基于单宁酸-壳聚糖复合胶体粒子的复合纳滤膜及其脱盐性能

以聚丙烯腈(PAN)超滤膜作为载体,以单宁酸(TA)-壳聚糖(CS)复合胶体粒子作为水相溶液,均苯三甲酰氯(TMC)的正已烷溶液作为有机相单体,通过界面聚合法成功制备了一种高通量、高截留的复合纳滤膜.对纳滤膜的表面形貌及性能进行分析,研究单体质量分数及界面聚合时间对纳滤膜性能的影响,用4种无机盐来考察膜的盐截留性能.结...     

壳聚糖/聚砜复合纳滤膜的制备

纳滤膜在水处理过程中的应用越来越受到关注。本试验通过在不同条件下制备壳聚糖/聚砜复合纳滤膜,研究了膜厚度,膜干燥温度,凝固浴浓度、温度和凝固时间,交联剂浓度、温度和交联时间,热处理温度和时间等因素对膜性能的影响。试验表明制备工艺条件对膜性能影响很大,主要体现在温度、浓度和反应时间方面。最后通过试验,获得了壳聚糖/聚砜复合纳滤膜的最佳制备条件。     

复合纳滤膜基膜的研制

分别以聚醚砜（ＰＥＳ）、磺化聚砜砜（ＳＰＳＦ）和聚醚砜（ＰＥＳ）合金膜为基膜,分析了相容性对膜性能以及不同种类基膜对界面缩聚的影响。用电镜分别观察到ＰＥＳ单组分膜和合金膜的断面形貌。结果表明：用小孔径的合金膜为基膜得到的复合膜具有较好的脱盐能力,对Ｎａ２ＳＯ４的脱除达到９０％。     

界面聚合制备壳聚糖和均苯三甲酰氯复合纳滤膜

以低分子量有机物脱盐为目标,实验以壳聚糖(CS)和均苯三甲酰氯(TMC)为反应单体,通过界面聚合反应在聚砜(PSF)/聚醚砜(PES)共混超滤膜上形成复合层制备纳滤膜.SEM扫描结果表明,该界面聚合反应可以在基膜的表面形成致密选择层;而红外检测结果表明该反应主要是CS分子上的-NH2与TMC分子上的酰氯基发生了酰化反应.实验结果表明:CS在醋酸水溶液中质量分数增大,TMC在正己烷中质量分数增大,界面聚合时间增长和热处理温度增高,都会导致膜的通量降低,同时膜对有机物和电解质的截留率增大.实验优化的界面聚合工艺条件为:CS 0.5%(wt);TMC 0.2%(wt); CS溶液浸没基膜10 min后与TMC溶液进行界面聚合反应2 min,在70℃下热处理10 min后浸泡在0.2%SDS溶液中2 h后晾干.在优化条件下,膜对PEG2000的截留率可达到92%,对NaCl、MgCl2、MgSO4和Na2SO4的截留率分别为7.8%、19.4%、23%和32.8%,该膜对于低分子量有机物与电解质的分离可能会有较好的结果.     

聚哌嗪酰胺复合纳滤膜制备及其性能表征

以聚砜超滤膜为基膜,采用界面聚合方法制备了聚哌嗪酰胺复合纳滤膜,并对其膜性能进行了表征。实验重点考察了基膜性质、聚合单体浓度、聚合反应时间、表面活性剂浓度、酸受体添加量等因素对纳滤膜性能的影响,确定了纳滤膜制备过程的界面聚合优化条件,即:水相单体(哌嗪)浓度0.08~0.12molL-1;有机相单体(间苯二甲酰氯和均苯三甲酰氯混合物)浓度0.08~0.1molL-1;聚合反应时间3~5min。在0.4MPa、25℃条件下,实验测得复合纳滤膜的水通量为4.12Lm-2h-1bar-1,膜对浓度为0.01molL-1的NaCl的截留率为30%~40%,对浓度为0.005molL-1的Na2SO4的截留率为80%~90%;对分子量不低于300gmol-1的有机物的截留率高于95%。该膜的分离性能接近于商业纳滤膜,其分离机理主要表现为“筛分机理以及膜与电解质之间的荷电作用。     

基于MXene中间层的复合纳滤膜制备及其盐水分离性能研究

通过湿法化学刻蚀得到单层MXene纳米片后,采用旋涂法将MXene纳米片负载至基膜上作为中间层制备聚酰胺复合纳滤膜,并探讨了MXene不同负载浓度对复合纳滤膜通量及盐截留性能的影响。结果表明引入MXene作为中间层,使得圆泡状形貌在所得膜表面形成,当旋涂1 mL浓度为0.1 g/L MXene时,通量为24.2 L/(m²·h),硫酸钠截留率为97.4%,相比传统膜(通量12.9 L/(m²·h),硫酸钠截留率96.3%)性能提升明显。随着MXene旋涂负载浓度增加,通量逐渐减小,而硫酸钠截留率则存在先增加后减小再稳定的趋势,截留率最高可达98.8%(通量16.3 L/(m²·h))。     

高性能聚砜中空纤维纳滤膜基膜的研制

采用干-湿法工艺制备聚砜基膜,研究了聚砜铸膜液中聚砜含量、添加剂种类、溶剂组成及含量和凝固浴温度对膜性能的影响。研究结果表明,铸膜液中聚砜含量和添加剂含量对膜性能影响较大;使用混合溶剂可有效改善膜的孔结构和提高聚砜基膜的性能;控制凝胶浴温度可以得到较高性能的基膜。通过选择最佳铸膜液组成及工艺条件,可以制备较高性能的基膜。     

羧甲基纤维素钠复合纳滤膜的制备与性能表征

以羧甲基纤维素钠(CMC)为活性层铸膜液,聚砜(PSF)超滤膜为基膜,戊二醛(GA)水溶液为交联剂,采用涂敷和交联的方法制得一种新型荷负电复合纳滤(NF)膜。测定了复合膜的截留相对分子质量,并对其表面形貌进行了表征。在铸膜液中添加质量分数为3.5%的不同种类有机小分子,研究了其对复合膜截留性能的影响。CMC/PSF复合膜对几种无机盐的截留顺序为:Na2SO4>NaCl>MgSO4>MgCl2。     

纳滤膜技术研究及市场进展

本文对纳滤膜的技术及市场现状进行了介绍,包括纳滤膜的特点、种类、应用领域、制备方法、国内专利情况、国内外的主要供应商的介绍等,并对目前市场上应用最广泛、综合性能最优的复合纳滤膜品种—聚哌嗪酰胺复合纳滤膜的结构及制备流程进行了重点介绍。目前,我国已经将纳滤膜的研制与发展列入《高性能膜材料科技发展"十二五"专项规划》中。最后,文章对纳滤膜的发展前景进行了预测。     

荷正电季铵化壳聚糖/聚醚酰亚胺复合纳滤膜的制备及性能研究

以无纺布增强具有耐溶剂、耐热特性的聚醚酰亚胺(PEI)超滤(UF)膜为支撑层,具有荷正电性和良好成膜性的2-羟丙基三甲基氯化铵壳聚糖(HACC)为功能层,制备了一种荷正电HACC/PEI复合纳滤(NF)膜。考察了聚合物浓度、反应时间、交联剂浓度及交联温度等对所制备的复合纳滤膜性能的影响,并利用扫描电镜(SEM)观察了该复合纳滤膜的表面形貌。结果表明:最佳制备条件下得到的HACC/PEI复合纳滤膜在0.3 MPa、20℃下对MgCl2具有较好的分离效果,其通量和截留率分别为10.9 L/(m2·h)和83.1%;另外,HACC/PEI复合纳滤膜呈现典型的荷正电特征,对二价无机盐具有较高的截留率。     

Preparation and performance of novel thermal stable composite nanofiltration membrane

The novel thermal stable composite nanofiltration membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly (phthalazinone ether) ultrafiltration substrate. The effects of polymerization and testing conditions on membrane performance were studied. The surface morphologies of the substrate and the composite membranes were observed by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). The separation properties of membranes for dyes and salts were tested. The composite membranes show good thermal stability. The rejection for Na2SO4 was kept over 96%, while the flux reached 400 L·m⁻²·h⁻¹ when it was tested at 1.0 MPa and 80°C. When tested at 1.0 MPa and 60°C, the rejection of the composite membrane for dyes was kept at high level, and the flux reached 180–210 L·m⁻²·h⁻¹, while the rejection for NaCl was lower than 20%. __________ Translated from the Journal of Functional Materials, 2007, 38(12): 2025–2027, 2031 [译自: 功能材料]     

新型还原氧化石墨烯/氮化碳复合纳滤膜制备及其性能

高性能石墨烯基复合膜的制备是目前国际研究热点,但是石墨烯基纳滤膜在脱盐中水通量较低,限制其在脱盐中的应用。采用聚多巴胺(PDA)改性聚砜(PSF)膜为基膜,将还原氧化石墨烯(rGO)和超薄氮化碳(uCN)纳米片通过真空抽滤法在基膜表面自组装制备新型还原氧化石墨烯/氮化碳复合纳滤膜。通过场发射扫描电子显微镜、透射电子显微镜、X 射线衍射仪、傅里叶变换红外光谱仪和X射线光电子能谱仪等研究uCN添加对膜结构和形貌的影响,并考察不同uCN添加比例、rGO用量及压力复合纳滤膜性能变化规律。结果显示当在100 mg·L^-1的rGO中添加uCN为20 mg·L^-1时所制备的rGO/uCN复合纳滤膜不仅保持良好盐离子截留率(对Na₂SO₄截留率85.86%,对NaCl截留率30.17%),且水渗透系数是rGO膜的2.15倍(88.50 L·m^-2·h^-1·MPa^-1)。     

氧化石墨烯-陶瓷复合纳滤膜的层层自组装制备及其性能

氧化石墨烯（GO）的片层边缘含有 COOH等含氧官能团,因而带负电荷,可以在带正电荷多孔基体上通过层层自组装实现快速沉积。以由3-氨丙基三乙氧基硅烷（APTES）修饰的多孔氧化铝管式陶瓷膜为基膜,令GO和聚乙烯亚胺（PEI）以溶液形态在其表面交替沉积实现自组装,继以环氧氯丙烷（ECH）交联之,制备新型氧化石墨烯-陶瓷复合纳滤膜。最佳制备工艺是,PEI浓度5 g·L^-1、pH=9,NaCl浓度0.3 mol·L^-1,GO浓度0.6 mg·ml^-1、pH 4.5,层数2层,ECH用量6.25 ml·L^-1,50℃条件下处理70 min。层数为1～4层的自组装膜在0.6 MPa操作压力下对2 g·L^-1的MgCl₂的截留率分别为90.16%、93.71%、97.54%、92.93%,其中1层自组装膜的渗透通量为21.92 L·m^-2·h^-1。氧化石墨烯-陶瓷复合纳滤膜对4种无机盐的截留率大小为MgCl₂ >MgSO₄ > NaCl >Na₂SO₄,符合典型正电荷纳滤膜的特征。     

壳聚糖/聚乳酸复合膜的制备及其吸附性能

为了减小水处理废弃膜对环境的危害,以静电纺聚乳酸(PLA)纤维膜为基底层,采用浸涂的方式将壳聚糖(CS)涂覆层与PLA基底层复合形成了CS/PLA复合膜。采用SEM、XRD对其进行了表征。考察了CS与PLA体积比对膜性能的影响。结果发现,当CS和PLA体积比为7∶5时,CS涂覆层表面致密且平整,其厚度为7μm,CS/PLA复合膜的拉伸强度为2.55 MPa,断裂伸长率为24.96%,纯水通量为115.32 L/(m²·h),对酸性染料的渗透通量为99.43 L/(m²·h),吸附率达96%;对牛血清蛋白和卵清蛋白的吸附率分别为86%和84%;对Cu²⁺、Pb²⁺和Cd²⁺的平衡吸附量分别为165.00、248.54和307.83 mg/g。     

Hexamethylene diisocyanate crosslinking 2‐hydroxypropyltrimethyl ammonium chloride chitosan/poly(acrylonitrile) composite nanofiltration membrane

The effects of membrane preparation conditions on membrane properties were studied in detail. The results suggested that composite nanofiltration (NF) membrane from 2.0 wt % 2‐hydroxypropyltrimethyl ammonium chloride chitosan (HACC) vaporized for 2.5 h at 50°C, and then crosslinked for 9 h at 50°C with hexamethylene diisocyanate (HDI)/ethanol (0.45/50 wt/wt) were found to have optimal performance. The resultant membrane was called HACC/PAN [poly(acrylonitrile)] NF membrane. The characteristics of this membrane such as pure water permeability, molecular weight cut‐off, rejection of salts, and swelling were investigated. And its cut‐off molecular weight (MWCO) was ～520 Da. At 25°C and 1.0 MPa, the permeability of water was 17.24 L/h m² MPa. Swelling in water decreased and rejection of salts increased with increasing HDI concentration, indicating pore contraction and increase in hydrophobicity as well as pore tortuosity due to crosslinking. The order of rejection to different salt solutes followed the decreasing of CaCl₂, MgCl₂, NaCl, KCl, and Na₂SO₄, suggesting that this membrane was positively charged. The rejections to MgCl₂ and CaCl₂ were more than 0.90; therefore, this membrane can be used for hardness removal in water treatment process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007.     

Preparation and separation properties of polyamide nanofiltration membrane

Utilizing an interfacial polymerization technique for the preparation of a polymeric composite nanofiltration membrane, both high permeation flux of water and high salt rejection can be achieved. Synthesis conditions, such as concentration of monomer, reaction time, and swelling agent, significantly affected the separation performance of composite membranes. The composite polyamide membrane had a permeation rate of ～2–5 gallon/ft²/day (gfd) and a salt rejection rate of ～94–99% when 2000 ppm aqueous salt solution was fed at 200 psi and 25°C. Also, a higher performance nanofiltration membrane could be prepared by suitably swelling the support matrix in the period of polymerization. The results of various feed concentrations showed that permeate flux decreased with increasing salt concentration in the feed solution. This result may be due to concentration polarization on the surface of polyamide membranes. The separation performance of polyamide membranes showed an almost independent relationship with operation pressure until it was up to 200 psi. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1112–1118, 2002     

具有PDA-UiO-66中间层耐溶剂复合纳滤膜的制备及性能

将多巴胺和Ui O-66纳米颗粒共沉积在经1,6-己二胺交联的聚醚酰亚胺（PEI）基膜上构建了纳米复合中间层（PDA-UiO-66），并在中间层上进行界面聚合反应制备了耐溶剂复合纳滤膜（TFN-U）。通过FTIR、XRD、SEM、AFM、水接触角测量仪对膜结构进行了表征和测试，探究了Ui O-66质量浓度对TFN-U膜耐溶剂性、耐污染性以及运行稳定性的影响。结果表明，PDA-Ui O-66纳米复合中间层的引入能提高TFN-U膜的渗透通量，当Ui O-66纳米颗粒质量浓度为0.2 g/L时，TFN-U2膜水通量为63.83 L/(m2·h)，甲醇通量为28.50L/(m2·h)，对刚果红水溶液和刚果红甲醇溶液的截留率为98.2%和93.2%，经无水乙醇、丙酮、乙酸乙酯、正己烷及N,N-二甲基甲酰胺（DMF）浸泡48h后，其对刚果红的截留率均>94%，通量恢复率达到78.1%，在连续24 h过滤刚果红甲醇溶液后，该膜的甲醇通量为14.13L/(m2·h)，截留率为98.3%，表明TFN-U2膜具有良好的耐溶剂性、耐污染性以及一定的运行稳定性。     

耐污染聚酰胺复合纳滤膜的制备及性能

以哌嗪(PIP)和均苯三甲酰氯(TMC)为反应单体,以聚乙烯醇(PVA)为添加剂,通过界面聚合法在聚砜超滤基膜上制备了复合纳滤膜,主要研究了PVA、PIP、TMC单体浓度、热处理条件对复合膜性能的影响,并通过扫描电子显微镜(SEM)、原子力显微镜(AFM)对复合纳滤膜结构和形貌进行表征。研究表明,PVA能够提高膜通量,增强膜亲水性,提高膜表面光滑度。最佳制膜条件是:PIP浓度为3.0 g/L,TMC浓度为1.0 g/L,PVA浓度为0.54 g/L,界面聚合时间为1 min,热处理温度为50℃,热处理时间10 min。制备的纳滤膜在处理Na2SO4、MgSO4、NaCl和MgCl2等4种盐溶液时,其截留性能与陶氏NF-270和星达NFX膜相近,而在深度处理造纸脱墨废水时,也表现出良好的分离性能和耐污染性能。     

Selective filtration of dye by tannic acid-molybdenum disulfide composite nanofiltration membrane

Dye-selective nanofiltration membranes have great potential for chemical dye separation and purification as well as dye wastewater treatment. Two-dimensional materials such as molybdenum disulfide (MoS₂) with excellent physical and chemical properties are ideal nanofiltration membrane materials. MoS₂ with few layers is used in combination with polyphenols to prepare highly selective filtration nanofiltration membranes for cationic dyes. The tannic acid (TA)-MoS₂ composite material is constructed on the surface of a micro-porous Mixed Cellulose Ester membrane by a vacuum filtration method, and the nanofiltration membrane exhibits good flexibility and excellent film-forming properties. The maximum filtration efficiency of TAMoS₂ nanocomposite film for R6G can reach 80%, while for EY and MO, it is only 9.6% and 6.1% respectively. Filtration studies on mixtures of two different types of dyes show that the composite nanofiltration membrane has excellent separation performance. The separation characteristics and mechanism of the composite nanofilm on dyes are carefully studied, showing good selectivity for cationic dyes, which can be ascribed to the synergistic effect of non-covalent interactions and steric hindrance. This work paves the way for the use of eco-friendly membranes for water and wastewater treatment and provides an environmentally friendly solution for various applications.