Abstract:
The preparation and performance control of the cellulose membrane are one of the hot topics in the environmentally friendly separation membrane field. In this study, microcrystalline cellulose (MCC) was prepared by microwave-assisted acidic hydrolysis of cellulose obtained from jute, followed by the use of a mixture of N-methylmorpholine-N-oxide and water as a solvent to obtain the homogeneous casting liquid, which was scraped and subsequently immersed in the coagulation bath to form a smooth and dense cellulose membrane. During membrane formation, the crystal structure of MCC changed from type I to type II, but the chemical structure remained unchanged. The mechanical strength and separation performance of the membrane were related to the content of MCC in the casting liquid. When the content of MCC was about 7%, the tensile strength of the membrane reached a maximum value of 13.49 MPa, and the corresponding elongation at break was 68.12%. The water flux (J) and rejection rate (R) for the bovine serum albumin were 19.51 L/(m2·h) and 95.37%, respectively, under an optimized pressure of 0.2 MPa. In addition, the coagulation bath had a significant effect on the membrane separation performance, and J and R were positively and negatively correlated with the polarity of the coagulation bath. Among them, it was note-worthy that J and R of membrane formed in ethanol were 33.95 L/(m2·h) and 91.43%, separately. Compared with water as a coagulation bath, J was increased by 74% at the situation and R was roughly equivalent, showing better separation performance. More importantly, the relationship between the structure and separation performances has also been studied preliminarily. This work provides certain guidance for the preparation of high-performance MCC membranes.
摘要:
纤维素膜的制备和性能控制是环境友好分离膜领域的研究热点之一。在这项研究中,采用微波辅助酸性水解黄麻纤维素制备微晶纤维素,然后使用N-甲基吗啉-N-氧化物和水的混合物作为溶剂,以获得均匀的流延液体,将其刮擦并随后浸入凝固浴中以形成光滑且致密的纤维素膜。在膜形成过程中,MCC的晶体结构由Ⅰ型转变为Ⅱ型,但化学结构保持不变。膜的机械强度和分离性能与流延液中MCC的含量有关。当MCC的含量约为7%时,膜的抗拉强度达到最大值13.49MPa,相应的断裂伸长率为68.12%。牛血清白蛋白的水通量(J)和排斥率(R)分别为19.51L/(m2·h)和95.37%,分别,在0.2MPa的优化压力下。此外,凝固浴对膜分离性能有显著的影响,J和R与凝固浴的极性呈正相关和负相关。其中,值得注意的是,在乙醇中形成的膜的J和R分别为33.95L/(m2·h)和91.43%,分开。与作为凝固浴的水相比,J在这种情况下增加了74%,R大致相当,表现出更好的分离性能。更重要的是,还初步研究了结构与分离性能之间的关系。该工作为制备高性能MCC膜提供了一定的指导。