有机溶剂对聚砜管式超滤膜性能的影响研究

采用不同种类的有机溶剂对聚砜管式超滤膜进行处理,并考察了其对膜性能及结构的影响.结果表明,用烷烃处理过的膜表面变光滑,碳元素含量增加,膜表面亲水性下降,水通量降低,对硫酸镁和卵清蛋白的截留率升高;用醇处理过的膜表面变粗糙,碳、氧元素含量增加,膜表面亲水性提高,膜水通量增加,对卵清蛋白截留率略有降低.     

一种简便快速测定超滤膜对卵清蛋白分子截留率的方法

本文研究的是紫外分光光度法测定卵清蛋白液浓度。在一定压力下用相对此较法测超滤前后卵清蛋白液的浓度,以测得的浓度值计算超滤膜对卵清蛋白分子的截留率来衡量自制管式超滤膜的膜孔径范围。这是一种简便、快速、准确、灵敏可取的好方法。     

高孔隙率聚偏氟乙烯中空纤维超滤膜的研究

以聚偏氟乙烯（ＰＢＤＦ）为膜材料,测定了不同温度下ＰＶＤ／ＤＭＡｃ、ＰＶＤＦ／ＮＭＰ溶液的非溶剂混合参数,得到非溶剂混合参数的顺序为丙醇〉乙醇〉甲醇〉水,此外,讨论了不同溶剂、添加剂及褒庇地膜孔隙率、通量和截留率的影响,其中ＰＤＶＦ中空纤维超江膜的孔隙率可达到８０％,通量为５８～１１０Ｌ（ｍ＾２．ｈ）,截留６７０００分子量物质时截留率为９５％,左右,通过测定纯水的通量、不同分子量蛋白质溶液的通量和     

膜过程集成提纯茶黄素的研究

以云南红碎茶为原料,以1：8与1：7的茶水比在90℃下浸提两次,每次30min,合并浸提液;以膜面积为1m^2、孔径为0．2μm的陶瓷膜、膜面积为4m^2、截留分子量为3500或10000的卷式超滤膜以及膜面积为4m^2、截留分子量为300的卷式纳滤膜依次进行微滤澄清、超滤分离与纳滤浓缩,系统研究了各膜滤过程的性能表征及其效应。结果表明：微滤对料液具有很好的澄清效果,茶黄素的得率达91．85％,且膜的再生能力强;3500膜超滤能有效去除蛋白质、碳水化合物,其截留率分别为91．23％,92．50％,茶黄素纯度为1．72％,但茶黄素得率只有27．35％;10000膜超滤对蛋白质、碳水化合物的截留率分别为50．19％,47．93％,茶黄素的得率与纯度分别为85．79％,1．00％;300膜纳滤浓缩10000膜超滤液至13．16倍,茶黄素截留率达93．39％,且茶黄素的纯度提高至1．14％;利用NaOH＋三聚磷酸钠（pH12）的清洗液清洗污染的超滤膜与纳滤膜,可使其得到很好的恢复。     

利用葡聚糖和蛋白质进行超滤膜切割分子量测试对比研究

采用切割分子量不同的葡聚糖和蛋白质标准物质,测试了几种进口商品平板膜和国产商品中空纤维超滤膜的切割分子量.结果表明:采用葡聚糖进行切割分子量测试时,测得的切割分子量明显大于商品超滤膜厂家提供的切割分子量数据,可能原因在于葡聚糖呈链状结构,易穿过膜孔;而采用蛋白质来评价超滤膜的切割分子量时,测试的切割分子量结果较为接近商品超滤膜厂家提供的数据.在对比不同膜对相邻分子量的测试物质截留率的变化趋势后发现,不同膜的孔径分布情况存在较大差异,传统上采用的单一膜的切割分子量指标未能全面反映膜的截留效能.     

聚对苯二甲酰对苯二胺多孔膜的制备及表征

以浓硫酸为溶剂,聚乙二醇(PEG)为致孔剂,采用溶液相转化法制备了聚对苯二甲酰对苯二胺(PPTA)多孔平板膜,考察了膜的纯水通量、力学强度、截留率等性能,并用场发射扫描电子显微镜观察膜形貌。结果表明,所得PPTA多孔膜为具有不对称结构的非均质膜,上表面(自由面)为致密层,下表面(玻璃板面)为多孔层,可观察到原纤化微孔结构,膜横截面存在典型的溶出指状孔。随PPTA含量降低、致孔剂相对分子质量和凝固浴温度提高,膜通透性均随之相应有所提高。PPTA多孔膜对卵清蛋白溶液截留率达90%以上,对油水乳化液截留率可达70%以上。     

聚对苯二甲酰对苯二胺多孔膜的制备及表征EI北大核心CSCD

以浓硫酸为溶剂,聚乙二醇(PEG)为致孔剂,采用溶液相转化法制备了聚对苯二甲酰对苯二胺(PPTA)多孔平板膜,考察了膜的纯水通量、力学强度、截留率等性能,并用场发射扫描电子显微镜观察膜形貌。结果表明,所得PPTA多孔膜为具有不对称结构的非均质膜,上表面(自由面)为致密层,下表面(玻璃板面)为多孔层,可观察到原纤化微孔结构,膜横截面存在典型的溶出指状孔。随PPTA含量降低、致孔剂相对分子质量和凝固浴温度提高,膜通透性均随之相应有所提高。PPTA多孔膜对卵清蛋白溶液截留率达90%以上,对油水乳化液截留率可达70%以上。     

壳聚糖超滤膜的研究

以壳聚糖为原料，2％乙酸为溶剂，选择适当的膜液组成和制备条件，可以制得截留分子量为67000的超滤膜．该膜对0．1％牛血清蛋白的截留率可达90％以上．研究了铸膜液组成和若干因素对膜性能的影响．     

TiO2纳滤膜对重金属离子的截留性能

采用孔径为1.5 nm的TiO2纳滤膜,在压力0.4～0.8 MPa,pH值3～7的条件下,考察了膜对浓度范围为50～500 mg/L的Cu(NO3)2、Ni(NO3)2、ZnC12和CdC12四种单组份重金属溶液的截留性能.结果表明:除Cd2+外,膜对重金属离子的截留率随溶液浓度的增大先增大,当浓度达到200 mg/L后趋于稳定;升高压力膜的离子截留率会略有增加;当pH=6时,膜对Ni2+和Cd2+的截留率最低,而对Cu2+和Zn2+的截留率在pH=5～6时达到最高.TiO2膜对Cu2+、Ni2+、Zn2+和Cd2+的最高截留率分别可以达到96.9％、95.9％、92.5％和83.2％.     

分光光度法和总有机碳法对超滤膜截留性能测定的比较

分别采用分光光度法和总有机碳(TOC)测定法测定超滤膜对6种标示物(牛血清蛋白,鸡蛋白,α-糜蛋白,PEG20000,PEG10000,PEG6000)的截留率,以比较两种分析方法对膜表征的影响.结果表明:分光光度法和TOC法截留率测定结果较吻合.从数据稳定性来看,两种方法能较一致的测定出超滤膜的切割分子量;但是当截留率较低时,滤出液成分较复杂,两种方法所得结果则存在一定差异.指出分光光度法存在蛋白泡沫、试样液浓度选择、稀释以及PEG显色时间影响问题,并介绍了避免或减轻以上情况的措施.通过比较,发现TOC测定法具有快速、稳定、精确度高、环保等优点.     

Screening the fabrication conditions of ultrafiltration membranes by using the uniform design and regression analysis methods

In this work, the concerned casting conditions for the fabrication of the ultrafiltration (UF) membrane from polysulfone were the gelation medium used, the temperature of the gelation bath, the gelation period, and the evaporation time of the cast sheet. The uniform design method was applied to substantially reduce the number of experiments for studying the influence of each of four casting conditions introduced in the preparation of UF-membranes. The pure water flux and the molecular weight cutoff (MWCO) of each of the four macromolecule-standards, namely egg white lysozyme, egg white albumin, bovine serum albumin and bovine γ-globulius, of each prepared UF-membrane were determined. These experimental responses were then analyzed by using a non-linear model with the backward regression method. The results of this work showed that the uniform design-non linear model (UD-NLM) method can substantially reduce the number of experimental runs for predicting the influences of the studied casting conditions on the ultrafiltration performance of the prepared asymmetric polysulfone membranes.     

纳滤/反渗透分离中有机物的特征参数对截留率的影响研究

采用ESNA1-2012纳滤膜和ESPA1-2012反渗透膜对有机物进行了分离研究,结果表明,在纳滤/反渗透分离过程中影响有机物截留率的因素较多,其中有机物的特征参数对其截留率的影响极大;有机物的特征参数影响的是膜与有机物间排斥力的作用,而有机物相对分子质量的相对大小影响的则是膜孔机械截留作用的大小.当有机物的相对分子质量小于膜的截留分子量时,有机物的特征参数成为影响其截留率的主要因素;当有机物的相对分子质量大于膜的截留分子量时,有机物的相对分子质量与其特征参数共同成为影响其截留率的主要因素.     

CaCl2对聚丙烯腈超滤膜性能的影响

在PAN／DMAC体系里，研究了添加剂CaCl2对聚丙烯腈超滤膜性能的影响，通过膜的纯水通量，切割分子量曲线以及场发射扫描电镜对所制得的膜进行了表征及研究．与无添加剂的PAN／DMAC体系相比，CaCl2的加入降低了膜液的黏度，提高了膜的纯水通量，而对膜的切割分子量无明显的影响．     

膜法纯化液相沉淀法合成的纳米Fe2O3水合物

采用超滤膜分离技术纯化由液相沉淀法合成的纳米氧化铁水合物,考察超滤膜材质及截留分子量(MWCO)、膜分离过程操作参数对透过通量大小及稳定性的影响;并研究膜污染机制及相应的清洗方案.结果表明,纯化效果好、效率高,且污染膜易于清洗,可重复使用,膜法纯化不失为一有效的纯化新途径.     

Membrane based strategies for the pre-treatment of acid dye bath wastewaters

This paper, as part of a study carried out for the recovery of the acid dye bath wastewaters of a carpet manufacturing industry by membrane processes, describes the evaluation of alternative strategies for the pre-treatment of acid dye bath wastewaters. Dead-end microfiltration (MF) simulating sand filtration with MF media having pore sizes of 2.5, 1.0, 0.45 and 0.2 microm and ultrafiltration (UF) with an UF membrane having a molecular weight cut off (MWCO) of 50,000 Da were tested in single and sequential stages in order to achieve the best treatment efficiency. Four alternative process trains were tested; single MF, sequential MF, single UF, and MF followed by UF. For both MF and UF, application of sequential filtration did not provide any significant benefit over single processes. In addition, chemical oxygen demand (COD) removal performance of all the alternative processes was similar where the highest removal was only 5%. On the other hand, color removals were much better; ranging from 15 to 100%, even with single MF. Comparison of all the process alternatives revealed that, single MF (0.45 microm), as the simplest process, is the most suitable pre-treatment method for the acid dye bath wastewaters.     

Cellulose Acetate and Polyetherimide Blend Ultrafiltration Membranes, I: Preparation, Characterization, and Application

Ultrafiltration (UF) techniques have particular advantages for simultaneous purification, concentration, and fractionation of macromolecules. In this study, polymeric blend ultrafiltration membranes based on cellulose acetate and polyetherimide were prepared by phase inversion technique and characterized in terms of compaction time, pure water flux (PWF), water content, membrane hydraulic resistance, and scanning electron microscopy (SEM). The blend membranes prepared were subjected to the separation of macromolecular proteins such as bovine serum albumin (BSA), egg albumin (EA), pepsin, and trypsin. The molecular weight cut-off (MWCO) of blend membranes obtained from the protein separation studies is also presented. Toxic heavy metal ions such as copper, nickel, zinc, and cadmium were subjected to separation by the blend membranes by complexing them with the polymeric ligand polyethyleneimine. The separation and permeate flux efficiencies of the blend membranes are compared with those of pure cellulose acetate membranes.     

青霉素发酵液超滤处理的膜材料

提出了处理具体发酵液所用膜材料的选择方法、流程、设备，并对青霉素发酵滤液进行处理、结果表明，膜技术用于青霉素发酵液后处理过程时选择合适的膜材料，不会对青霉素造成吸附和破坏。实验中选用的超滤膜用于青霉素发酵滤液的处理是合适的，膜不会溶胀、变性，能长期使用。     

高通量聚丙烯腈超滤膜的研究

以聚丙烯腈（ＰＡＮ）为原料,二甲基乙酰胺（ＤＭＡＣ）为溶剂,研究了铸膜液组成和若干因素对膜性能的影响。选择适当的膜液组成和制膜条件,可制得截留相对分子质量为１５万（Ｒ＝９０％）,透水量达１５０％～２００ｍＬ（ｃｍ＾２·ｈ）的超滤膜。     

Proteomic analisys of protein extraction during hemofiltration with on-line endogenous reinfusion (HFR) using different polysulphone membranes

In end-stage renal disease patients, extracorporeal dialytic therapy is not able to prevent the accumulation of toxins related to the uremic syndrome, a severe complication that increases morbidity and mortality rate. In this paper, hemoFiltration with on-line Reinfusion (HFR) architecture is used to evaluate the effect of a more permeable membrane on the extraction of medium–high molecular weight molecules. The aim of this study was to compare two polysulphone membranes for convective chamber: polyphenylene High Flux (pHF) and polyphenylene Super High-Flux (pSHF). Fourteen patients were subjected to HFR with pHF and pSHF membranes and ultra filtrate (UF) samples were collected to evaluate molecular weight cut-off (MWCO) and to identify extracted proteins. Furthermore, image analysis software was used in order to evaluate change in protein extraction during the dialysis. The quantification of four proteins by immunoassay demonstrates a higher permeability of pSHF membrane. Two-dimensional electrophoresis (2-DE) gels showed, for both membranes, the greater number of protein spots at 235 min. Some of the identified proteins, involved in nephropathic disease complications, were compared to assess differences in extraction during dialytic treatment by PDQuest analysis. UF proteomic analysis demonstrated a different behavior for the two membranes; pHF membrane was more permeable at the beginning of HFR treatment (15 min), while pSHF membrane at the end of treatment (235 min). Proteomic analysis is a suitable approach to investigate the behavior of different membranes during dialysis. Results indicated that pSHF membrane offers the higher permeability, and showed higher efficiency in removal of middle molecules related to uremic syndrome.     

超声辅助溶胶-凝胶法制备中空纤维TiO2超滤膜

TiO₂膜具有亲水性强和热化学稳定性好等优点而用于超滤分离, 但是TiO₂膜以管式膜为主, 渗透通量低且制备周期长。为了提高TiO₂膜的渗透通量, 并缩短膜的制备周期, 本工作以钛酸四丁酯为前驱体, 采用超声辅助溶胶-凝胶法制备高通量的中空纤维负载型TiO₂超滤膜。系统考察了硝酸与钛酸四丁酯的摩尔比(酸钛比)、超声时间和煅烧温度对TiO₂溶胶粒径及膜截留性能的影响。结果表明：当酸钛比为0.25时, 溶胶的平均粒径为3252 nm, 采用超声处理30 s后, 平均粒径减小至1817 nm。采用超声后的溶胶循环涂膜并在350 ℃煅烧两次后可得到完整无缺陷的中空纤维TiO₂超滤膜, 膜层平均厚度为1 μm, 膜的纯水渗透通量为145 L·m^-2·h^-1·bar^-1(1 bar=0.1 MPa), 葡聚糖截留分子量为2586 Da, 对应的平均孔径为2.5 nm。