文献报道中关于高分子链折叠与组装的研究主要集中于热力学平衡态转变方面，对于相关的动力学缺乏足够的认识，而理解这一过程对高分子组装体的形态、性质和功能调控等至关重要。本项目采用停流光谱手段系统研究了合成高分子链折叠、聚集和组装的过程，首次获得了链折叠与组装的动力学实验数据，并在此基础上与相关的理论计算结果相对照，阐明了高分子链组装的机理。停流法能通过溶剂快速混合方式方便地实现在毫秒级时间内pH值，温度和盐浓度的跃变。研究了荧光探针标记高分子的单链塌缩过程，从实验上获得单链折叠过程的特征驰豫时间和分子量之间的标度关系，首次为de Gennes在1985和1997年提出高分子单链折叠动力学模型提供了直接的实验证据；制备了温度响应型环形聚合物，利用激光光散射和停流光谱等手段详细研究了环形和线型聚合物热诱导折叠/聚集的热力学和动力学过程，阐明了链拓扑结构的差异对折叠/聚集过程的影响；应用停流光谱法研究了两亲性和双亲性嵌段聚合物的胶束化动力学过程，提出了组装的机理；采用停流技术研究了微凝胶(网络状交联的单链体系)溶胀/塌缩的动力学过程，获得了微凝胶塌缩的特性驰豫时间与微凝胶初始尺寸之间的标度关系。

Previous literature reports concerning the folding and assembly of synthetic polymers mainly focused on transitions of thermodynamic equilibrium states, whereas our knowledge of the kinetic aspects is quite insufficient, the undrestanding of which can shed much light on the tuning of morphologies, properties, and functions of polymeric assemblies. In this project, we utilized the stopped-flow (SF) technique to investigte the folding, aggregation, and assembling kinetics of synthetic polymer chains; we obtained direct experimental evidences of relevant kinetic processes, then compared the experimental results to previously reported theoretical models, and elucidated the mechanism of polymer assembly. The SF technique can conveniently achieve abrupt jumps of solution pH, temperature, and ionic strengths within a few milliseconds via the solvent mixing approach. We investigated the collapsing kinetics of single synthetic polymer chains and experimentally obtained the scaling relationship between characteristic relaxation times and polymer molecular weights, which provided direct experimental evidences for the single chain collapsing model proposed by de Gennes in 1985 and 1997, respectively. Thermosensitive cyclic polymers were synthesized, the collapsing and aggregation kinetics of cyclic and linear polymers were investigated by laser light scattering and stopped-flow techniques, and the effect of chain topology on chain collapsing and aggregation kinetics were elucidated. We utilized the SF technique to investigate the micellization kinetics of amphiphilic and double hydrophilic block copolymers, the assembling mechanism has been proposed. The SF technique was also employed to investigate the swelling and deswelling kinetics of microgels, which can be considered as cross-linked single chain network, and we obtained the scaling between characteristic microgel deswelling times and initial microgel sizes.

文献报道中关于高分子链折叠与组装的研究主要集中于热力学平衡态转变方面，对于相关的动力学缺乏足够的认识，而理解这一过程对高分子组装体的形态、性质和功能调控等至关重要。本项目采用停流光谱手段系统研究了合成高分子链折叠、聚集和组装的过程，首次获得了链折叠与组装的动力学实验数据，并在此基础上与相关的理论计算结果相对照，阐明了高分子链组装的机理。停流法能通过溶剂快速混合方式方便地实现在毫秒级时间内pH值，温度和盐浓度的跃变。研究了荧光探针标记高分子的单链塌缩过程，从实验上获得单链折叠过程的特征驰豫时间和分子量之间的标度关系，首次为de Gennes在1985和1997年提出高分子单链折叠动力学模型提供了直接的实验证据；制备了温度响应型环形聚合物，利用激光光散射和停流光谱等手段详细研究了环形和线型聚合物热诱导折叠/聚集的热力学和动力学过程，阐明了链拓扑结构的差异对折叠/聚集过程的影响；应用停流光谱法研究了两亲性和双亲性嵌段聚合物的胶束化动力学过程，提出了组装的机理；采用停流技术研究了微凝胶(网络状交联的单链体系)溶胀/塌缩的动力学过程，获得了微凝胶塌缩的特性驰豫时间与微凝胶初始尺寸之间的标度关系。