| 摘要: |
| 界面聚合制备方法通常用于制备纳滤膜或反渗透膜，单体一般为间苯二胺或哌嗪。但是这些水相单体具有较大的毒性、刺激性等不利因素，会对环境及人体造成危害。壳寡糖（chitosan oligosaccharide, COS）是壳聚糖经特殊的生物酶处理得到的较低分子量的海洋多糖类高分子聚合物，绿色无毒，与壳聚糖相比其溶解性大大提高。壳寡糖与壳聚糖的化学性质相似，其分子中含有氨基、羟基，适合作为水相单体通过界面聚合反应制备复合纳滤膜。本研究以壳寡糖为水相单体，均苯三甲酰氯（trimesoyl chloride, TMC）为油相单体，通过界面聚合法在聚醚砜超滤膜（PES）上成功制备COS/PES复合纳滤膜。采用场发射扫描电子显微镜（SEM）和原子力显微镜（AFM）对膜表面进行分析表征；通过错流过滤测试膜通量及染料分离性能。实验结果显示，COS/PES-2复合纳滤膜表面出现斑点状结构，具备较高的膜通量；根据Zisman的临界表面张力外推方法将液体的表面张力与cosθ作图，发现COS/PES复合纳滤膜具有较好的防生物黏着的性能；进一步采用牛血清蛋白质模拟生物质膜污染物，开展了比通量（J/Jw）下降的实验，结果表明COS/PES复合纳滤膜的比通量始终高于商业PES超滤膜，说明交联壳寡糖活性层具有一定的抗生物质膜污染的性能；染料分离实验结果显示，壳寡糖复合纳滤膜对甲基橙的截留率在0.45 ~ 0.53之间，樱草灵的截留率在0.66~0.77之间，染料分子量大于600 Da时，不同浓度（1%、2%、3%，wt）制备的壳寡糖复合膜的染料截留率均保持在90%以上，证明所制备的复合膜属于纳滤的范畴。本研究制备的COS/PES复合纳滤膜符合国内外对发展环境友好型海洋新材料的需求，在环保、医药方面极具应用潜力。 |
| 关键词: 海洋生物高分子 壳寡糖 纳滤 分离 染料 |
| DOI：10.3969/J.ISSN.2095-4972.20221121001 |
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| 基金项目:福建省自然科学基金（2020J01103）；国家重点研发计划“科技助力经济2020”重点专项（SQ2020YFF0426314）；福建省海洋经济发展专项资金（FJHJF-L-2022-5） |
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| Nanofiltration membranes form throughinterfacial polymerization and its property of dye separation |
| WU Peng,HUANG Jiaqi,TANG Xu |
| (Third Institute of Oceanography, MNR, Xiamen 361005, China) |
| Abstract: |
| In general, m-phenylenediamine or piperazine could be used as an aqueous phase monomer for the preparation of nanofiltration and reverse osmosis membrane by the interfacial polymerization method. However, these monomers were toxic and irritants risking both human health and environments. Chitosan oligosaccharide (COS), as a green renewable and nontoxic marine polysaccharide with low molecular weight obtained from chitosan by special enzyme treatment. The water-soluble property of COS was better than chitosan. COS had similar chemical properties to chitosan, and their molecules contained amino and hydroxyl groups, which were suitable for preparing nanofiltration composite membranes through interfacial polymerization reaction as aqueous monomers. In this study, COS/PES membranes were successfully prepared on polyether sulfone ultrafiltration membrane (PES) by interfacial polymerization with COS as aqueous phase monomer and trimesoyl chloride (TMC) as oily phase monomer. The surface of membrane was characterized by Field Emission Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The membrane flux and dye separation performance were tested by cross flow filtration. Results show that the surface of COS/PES-2 membrane had a spot-like structure and a high membrane flux. According to Zisman-s critical surface tension extrapolation method, the surface tension of liquid was mapped with cosθ, and it was found that COS/PES membrane had better anti-biological adhesion performance. The specific flux (J/Jw) of COS/PES membrane was always higher than that of commercial PES ultrafiltration membrane, indicating that the cross-linked chitosan oligosaccharide active layer has a certain performance of anti-microbial fouling. The results of dye separation experiment showed that the rejection rate of chitosan oligosaccharide composite nanofiltration membrane for methyl orange was between 0.45-0.53, and the rejection rate of primroselin was between 0.66-0.77. When the molecular weight of dye molecule was greater than 600 Da, three types of COS/PES membrane remained above 90%, which proved that the prepared COS/PES membranes belonged to the category of nanofiltration membrane. The COS/PES composite nanofiltration membrane is responsive to the development demands of environmentally friend new marine materials home and abroad, and it is a far reaching application potential in environmental protection fields and medicine industries. |
| Key words: marine biopolymer chito-oligosaccharide nanofiltration separation dye |
