蛋白类污染物在PVDF/GO杂化膜表面的吸附特性

Adsorption characteristics of protein contaminants in PVDF/GO hybrid membrane surface

为从微观层面探讨蛋白质在膜表面的污染特性,采用改性Hummers法制备出具有"二维结构"的氧化石墨烯(GO),制得不同GO添加量的改性膜,通过自制的镀膜芯片,结合耗散型石英晶体微天平(QCM-D)等研究了牛血清蛋白(BSA)对改性膜污染的动态过程。结果表明:GO表面含有大量的亲水性官能团,其添加量不同,改性膜的接触角呈现不同程度的降低,且改性膜的亲水性越高,BSA在膜面的吸附速率和饱和吸附量相对越低。吸附过程中污染物在改性膜面的吸附累积经历了2个阶段,吸附初始阶段BSA在膜面快速累积,污染层的黏弹性较小;吸附过程中GO改性膜表面的亲水性官能团促使水分子不断地渗透到污染层中,改变吸附层的构象,导致其黏弹性显著增大,使改性膜的抗污染性能得到有效提高。

In order to investigate the fouling behavior of proteins on the surface of membranes,this experiment adopted modified Hummers to prepared the ＂two-dimensional structure＂of graphene oxide（GO）.We prepared modified membranes with different amounts of GO addition and unraveled the dynamic process of pollution of bovine serum albumin（BSA） on the surface of modified membranes by self-made coated chips and dissipative quartz crystal microbalance（QCM-D） and so on.The results show that the surface of GO contains a large number of hydrophilic functional groups,and the contact angles of the modified membrane decreased in different degrees with the variational of GO additions,the higher the hydrophilicity of the modified membrane,the lower the adsorpted rate and saturation adsorption capacity of BSA on the membrane surface.The adsorption and accumulation of pollutants on the modified membrane surface underwent two stages in the adsorption process,first BSA accumulated rapidly on the membrane surface and the viscoelasticity of the polluted layer was smaller at the initial stage,the hydrophilic functional groups on the surface of the GO modified membranes contributed the water molecules to permeate into the polluted layer during the later adsorption period continuously and change the conformation of the adsorbed layer,resulting in a significant increase in its viscoelasticity,so the anti fouling performance of modified membrane was higher improved.