Process Development for Rapid Self-Assembly of PPV-b-PMMA Block Copolymer

• Main Authors: Ting-Chung Kao, 高挺鐘
• Other Authors: Wei-Fang Su
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/91030719978214983258

碩士 === 國立臺灣大學 === 高分子科學與工程學研究所 === 104 === Rod-coil block copolymers have long been a research interest for their great potentials in nanolithography and flexible optoelectronics applications. By adjusting interactions between segments and their volume fractions, one can acquire various nanoscale morphologies. However, the segment interactions of rod-rod and rod-coil of the copolymers are very strong, the formation of ordered structure is rather difficult even they are annealed under a fairly high temperature for a long time. To promote the formation of ordered structure of rod-coil block copolymer, chemical modifications of side chain or main chain are usually used to suppress interactions, but that affects the original physical properties of pristine copolymers. In this work, we’ve developed a facile method to form a highly ordered nanostructure of PPV-b-PMMA at low temperature and short time without any chemical modification. By adding high boiling point selective additives in the copolymer, the thermodynamic equilibrium of ordered structure can be reached with relatively low temperature and short time. If the high boiling point additive cannot remove during the annealing process completely that will affect the chemical and physical properties of the copolymer. Therefore, we further improve the process by treating the samples under different annealing environment. Two new systems are investigated: open system and vacuum system as compared with the original confined system (sample annealed in a metal washer). The additive has more room to facilitate the movement of copolymer and to be evaporated effectively during the annealing. By optimizing the annealing condition, we can not only retain the nanostructure of the copolymer, but also improve the quality of ordered structure without presence of any additive. For example, vaccum system can help copolymer to form structure in 1.5hr annealing period. This technique provides an efficient and energy-saving process for self-assembly copolymers to form highly ordered structures.