Al-DTPA microfiber assisted formwork construction technology for high-performance SiC membrane preparation

High gas permeance and particle interception efficiency are critical for the performance of dust filtration membrane, which requires the membrane to have higher porosity support and ultrathin separation layer. In this work, Al-DTPA (aluminium-diethylenetriamine pentaacetic acid) microfibers were prepared as the sacrificial intermediate layer to bridge the gaps between the large pore support for ameliorating the infiltration of the suspension in the membrane preparation process. The temporary Al-DTPA constructed layer was subsequently removed via calcination, which has few effects on decreasing the combine force of support and separation layer. An ultrathin SiC membrane with its thick of ~100 μm and pore size of 2–5 μm was successfully prepared on the SiC support with a pore size of 30 μm. The preparation and defect formation mechanism were analyzed by investigating the formula and the preparation process. The resulting asymmetric, transition layer-free, defect-free SiC membrane exhibited excellent gas permeance (240–277 m3 m−2 h−1·kPa−1) and dust interception efficiency (99.8%) for particles less than 0.5 μm. The successful fabrication of this transition layer-free and defect-free asymmetric membrane enable the use of mismatched particle size between the support and separation layer, which may provide a new route for the preparation of high-performance gas-solid separation ceramic membranes.