DOC《南京林业大学》

南京林业大学本科毕业设计(论文) 学生姓名: 沈薇 学号: N070804212 学院(系)南方学院专业: 高分子材料与工程 题目: 分布辐照接枝法制备荷负电纳滤膜 指导教师: 曹绪芝 职称: 讲师

2011 年05 月15 日 摘要 纳滤膜最早出现于20世纪70年代末,是近年来国际上发展较快的膜品种之一,其分离性能介于反渗透和超滤之间.

纳滤膜可分为非荷电膜和荷电膜,与非荷电膜相比,荷电膜除了基于孔径大小的物理筛分之外,还有着独特的Donnan效应.目前纳滤膜已在食品、生化制药、水处理、染料工业等领域得到了广泛应用.目前工业上的纳滤膜大都是荷电膜,其制备关键是根据被分离的对象的性质来决定是荷负电还是荷正电.纳滤膜的制备有多种方法,其中紫外辐照接枝法是目前世界上制备纳滤膜的有效方法之一,该法的关键是单体在接枝液中的浓度和接枝的时间. 本文通过用紫外光分步接枝的方法对聚醚砜(PES)树脂超滤膜表面进行改性制备了亲水性荷负电纳滤膜.研究了单体丙烯酸(AA)和对苯乙烯磺酸钠(SSS)接枝不同浓度和时间制得的改性膜对盐溶液的截留性能,证明了Donnan电荷效应对纳滤膜分离性能的影响.在此基础上,选择出合适的时间和浓度,成功地制备出膜的表观截留率和渗透通量都较高的纳滤膜.最后,我们研究了一些外在条件(例如:操作压力、料液浓度)对改性膜的性能有什么影响. 关键词 紫外辐照接枝、PES、荷负电纳滤膜、AA、SSS Abstract Nanofiltration first appeared in the late 20th century, 70, is the rapid development in recent years, the international varieties of the membrane, the separation between the performance between the reverse osmosis and ultrafiltration. Nanofiltration can be divided into non-charged membrane and membrane, compared with non-charged membrane, charged membrane pore size in addition to the physical screening based on, there are unique Donnan effect. Nanofiltration has been present in the food, chemical and biological pharmaceuticals, water treatment, dye industry and other fields has been widely used. The current industry are mostly on the nanofiltration membrane, its preparation is the key to be separated according to the nature of the object to the decision positively charged or negatively charged. Nanofiltration Membrane with a variety of methods, including ultraviolet irradiation grafting is currently the world an effective way to prepare nanofiltration one of the law is the key monomer in the grafting solution concentration and grafting time . This step by UV grafting method PES (PES) ultrafiltration membrane surface modification of resin were prepared hydrophilic negatively charged nanofiltration membrane. Of the monomer acrylic acid (AA) and sodium styrene sulfonate (SSS) grafted with different concentrations and times obtained by the modified membrane rejection of the salt solution, and proved the Donnan charge effect on the separation performance of nanofiltration impact. On this basis, choose the appropriate time and concentration, the membrane was successfully prepared and the apparent retention rate is higher permeation flux nanofiltration. Finally, we studied a number of external conditions (for example: operating pressure, feed concentration) on the performance of the modified layer have any effect. Keywords: UV irradiation;

PES;

Negatively charged nanofiltration membrane;

acrylic acid (AA);

sodium styrenesulfonate (SSS) 目录