Macromolecular Theory and Simulations最新文献

{"title":"Revisiting the Master Curve Relationship for the Dimensions of Network Polymers","authors":"Hidetaka Tobita","doi":"10.1002/mats.202500084","DOIUrl":"https://doi.org/10.1002/mats.202500084","url":null,"abstract":"<div>\u0000 \u0000 <p>The graph diameter correlates with the mean-square radius of gyration and can be used to represent the 3D size of the polymer molecules. The graph diameter of the finite network polymer is investigated for both random and nonrandom architectures. By considering miniemulsion copolymerization of vinyl and divinyl monomers in Monte Carlo simulations, various types of networks are generated for investigation. The master curve relationship between the fraction <i>d</i> of diameter chain and cycle rank found earlier is revisited, which represents the maximum <i>d</i> of a randomly crosslinked homogeneous network for a given cycle rank. The relationship applies in a wide range of network maturity index NMI that is the number of cycle ranks per primary chain, approximately 3&lt; NMI &lt; 20. For the nonrandom inhomogeneous networks, the maximum <i>d</i> for a given cycle is <i>f</i>_d times the master curve, and the calibrated <i>d</i>/<i>f</i>_d curve follows the master curve. Larger NMI-values are needed for inhomogeneous networks to reach the maximum <i>d</i>, however, setting NMI larger than about 5 allows <i>d</i> to be larger than the corresponding random networks. Although the current study focuses on microgels, the design concept can also be applied to the synthesis of macrogels.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145970123","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}

{"title":"Fluid to Solid Transition in Colloidal Suspensions of Thermo Responsive Core–Shell Soft Particles Interacting through Multi-Hertzian Pair-Potential: A Monte Carlo Study","authors":"Sivaram Vintha,&nbsp;Anoop Mutneja,&nbsp;Smarajit Karmakar,&nbsp;Manimaran P,&nbsp;B. V. R. Tata","doi":"10.1002/mats.202500080","DOIUrl":"https://doi.org/10.1002/mats.202500080","url":null,"abstract":"<p>Maxime J. Bergman et al. have proposed a Multi-Hertzian (MH) pair-potential by modeling the core–shell structure of thermo-responsive poly (N-isopropyl acrylamide) (PNIPAM) soft microgel particles, which are known to be soft and can be over-packed beyond a volume fraction <i>ϕ</i> &gt; 0.68. There have been no studies in the literature on the applicability of the MH pair potential to understand the phase behavior and dynamics of dense PNIPAM microgels. We report here the results of Monte Carlo (MC) simulations on PNIPAM microgel suspensions interacting with MH potential over a wide range of volume fractions (<i>ϕ</i> = 0.3–0.68), under over-packed conditions (<i>ϕ</i> = 0.68–1.0), and also in the temperature range of <i>T</i> = 15°C–30°C. MC simulations show a fluid (liquid-like ordered) to solid (crystalline) transition as a function of increasing volume fraction, <i>ϕ</i>, and a solid to fluid transition upon increasing temperature, <i>T</i>, which are in accordance with experimental observation. We also studied the dynamics of PNIPAM particles by computing the mean square displacement (MSD) as a function of Monte Carlo (MC) time for different volume fractions and at various temperatures. Although our simulations predict the phase behavior of PNIPAM suspensions similar to that observed in experiments, but failed to predict the reported experimental observations under over-packed conditions, viz., the report of sub-diffusive dynamics at small time scales by Joshi et al., which indicates the existence of entanglement of dangling polymer chains between shells of the neighboring PNIPAM microgel particles. Our simulations suggest the need for improvements in the MH pair-potential to account for the dangling polymer chains.</p>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202500080","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145963796","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}

{"title":"Bayesian Optimization in Polymer Modeling: From Coarse-Graining Foundations to Autonomous Inverse Design","authors":"Zakiya Shireen","doi":"10.1002/mats.202500081","DOIUrl":"https://doi.org/10.1002/mats.202500081","url":null,"abstract":"<div>\u0000 \u0000 <p>Coarse-graining (CG) is crucial for simulating polymers at extended scales, addressing the computational limitations of atomistic molecular dynamics. However, developing accurate and transferable CG force fields remains a formidable challenge, due to high-dimensional parameter spaces, conflicting objectives, and inherent noise. This review highlights Bayesian Optimization (BO) as a transformative, data-driven framework for automating the parameterization of CG force fields. BO leverages probabilistic Gaussian process surrogates and acquisition functions to navigate complex landscapes efficiently, minimizing expensive simulations while quantifying uncertainty. We survey BO's application in CG model development, from single- to multi-objective optimization for achieving structural, thermodynamic, and dynamic fidelity, and enhancing transferability across conditions. Key examples include CG models for electrolytes, block copolymers, and epoxy resins, often integrated with advanced machine learning techniques for learning potentials, optimal mappings, and active data acquisition. We also discuss emerging autonomous pipelines like SPACIER, RAPSIDY, CAMELOT, and PAL 2.0, which streamline the inverse design. Finally, we outline persistent challenges such as surrogate scalability, handling nonstationarity, and extending to reactive/multiscale systems, and envision BO as a cornerstone of future automated materials discovery, accelerating the design of novel polymeric materials.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145964439","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}

{"title":"3D Multi-Physics Finite Element Simulation of the Selective Laser Sintering Process for Polyamide 12: Effects of Laser Parameters on Melt Pool Formations and Sintering Quality","authors":"Oğulcan EREN","doi":"10.1002/mats.202500094","DOIUrl":"https://doi.org/10.1002/mats.202500094","url":null,"abstract":"<div>\u0000 \u0000 <p>Selective Laser Sintering (SLS) is an additive manufacturing method that enables the rapid and cost-effective production of complex polymer parts with high strength and dimensional accuracy. However, achieving these improved properties depends on laser processing parameters, which significantly influence melt behavior, melt pool properties, and the overall quality of the components. Because empirical approach is both time-consuming and cost-intensive, finite element method (FEM)-based simulations have become a popular field of study. However, existing simulation models are often oversimplified and inadequate to fully understand the multi-physics nature of SLS. To address this gap, a comprehensive 3D multi-physics finite element model was developed to simulate the SLS processing of Polyamide 12 powder. This study incorporates multiple interacting physical phenomena, such as heat transfer, fluid flow dynamics, melt-solidification kinetics, and phase transformations, to provide a realistic depiction of the transient thermal and fluid behavior of the SLS process. The simulation systematically examined the influence of laser process parameters on molten pool formation, temperature distribution, and overall sintering quality. The results show that insufficient volumetric energy density (VED) or high scan speeds resulted in incomplete melting and porosity, whereas excessive energy input promoted overheating and material degradation.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145970207","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}

{"title":"Issue Information: Macromol. Theory Simul. 5/2025","authors":"","doi":"10.1002/mats.70023","DOIUrl":"https://doi.org/10.1002/mats.70023","url":null,"abstract":"","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.70023","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102064","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}

{"title":"Rheological and Thermal Behavior of Calendering Process of Hybrid Nanofluid: A Magnetohydrodynamic Thin Film Analysis","authors":"Hasan Shahzad,&nbsp;Moataz Alosaimi","doi":"10.1002/mats.202500088","DOIUrl":"https://doi.org/10.1002/mats.202500088","url":null,"abstract":"<div>\u0000 \u0000 <p>The current investigation reports the rheological implications on thin film production with magnetized hybrid nanofluid during the calendering process. Hybrid nanofluids are reported to have better rheological characteristics, improved mechanism of heat transfer in liquid, viscosity modification, and thermal conductivity enhancement as related to the usual unitary nanofluid. Lubrication Approximation Theory (LAT) is applied to simplify the respective system of non-dimensional equations and solved by employing analytical as well as numerical approaches to find velocity, temperature, pressure gradient, exiting film thickness, pressure, and other mechanical quantities. The graphical illustrations are thoroughly explained by providing physical reasoning for the obtained variations. Hybrid nanoparticle-based molten polymer modifies the fluid viscosity, enhancing pressure gradient and temperature distribution. The relation between film attachment and detachment point also varies under hybrid nanoparticle volume fraction and Hartmann number. Engineering quantities like separating force and power input are enhanced due to hybrid nanoparticles because of higher fluid viscosity and pressure distribution, but an opposite trend is detected due to MHD. The current investigation focuses on the rheology and controlling factors for the heat transfer mechanism and film thickness, without extensive experimentation to save project cost and precious time. It also helps improve product performance and quality in industrial thin film applications.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145969969","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}

{"title":"A Computational Study of Physical Properties of Nitrile-Butadiene Rubber via Molecular Dynamics Simulations","authors":"Fuyuan Tian,&nbsp;Tiancong Wang,&nbsp;Zongxia Guo,&nbsp;Zhanfu Yong,&nbsp;Jianhui Song","doi":"10.1002/mats.202500070","DOIUrl":"https://doi.org/10.1002/mats.202500070","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;As a widely used elastomer, the properties of nitrile butadiene rubber (NBR) are strongly influenced by its monomer composition and molecular structure. In this work, we employ all-atom molecular dynamics simulations to systematically investigate the effects of chain length, acrylonitrile (ACN) content, and trans-butadiene (T-B) ratio on the properties of NBR. Key properties examined include density (&lt;i&gt;ρ&lt;/i&gt;), unit free volume (UFV), root-mean-square radius of gyration (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mo&gt;¯&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$ &lt; bar{R}_g^2{{ &gt; }^{1/2}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;), and glass transition temperature (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{T}_g}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;). We also analyze two dynamic parameters: mean square displacement (MSD) and diffusion coefficient (DC). Our results indicate that increasing the chain length leads to higher density and larger &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mover&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mo&gt;¯&lt;/mo&gt;\u0000 &lt;/mover&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;msup&gt;\u0000 &lt;mo&gt;&gt;&lt;/mo&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$ &lt; bar{R}_g^2{{ &gt; }^{1/2}}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, while reducing UFV, which consequently decreases molecular mobility. With increasing ACN content, density, and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;T&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;annotation&gt;${{T}_g}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; rise, whereas all other structural and dynamic parameters decline. In contrast, variations in T-B content ratio have a minor effect on density; however, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;&lt","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145983717","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}

{"title":"Aging of Tetrafluoroethylene Propylene (FEPM) Material in High-Pressure HighTemperature Hydrogen Sulfide Downhole Environment: Theory, Modeling, Experiments, and Material Lifetime Prediction","authors":"Aref Ghaderi,&nbsp;Hadis Nouri,&nbsp;Roozbeh Dargazany,&nbsp;Scott Meng,&nbsp;Peixiang Xing,&nbsp;Jiaxiang Ren,&nbsp;Peng Cheng","doi":"10.1002/mats.202500044","DOIUrl":"https://doi.org/10.1002/mats.202500044","url":null,"abstract":"<p>This paper presents a physics-driven neural network (PINN) model to capture the constitutive behavior, elongation at break (EAB), modulus, and tensile strength of FEPM material in high-pressure, high-temperature (HPHT) hydrogen sulfide (H2S) downhole environment. The model comprises a deep neural network structure and a physics-based constitutive equation. The PINN model was trained using experimental data from the FEPM material properties before and after the ISO-23936-2 immersion tests. It is shown that the PINN model can accurately predict the FEPM material behavior under HPHT sour service conditions. The predictions of our DL model agree well with the experimental data. Predictions were also made via the Arrhenius approach per ISO 23936-2 based on the same data set, and the results were compared to those from the PINN model. The comparison highlights that the Physics-Informed Neural Network (PINN) model excels in predicting material longevity across a broad temperature spectrum. This research underscores the effectiveness of PINN models in precisely forecasting material performance in high-pressure, high-temperature (HPHT) sour downhole conditions, paving the way for the development of advanced materials.</p>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mats.202500044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145909193","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}

{"title":"Effect of Weight Functions on the Dynamics and Rheology of Dilute Polymer Solutions in Dissipative Particle Dynamics Simulations","authors":"Sanjay Jana,&nbsp;Indranil Saha Dalal","doi":"10.1002/mats.202500071","DOIUrl":"https://doi.org/10.1002/mats.202500071","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;Dissipative particle dynamics (DPD) is a mesoscale simulation technique that has shown promise for studying polymer solutions, particularly in complex flow geometries. However, its application in rheological studies of polymer solutions remains limited compared to Brownian dynamics (BD) simulations. This is partly due to lack of investigations of the effect of modeling parameters on rheological results, in flow fields. This study investigates the influence of the weight function parameter &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;annotation&gt;$s$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; in DPD simulations on the behavior of dilute polymer solutions, comparing the conventional value &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$s = 2$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$s = 0.5$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, which has been suggested to better mimic liquid-like behavior. We perform detailed DPD simulations at equilibrium and under flow conditions, including both extensional and shear flows, using a highly resolved polymer chain model. Our results show that while the equilibrium chain size predictions are nearly identical for both &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;annotation&gt;$s$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; values, the dynamics differ significantly. Specifically, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$s = 0.5$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; results in slower chain relaxation times and suppresses excluded volume effects. Drag forces with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$s = 0.5$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; are larger, leading to higher chain stretch at moderate flow rates. With start-up extension, the time distribution for unraveling with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$s = 0.5$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; remains significantly narrow, with no outlier configurations with delayed stretching. In shear flows, the end-over-end tumbling dynamics is slower with &lt;span&gt;&lt;/span&gt;&lt;math","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"35 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145964326","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}

{"title":"Effect of Patch Size and Attraction Energy on Polymer Chain Adsorption in Slits Created by Opposing Patch-Patterned Surfaces","authors":"Han-Da Liu,&nbsp;Shuai Li,&nbsp;Qing-Hui Yang,&nbsp;Meng-Bo Luo","doi":"10.1002/mats.202500076","DOIUrl":"https://doi.org/10.1002/mats.202500076","url":null,"abstract":"<div>\u0000 \u0000 <p>The adsorption behavior of a polymer chain within a slit composed of two patch-patterned surfaces is investigated using Langevin dynamics simulations. Each surface exhibits periodic attractive square patches (period <i>d</i>, size <i>L</i>, attraction energy ε_ps), with a 0.5<i>d</i> misalignment between the two surfaces. The adsorption degree increases with <i>L</i>, while the mean number of occupied patches &lt;<i>n</i>_pa&gt; and the surface-parallel component of the mean square radius of gyration &lt;<i>R</i>²_g,xy&gt; exhibit a complex dependence on <i>L</i>. We identify distinct adsorption regimes: a single-surface and single-patch adsorbed state for <i>L</i> &gt; <i>L</i>_s, an upper-lower and multi-patch adsorbed state for <i>L</i> &gt; <i>L</i>_m, and a complete adsorbed state for <i>L</i> &gt; <i>L</i>_c. At weak ε_ps, the polymer chain adopts single-surface and single-patch adsorption for middle <i>L</i> and upper-lower and multi-patch adsorption for large <i>L</i>. Conversely, a strong ε_ps promotes upper-lower and multi-patch adsorption for small <i>L</i>, and single-surface and single-patch adsorption as <i>L</i> increases. The adsorption degree increases monotonically to saturate with ε_ps, while &lt;<i>n</i>_p&gt; initially increases and subsequently decays toward stability. Notably, &lt;<i>R</i>²_g,xy&gt; first decreases, then increases, and finally decreases to stabilize as ε_ps increases. These results highlight the role of patch geometry and interaction strength in governing polymer adsorption behavior.</p>\u0000 </div>","PeriodicalId":18157,"journal":{"name":"Macromolecular Theory and Simulations","volume":"34 6","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145533686","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}