水相/有机相界面扩散控制聚苯胺纳米线生长  

Diffusion-controlled growth of polyaniline nanofibers ataqueous/organic interfaces

作　　者：郑剑锋[1,2] 赵江红[1] 宋金玲[1,2] 朱珍平[1] 

机构地区：[1]中国科学院山西煤炭化学研究所,太原030001 [2]中国科学院研究生院,北京100039

出　　处：《化工新型材料》2009年第5期40-42,共3页New Chemical Materials

摘　　要：将过硫酸铵的盐酸溶液注入溶有苯胺的有机溶剂中形成水相/有机相界面,反应物分子从体相到界面的扩散以及产物从界面到水相的快速扩散可以有效抑制聚苯胺纳米线的团聚。通过使用不同密度的有机溶剂调整水相有机相的相对位置,使纳米线扩散方向与重力方向一致,制备的纳米线长度(由原来的900nm左右增长到2μm左右)和直径分布得到改善,原因是重力由扩散的阻力转变为扩散的助力,纳米线可以更快离开反应界面分散到水相更有效地避免团聚;采用小直径反应器增加反应物扩散程长,提高了聚苯胺纳米线长度(平均长度可达2.5μm左右)并缩小了直径分布范围,分析是因为界面处反应物浓度减小,减缓了苯胺聚合与纳米线的生长速率,使纳米线局部浓度增大变慢从而有效抑制其团聚。In the synthesis process of polyaniline nanofibers at the aqueous/organic interfaces, the diffusion of reactant molecules from bulk solutions to the aqueous/organic interface and of the formed fibers from the interface to bulk solution were centrally effective for the restraining of the fiber aggregation. Mixing the reactants （organic aniline and aqueous （NH4）2S208 solutions） in a reactor with high cross section, as employed previously, resulted in polyaniline nanofibers with length of about 900 nm and a wide diameter distribution. Allowing the diffusion direction of the formed fibers parallel to the gravity direction by using organic solvents with different densities to make aqueous phase and organic phase position adverse can significantly improved fiber length （up to about 2 tan） and the diameter distribution which was likely derived from a help from the fiber gravity for their quick diffusion from the interface to bulk solution to minimize possible aggrega- tion and cross-linking. In addition, using a reactor with lower cross section to enlarge the diffusion distance length can further facilitated the control of fiber length （up to about 2.5μm） and lead to a quite narrow diameter distribution. The polymerization rate of aniline and the growth rate of polyaniline nanofibers decreased by using a reactor with lower cross section to enlarge the diffusion distance and the nanofibers aggregation can be suppressed efficiently due to the small local concentration of nanofibers.

关 键 词：聚苯胺 纳米线 扩散 控制生长 

分 类 号：TB383.1[一般工业技术—材料科学与工程]