磺化聚苯胺/对苯二胺功能化多壁碳纳米管
                纳米复合材料的形貌和表面分析
                许军123，王艳霞１，李轩１，王惠1，崔兰1，姚琲1*
                            1天津大学分析测试中心
                            2天津大学材料学院
                            3中国民航大学理学院

摘要：用对苯二胺 (p-PDA) 对多壁碳纳米管 (MWNTs) 进行表面修饰，采用氧化法原位合成了聚苯胺 (PANI) / 对苯二胺功能化多壁碳纳米管（p-MWNTs）纳米复合材料，通过进一步磺化和水解反应制备了水溶性的磺化聚苯胺/多壁碳纳米管（SPAN/p-MWNTs）纳米复合材料。采用环境扫描电镜、透射电镜、X-射线光电子能谱分别研究了功能化多壁碳纳米管、PANI/p-MWNTs和SPAN/p-MWNTs纳米复合材料的形貌和表面化学结构。研究结果表明：修饰后多壁碳纳米管的长度减短、表面变粗糙，苯胺基团通过酰胺键连接到多壁碳纳米管侧壁上; 连接在修饰后碳管表面上的苯胺基团被过硫酸铵氧化后引发苯胺单体在碳管表面原位聚合，p-MWNTs作为自组装模板使聚苯胺包覆在p-MWNTs 表面形成了以p-MWNTs为核聚苯胺为壳的“核-壳”纳米结构；在磺化和水解后的SPAN/p-MWNTs纳米复合材料中，磺酸基团以接近1：1的S/N 比率连在磺化聚苯胺的分子骨架上，同时水溶性SPAN分子链通过共价键连接在p-MWNTs表面，导致SPAN/p-MWNTs纳米复合材料在水中的溶解度达到43.56 mg/mL，并使SPAN/p-MWNTs纳米复合材料中的p-MWNTs能够长期稳定地分散在水中。
关键词：多壁碳纳米管；聚苯胺；纳米复合材料；形貌；表面分析。
*联系人：姚琲 教授 博导，天津大学分析测试中心。
基金来源：天津市科技发展应用基础研究计划重点项目（项目号：05YFJZJC00200）。

Morphology and Surface analysis of sulfonated polyaniline / para-phenylenediamine functionalized multi-walled carbon nanotubes nano-composite
    Jun Xu123，Yanxia Wang1，Xuan Li1, Hui Wang1, Lan Cui1，Pei Yao1
    1 Centre for Analysis, Tianjin University, Tianjin City 300072, P.R.China
    2 School of Material Science and Engineering, Tianjin University
    3 College of Science, Civil Aviation University of China

Abstract：Mutiwalled carbon nanotubes (MWNTs) was functionalized with p-Phenylenediamine, and water-soluble sulfonated polyaniline (SPAN) / p-phenylenediamine functionalized MWNTs (p-MWNTs) nano-composite were synthesized by in-situ oxidation polymerization followed by sulfonation and hydrolysis. The morphology and surface chemical state of functionalized MWNTs，PANI/p-MWNTs and SPAN/p-MWNTs nano-composites were investigated by SEM, TEM and XPS，respectively. The results show that length of functionalized MWNTs decreases and the its side walls are very rough, and phenylamine groups are covalently grafted on the defect sites of the side walls of MWNTs via amide bond. Oxidized phenylamine groups initiate polymerization and contribute to the formation of PANI coatings. As self-assembly templates, p-MWNTs are encapsulated by PANI forming a homogeneous core (p-MWNTs) –shell (PANI) nano-structure. After sulfonation and hydrolysis, –SO3H groups have been attached to backbones of sulfonated polyaniline chains with molar ratio of –SO3H groups to nitrogen atoms closed to 1:1 and water soluble SPAN chains covalently attached to p-MWNTs，which result in the solubility of SPAN/p-MWNTs nano-composite in water is 43.56 mg/mL and further p-MWNTs stable dispersed in water.
Keywords: Multi-walled carbon nanotubes；Polyaniline；Nano-composites；Morphology；Surface analysis.