反渗透复合膜研究(Ⅱ)初生态膜的原位改性

界面聚合是制备超薄复合膜是通过两种互不相溶的单体溶液在多孔支撑的表面进行聚合,再经热处理,洗涤等工艺后得到超薄复合膜。初生态膜(IniM)是指完成界面聚合反应而未经后处理（热处理,洗涤等）的膜。采用间苯二胺和均苯三甲酰氯通过在多孔聚砜膜上界面聚合得到初生态反渗透复合膜,再用四乙烯五胺对初生态膜进行表面原位改性,经后处理得到改性反渗透复合膜。对改性反渗透复合膜面XPS分析结果为：改性膜表面的O/N比明显低于未改性的,这说明四乙烯五胺通过反应接枝在膜表面;同时,改性膜面接触角大于未改性膜的,进一步证明了这一点。脱盐性能测试结果为：改性反渗透复合膜的水通量和NaCl脱除率随着进水pH值的增大而减小,这与未改性的反渗透复合膜变化趋势完全相反;这是因为改性反渗透复合膜面含有氨基（—NH₂）或亚胺基（=NH）,当pH值增大时,其与水的亲和力减小;而未改性的反渗透复合膜表面含有羧基（—COOH）, 当pH值增大时,其与水的亲和力增大。     

反渗透复合膜的表面特性及表面改性

对反渗透复合膜的表面特性及其改性方法作详细综述,以期为高性能反渗透复合膜的研制提供一定的理论指导.反渗透复合膜的表面特性(如表面粗糙度、亲水性、表面电荷等)对反渗透膜的通量、截流率和抗污染性能等具有重大影响,光滑、亲水、电中性的膜具有较好的分离性能,特别是抗污染性.表面涂层、接枝、水解等表面改性技术,可有效实现对反渗透复合膜表面性质的调控和加工,改进和优化复合膜表面的粗糙度、亲水性、荷电特性,实现对复合膜性能的调节和优化.     

新型反渗透复合膜

探讨了反渗透复合膜表层功能高分子材料的设计原则,提出了一种类液晶的表层材料聚集态结构,并采用表面聚合反应方式研制出一种新的反渗透复合膜。研究了该膜的制备条件,考察了在不同进水盐浓度及操作压力下的膜分离性能。在30kg/cm~2操作压力下该膜对天津自来水的脱盐率达95%以上,水通量为25L/(m~2·h)以上;对高盐度苦成水也有良好的脱盐性能。     

高脱盐反渗透复合膜初步放大研究

本文扼要介绍了高脱盐反渗透复合膜的试制,放大和初步性能研究。结果表明,该膜具有优异的性能,在很宽的苦咸水范围内表现出９８．５％以上的脱盐率,说明国产复合膜配方,成膜工艺及设备等关键技术的有显著突破。     

海水淡化反渗透复合膜元件的制备

论述了海水淡化膜元件制作过程中,支撑底膜的孔结构、水相及有机相单体的种类、浓度,界面聚合的时间、热处理温度以及产业化生产过程中各个工艺条件的控制对海水淡化反渗透复合膜性能和均匀性的影响;介绍了膜元件卷制的工艺对元件性能的影响以及国产海水淡化反渗透复合膜元件在实际工程中的应用情况及与进口膜元件的性能对比。     

超低压反渗透复合膜研制

研究了以聚砜作为支撑层,间苯二胺和均苯三甲酰氯为主要聚合单体,并使用多种添加剂,经界面聚合制备超低压反渗透复合膜,探讨了超低压反渗透复合膜制备的成膜规律和主要影响因素：底膜支撑层、水相、有机相、添加剂的种类,聚合时间和热处理温度等。试验结果表明,在适当的试验条件下制备的超低压反渗透复合膜,具有优良的分离性能。在1.0MPa测试压力,4L/min流速下,对温度25℃、浓度1500mg/L的氯化钠溶液,脱盐率可以达到99.2%,水通量达到50L/m2.h。     

共溶剂对反渗透复合膜表面形貌及分离性能的影响

以聚砜超滤膜为底膜,间苯二胺为水相单体,均苯三甲酰氯为有机相单体,通过界面聚合的方法制备了聚酰胺反渗透复合膜。研究了有机相共溶剂1,3-二甲基-2-咪唑啉酮、N,N-二甲基丙烯基脲、磷酸三丁酯对聚酰胺反渗透复合膜表面形貌及分离性能的影响。扫描电子显微镜观察表明,共溶剂的存在有助于复合膜表面形成"叶片状"结构;傅里叶变换红外光谱仪则对聚酰胺分离层化学结构进行了分析。通过改变共溶剂的种类和含量,可有效改变聚酰胺复合膜的表面形貌,最终调控膜的水通量和截留率。     

用于反渗透复合膜的海绵状结构支撑膜制备研究

通过调节铸膜液中聚砜浓度和非溶剂含量,浸没沉淀法制备海绵状结构的支撑膜,并在支撑膜上界面聚合制备聚酰胺反渗透复合膜。分别对支撑膜及反渗透复合膜的结构和性能进行表征,考察聚砜浓度对支撑膜结构和性能的影响,以及不同结构支撑膜对反渗透复合膜结构和性能的影响。结果显示,随着聚砜浓度的增加,支撑膜表面孔径和孔隙率下降,断面结构变致密,耐压性增强。在不同支撑膜上制备的反渗透复合膜具有不同的通量和脱盐率。综合考虑支撑膜及反渗透复合膜的性能,以聚砜浓度为15%制备的海绵状结构支撑膜更适于作为制备反渗透复合膜的支撑层。     

聚酯酰胺反渗透复合膜的制备及其表征

以间苯二胺、氨基葡萄糖与均苯三甲酰氟为反应物,在聚砜基膜上用界面聚合法制备聚酯酰胺反渗透复合膜。用红外光谱仪（FT-IR）和扫描电子显微镜（SEM）及原子力显微镜（AFM）对所制备膜的结构和形态进行表征。红外光谱的结果表明有聚酰胺和聚酯结构的生成,扫描电镜结果显示复合膜表面呈明显的峰谷状结构,原子力显微镜分析结果表明聚酯酰胺膜表面粗糙度较聚酰胺膜表面粗糙度大。实验考察了界面聚合反应中的水相单体配比对所制备复合膜分离性能的影响;并进一步考察了操作条件及物料性质对制备的聚酯酰胺反渗透复合膜分离性能的影响。研究表明：随水相中氨基葡萄糖配比的增加,复合膜的脱盐率下降,通量上升。聚酯酰胺反渗透复合膜在1．6MPa操作压力下水通量达到27．4L／m^2·h以上,对2000mg／L的NaCl、KCl、MgCl2、Na2SO4、MgSO4等无机盐的脱盐率均在97．5％以上。     

反渗透复合膜研究进展与展望

反渗透技术凭借其高效率、操作维护方便等优点在近几十年得到长足的发展,并超越蒸馏等热法技术成为主流淡化技术。反渗透膜是反渗透技术的核心,其中芳香聚酰胺复合膜相比其他反渗透膜具有更高的通量和脱盐率、更好的耐压性和酸碱耐受范围,在反渗透技术中应用最为广泛。但聚酰胺类复合膜因较高的能耗,较弱的耐污性和较差的耐氯性,限制了其在海水淡化技术领域的发展,也成为研究人员关注的热点和和亟待解决的问题。随着新型功能性聚合物以及无机纳米材料的引入,反渗透复合膜的潜力被不断挖掘,研究人员进行了大量新型反渗透膜的制备研究,当前存在的问题有望得到解决。本文将分别针对聚酰胺反渗透膜的缺陷,结合反渗透技术和复合反渗透膜的研究现状,讨论新型反渗透膜的改进策略,并对其发展进行展望。     

二次界面聚合法制备聚酰胺-脲-酰亚胺反渗透复合膜

本论文采用二次界面聚合法制备得到一种新型的聚酰胺-脲-酰亚胺反渗透复合膜。先将关键功能单体5-异氰酸酯-异酞酰氯（ICIC）与4-甲基-间苯二胺（MMPD）经单面界面聚合形成初生态的基膜,之后将关键功能单体N,N’-二甲基间苯二胺（DMMPD）与初生态基膜上残留的ICIC及未反应完的酰氯基团（-COCl）进行二次界面聚合,再经热处理、水漂洗制得一种新型的聚酰胺-脲-酰亚胺（MMPD-ICIC-DMMPD）反渗透复合膜。采用傅立叶衰减全反射红外光谱（ATR-FTIR）和X射线光电子能谱分析了膜活性分离层的化学结构,利用扫描电镜（SEM）和原子力显微镜（AFM）观察了所成膜的表面形态,同时测试了膜的耐氯性能,并以单次聚合聚酰胺-脲（MMPD-ICIC）膜作对比。结果表明：采用二次界面聚合法在功能化基膜MMPD-ICIC上引入一超薄ICIC-DMMPD层,使得所成二次聚合膜MMPD-ICIC-DMMPD的活性分离层相对稍厚,表面更光滑,且亲水性和耐氯性能更好。     

磺化聚醚砜/纳米TiO2复合超滤膜制备及其抗污染机理

Membrane fouling is one of the major obstacles for reaching a high flux over a prolonged period of ultrafiltration (UF) process. In this study, a sulfonated-polyethersulfone (SPES)/nano-TiO2 composite UF membrane with good anti-fouling performance was fabricated by phase inversion and self-assembly methods. The TiO2 nanoparticle self-assembly on the SPES membrane surface was confirmed by X-ray photoelectron spectroscopy (XPS) and FT-IR spectrometer. The morphology and hydrophilicity were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle goniometer, respectively. The anti-fouling mechanism of composite UF membrane was discussed through the analysis of the micro-structure and component of UF membrane surface. The results showed that the TiO2 content and the micro-structure of the composite UF membrane surface had great influence on the separation and anti-fouling performance.     

Feasibility of recycled newspaper as cellulose source for regenerated cellulose membrane fabrication

An environmental friendly regenerated cellulose membrane (RCM) was successfully prepared via NaOH/urea aqueous solution system by utilizing recycled newspaper (RNP) as the cellulose source. The morphological and chemical structure of resulting membrane were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD) spectroscopy, and thermogravimetric analysis (TGA). Results from FTIR and XRD verified that the transparent RCM possesses cellulose II structure. SEM observation revealed that the transparent RCM consist of homogeneous dense symmetric membrane structure and composed of a skin layer with mean roughness parameter R_a, obtained from AFM analysis of 29.53 nm. Pure water flux, water content, water contact angle, porosity, and pore size of the resulting membrane were also measured. This study promotes the potential of the cellulose‐based membrane obtained from low cost cellulose source for application in filtration and separation system. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42684.     

单宁酸-多巴胺涂覆制备染料分离用纳滤膜

通过单宁酸及聚多巴胺涂覆,制备了单宁酸(TA)-聚偏氟乙烯(PVDF)纳滤膜,同时评价了改性膜对刚果红、伊文思蓝、活性嫩黄等染料的分离性能。结果表明,改性后膜表面粗糙度略微增大,亲水性明显增强。同时,改性膜具有水下超疏油的性质,能够完全抵抗水下油污的污染。2wt% TA-PVDF纳滤膜对多种染料的截留率能达到96.5%以上,且对刚果红、伊文思蓝、活性嫩黄等染料的截留通量都超过65.7 L/(m2?h?bar)。另外,改性膜在染料分离时截留通量基本不变,稳定性较强,在工业染料废水处理方面有一定的应用前景。     

Surface immobilization of polymer brushes onto porous poly(vinylidene fluoride) membrane by electron beam to improve the hydrophilicity and fouling resistance

Poly(vinylidene fluoride) (PVDF) membrane was pre-irradiated by electron beam, and then poly(ethylene glycol) methyl ether methacrylate (PEGMA) was grafted onto the membrane surface in the aqueous solution. The degree of grafting was significantly influenced by the pH value of the reaction solution. The surface chemical changes were characterized by the Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS). Combining with the analysis of the nuclear magnetic resonance proton and carbon spectra (¹H NMR and ¹³C NMR), PEGMA was mainly grafted onto the membrane surface. Morphological changes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The porosity and bulk mean pore size changes were determined by a mercury porosimeter. The surface and bulk hydrophilicity were evaluated on the basis of static water contact angle, dynamic water contact angle and the dynamic adsorption process. Furthermore, relative high permeation fluxes of pure water and protein solution were obtained. All these results demonstrate that both hydrophilicity and fouling resistance of the PVDF membrane can be improved by the immobilization of hydrophilic comb-like polymer brushes on the membrane surface.     

Protein immobilization onto poly (vinylidene fluoride) microporous membranes activated by the atmospheric pressure low temperature plasma

Hydrophobic poly (vinylidene fluoride) (PVDF) membrane surface was treated with atmospheric pressure low temperature plasma and investigated physical and chemical surface characterization. The contact angle of water on the exposed membrane surface was reduced with increasing of the treatment voltage and time, so indicates that the treatments can modify the PVDF membrane surface from hydrophobic to hydrophilic. In order to analyze the phenomenon in detail, the progress of defluorination including dehydrofluorination and oxidation reactions onto the surface was examined by X-ray photoelectron spectroscopy (XPS), and revealed the most effective treatment condition. The degree of grafting used acrylic acid monomer onto the surface has influenced with monomer concentration, reaction temperature and reaction time. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to study the surface morphology. The membrane surfaces conjugated bovine serum albumin (BSA) as a protein were surely detected the nitrogen element contained with BSA.     

Surface modification of polypropylene microporous membrane by grafting acrylic acid using physisorbed initiators method

Surface modification of microporous polypropylene (PP) membrane was performed by graft polymerization of acrylic acid using physisorbed initiators method. The factors effecting on the grafting degree such as monomer concentration, reaction temperature and initiator density were determined. The morphological and microstructure changes of the membrane were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR). The pure water contact angle, protein adsorbed amount, water flux, and antifouling property of the grafted membrane were investigated. The results indicated that the pore size and porosity of the grafted membrane were reduced and the static contact angle of pure water on the grafted membrane decreased from 108° to 40° with the increase of grafting degree. The amount of protein adsorbed on the grafted membrane decreased about 30% compared to the virgin polypropylene membrane when the grafting degree was 18.71%. Though the water flux reduced, the flux recovery of the grafted membrane increased 82.66% with the grafting degree 16.0%. The hydrophilic and antifouling property of the grafted membrane also were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and characterization of poly(γ‐methacryloxypropyltrimethoxysilane)‐grafted silica hybrid nanoparticles prepared by surface‐initiated atom transfer radical polymerization

Poly(γ‐methacryloxypropyltrimethoxysilane) (PMPTS)‐grafted silica hybrid nanoparticles were prepared by surface‐initiated atom transfer radical polymerization (SI‐ATRP). The resulting PMPTS‐grafted silica hybrid nanoparticles were characterized using Fourier transform infrared spectroscopy (FTIRS), nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy (SEM), static water contact angle (WCA) measurement, and thermogravimetric analysis (TGA). Combined FTIRS, NMR, XPS, SEM, and TGA studies confirmed that these hybrid nanoparticles were successfully prepared by surface‐initiated ATRP. SEM and AFM studies revealed that the surfaces of the nanoparticles were rough at the nanoscale. In addition, the results of the static WCA measurements showed that the nanoparticles are of low surface energy and their surface energy reaches as low as 6.10 mN m^?1. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

纳米聚苯胺改性聚哌嗪酰胺纳滤膜的制备

以导电态纳米聚苯胺(PANI)为添加剂, 哌嗪和均苯三甲酰氯(TMC)为反应单体, 通过界面聚合反应在聚砜超滤膜上形成复合层制备纳滤膜。采用扫描电子显微镜(SEM)和原子力显微镜(AFM)等对复合膜的性能和结构分别进行了测试和表征。SEM照片证实PANI含量低时, 可以在复合膜上分布得比较均匀;AFM图像看出膜表面粗糙度的增加;膜性能的测试结果证实了添加PANI的复合膜水通量得到了提高, 同时脱盐率也有变化。最优实验条件下, 膜对Na₂SO₄、MgSO₄、MgCl₂和NaCl的截留率分别为99.4%、98.5%、85.4%和59.2%。试验结果表明, 加入PANI能够提高膜的水通量, 并提升了膜的脱盐性能。     

Accelerated ultraviolet aging study of the Vectran fiber

Aging behavior of Vectran fiber exposed to ultraviolet (UV) radiation was investigated. Vectran fiber was subjected to UV‐accelerated degradation environment. Tensile strength of Vectran fiber was determined at room temperature using a two‐parameter Weibull distribution. The average tensile strength loss was 42.75% when the irradiation time reached 186 h. The surface morphology of the degraded fiber was examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X‐ray photoelectron spectroscopy (XPS) and ¹³C‐NMR were used to provide a molecular characterization of fibers. SEM and AFM showed that UV exposure result in microvoids on the surface of fibers. The results of the XPS and ¹³C‐NMR indicated that the UV radiation could lead to chain scission of fiber surface layer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012