Novel pore size tuning method for the fabrication of ceramic multi-channel nanofiltration membrane

A novel pore size tuning method was proposed for the fabrication of TiO2 multi-channel nanofiltration membrane from TiO2 ultrafiltration substrate using in situ chemical deposition. Titanium isopropoxide and isopropanol were employed as the precursor and solvent, respectively. The effects of solvent, precursor, pore size of ultrafiltration substrate, as well as thermal treatment temperature, on the performance of TiO2 multi-channel nanofiltration membrane were studied. The optimized TiO2 multi-channel nanofiltration membrane, prepared from ceramic ultrafiltration substrate with an MWCO of approximately 5 kDa, showed a high pure water permeability of approximately 20 Lm(-2) h(-1) bar(-1) and a low MWCO of approximately 800 Da. The average membrane pore radius was tuned from 2.4 nm to 0.9 nm. The TiO2 multi-channel nanofiltration membrane was successfully applied to the decolorization of sodium dehydroacetate. The decolorization rate was similar to 89.5%, and the sodium dehydroacetate recovery rate reached 98%, which is 2-3% higher than that obtained using the traditional activated carbon decolorization process. The in situ chemical deposition method has great potential as a novel and facile pore size tuning technique for ceramic ultrafiltration membrane for the fabrication of the ceramic multi-channel nanofiltration membranes, especially for large-scale production.

提出了一种新颖的孔径调节方法，用于通过原位化学沉积从二氧化钛超滤基底制备二氧化钛多通道纳滤膜。分别采用异丙醇钛和异丙醇作为前驱体和溶剂。研究了溶剂、前驱体、超滤基底的孔径以及热处理温度对二氧化钛多通道纳滤膜性能的影响。由截留分子量约为5 kDa的陶瓷超滤基底制备的优化后的二氧化钛多通道纳滤膜，表现出约20 Lm⁻²h⁻¹bar⁻¹的高纯水渗透率和约800 Da的低截留分子量。膜的平均孔径从2.4 nm调节到0.9 nm。二氧化钛多通道纳滤膜成功应用于脱氢乙酸钠的脱色。脱色率约为89.5%，脱氢乙酸钠回收率达到98%，比传统活性炭脱色工艺高2 - 3%。原位化学沉积法作为一种新颖且简便的陶瓷超滤膜孔径调节技术，对于陶瓷多通道纳滤膜的制备，特别是大规模生产，具有巨大潜力。