环形/尾形吸附构型二元刷的温敏-共（非）溶组合效应

A key factor in preparing polymer brushes for surface modification and smart tuning of material is sufficiently high grafting density. How to enhance the functional performance of brushes under a given grafting density is an unavoidable problem. Recently the unique advantage of cyclic brushes over their linear counterparts in the fields such as colloidal stabilization, antifouling surface, and lubrication have been highlighted. Meanwhile, few theoretical or experimental studies have looked at the temperature sensitivity or co(non)solvency of loop brushes which can serve as approximate alternatives or flexible extensions to cyclic brushes. Considering the entropy-induced tunable/switching properties and compatibility with foreign objects of different sizes of loop/tail binary brushes, a unified but convenient theoretical tool is needed to investigate the stimuli-responsive problems including thermoresponsive behavior and co(non)solvency effect. Therefore, this project intends to use polymer lattice density functional theory to study solvent responsive behavior of loop/tail binary brushes with entropy-induced tunable/switchable steric stabilization or energy dissipation, combine the design of functional block copolymers and their corresponding temperature-control or co(non)solvency mechanisms, and explore multi-tunable or non-monotonic but controllable stimuli-responsive mechanism for the design and preparation of smart surfaces.

制备用于材料表面改性和智能调控的聚合物刷的一个关键要素是较高的接枝密度，如何在接枝密度不变的前提下，提升聚合物刷的特定功能特性，是一个不可回避的问题。近年来，相对于传统的线形分子刷，环形分子刷在胶体稳定性、抗蛋白吸附、表面润滑等领域的独特优势受到研究者重视。同时，环形吸附构型刷作为环形分子刷的近似替代物和灵活扩展，有关其温敏或共（非）溶行为的理论或实验研究仍然较少。考虑到环形/尾形吸附构型二元刷的熵致可调/开关特性和对外来吸附物的尺寸兼顾性，需要针对其热响应行为和共（非）溶效应等受激响应问题建立相对统一且方便的理论研究工具。本项目拟应用聚合物格子密度泛函理论，研究以环形/尾形吸附构型二元刷的空间位阻或能量耗散的熵致可调/开关性为基础的溶剂响应行为，结合功能化嵌段共聚物的设计和相应温控或共（非）溶机制，探索具有多重可调性或非单调且可控的受激响应机制，为相应智能表面的设计和制备，提供理论支持。

本项目针对高分子溶液的温敏-共（非）溶组合效应和高分子溶液诱导的表面间溶剂化力，发展了格点密度泛函理论（PLDFT），使之可应用于被实验研究广泛关注的球形胶束或纳米粒子热响应行为的建模。我们就“ABA对称三嵌段高分子LCST的可调性”、“共非溶诱导聚合物刷改性表面间吸引力的可调性”、“温敏/非温敏二元刷LCST行为的可调性”、“响应/非响应二元刷的共溶剂响应行为的可调性”、“温敏高分子LCST行为的共溶剂调控”等问题建立了适用于实验研究的定量规律，这些规律是构建相应环形/尾形吸附构型二元刷的基础，如果根据实验条件进一步改进理论模型及相应参数，可望挖掘出更多具体的有待实验验证的问题和规律。