2.5. Preparation of the zirconia top layer
The powder suspension technique was used to prepare the zirconia
top layer. A deflocculated suspension of zirconia was obtained by
the mixing of l0 wt% ZrO2 powder, 30 wt% PVA and 60 wt% DW. Afterwards,
it was deposited on an anorthite layer by using the slip casting
method. The time of deposition was about 5 min. Then, after drying
at a room temperature the membrane was sintered at 1100 °C for 1 h.