陶瓷膜表面接枝改性及其在膜蒸馏过程中的应用

Surface graft modification of ceramic membranes and its application in membrane distillation

以二甲基二氯硅烷为改性剂,采用表面接枝方法制备疏水性Al2O3陶瓷膜,并将其应用于NaCl溶液的气隙式膜蒸馏过程。利用傅立叶红外光谱仪、接触角测定仪和SEM对改性膜进行表征。结果发现,改性剂成功接枝聚合到陶瓷膜表面;改性陶瓷膜具有良好的疏水性能;改性前后膜表面形貌和孔径没有明显变化。实验测得改性陶瓷膜的液体进入压力(LEP)为0.11MPa。膜蒸馏结果表明,渗透通量随溶液温度和流量的增大而增大、随溶液浓度的增大而减小;溶液温度是影响过程的主要因素;NaCl截留率>98.53%。研究结果证明,用二甲基二氯硅烷改性的陶瓷膜完全可用于NaCl溶液的膜蒸馏过程。

Hydrophobic Al2O3 ceramic membranes were prepared through surface graft modification with dimethyldichlorosilane as a modifying agent,and then applied to air gap membrane distillation of NaCl solutions.Modified ceramic membranes were characterized with FT-IR,contact angle analyzer and SEM.Results show that the modifying agent was successfully grafted on the membrane surface;the modified membranes have a very good hydrophobic characteristic;and no significant changes are observed in surface morphologies and pore sizes of the membranes before and after grafting.The LEP of the modified membranes was measured to be 0.11 MPa.Membrane distillation results show that permeate fluxes increase with the increases in solution temperature and flow rate,but decrease with the increase in solution concentration;the solution temperature was the major factor affecting the membrane distillation;over 98.53%of NaCl rejection rate was achieved in each run of experiments.Research results demonstrate that the prepared ceramic membranes modified with the dimethyldichlorosilane can be sufficiently used in the membrane distillation of NaCl solutions.