Studies of the self-assembly of P3HT-b-PMMA rod-coil diblock copolymer

• Main Authors: Mei-Tsu Lai, 賴美足
• Other Authors: Hsin-Lung Chen
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/91352740866317339864

碩士 === 國立清華大學 === 化學工程學系 === 94 === Block copolymer (BCP) self-assembly is an essential part of nanotechnology, and it offers one of the few practical strategies for making ensembles of nanostructures. Self-assembled BCPs have found applications in a number of fields of nanotechnology such as photonic band gap materials, nanostructured networks, nanolithographic templates, etc. Most of the research in this field has been focused on coil-coil BCPs with flexible polymer chains. During the past two decades, rod-coil BCPs, where one of the constituting blocks has a rigid conformation and the other is flexible, have attracted great attention. Due to the combination of two extreme polymer chain conformations (rigid and flexible), complex phase structures and morphologies have been observed. In this study, the self-assembled structure of a conjugated rod-coil P3HT47-b-PMMA220 diblock copolymer was investigated using SAXS, WAXS and TEM. The results showed that this copolymer self-organized to from hierarchical structure with two different length scales. The larger-length-scale structure was formed due to microphase separation between P3HT and PMMA block resulting in P3HT microdomain of ca. 20 nm in diameter embedded in PMMA matrix. The P3HT microdomain further consisted of a smaller-length-scale structure due to the formation of ca. 5 nm in diameter nano-ribbons. The regular layered structure due to the microphase separation between to backbone and side chain of P3HT, in this case, was hindered due to covalent linking with PMMA chains. Furthermore, from temperature-dependent SAXS experiment, an order-disorder transition (ODT) of the nano-ribbon structure in the copolymer was revealed between 50 ~ 80℃.