聚酰胺复合反渗透膜的制备与工艺探索

发布时间：2018-05-21 21:26

本文选题：反渗透 + 基膜　；参考：《天津工业大学》2016年硕士论文

【摘要】：反渗透技术在经历了半个多世纪的发展后,已经广泛的应用于工业、食品、医药等领域之中,其具有能耗低、操作简易、可持续发展等优点,被誉为“21世纪净化水技术”。如今,借助压力驱动的反渗透技术是淡水制备中最具有前景的技术。但由于我国对复合反渗透膜的研究开始时间较晚,虽然当前国内的反渗透技术发展迅速,但从整个反渗透领域来看,我国与国际先进水平仍存在着较大的差距,所以探索与优化当前的复合反渗透膜制备工艺是十分必要的。首先以聚砜(PSF)作为基底物,聚乙二醇(PEG)作为添加剂,N,N-二甲基乙酰胺(DMAc)作为溶剂,通过相转化法制备与优化了基膜。通过基膜的水通量、截留率、水接触角、抗压性等测试分析,以及使用场发射扫描电镜(SEM)考察了基膜截面结构,发现使用PSF-24wt%/PEG2000-22wt%的配比制备的基膜适合作为复合膜的基膜,其截留率较高(98.67%),具有一定的水通量(443L·m-2·h-1,0.2MPa)。其次在优化了基膜的基础上,实验使用了工业生产中较为常见的水相单体间苯二胺(MPD)与有机相单体均苯三甲酰氯(TMC)为聚合单体,探索与优化聚酰胺脱盐层的制备工艺。分析考察了水相单体浓度、有机相溶剂类型、界面聚合时间、后处理温度与时间对复合反渗透膜的性能与形貌影响,得到了一组较为优化的实验数据,其制备的复合膜在1.6MPa,2000ppm (mg/L) NaCl测试条件下,脱盐率96%,水通量45L-m-2·h-1。最后实验使用较为常见的阴离子表面活性剂十二烷基磺酸钠(SDS)作为基膜表面处理物。发现使用SDS溶液处理后的基膜,其亲水性与水通量有了一定上升,但SDS离子的吸附力较差,易脱落。使用SDS改性后的基膜制备的复合膜,其截留率略有上升,通量有所下降。
[Abstract]:After more than half a century of development, reverse osmosis technology has been widely used in industry, food, medicine and other fields. It has the advantages of low energy consumption, simple operation and sustainable development. It is known as "water purification technology in the 21st century". Nowadays, pressure-driven reverse osmosis is the most promising technology in freshwater preparation. However, the research on the composite reverse osmosis membrane is relatively late in our country. Although the domestic reverse osmosis technology is developing rapidly at present, there is still a big gap between China and the international advanced level in the whole reverse osmosis field. Therefore, it is necessary to explore and optimize the current preparation process of composite reverse osmosis membrane. At first, the base film was prepared and optimized by phase inversion method with polysulfone (PSF) as substrate and polyethylene glycol (PEG) as additive N- N- dimethyl acetamide (DMAC) as solvent. The cross-section structure of the composite membrane was investigated by the measurements of water flux, rejection rate, water contact angle, compression resistance and field emission scanning electron microscope (SEM). It was found that the substrate prepared with PSF-24wt / PEG2000-22wt% ratio was suitable for the composite membrane. Its rejection rate is higher (98.67%), and it has a certain water flux of 443L m-2 h-1 (0.2MPA). Secondly, on the basis of optimizing the base film, the preparation process of polyamide desalination layer was explored and optimized by using the water phase monomer MPD and the organic phase monomer, trimethoyl chloride (TMCC), as polymeric monomers, which were commonly used in industrial production. The effects of aqueous monomer concentration, solvent type of organic phase, interfacial polymerization time, post-treatment temperature and time on the properties and morphology of the composite reverse osmosis membrane were investigated. The desalination rate of the composite membrane was 96 and the water flux was 45L-m-2 h-1 under the condition of 1.6 MPA / 2000ppm mg / L NaCl test. Finally, the anionic surfactant sodium dodecyl sulfonate (SDS) was used as the substrate surface treatment. It was found that the hydrophilicity and water flux of the base membrane treated with SDS solution increased to a certain extent, but the adsorption capacity of SDS ion was poor and easy to fall off. The retention rate of the composite membrane modified by SDS increased slightly and the flux decreased.
【学位授予单位】：天津工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ051.893

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