玉米苞叶纤维素纳米晶的制备及其聚砜复合膜的抗污染性能

Preparation of cellulose nanocrystal from corn husk and its antifouling performance for polysulfone composite membrane

为了提高玉米苞叶的经济价值,以玉米苞叶为原料,采用高强度超声波法制备纤维素纳米晶(CNC),并协同共混相转化法制备聚砜(PSF)/CNC复合膜。采用扫描电子显微镜、透射电子显微镜、X射线衍射以及超滤装置测试了CNC和PSF/CNC复合膜的形态结构和性能;探讨了CNC含量对复合膜的强度,亲水性,水通量以及抗污染性能的影响。结果显示,从玉米苞叶中提取的CNC,平均直径为18.82 nm,平均长度为569.95 nm,晶型结构为纤维素I型,结晶度为53.86%。CNC的加入提高了PSF膜的断裂强度,并可改善PSF膜的亲水性和抗污染性能。综合考虑CNC对PSF复合膜结构和性能的影响,得出CNC最佳添加量为2%,相应复合膜的水通量和抗污染性能分别为纯PSF膜的2.13倍和1.32倍,蛋白质截留率为48.34%。

In order to improve the economic value of corn husk, cellulose nanocrystal （CNC） was extracted from corn husks by a ultrasonic process. Polysulfone （PSF）/CNC blend membranes were prepared by an immersion phase inversion process. The morphology, structure and properties of CNC and blend membranes were investigated by SEM, TEM, XRD and filtration experiments. The influence of CNC on the strength, water flux, hydrophilic and antifouling performances of PSF/CNC membranes were researched. The results show that the isolated CNC from corn husk has an average diameter of 18.82 nm and an average length of 569.95 nm. The polymorph of CNC is cellulose I, and the crystallinity of CNC is 53.86%. CNC can improve the break strength, hydrophilicity and antifouling performance of pure PSF membrane. The blend membrane reaches optimal properties at 2% CNC content, which is 2.13 and 1.32 times in pure water flux and antifouling property compared with pure PSF membrane. The bull serum albumin（BSA） rejection of blend membrane is 48.34%.