摘要
采用聚苯乙烯-b-聚甲基丙烯酸甲酯嵌段共聚物(PS-b-PMMA)的甲苯稀溶液滴膜法制备PMMA伸展链,用原子力显微镜观察了PMMA分子链形貌及其在丙酮、水蒸气退火后的构象转变.结果表明,浓度(聚合物质量/溶液质量)为1×10^(-6)的PS-b-PMMA甲苯溶液可以在云母基底表面制备出高度为0.2 nm、长度为100~300 nm的PMMA伸展链;该方法可以适用于不同分子量的PS-b-PMMA共聚物,当PMMA嵌段分子链大于PS时,更容易制备高度伸展的PMMA分子链.丙酮蒸气退火可使胶束中的PMMA伸展链迅速收缩并与PS核融为一体变成球形结构.水蒸气退火作用下PMMA分子链的构象转变与制备胶束的起始浓度有关,浓度为1×10^(-6)的胶束只形成球状结构;浓度为5×10^(-6)的胶束含有较多的PMMA伸展链,在水蒸气退火后可形成花状胶束并可以组装成周围带有台阶状PMMA分子层的棒状胶束.
PMMA stretched chains was prepared successfully by dropping dilute PS-b-PMMA toluene solution,and the morphology and the conformation transition of PMMA stretched chains under acetone and water vapour annealing were characterized by using AFM. The results showed the PMMA stretched chains with height of 0.2 nm and length of 100 nm - 300 nm can be formed on the mica substrate by dropping dilute PS- b-PMMA toluene solution with concentration of 1 x 10-6 ; this method can be used for PS-b-PMMA materials with different molecular weights,the highly stretched PMMA chains can be prepared easily when the molecular weight of PMMA segment was larger than that of PS segment. The PMMA stretched chains will be contracted rapidly and fused with PS core to form spherical structure when the surface micelles were annealed by acetone vapour; the conformation transition depended on the initial concentration of preparing surface micelles during annealing with water vapour,the surface micelles prepared by dilute solution of 1 × 10- 6 can be changed into spherical structure only; the micelles having much more PMMA stretched chains prepared with a concentration of 5 × 10 -6 can be assembled into flower like mieelles and rod micelles with step-like PMMA molecular layers.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2016年第4期422-427,共6页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51403094)资助项目
