微结构化和可变序列共聚物液体的质心扩散与粘度理论
Theory of the center-of-mass diffusion and viscosity of microstructured and variable sequence copolymer liquids
AI总结：
本研究提出微观动力学理论，结合PRISM积分方程理论的结构信息与单体尺度力自相关函数演化，分析规则多嵌段共聚物溶液的扩散与粘度，明确序列、吸引强度等对动力学减速的影响及关键序参量。
摘要：
通过蛋白质和核酸相分离形成的生物分子凝聚体已被广泛观测到，为以无膜方式组织细胞内物质提供了一种基本途径。传统上，这些凝聚体被视为均匀的各向同性液体。然而，类比于某些合成共聚物体系，我们近期的理论研究表明，模型生物分子凝聚体可呈现出类微乳液的内部结构，这取决于具体序列、链间位点-位点相互作用以及浓相聚合物密度。本研究中，我们提出了一种微观动力学理论，用于描述浓相非缠结A/B规则多嵌段共聚物溶液的自扩散系数和粘度。我们的方法整合了两方面内容：一是从PRISM积分方程理论获得的静态平衡局域及微畴尺度结构信息，二是质心层面单体尺度力的自相关函数的时间演化——后者决定了远离玻璃化或凝胶转变的弱笼蔽区域中的聚合物扩散系数和粘度。出于简化考虑，同时也因其与合成高分子科学的相关性，我们聚焦于规则多嵌段体系。我们明确了序列和链间吸引强度对共聚物质量输运与流动减速的影响，这种减速源于局域团簇增强的碰撞摩擦，以及由涌现的微畴尺度有序化导致的运动迟滞。本研究采用解析分析和生物分子凝聚体研究中使用的度量指标，以识别关键序参量，这些序参量可量化吸引力、堆积结构、多嵌段序列和共聚物密度如何决定向涨落聚合物微乳液态转变之上和之下的动力学减速程度。
英文摘要：
Biomolecular condensates formed through the phase separation of proteins and nucleic acids are widely observed, offering a fundamental means of organizing intracellular materials in a membrane-less fashion. Traditionally, these condensates have been regarded as homogeneous isotropic liquids. However, in analogy with some synthetic copolymer systems, our recent theoretical research has demonstrated that model biomolecular condensates can exhibit a microemulsion-like internal structure, contingent upon the specific sequence, inter-chain site-site interactions, and concentrated phase polymer density. In this study, we present a microscopic dynamical theory for the self-diffusion constant and viscosity of concentrated unentangled A/B regular multiblock copolymer solutions. Our approach integrates static equilibrium local and microdomain scale structural information obtained from PRISM integral equation theory and the time evolution of the autocorrelation function of monomer scale forces at the center-of-mass level that determine the polymer diffusion constant and viscosity in a weak caging regime far from a glass or gel transition. We focus on regular multi-block systems both for simplicity and for its relevance to synthetic macromolecular science. The impact of sequence and inter-chain attraction strength on the slowing down of copolymer mass transport and flow due to local clustering enhanced collisional friction and retardation of motion due to emergent microdomain scale ordering are established. Analytic analysis and metrics employed in the study of biomolecular condensates are employed to identify key order parameters that quantity how attractive forces, packing structure, multiblock sequence, and copolymer density determine dynamical slowing down above and below the crossover to a fluctuating polymeric microemulsion state.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
