凝固浴组成对PVDF-g-PACMO共聚物膜结构与抗污染性能的影响

采用亲水、无毒、生物相容性好、对蛋白质吸附有排斥作用的丙烯酰吗啉(ACMO)对聚偏氟乙烯(PVDF)本体进行亲水改性,研究了凝固浴中不同乙醇含量(乙醇:去离子水的质量比分别为0∶100,15∶85,30∶70,45∶55)对PVDFg-PACMO共聚物膜抗污染性能的影响。结果表明,随着凝固浴中乙醇含量的增加,膜断面孔结构向海绵状转变,膜平均孔径和孔隙率增大,纯水通量增加,牛血清蛋白(BSA)截留率降低,膜表面亲水性增加,抗污染性能提高。当凝固浴中乙醇质量分数为45%时,膜表面BSA的吸附量由115.4μg/cm2降至20.6μg/cm2,通量恢复率高达97.6%,总污染指数低至0.148。因此,通过改变凝固浴中乙醇的含量,能使PVDF-g-PACMO膜表面亲水性明显提高,制得了具有良好抗蛋白质污染能力的改性PVDF膜。

Effect of Coagulation Bath Composition on Structures and Antifouling Property of PVDF-g-PACMO Membrane

Acryloyl morpholine (ACMO) with hydrophilic,non-toxic,good biocompatibility and inhibiting effect of protein adsorption was adopted to modify polyvinylidene fluoride (PVDF).Based on our previous work,coagulation bath composition with different ethanol content (the mass ratio of ethanol and deionized water of 0:100,15:85,30:70,45:55) was used to study the influence on the antifouling property of PVDF-g-PACMO copolymer membrane.The results show that,with increase of the ethanol content in the coagulation bath,the film thickness reduces,section structure tends to transfer to spongy structure,the average pore diameter and porosity of membrane increase,fracture strength scarcely changes,the pure water flux increases,BSA rejection rate reduces,hydrophilicity increases and pollution resistance is improved obviously.Especially when the ethanol content in the coagulation bath is 45％,the BSA adsorption on membrane surface decreases from 115.4μg/cm2 to 20.6μg/cm2,the flux recovery rate is up to 97.6 ％ and the total pollution index decreases to 0.148.Therefore,the modified PVDF membrane with excellent surface hydrophilicity and antifouling property is prepared by changing the ethanol content in coagulation bath.