疏水性Al_2O_3膜在真空膜蒸馏中的应用

Application of hydrophobic alumina membranes in vacuum membrane distillation

采用表面接枝改性法,将十六烷基三甲氧基硅烷(C16)接枝于陶瓷膜表面,获得疏水性Al_2O_3膜。傅里叶红外光谱结果表明,C16接枝到陶瓷膜表面;接触角实验结果显示:接枝C16分子后的Al_2O_3膜表面呈现疏水特性,接触角为158°。将改性后的Al_2O_3膜应用于真空膜蒸馏(VMD)的脱盐实验中,结果表明:在料液流速160 L/h、料液温度70℃、真空度0.095 MPa时,VMD过程可以获得较高渗透通量。将疏水性Al_2O_3膜应用在VMD过程的稳定性实验中,在300 min的运行过程中,渗透通量基本稳定在20 kg/(m^2·h),脱盐率大于99.9%。

The hydrophobic ceramic membrane was prepared via surface modification,grafting by hexadecyltrimethoxysilane(C16)molecules.Fourier transform infrared spectroscopy(FT-IR)confirmed the grafting of C16molecules onto the ceramic membrane surface.The contact angle values of C16modified alumina membrane was158°by water contact angle measurements,which showed good hydrophobic character.This kind of modified alumina ceramic was applied in vacuum membrane distillation(VMD)process of NaCl solutions.The higher permeate flux was achieved at flow rate160L/h,feed temperature of70℃,vacuum of0.095MPa.The VMD performance of hydrophobic alumina membrane under the optimal conditions was studied.During the300min operation process,the flux was about20kg/(m2·h),and the salt rejection could be stable at high values(>99.9%).