一步法合成聚苯胺/十二烷基苯磺酸钠超疏水复合材料

在阴离子表面活性剂十二烷基苯磺酸钠(SDBS)体系中,采用一步法制得聚苯胺/SDBS超疏水复合材料.利用场发射扫描电子显微镜(FESEM)观察产物形貌并测定其元素组成.通过傅里叶变换红外光谱仪、紫外-可见光谱仪、X射线衍射等对其结构进行表征,用视频接触角测量仪测定材料的亲疏水性.考察SDBS浓度和溶液酸度对产物形貌及疏水性能的影响,探讨疏水机理.结果表明:在pH=1-9,SDBS浓度大于0.016 mol?L-1条件下,所制备复合材料的水接触角大于150°,SDBS掺杂使得苯胺单体的转化率高达98%.两亲分子SDBS亲水磺酸基与聚苯胺主链上的亚胺基不仅存在静电引力,而且能形成磺酰胺键,聚苯胺主链间又以氢键相互连接,SDBS分子的疏水烃基有序排列朝向聚苯胺主链外侧,从而组装形成具有微纳结构的聚苯胺/SDBS超疏水复合材料.本文结果有利于更好地理解聚苯胺/SDBS超疏水性复合材料的形成机理,对超疏水材料的设计提供新思路.

One-Step Preparation of Superhydrophobic Polyaniline/Sodium Dodecylbenzenesulfonate Composites

Superhydrophobic polyaniline (PANI)/sodium dodecylbenzenesulfonate (SDBS) composites were fabricated in one-step, by the oxidative polymerization of aniline in the presence of SDBS. The morphology and elemental composition of the PANI/SDBS composite were characterized by field-emission scanning electron microscopy. The chemical structure was confirmed by Fourier transform-infrared spectroscopy, ultraviolet-visible spectrophotometry, and X-ray powder diffraction. The superhydrophilic and superhydrophobic properties of the PANI/SDBS composite were determined from water contact angle (WCA) measurements, and were dependent on SDBS concentration, pH, and composite morphology. The formation and superhydrophobic mechanism of the PANI/SDBS composite are discussed. The composite surface had a WCA of >150° at pH 1-9 and SDBS concentration more than 0.016 mol·L^-1. SDBS doping resulted in a 98% conversion of the aniline monomer. The superhydrophobic PANI/SDBS composite formed from electrostatic interaction, and sulfamic bonding between the hydrophilic ―SO₃^- groups of SDBS and ―NH⁺＝ of PANI chains. Hydrogen bonding existed between N and H atoms among PANI chains. The electrostatic interaction and hydrogen bonding immobilized the hydrophilic ―SO₃^- head groups of SDBS around PANI chains, which resulted in the SDBS hydrophobic alkyl chain protruding. These results aid our understanding of the formation of superhydrophobic PANI/SDBS composites, and the design of superhydrophobic materials.