Characterization on Modified Multi-wall Carbon Nanotube for Synthesis Polyimide/MWNT Nanocomposites

• Main Authors: Shang-Chih Chou, 周上智
• Other Authors: Yao-Yi Cheng
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/vne696

博士 === 國立臺北科技大學 === 工程科技研究所 === 99 === Carbon Nanotubes (CNTs) with excellent electrical conductivity, mechanical and thermal properties are potential useful as nano-reinforcements in polymer composite which has attracted much attention recently. The lack of interfacial interactions between CNTs and polymer matrix causes facile aggregation of CNTs, therefore, it is necessary to modify CNT to form a polar functional group on the tube surface to enhance the compatibility within a polymer matrix. In this work, we study the various surface modifications of multi-walled carbon nanotubes (MWNT), various methods including thermal purification, ultra-sonication, acid-treatment processes by H2SO4/HNO3 (3:1 by volume) mixture or HNO3, and treatment of amino functional molecules. Thermal purification successfully removes the impurities on CNT surface such as amorphous carbon, and surface modification effectively form polar functional molecules on the tube surface. Homogenous dispersion of polyimide (PI) nanocomposites with various ratios of these modified MWNT was fabricated. Dues to the high aspect ratio of CNT, the formation of a network structure between PI and modified MWNT significantly improves electrical conductivity and also reduces the mobility of PI molecules, thereby increasing its thermal and mechanical properties.