超滤过程中蛋白质的空间分布规律

Spatial distribution of protein during ultrafiltration

为了研究超滤过程中蛋白质对膜污染的贡献,以异硫氰酸荧光素(FITC)对牛血清蛋白(BSA)进行标记,通过激光共聚焦显微镜(CLSM)观察聚偏氟乙烯(PVDF)中空纤维超滤膜过滤过程中BSA的膜相分布,探讨过滤通量及多巴胺改性对PVDF超滤膜过滤性能的影响。结果表明:在超滤过程中,BSA在疏水作用下逐渐吸附在膜孔内壁,表现出由表及里的BSA附着现象;当过滤通量由120 L/(m^2·h)提高至240 L/(m^2·h)时,BSA在膜内的附着量和过滤阻力均无显著变化;而经多巴胺改性后由于膜表面吸附的BSA量下降可使得过滤阻力比未改性时降低了40%。

In order to study the contribution of protein to membrane fouling during ultrafiltration, bovine serum albumin (BSA) was labeled with fluorescein isothiocyanate(FITC) and its spatial distribution in polyvinylidene fluoride (PVDF) hollow fiber membrane was observed during the filtration by confocal laser scanning microscopy(CLSM). The effects of filtration flux and dopamine modification on the filtration were investigated. The BSA molecules penetrated into membrane and adsorbed onto the walls of membrane pores due to the hydrophobic interaction. BSA gradually adsorbed in the membrane matrix from the membrane top to bottom with the ultrafiltration process. However, when the filtration flux was increased from 120 L/(m^2·h) to 240 L/(m^2·h), the amount of BSA adsorbed as well as the filtration resistance did not changed significantly. Dopamine modification markedly mitigated the BSA attachment on membrane surface, and therefore the overall filtration resistance decreased by around 40%.