浙江大学学报（理学版）JournalofZhejiangUniversity（ScienceEdition）http：//www.zjujournals.com/sci第50卷第5期2023年9月Vol.50No.5Sept.2023聚电解质链在柱状受限下的构象转变高菊先，丁斌远，何林李*（温州大学数理学院，浙江温州325035）摘要：采用粗粒化分子动力学模拟方法，研究了受限于圆柱体内的聚电解质链的构象行为。通过计算链平均回旋半径、平均持久长度和平均形状因子等物理量，重点探究反离子价态、链刚性和受限孔径等对聚电解质链尺寸和构象转变的影响。结果表明，受限聚电解质链可形成稳定的棒状、球状、折叠链状和环状结构。尤其在三价反离子诱导下，半刚性聚电解质链可形成稳定的环状结构，并由切向相关函数表征。通过统计反离子分布，进一步探讨了聚电解质链和离子凝结的机制。同时讨论了环的成核和生长动力学特征，为进一步揭示生物大分子在有限空间内的构象行为提供了理论指导。关键词：分子动力学；受限；链刚性；反离子价态；构象转变中图分类号：O469文献标志码：A文章编号：1008⁃9497（2023）05⁃580⁃08GAOJuxian,DINGBinyuan,HELinli（DepartmentofPhysics，WenzhouUniversity，Wenzhou325035，ZhejiangProvince，China）Theconfigurationaltransitionofpolyelectrolytechainconfinedinacylinder.JournalofZhejiangUniversity(ScienceEdition),2023,50(5):580⁃587Abstract:Theconfigurationaltransitionofpolyelectrolytechainconfinedinacylinderwasstudiedbymeansofcoarse-grainedmoleculardynamicssimulation.Specifically,theeffectsonthesizeandconfigurationtransitionofpolyelectrolytechainundertheparametersofcounterionvalence,chainstiffnessandconfinementradiuswerestudiedbycalculatingtheaverageradiusofgyration,averagepersistencelength,andaverageshapefactor.Ithasbeenfoundthattherearestablerod-like,globular,folded-chainandringstructuresinconfinedspace.Inthecaseoftrivalentcounterions,thepolyelectrolytechainwithmoderatestiffnessformsastableringstructure,whichcanbewellcharacterizedbyatangentcorrelationfunction.Themechanismofcondensationofpolyelectrolytechainandcounterionisfurtherexploredbystatisticalanalysisofpolyelectrolytechainandcounterionsdistribution.Finally,thekineticcharacteristicsofthenucleationandgrowthoftheringstructurearediscussed,andt...
