Macromolecular Theory and Simulations最新文献

Issue Information: Macromol. Theory Simul. 5/2025 发布信息：Macromol。理论模拟。5/2025

IF 1.6 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-09-18 DOI: 10.1002/mats.70023

引用次数: 0

Front Cover: Macromol. Theory Simul. 4/2025 封面：Macromol。理论模拟，4/2025

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-07-22 DOI: 10.1002/mats.70010

引用次数: 0

Issue Information: Macromol. Theory Simul. 4/2025 发布信息：Macromol。理论模拟，4/2025

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-07-22 DOI: 10.1002/mats.70009

引用次数: 0

A Versatile Molecular Dynamics Force Field for Modelling Polyhydroxyalkanoate Structure and Barrier Properties 用于模拟聚羟基烷酸酯结构和势垒性质的通用分子动力学力场

IF 1.6 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-07-16 DOI: 10.1002/mats.202500048

Nisha Middleton, Dominic Wadkin-Snaith, Paul Mulheran, Karen Johnston

{"title":"A Versatile Molecular Dynamics Force Field for Modelling Polyhydroxyalkanoate Structure and Barrier Properties","authors":"Nisha Middleton, Dominic Wadkin-Snaith, Paul Mulheran, Karen Johnston","doi":"10.1002/mats.202500048","DOIUrl":"https://doi.org/10.1002/mats.202500048","url":null,"abstract":"<p>Polyhydroxybutyrate (PHB) is a sustainable and compostable polyester, which has great potential for use as food packaging film, having similar barrier properties to conventional plastics. PHB is semi-crystalline and is often copolymerised with polyhydroxyvalerate (PHV) to form poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Molecular dynamics (MD) simulations provide valuable insight into the polymer structure and gas diffusion, but the accuracy of MD simulations depends on the force field. This work presents a modified all-atom General Amber Force Field that enables PHB, PHV and PHVB copolymers to be modelled. The structural properties of crystal and amorphous phases of PHB and PHV were in good agreement with experiment. The diffusion coefficients of water and oxygen in amorphous PHB were also in good agreement with experimental values. The diffusion coefficient of oxygen in PHV was larger than in PHB, mainly due to the lower density of PHV. The diffusion coefficient of water in PHV was similar to PHB as its diffusion is hindered by the interaction of water with the polar ester groups on the polymer chains. This force field can be used to investigate the diffusion of water and oxygen in PHB, PHV and PHBV copolymers, and to optimise the barrier properties of PHBV-based plastic film.</p>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202500048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101347","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

Assessing Dynamic Viscosity of Polyethylene Glycol (PEG): Sensitivity Analysis and AI-Based Modeling 聚乙二醇（PEG）动态粘度评估：敏感性分析和基于人工智能的建模

IF 1.6 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-07-13 DOI: 10.1002/mats.202500032

Juan Li, Soud Khalil Ibrahim, Ramdevsinh Jhala, Anupam Yadav, Ramachandran T, Aman Shankhyan, Karthikeyan A, Dhirendra Nath Thatoi, Rafid Jihad Albadr, Waam Mohammed Taher, Mariem Alwan, Mahmood Jasem Jawad, Hiba Mushtaq, Samim Sherzod, Aseel Smerat

{"title":"Assessing Dynamic Viscosity of Polyethylene Glycol (PEG): Sensitivity Analysis and AI-Based Modeling","authors":"Juan Li, Soud Khalil Ibrahim, Ramdevsinh Jhala, Anupam Yadav, Ramachandran T, Aman Shankhyan, Karthikeyan A, Dhirendra Nath Thatoi, Rafid Jihad Albadr, Waam Mohammed Taher, Mariem Alwan, Mahmood Jasem Jawad, Hiba Mushtaq, Samim Sherzod, Aseel Smerat","doi":"10.1002/mats.202500032","DOIUrl":"https://doi.org/10.1002/mats.202500032","url":null,"abstract":"<div>\u0000 \u0000 <p>In this study, the hyperparameters of a gradient boosting decision tree (GBDT) machine learning model are meticulously fine-tuned using four distinct evolutionary optimization approaches: Evolutionary Strategies (ES), Bayesian Probability Improvement (BPI), Batch Bayesian Optimization (BBO), and Self-Adaptive Differential Evolution (SADE) to predict (polyethylene glycol) PEG viscosity. Analysis of the correlation matrix indicates that pressure and molecular weight have influence on dynamic viscosity. Pressure displays a negligible positive correlation (0.17), while molecular weight shows a positive correlation (0.24). On the other hand, temperature exhibits an inverse relationship (−0.75) with dynamic viscosity, establishing it as the most critical factor affecting viscosity. Thus, temperature significantly impacts dynamic viscosity, whereas molecular weight and pressure contribute marginally. These observations are essential for comprehending system behavior and enhancing process efficiency. Among the optimization techniques, SADE outperforms the others, yielding the most accurate GBDT-based hybrid predictive model, as evidenced by performance metrics, including R-squared, mean squared error (MSE), and average absolute relative error (AARE). Despite its extended runtime, SADE's exceptional precision, reflected in the lowest MSE and AARE. Sensitivity analysis confirms that all input variables affect the target parameter, with SHapley Additive exPlanations (SHAP) analysis highlighting temperature as a dominant factor influencing PEG viscosity.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145101123","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

A Model to Predict the Flow Rate in Single Conical Screw Extruder 单螺杆挤出机流量预测模型

IF 1.6 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-07-10 DOI: 10.1002/mats.202500034

Haonan Wang, Ruidi Qi, Zhitao Liu, Liangzhi Xia

{"title":"A Model to Predict the Flow Rate in Single Conical Screw Extruder","authors":"Haonan Wang, Ruidi Qi, Zhitao Liu, Liangzhi Xia","doi":"10.1002/mats.202500034","DOIUrl":"https://doi.org/10.1002/mats.202500034","url":null,"abstract":"<div>\u0000 \u0000 <p>A novel general model for predicting the flow rate and pressure in conical screw extruders for polymer processing has been developed, addressing a crucial need in polymer manufacturing. Based on single screw extruder flow Equations and mass conservation principles, we derived a flow rate Equation for a single conical screw, accounting for variations in screw diameter and slot depth along the length. Recognizing the significant impact of slip phenomena on flow rates, especially for energetic materials, we incorporated a slip velocity correction for non-Newtonian fluids. This correction was based on simulations across various diameters and rotational speeds, enhancing the model's accuracy for real-world polymer extrusion processes. The model's predictive power was validated through experimental data, yielding impressive accuracy with simulation calculation errors of 1.59% and numerical derivation errors of 7.40%. This research bridges the gap between theoretical polymer rheology and practical extrusion processes, offering a method for optimizing the design technology of single conical screws.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145100877","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

A Comparison of Bead-Spring and Site-Binding Models for Weak Polyelectrolytes 弱聚电解质珠-弹簧和位点结合模型的比较

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-05-28 DOI: 10.1002/mats.202500020

Loris Burth, David Beyer, Christian Holm

{"title":"A Comparison of Bead-Spring and Site-Binding Models for Weak Polyelectrolytes","authors":"Loris Burth, David Beyer, Christian Holm","doi":"10.1002/mats.202500020","DOIUrl":"https://doi.org/10.1002/mats.202500020","url":null,"abstract":"<p>Understanding the ionization behavior of weak polyelectrolytes in aqueous solutions with added salt is crucial for designing advanced materials. Predicting the ionization states of weak polyelectrolyte is challenging due to the interplay between long-range Coulomb interactions, conformational flexibility, and chemical equilibria. Bead-spring models with explicit ion treatment provide accurate results but are computationally expensive. In contrast, Ising-like site-binding models are computationally efficient but neglect conformational flexibility and use an implicit salt description. To assess the validity of these approximations, a site-binding model is compared with bead-spring models that include implicit and explicit ion treatments. These results show that under strong electrostatic coupling, explicit ion treatment is critical for accurately modeling ionization behavior. Both the site-binding and implicit bead-spring models overestimate monomer correlations in this regime, leading to significant deviations from the explicit bead-spring model. Under weak coupling, typical of aqueous environments with monovalent salts, all models give reasonable ionization curves, with slight differences. The implicit bead-spring model shows slightly stronger suppression of ionization, while the site-binding model aligns more closely with the explicit bead-spring model due to compensating errors in ion treatment and flexibility. In conclusion, while all models perform well under weak coupling, explicit ion treatment is essential for accurate ionization under strong coupling.</p>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202500020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144673187","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 Simulation and Analysis of CO2 Bubble Deformation in PET Continuous Extrusion Process PET连续挤压过程CO2气泡变形的数值模拟与分析

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-05-21 DOI: 10.1002/mats.202500006

Lihua Cai, Wangyongjia Zhong, Haifeng Fang, Zheng Rong, Sipeng Zhang

{"title":"Numerical Simulation and Analysis of CO2 Bubble Deformation in PET Continuous Extrusion Process","authors":"Lihua Cai, Wangyongjia Zhong, Haifeng Fang, Zheng Rong, Sipeng Zhang","doi":"10.1002/mats.202500006","DOIUrl":"https://doi.org/10.1002/mats.202500006","url":null,"abstract":"<p>In this paper, the dynamic deformation of supercritical CO<sub>2</sub> bubbles in the shear flow field of polyethylene terephthalate (PET) is analyzed, and the dynamic continuous extrusion process of PET microcellular foaming is numerically simulated. The extrusion process of PET supercritical CO<sub>2</sub> homogeneous solution is simulated by the user defined function (UDF) program, and the volume of fluid (VOF) method is used to track the gas-liquid interface. The deformation of supercritical CO<sub>2</sub> bubbles in the PET microcellular foaming extrusion process is simulated in FLUENT software. It is found that in the continuous dynamic extrusion process, the bubble moves with the polymer at a certain angle, and there will be an area at the two ends to inhibit the shear thinning of the melt, which affects the movement pattern of the bubble. The increase in shear rate is the main factor causing the increase in the aspect ratio of the bubble. The increase of the rheological index can promote the bubble to maintain the spherical shape by affecting the shear flow field around the bubble. In addition, it is found that the effect of surface tension on bubble morphology in the shear flow field is not as large as that in the static flow field.</p>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 4","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672798","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

Issue Information: Macromol. Theory Simul. 3/2025 发布信息：Macromol。理论模拟3/2025

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-05-19 DOI: 10.1002/mats.202570006

引用次数: 0

Computational Modeling of the Continuous Separation of a Molten Polymer Mixture in a Centrifugal Field 熔融聚合物混合物在离心场中连续分离的计算模型

IF 1.8 4区工程技术

Macromolecular Theory and Simulations Pub Date : 2025-05-19 DOI: 10.1002/mats.202570005

V. Medvid, H. Steiner, C. Irrenfried, M. Feuchter, G. Brenn

引用次数: 0