嵌段共聚物在选择性溶剂中诱导自组装行为的模拟退火研究

The directed self-assembly of block copolymers in selective solvents can be used to make advanced nanomaterials with complex structures. Studying the influences of inducer on self-assembly of block copolymers in selective solvents is useful for understanding the morphology and morphological transition of aggregates. Subsequently, it is also helpful to tuning the morphology of aggregates. Now it has been known less about the relationship between inducer and the morphology and morphological transition of the aggregates because of very few investigations of the directed self-assembly of block copolymers in selective solvents. In this project, we are going to investigate the directed self-assembly of block copolymers in selective solvents by using the simulated annealing method; to reveal the relationship between the inducer's shape, scale, the property of surface and the morphology of aggregates, chain packing, configuration of block copolymer; to induct and clarify the transition law of the aggregates' morphology, chain packing, configuration of block copolymer with changing of the shape, the scale, the surface property of inducer; and finally to provide indirection for effectively tuning the morphology of aggregates.

嵌段共聚物在选择性溶剂中的诱导自组装行为可用于制备具有复杂结构的多功能纳米材料。研究诱导物对嵌段共聚物在选择性溶剂中自组装行为的影响对于深入认识聚集体形貌结构及其转变机理有重要意义，从而有助于调控聚集体的形貌结构。但是目前关于嵌段共聚物在选择性溶剂中诱导自组装行为的研究不多，人们对诱导物与聚集体形貌结构及其转变规律之间关系的认识非常有限。本项目拟采用模拟退火方法研究诱导条件下嵌段共聚物在选择性溶剂中的自组装行为，揭示诱导物形状、尺寸、表面性质等与聚集体形貌结构、共聚物链构象及其在聚集体中堆砌方式之间的关系，归纳并阐明共聚物链构象及其堆砌方式、聚集体形貌结构随诱导物形状、尺寸、表面性质的转变规律，为有效地调控聚集体形貌结构提供依据。

在溶剂中，嵌段共聚物可诱导自组装为具有复杂分级结构的高级多功能纳米材料。明晰诱导物与嵌段共聚物及诱导物所组成聚集体的形貌之间的关系有助于精确地调控这些聚集体的形貌。在本项目中，我们采用模拟退火方法研究了两嵌段共聚物在选择性溶剂或者不良溶剂中的诱导自组装行为和软受限环境中三嵌段共聚物或两嵌段共聚物与均聚物共混体系的自组装行为。模拟结果显示小尺寸的诱导物对两嵌段共聚物聚集体的形貌几乎没有影响。相反，当诱导物尺寸非常大时，两嵌段共聚物在选择性溶剂中形成单层圆片附着在诱导界面上,离开诱导物时，这些共聚物会自组装成柱状胶束；当诱导物尺寸适中时，诱导界面的形状与共聚物聚集体或聚集体一部分的形状相似。在软受限环境中，本来会形成椭球形轴向叠罗圆片聚集体的两嵌段共聚物在圆柱状诱导物的诱导下会形成筒状聚集体。筒状聚集体的内部结构随着筒壁厚度减小依次由轴向叠罗圆环结构转变为螺旋结构和吊带结构。三嵌段共聚物或者两嵌段共聚物与均聚物混合体系在软受限条件下都能形成俱有奇特形貌的聚集体。这些形貌有助于研究三嵌段共聚物或者两嵌段共聚物与均聚物混合体系在软受限环境总的诱导自组装行为。研究中所得结论在制备含有有机或无机粒子的聚合物粒子时有一定的指导作用。