Fabrication of La/Y-codoped microporous organosilica membranes for high-performance pervaporation desalination
Fabrication of La/Y-codoped microporous organosilica membranes for high-performance pervaporation desalination
复制标题
用于高性能渗透蒸发海水淡化的La/Y共掺杂微孔有机硅膜的制备
DOI：
10.1016/j.memsci.2019.05.023
复制
发表时间：
2019
影响因子：
9.5
通讯作者：
Xiao-Liang Zhang
中科院分区：
文献类型：
--
作者：
Hua-Yu Zhang;Jiu-Li Wen;Qi Shao;Ai Yuan;Hai-Ting Ren;Fang-Ying Luo;Xiao-Liang Zhang
以1,2-二（三乙氧基硅基）乙烷（BTESE）为前驱体，采用溶胶-凝胶法制备了La/ y共掺杂有机硅微孔膜。通过各种表征证实，在溶胶-凝胶过程中，稀土元素被掺杂到二氧化硅骨架中，这将减小btese衍生溶胶的粒径和粒径分布，并形成水热稳定的Si-O-RE （La和Y的RE）键。它可以显著影响La/ y共掺杂膜的表面形貌、微观结构和亲水性，从而提高其脱盐性能。在优化的制备条件下，La25Y75-SiO2（La:Y = 25:75,mol%）膜在室温为25 °C时，水通量最高，为10.3 kg m−2h−1，对3.5 wt% NaCl进料溶液的去除率接近100%。这是由于la25y75 - sio2膜的亲水性最强，微观结构最精细，水渗透质量阻力最低。此外，这些有机硅膜在200 h的模拟海水淡化试验中表现出良好的稳定性，在25-60 °C的不同浓度的盐溶液中，分离性能没有明显变化，并且具有良好的水热耐久性。
La/Y-codoped microporous organosilica membranes were successfully fabricated by sol-gel procedure with 1,2-bis(triethoxysilyl)ethane (BTESE) as silica precursor for efficient desalination. The rare earth elements were confirmed to be doped into silica frameworks during the sol-gel procedure by various characterizations, which would decrease particles size and size distribution of BTESE-derived sols and form hydrothermally stable Si–O–RE (RE for La and Y) bonds. It could significantly influence membrane surface morphology, microstructure properties and hydrophilcity of La/Y-codoped membranes, and then improve their desalination performance. Under the optimized preparation conditions, La25Y75-SiO2(La:Y = 25:75, mol%) membranes exhibited the highest water flux of 10.3 kg m−2h−1and NaCl rejection of nearly 100% towards 3.5 wt% NaCl feed solution even at room temperature of 25 °C. It was attributed to strongest hydrophilcity, finest microstructure, and lowest mass resistance of water permeation for La25Y75-SiO2membranes. Moreover, such these organosilica membranes demonstrated good stability for 200 h simulated seawater desalination tests without any significant changes of separation performance and promising hydrothermal durability under various salts solutions with different concentrations at 25–60 °C.