PEG交联有机硅/陶瓷杂化膜的制备及反渗透脱盐性能

Fabrication of PEG Crosslinked Organosilica Hybrid Membranes for Reverse Osmosis Desalination

采用聚乙二醇(PEG)和1,2-双(三乙氧基硅基)乙烷(BTESE)进行交联共聚,以多孔α-Al_2O_3陶瓷膜为支撑体制备了一系列PEG交联的有机硅杂化膜。通过原子力显微镜(AFM)、场发射扫描电镜(FE-SEM)、傅里叶红外光谱(FT-IR)、热重分析(TGA)和水接触角测试(CA)对膜结构和物化性质进行了表征。将制备的BTESE/PEG杂化膜应用于反渗透脱盐,考察了PEG含量、操作压力、进料浓度和操作温度等因素对改性杂化膜分离性能的影响。实验结果表明,相比于未改性的BTESE膜, 10wt%PEG交联的有机硅杂化膜BTESE/PEG-10的水渗透率和盐离子表观截留率均有所提高。随着操作压力的升高和进料盐含量的下降,NaCl截留率上升而水渗透率基本恒定。在高达70℃的温度循环实验中,BTESE/PEG-10杂化膜表现出优异的水热稳定性,NaCl表观截留率始终保持在97%以上,水渗透率高达1.2×10^(-12) m^3/(m^2·s·Pa)。

A series of poly（ethylene glycol）（PEG） crosslinked organosilica hybrid membranes were fabricated viaco-polymerization with PEG as crosslinker and bis（triethoxylsilyl）ethane（BTESE） as the Si precursor, using porous α-Al2O3 membranes as the support. The membrane structure and physicochemical properties were characterized by atomic force microscopy（AFM）, field emission scanning electron microscopy（FE-SEM）, Fourier transform infrared spectroscopy（FT-IR）, thermal gravimetric analysis（TGA） and water contact angle measurements（CA）. The prepared BTESE/PEG hybrid membranes were applied to desalination by reverse osmosis（RO）. The effects of PEG content, operating pressure, feed concentration, and operating temperature on RO performances of the membrane were investigated. Compared with the un-modified BTESE membrane, the BTESE/PEG hybrid membrane with an optimum PEG content of 10 wt% exhibited higher water permeability and observed NaCl rejection in RO experiments. In addition, the observed NaCl rejection increased whereas the water permeability remained almost constant with an increase in operating pressure and a decrease in salt concentration. Moreover, the BTESE/PEG-10 membrane exhibited high hydro-thermal stability in temperature cycles up to 70℃, always delivering high NaCl rejections of 97% and excellent water permeabilities of up to 1.2×10-12 m3/（m2·s·Pa）.