嵌段共聚物PS-b-PLA薄膜自组装形貌和结构及应用的研究

发布时间：2018-06-14 06:17

  本文选题：聚苯乙烯-b-聚乳酸 + 嵌段共聚物薄膜　； 参考：《上海交通大学》2015年硕士论文

【摘要】：嵌段共聚物(block copolymer)一般指的是两种或两种以上的化学组成不同的高分子链段通过化学键合而成的高分子聚合物。由于不同链段热力学不相容性,嵌段共聚物可发生微相分离形成纳米范围的有序结构,此结构受其本身分子参数、薄膜厚度、基底性质、外界场等控制。本文采用旋涂法在不同特性的硅基底表面上制备出了聚苯乙烯-b-聚乳酸(PS-b-PLA)薄膜。用原子力显微镜(AFM)表征了基底性质、溶液浓度、薄膜厚度、退火温度时间以及退火溶剂和均聚物的添加对PS-b-PLA薄膜自组装行为的影响。结果表明:不同的基底性质影响PS-b-PLA自组装薄膜的形貌与结构。选择性溶剂退火有助于PS-b-PLA薄膜微相分离,而用共溶剂退火对相分离无明显影响。亲水硅基底上PS-b-PLA薄膜在130℃温度退火,无法得到有序结构薄膜;在150℃退火时形成垂直基底条纹、平行条状混合有序结构;而在170℃退火时形成垂直基底平行条纹有序结构。添加均聚物聚乳酸(PLA)后,其与嵌段共聚物共同发生分离,并改变了形成的有序结构的尺寸,同时得到有序结构的时间延长了。此外,本文将疏水硅基底上的PS-b-PLA薄膜在170℃退火2h得到垂直基底平行条状结构,继续退火30h得到了垂直基底的柱状结构。通过一定浓度NaOH溶液除去条纹状结构薄膜中PLA相后,用氢氟酸处理得到了表面“枝状”硅片基底,测得其光反射率约为60%;对柱状结构薄膜采用同样的处理后得到了表面多孔状硅片基底,其光反射率约为30%。
[Abstract]:Block copolymer is a kind of polymer which is formed by chemical bonding of two or more polymer chains with different chemical composition. Due to the thermodynamic incompatibility of different segments, the block copolymers can be separated into ordered structures in nanometer range, which are controlled by their own molecular parameters, film thickness, substrate properties and external fields. Polystyrene-b-lactic acid (PS-b-PLA) thin films were prepared on silicon substrates by spin-coating method. The effects of substrate properties, solution concentration, film thickness, annealing temperature and time, and the addition of annealing solvent and homopolymer on the self-assembly behavior of PS-b-PLA thin films were characterized by atomic force microscopy (AFM). The results show that the morphology and structure of PS-b-PLA self-assembled films are affected by different substrate properties. Selective solvent annealing is helpful to the microphase separation of PS-b-PLA films, but cosolvent annealing has no obvious effect on the phase separation. The PS-b-PLA films annealed at 130 鈩，

本文编号：2016404