界面聚合制备氧化石墨烯气体分离复合膜研究

发布时间：2018-03-05 11:30

本文选题：气体分离膜　切入点：超声裁剪　出处：《西南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：利用纳米材料为填料制备高性能复合膜是目前膜技术发展领域的研究热点。为了提高复合膜的气体分离性能,本文以氧化石墨烯(graphene oxide,GO)为纳米填料制备气体分离复合膜。采用超声裁剪调控纯水中GO尺寸,通过二胺原位改性控制GO层间距,采用界面聚合制膜,从而在膜中构筑适宜气体分离的通道,提高膜的气体分离性能。首先,为了有效控制GO片层的尺寸,我们采用超声在纯水中裁剪GO,制得尺寸可控的纳米单层GO。研究了超声裁剪过程对GO含氧官能团的影响,结果表明超声裁剪不影响GO片层上含氧官能团的种类,但会显著改变GO片层上含氧官能团的含量。基于实验结果,提出了超声裁剪GO片层的机理。然后,利用4,7,10-三氧-1,13-癸烷二胺(DGBAmE)对水溶液中的GO进行改性。DGBAmE的胺基基团在加热的条件下可以与GO的羧酸基团、环氧基团发生化学反应,从而以共价键结合在GO片层中,调控GO层间距。红外光谱(FTIR)和X射线光电子能谱(XPS)表征结果表明,DGBAmE与GO发生了化学反应;X射线衍射(XRD)结果表明改性后GO层间距增大,证实改性过程成功调控了GO层间距。最后,以改性后的GO溶液为水相,以均苯三甲酰氯(TMC)的正己烷溶液为有机相,采用界面聚合制备GO复合膜。考察了GO片层尺寸、GO原位改性、以及改性温度等条件对膜气体分离性能的影响。结果表明,直径为70nm的较小尺寸GO可以有效提高复合膜的气体分离性能;经过原位改性后,GO层间距更适宜气体分离,膜的CO2/N2分离因子显著提高,而膜的CO2渗透速率保持不变;在最优改性温度下,膜的CO2渗透速率达到1600GPU、CO2/N2分离因子为238,在CO2分离过程中表现出良好的应用前景。
[Abstract]:The preparation of high performance composite membranes using nanomaterials as fillers is a hot research topic in the field of membrane technology. In order to improve the gas separation performance of composite membranes, In this paper, the gas separation composite membrane was prepared by using graphene oxidegox oxide as nano-filler, the go size in pure water was controlled by ultrasonic cutting, the spacing of go layer was controlled by in-situ modification of diamine, and the film was prepared by interfacial polymerization. Thus a suitable gas separation channel is constructed in the membrane to improve the gas separation performance of the membrane. Firstly, in order to effectively control the size of go layer, In this paper, we use ultrasound to cut goo in pure water to prepare nanometer monolayer go with controllable size. The effect of ultrasonic cutting on go oxygen functional groups is studied. The results show that ultrasonic cutting does not affect the types of oxygen functional groups on go lamellae. On the basis of the experimental results, the mechanism of ultrasonic clipping of go lamellae is proposed. The Amino group of go in aqueous solution was modified by 4 ~ (7) / 10 ~ (10) -trioxy-1 ~ (13) -decane diamine (DGBAmE). The amino group of DGBAmE could react with carboxylic acid group and epoxide group of go under the condition of heating, and then bond in go lamellae by covalent bond. The results of FTIR and X-ray photoelectron spectroscopy (XPS) characterization showed that the chemical reaction between go and go took place. The results showed that the distance between go layers was increased after modification, which proved that the modification process successfully regulated the go layer spacing. Go composite films were prepared by interfacial polymerization using modified go solution as aqueous phase and n-hexane solution of trimethoyl chloride (TMC) as organic phase. The in situ modification of go lamellar size was investigated. The effect of modification temperature on the gas separation performance of the membrane was studied. The results showed that the gas separation performance of the composite membrane could be improved effectively by the smaller size go with the diameter of 70 nm, and the gas separation was more suitable after in-situ modification. The CO2/N2 separation factor of the membrane increased significantly, while the CO2 permeation rate of the membrane remained constant, and the CO2 permeation rate of the membrane reached 1600 GPA UCO _ 2 / N _ 2 separation factor of 238 at the optimum modification temperature, which showed a good application prospect in the process of CO2 separation.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.893

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