Abstract
Deposition of top layers on the porous support system in ceramic membrane formation using dip-coating process, plays a key role to obtain high quality membranes.Hence, the quantitative analysis of dip-coating process is inevitably required.In this work, α-Al2O3 membranes were prepared by this process and investigated based on full factorial design of experiments. The statistical analysis showed that the effects of two variables; dipping time and withdrawal speed of substrate, were highly significant on the top layers thickness (α<0.001). Also a modified model was developed to interpret the formation process of top layers onto porous substrate during dip-coating, quantitatively. In this model, unlike to the other previous models, the effects of all variables on the top layers thickness were considered simultaneously. The experimental data for α-Al2O3 membranes obtained of suspensions with different volume fractions of ceramic powder showed very good agreement with the modified model.
