浸浆制备过程中载体微结构及涂膜工艺参数对膜厚度的影响

Effects of microstructure of supports and technological controllers of film coating on ceramic membrane thickness during dip-coating process

以“浸浆”成型法制备α-Al2O3陶瓷膜过程为研究对象,提出以载体的纯水渗透性能关联载体的微结构参数来预测载体对膜厚度的总体影响的方法·实验考察了涂膜工艺参数(浸浆时间和流动速度)以及载体纯水渗透性能对膜厚度的影响·结果表明:浸浆时间越长,所形成的膜层厚度越厚且膜厚度与浸浆时间的1/2次方呈正比·而当载体孔道被完全充满后,膜厚度随着时间延长而下降;在制膜液进入载体和脱离载体过程中,膜厚度首先随着制膜液的流动速度的2/3次方线性增长,当流动速度超过一定值后,膜厚度不再变化;载体的渗透性能越优越,越有利于膜厚的形成,且膜厚度与载体的纯水渗透通量呈线性关系.

α-Al2O3 membrane coating （top layer） was formed by dip-coating and the effects of microstructure of supports and technological controllers of film coating, which included dipping time and the flow rates of the suspension into/out the supports, on the membrane thickness were investigated based on experiments; The water flux of supports was used to correlate the support microstructure and its effect on the membrane thickness was studies. The results showed that the membrane thickness increased proportionally with the 1/2 root of dipping time, with 2/3 root of flow rate and increased linearly with the water flux of supports, respectively. In addition, experimental results also showed that the membrane thickness decreased with the increase of dipping time when the dipping time was longer than the saturation time of supports. When the flow rate of the suspension was higher than a certain value, the membrane thickness would no change with the increase of flow rate.