Tiron对纳米Al_2O_3悬浮液性能的影响

Effect of Tiron on the Properties of Nano-sized Al_2O_3 Suspension

以1,2-二羟基苯-3,5-二磺酸钠(Tiron)为分散剂获得了平均粒径约为57nm的氧化铝粉体的稳定悬浮液.通过测定等温吸附曲线及悬浮液的Zeta电位,研究了Tiron对粉体表面特性的影响.结果表明,Tiron在Al2O3表面发生化学吸附,磺酸基的离解使胶粒表面电荷更负,显著提高颗粒表面的带电量,从而改善浆料的稳定性.FTIR研究表明:Tiron分子结构中两个相邻羟基与Al-OH形成内环结构,从而提高了吸附强度.流变测试确定了制备高固含量稳定浆料在pH=8.5时所需的最佳分散剂用量为0.8wt％.

Tiron (1,2-dihydroky-3,5-benzenedisulfonic acid sodium salt) was used as a dispersant for nano-sized alumina suspensions. Surface chemistry of the suspensions was evaluated via isotherm adsorption and zeta potential measurements. FTIR was used to probe the adsorption mechanism. It was found that the strong adsorption should be due to the formation of an inner sphere complex between metal ions on the surfaces and alcohol groups of Tiron. With two sulfate groups, Tiron addition in the suspension led to a higher density of negative charge. The rheological measurements of Al2O3 suspensions indicated that the optimum content of Tiron was 0.8wt% at pH=8.5.