硬脂酸/钛酸四丁酯复合改性剂处理掺锑二氧化锡纳米粉体
来源期刊：中南大学学报(自然科学版)2006年第3期
论文作者：吴湘伟 陈振华 严红革 黄培云
文章页码：444 - 449
关键词：表面改性;掺锑二氧化锡;纳米粉体;疏水
Key words：surface modification; antimony doped tin oxide; nano powders; hydrophobicity
摘 要：用硬脂酸/钛酸四丁酯复合改性剂对掺锑二氧化锡(ATO)纳米粉体进行表面有机化改性处理。通过润湿性、分散稳定性测试研究处理温度、分散介质以及钛酸四丁酯与硬脂酸的量比对改性效果的影响。采用热重分析、透射电镜分析、红外光谱分析、X射线光电子能谱等测试方法对改性后粉体的表面包覆率、形貌、分散状态以及改性机理进行研究。研究结果表明,提高处理温度、适当增加复合改性剂中硬脂酸的量并选用极性弱的有机溶剂可达到比较理想的改性效果;钛酸四丁酯的作用是与粉体粒子表面的羟基以及吸附水反应产生偶联点,如M—O—Ti—OH,这些偶联点易于与羧酸反应;在低温时RCOO-与偶联点的Ti(IV)之间以配合物的形式发生作用,在回流温度下处理时,主要发生酯化反应,使硬脂酸更牢固地嫁接到粉体粒子表面,改性效果更好。
Abstract: Stearic acid and tetrabutyl titanate were used to improve the hydrophobicity of antimony doped tin oxide (ATO) nano-powders . The effects of temperature, dispersion medium and molar ratio of tetrabutyl titanate to stearic acid on the wettability and dispersion stability of powder in liquid paraffin were studied. The coated powder particles were characterized by thermo- gravimetry, infrared spectro-scopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results indicate that improving temperature to reflux, using low polarity solvent as dispersion medium and proper molar ratio of tetrabutyl titanate to stearic acid can bring out good modification. The function of tetrabutyl titanate is to react with the surface hydroxyl groups and adsorbed H2O on the powder particles to produce new binding sites such as M—O—Ti—OC4H9and M—O—Ti—OH, which can easily react with the carboxylic acid. As temperature increases from room temperature to reflux temperature, the reactions between RCOO- and Ti(IV) change from coordinate bonds to covalent bonds, which makes the carbon chains of stearic acids more strongly bound with the powder particles surface.
基金信息：国家自然科学基金资助项目
