【作者】 周勇；

【导师】 高从堦； 陈欢林；

【作者基本信息】 浙江大学 ， 化学工程， 2006， 博士

【摘要】 目前国内反渗透复合膜功能材料单一,性能相对较差,严重影响高性能反渗透的开发,制约我国反渗透工程中的国产化率。本文从功能单体入手,筛选与合成关键功能单体,分析和验证单体结构与纯度;通过对界面反应机理的研究筛选功能单体和优化分离层结构,制备出几种不同性能的反渗透复合膜;结合复合膜性能评价和结构表征开展复合膜成膜机理及其模型化研究,为反渗透复合膜制备工艺的进一步优化与完善,最终开发出高性能反渗透复合膜打下良好的基础。 首先,建立反渗透复合膜相应功能单体的制备工艺路线,通过对功能单体合成的工艺参数进行优化,合成出四种功能单体:5-氧甲酰氯-异酞酰氯(CFIC;最大收率为29.3%,纯度为99.1%)、5-异氰酸酯异酞酰氯(ICIC;最大收率为64.4%,纯度为99.2%)、1,4-环己二胺(HDA;最大收率为55%;纯度为99.5%)和1,3,5-环己烷三甲酰氯(HT:第一步最高收率为99%;纯度为99.5%。第二步最高收率为85%)。其中前两种单体采用相对安全的酰氯化剂(三光气和草酰氯)替代传统的光气,反应条件由文献报导的高温、高压法改进为常温、常压法,并取得了较高的产品收率及符合界面聚合纯度要求的产品;后两种参照文献报道的方法制备,所获得的产品收率与报道结果相近。所有单体的化学结构通过红外光谱(IR)、核磁共振(NMR)、气-质联机(GC-MS)和元素分析(EA)等仪器分析加以验证确定。 其次,选用合成和现有功能单体通过界面聚合法制得多种复合膜分离层材料,分析了膜分离层材料的结构,测量膜分离层材料的吸水性和耗氯量。结果表明:不同酰氯与间苯二胺(MPD)或1,4-环己二胺(HDA)生成聚合物的吸水性的大小顺序为:HT>ICIC>TMC>CFIC;不同胺与同种酰氯,生成聚合物的吸水性的大小顺序为:HDA>MPD;因而,在聚合物链中引入脂环结构可提高复合膜的水通量;CFIC/MPD聚合物在相同的时间内吸收的水量最少,但达到吸收平衡的时间最长,可能是由于其结构较致密,这对制备高脱盐反渗透复合膜十分有利;ICIC与多元胺反应生成聚合物的耗氯量大于HT、TMC、CFIC与多元胺反应生成聚合物的耗氯量,不能用于抗氧化膜的制备;对于多元胺而言,甲基间苯二胺(MMPD)与酰氯生成聚合物的耗氯量远小于HDA、MPD与同样酰氯生成聚合物的耗氯量。 然后,基于膜分离层材料的研究基础,采用界面聚合工艺制备四类八种新型反渗透复合膜:其中抗氧化反渗透复合膜3种(CFIC/MMPD、HT/MMPD、TMC-HT/MMPD);耐污染反渗透复合膜1种(ICIC/MPD);高通量反渗透复合膜3种,(TMC/MPD-SMPS(5-磺酸基间苯二胺)、ICIC-IPC/MPD、ICIC-HT/MPD);高脱盐海水反渗透复合膜1种(CFIC/MPD)。采用傅立叶变换全反射红外、X-射线光电子能谱、探针式原子力显微镜,电子扫描显微镜等分析检测仪器,以及反渗透复合膜性能评价测试,探讨了膜的分离性能与膜分离层化学结构、表面形态之间的关系。研究结果表明:在多元胺的苯环上引入一个甲基可明显提高膜的抗氧化性;耐污染性与膜表面的平滑程度、荷电性也有较大联系;复合层交联程度或复合层中的脂环结构比例与水通量有较大的关联性,在一更多还原

【Abstract】 Nowadays the percentage of indigenous reverse osmosis (RO) membrane applied in our country is low for the deficiency of RO membrane functional materials which lead to little species RO membranes. Investigation of functional materials and film formation mechanism is crucial for preparation of high performance RO composite membranes. In this study there are four main parts which were synthesis of monomers, preparation and characterization of functional membrane materials, preparation and characterization of RO composite membranes, as well as analysis of film formation process by interfacial polymerization.Four functional monomers were synthesized firstly including 5-chloroformloxy-isophthaloyl chloride(CFIC;the best yield was 29.3%, purity ≥ 99.1%), 5-isocyanate -isophthaloyl chloride(ICIC;the best yield was 64.4%, purity ≥ 99.2%), 1, 4-cylohexane diamine(HDA;the best yield was 55%, purity ≥ 99.5%) and 1,3,5-cyclohexane triacyl chloride(HT;the best yield was 99%, purity ≥ 99.5% for the first step, the best yield was 85% for the second step). The chemical structure of all monomers was proved by Infrared Spectroscopy (IR), Nuclear Magnetic Resonance Spectroscopy (NMR), Gas Chromatogram -Mass spectrum(GC-Ms) and Element Analysis (EA).CFIC and ICIC were prepared with triphosgene and oxalic chloride respectively to replace phosgene in traditional technics at room temperature and low pressure, high yield and good purity were obtained;HDA and HT were prepared according to related reference, similar yield and purity were obtained.Secondly, membrane barrier’s materials were prepared with synthesized monomers and purchased monomers through interfacial polymerization technique and characterized by water vapor adsorption and active chloride consumption to decide preliminarily which monomers were suitable to prepare which kind RO composite membranes. Results revealed that the order of water vapor adsorption for polymer prepared with m-phenylenedi amine (MPD) (or HDA) and various multiacyl chloride is: HT>ICIC>TMC>CFIC;the order of water vapor adsorption for polymer prepared with different multiamines and the same multiacyl chloride is: HDA>MPD. So the structure of cyclohexane is helpful for improving the water flux. Although CFIC/MPD material had lowest weight gain, its time consumption of reaching to adsorption balance is much longer than others because of its compact structure which is potential to prepared RO composite membrane with high rejection for sodium chloride. The active chlorine consumption of polymer prepared with methyl-m-phenylenediamine (MMPD) is less than the others and the active chlorine consumption of polymers prepared with ICIC is more than others. So MMPD is suitable to prepared chlorine-resistant RO composite membrane and ICIC is not.Thirdly, some new reverse osmosis composite membranes were prepared with multiacylchloride (chloroformloxy or isocyanate) monomers and diamine monomers through interfacial polymerization technique on the polysulphone supporting film. It contains four kinds RO composite membranes: Chlorine-resistant RO composite membrane (CFIC/MMPD. HT/MMPD, TMC-HT/MMPD),Antifouling RO composite membrane (ICIC/MPD),High flux RO composite membrane (TMC/MPD- SMPD (5-sulfonic acid m-phenylenediamine) , ICIC-IPC/MPD, ICIC-HT/MPD) and High rejection RO composite membrane (CFIC/MPD).The membranes were characterized using permeation experiments with salt water, Attenuated total reflectance infrared (ATR-IR), X-ray photoelectronic spectrum(XPS), as well as imaging using atomic force microscopy (AFM) , scanning electronic microscopy (SEM) and so on. Results revealed that introducing a methyl on aromatic multiamine can improve chlorine-resistance property of RO composite membranes;the surface of antifouling RO composite membranes was smoother than the others and its absolute value of surface zeta potential was less than the others which lead to a good antifouling property;the flux can be enhanced more than 30% with little decrease of rejection for sodium chloride by changing the cross-linking degree of high flux RO composite membrane’s barrier or introducing cyclohexane structure in its polymer chain;there were much hydroxyl in the high rejection RO composite membrane’s barrier which lead to its rejection for sodium chloride decreasing much more slowly than the others.Lastly, hydrolysis of multiacyl chloride and interfacial polymerization of multiacyl chloride and multiamine were monitored by a pH measurement with continuous record. Result revealed that hydrolysis of multiacyl chloride is relatively so slow that can be ignored. The diffusion of multiamine from aqueous solution to oil solution was correlative to their partition coefficient in two solutions. A mathematic model for film formation by interfacial polymerization was set up based on diffusion of multimode from aqueous solution to oil solution and the increase of film thickness layer by layer. The equation of membrane thickness, time, monomer concentration et al is obtained. The effective membrane thickness was defined as the thickness of cross linking polymer membrane. When the average function degree of reactive zone is 2, the efficient membrane thickness is the maximum, just as follow:The mathematic model of membrane thickness, time, monomer concentration et al agreed with the experiment well. It described the process of interfacial polymerization quantificationally and was useful to control the process of interfacial polymerization.更多还原