration on the stability of the simulated emulsions was assessed through multiple light scattering experiments. The results demonstrated that HPAM significantly enhanced the stability of both oil-in-water (O/W) and water-in-oil (W/O) emulsions. The HPAM concentration escalated from 200 mg L−1 to 1000 mg L−1, increasing from 1.24% to 1.31% at 60 minute in the average backscattering of W/O emulsions. The average transmittance of O/W emulsions exhibited a significant decline from 2.54% to 0.12%. The NaCl concentration had a small effect on the stability of the emulsions. Molecular dynamics simulations revealed that HPAM adsorbed at the oil water interface by the point-like nature, with stronger interaction between its amide group and the oil molecule than its carboxyl group. The hydrogen bond number and the hydrogen bond lifetime of HPAM-H2O and HPAM-HPAM increase with increasing the number of HPAM molecules at the oil-water interface, slowing diffusion coefficient of water molecules and increasing the interface thickness. Increasing salinity can weaken the HPAM-water interaction, reducing the emulsification stability. This work provides insights into the emulsification characteristics and mechanisms of HPAM.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207029","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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The Importance of the Knowledge of Errors in the Measurements in the Determination of Copolymer Reactivity Ratios from Composition Data 从成分数据中确定共聚物反应率时了解测量误差的重要性

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-08-27 DOI: 10.1002/mats.202400043

Alexander Maria van Herk, Quan Liu

{"title":"The Importance of the Knowledge of Errors in the Measurements in the Determination of Copolymer Reactivity Ratios from Composition Data","authors":"Alexander Maria van Herk, Quan Liu","doi":"10.1002/mats.202400043","DOIUrl":"10.1002/mats.202400043","url":null,"abstract":"Often the errors in the measurement of copolymerizations are not accurately determined or included in the calculation of reactivity ratios. Some knowledge of the errors in the initial monomer ratio, conversion, and copolymer composition is however essential to obtain reliable (unbiased) reactivity ratios with a realistic uncertainty. It is shown that the errors serve a trifold purpose; they can serve as weighing factors in the fit, they can be compared with the fit residues to decide whether the chosen model is adequate for the data and they can be used to construct a realistic joint confidence interval for the reactivity ratios. The best approach is to have an estimate of the individual errors in the copolymer composition, either from a thorough error propagation exercise or from replicate measurements. With these errors, the χ2-joint confidence intervals can then be constructed which gives a realistic estimate of the errors in the reactivity ratios. Utilizing the Errors in Variables Method (EVM) is correct and useful, but only if the individual errors in all the variables in each experiment are more or less known.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202400043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142207030","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}

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Mechanical Effect Produced by Photo-Switchable Reactions: Insights from Molecular Simulations 光开关反应产生的机械效应：分子模拟的启示

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-07-29 DOI: 10.1002/mats.202400033

Orlando Villegas, Marta Serrano Martínez, Laura Le Bras, Alistar Ottochian, Nicolas Pineau, Aurélie Perrier, Claire A. Lemarchand

{"title":"Mechanical Effect Produced by Photo-Switchable Reactions: Insights from Molecular Simulations","authors":"Orlando Villegas, Marta Serrano Martínez, Laura Le Bras, Alistar Ottochian, Nicolas Pineau, Aurélie Perrier, Claire A. Lemarchand","doi":"10.1002/mats.202400033","DOIUrl":"10.1002/mats.202400033","url":null,"abstract":"Light-responsive shape-changing polymers are photonastic materials: they can convert light into mechanical energy through macroscopic transformations. Indeed, photochromic molecules embedded in these polymer films present light-induced structural modifications that can trigger a significant macroscopic deformation. In this theoretical study based on molecular dynamics simulations, analysis tools ranging from atomic to supramolecular scales are developed to investigate this photonastic phenomenon. To this purpose, a model system built upon an azobenzene photochrome embedded in different environments (tetrahydrofuran, cis-1,4-polybutadiene and hydroxyl-terminated polybutadiene) is considered. First, the impact of the environment on the photochrome properties is discussed through the analysis of the structural properties, ultra-violet visible (UV–vis) absorption spectra and dynamical properties of the photoswitch. Then, the impact of the presence of the photochrome on the polymer is studied. At the atomic scale, the radial distribution functions show some differences between the cis and trans isomers due to geometrical effects. At the molecular scale, the analysis of the size and shape of the polymer chains reveals that the photochrome has no impact on the chain properties. Finally, at the macroscopic scale, the cohesive energy density shows that the polymer is stabilized by the presence of photochrome molecules.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"33 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202400033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870406","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}

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Potential of Phenylalanine‐, Tryptophan‐, and Tyrosine‐MOF‐5 Composites for Selective Carbon Dioxide and Methane Adsorption 苯丙氨酸、色氨酸和酪氨酸-MOF-5 复合物选择性吸附二氧化碳和甲烷的潜力

IF 1.4 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2024-07-26 DOI: 10.1002/mats.202400051

Abdullahi Moyosore, Haslina Ahmad, Muhammad Alif Muhammad Latif, Mostafa Yousefzadeh Borzehandani, Mohd Basyaruddin AbdulRahman, Emilia Abdelmalek

{"title":"Potential of Phenylalanine‐, Tryptophan‐, and Tyrosine‐MOF‐5 Composites for Selective Carbon Dioxide and Methane Adsorption","authors":"Abdullahi Moyosore, Haslina Ahmad, Muhammad Alif Muhammad Latif, Mostafa Yousefzadeh Borzehandani, Mohd Basyaruddin AbdulRahman, Emilia Abdelmalek","doi":"10.1002/mats.202400051","DOIUrl":"https://doi.org/10.1002/mats.202400051","url":null,"abstract":"Metal‐organic frameworks (MOFs) have emerged as versatile materials with exceptional properties, including high porosities, large surface areas, and remarkable stabilities, making them attractive for various applications. MOF‐5 stands out for its thermal stability and surface area, making it promising for diverse applications, including drug delivery and gas adsorption. This study explores the potential of amino acid MOF (AA‐MOF) composites, integrating phenylalanine, tryptophan, and tyrosine, for selective CO2 and CH4 adsorption using grand canonical Monte Carlo (GCMC) simulations. The impact of amino acid composition and spatial arrangement within MOF‐5 on selective CO2 and CH4 adsorption performance have been investigated. The results indicate that tryptophan‐MOF‐5 exhibits the highest CO2 uptake due to the interaction between CO2 and tryptophan, while phenylalanine‐MOF‐5 demonstrated the lowest affinity for gas adsorption. Radial distribution function (RDF) analysis reveals distinct gas distribution patterns within the composites, with tryptophan playing a dominant role in gas adsorption. Additionally, analysis of total energy, enthalpy of adsorption, and Henry's coefficient provide insights into the thermodynamic aspects of gas adsorption onto AA‐MOF composites. This study enhances the understanding of the fundamental mechanisms underlying CO2 and CH4 selective adsorption in amino acid MOF composites, facilitating the development of efficient gas separation technologies.","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"42 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141783798","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