工业化陶瓷超滤膜的表征

以液-液排除法测定工业化陶瓷超滤膜的孔径及孔径分布，比较了两种渗透体系对测定结果的影响；用已知分子量标准物质考察了不同膜的截留行为，获得了各膜的切割分子量值，并分析了截留率与孔径的对应关系，为工业化陶瓷膜的开发提供依据。     

液液界面法测超滤膜孔径及孔径分布

本采用液液界面法，利用毛细管现象测定了截留分子量为２×１０＾４和５×１０＾４聚砜超滤膜ＰＳ－２，ＰＳ－５的孔径及孔径分布。结果表明，利用水－正丁醇体系能测定超滤膜的孔径及孔径分布，并且具有操作简便，测试压力接近膜工作压力的优点，对于ＰＳ－２超滤膜，测试压力达０．５ＭＰａ即能得到膜完整的孔径分布曲线。     

中空纤维膜孔径及其分布的测定

研究了中空纤维膜孔径及其分布的测定方法．液液置换法。通过研究建立了能够准确描述跨膜压差与流体通量的数学模型，采用不同的液液体系（正丁醇．纯净水、正戊醇．纯净水和正己醇一纯净水）测定了膜孔径为0.2μm的中空内压疏水膜的孔径及其分布，并对测试结果进行比较分析。实验研究结果与电镜扫描结果符合较好，研究表明液液置换法装置简单、易操作、是一种理想的膜孔径分布表征方法。     

检测条件对中空纤维超滤膜截留率的影响研究

以PES中空纤维超滤膜为研究对象,以牛血清白蛋白和α-糜蛋白酶为测试标准物质,对影响中空纤维超滤膜截留率的检测条件—测试液温度、测试液浓度和膜面流速进行了实验研究。结果表明:常温下,选择较低的测试液浓度和较高的膜面流速能更好的反映膜的截留率。     

聚砜酰胺的分子量对其超滤膜性能的影响——Ⅱ.膜性能与成膜机理

研究了PSA的分子量对其超滤膜性能的影响,发现PSA分子量高,膜孔径大、分布宽;分子量低,膜孔径小、分布窄;但分子量过低,孔径变大,且分布宽。并就分子量对PSA超滤膜的透水率、截留率、压实性能,以及制膜液的相分离等性能进行比较,讨论成膜机理,改进了的成膜机理较好地解释了实验结果。     

液体排除法测定多孔陶瓷膜孔径分布

利用液体排除法实验测定了多孔陶瓷膜的孔径分布。对比了浸润渗透体系对测定结果的影响及其测定重复性,并与气体泡压法、压汞法、气体吸附脱附法和渗透孔度法进行了比较。实验结果表明该方法可用于测定陶瓷超滤膜和微滤膜的孔径分布。     

PVC/PAN 共混超滤膜的研究 Ⅰ.PVC 与 PAN 相容性对共混超滤膜结构与性能的影响

在增混剂用量固定情况下,PVC 与PAN 的共混比直接影响其相容性。而相容性主要对PVC/PAN 共混超滤膜的表层孔径产生影响。相容性较好时,表层孔径极小,膜呈明显的不对称性,截留率高,但透水率较低,反之亦然。可见,通过对两种高聚物相容性的调整,有可能在一定范围内实现对超滤膜平均孔径的控制,尤其对制备技术难度较大的大孔径超滤膜可期有实用价值。     

不同标准物表征超滤膜截留性能的比较

本文用蛋白，聚乙二醇和葡聚糖三种不同溶质对聚砚，聚砚酰胺及磺化聚砚三种超滤膜的截留率－分子量曲线进行了测定。对同一种膜，具有相同分子量的不同溶质来说，它们的截留率是不同的。膜对蛋白的截留率高于它对聚乙二醇和葡聚糖的截留率。     

超滤膜孔径及其分布的测定方法：I.常用测定方法讨论

讨论了超滤膜孔径的物理意义，指出其与固体表面吸附体系中孔径概念的区别，讨论了现行各种测定方法的原理及在超滤膜孔径测定中的适用性。     

合金超滤膜的特点及应用

从理论方面介绍了合金超滤膜的特点——孔径较小、较高的水通量和截留率;通过实例介绍了合金超滤膜的工程应用并对其研究发展做了展望。     

Modeling of the Relationship Between Pore Size Distribution and Thickness of Ceramic MF Membrane

The pore size distribution(PSD)measured by the gas bubble point(GBP)method ofceramic microfiltration(MF)membranes prepared by suspension technique was found to be signifi-cantly influenced by the membrane thickness.A culm-like model for pore structure was introduced tocharacterize the membrane pores instead of the conventional model which does not reflect the radiusvariation along the pore passages and is unable to explain the thickness effect on the membrane PSD.A laminate structure,taking the culm-like model for pore structure into consideration,was hypoth-esized for ceramic MF membranes.A mathematical model was then established to quantitativelydescribe the relationship between the membrane number PSD and the membrane thickness.Goodresults were obtained for the correlation of mean pore size and simulation of the PSD for ceramicMF membranes.     

致密超细球形氧化铝制备性能良好的陶瓷超滤膜

热等离子体制备的超细球形氧化铝具有表面致密光滑、分散性好等特点，本工作以超细球形氧化铝为原料，通过浸渍提拉烧结法，制备了孔径分布窄、渗透通量高的陶瓷超滤膜，研究了烧结温度对陶瓷膜微孔结构的演化、孔径分布和渗透通量的影响。随后对1250℃下烧结的陶瓷膜进行了纳米硅水分散液过滤处理，采用不同堵塞模型分析了陶瓷膜过滤纳米硅水分散液的膜污染过程。结果表明，通过调节烧结温度调控陶瓷膜的微孔结构，当烧结温度为1250℃时，陶瓷膜的孔径分布较窄，孔径大小为25?65 nm，渗透通量为986.4 L/(m2?h)。超细球形氧化铝粒径分布较窄及表面致密光滑有助于1250℃下烧结形成均匀的烧结颈，提供了陶瓷膜较窄的孔径分布。对1250℃下烧结的陶瓷膜进行了纳米硅水分散液过滤处理后其浊度下降为0.231 NTU，浊度去除率达99.96%。采用不同堵塞模型分析了陶瓷膜过滤纳米硅水分散液的膜污染过程，结果表明，纳米硅水分散液的堵塞模型是滤饼过滤，属于可逆污染。     

Design and fabrication of whisker hybrid ceramic membranes with narrow pore size distribution and high permeability via co-sintering process

Ceramic microfiltration membranes (MF) with narrow pore size distribution and high permeability are widely used for the preparation of ceramic ultrafiltration membranes (UF) and in wastewater treatment. In this work, a whisker hybrid ceramic membrane (WHCM) consisting of a whisker layer and an alumina layer was designed to achieve high permeability and narrow pore size distribution based on the relative resistance obtained using the Hagen-Poiseuille and Darcy equations. The whisker layer was designed to prevent the penetration of alumina particles into the support and ensure a high porosity of the membrane, while the alumina layer provided a smooth surface and narrow pore size distribution. Mass transfer resistance is critical to reduce the effect of the membrane layers. It was found that the resistance of the WHCM depended largely on the alumina layer. The effect of the support and whisker layer on the resistance of the WHCM was negligible. This was consistent with theoretical calculations. The WHCM was co-sintered at 1000?°C, which resulted in a high permeability of ~?645?L?m^?1 h^?1 ;bar^?1 and a narrow pore size distribution of ~?100?nm. Co-sintering was carried out on a macroporous ceramic support (just needed one sintering process), which greatly reduced the preparation cost and time. The WHCM (as the sub-layer) also showed a great potential to be used for the fabrication of ceramic UF membranes with high repeatability. Hence, this study provides an efficient approach for the fabrication of advanced ceramic MF membranes on macroporous supports, allowing for rapid prototyping with scale-up capability.     

颗粒粒径和膜孔径对陶瓷膜微滤微米级颗粒悬浮液的影响

通过测定颗粒悬浮液通过陶瓷微滤膜时的参透通量及污染阻力,确定了陶瓷膜处理微米级颗粒悬浮液时,颗粒粒径和膜孔径对微滤过程的影响和膜污染机理,获得了微米级颗粒悬浮液微滤过程中膜孔径的选择方法。     

Sol-gel preparation of selective layers of ceramic ultrafiltration membranes based on titania

A sol-gel method for preparing selective layers of ceramic ultrafiltration membranes based on titania hydrosols is considered. The characteristics of the pore structures of the selective layers are considered as a function of the initial composition and the firing temperature. All of the selective layers have a narrow range of the pore size distribution and meet the requirements imposed on ultrafiltration membranes.     

前驱物裂解法低温制备碳化硅陶瓷膜

将碳化硅(SiC)粉体和一定量聚碳硅烷(polycarbosilane,PCS)、蒸馏水、聚丙烯酰胺(polyacrylamide,PAM)、聚丙烯酸(polypropylene acid,PAA)混合球磨以制备水性SiC浆料并测定了SiC粒子的动电位及粘度;将浆料均匀涂在SiC支撑体上,在1100℃真空条件下烧成,制备了SiC陶瓷膜并测定陶瓷膜的孔径分布及纯水通量及观察其形貌.研究结果表明:涂膜所用的浆料在pH值为11左右时,SiC粒子动电位最大达到-40 mV,浆料表观粘度最小为20 mPa·s,制备的陶瓷膜孔径大小集中在1μm左右,纯水通量达40 m3/(m2·h).     

Cellulose acetate and sulfonated polysulfone blend ultrafiltration membranes. II. Pore statistics,molecular weight cutoff,and morphological studies

The determination of the pore size, porosity, number of pores, molecular weight cutoff (MWCO), and morphology of an ultrafiltration membrane is necessary for predicting the performance of a membrane for a specific application. For ultrafiltration membranes prepared from cellulose acetate and sulfonated polysulfone in the presence and absence of various concentrations of the additive poly(ethylene glycol) 600, pore statistics and MWCOs were determined in studies with dextrans of different molecular weights. Surface and cross‐sectional morphologies of the membranes were analyzed with scanning electron microscopy at different magnifications. The pore size increased with increasing concentrations of sulfonated polysulfone and additive in the casting solution. Similarly, the MWCOs of the membranes ranged from 19 to 150 kDa, depending on the various polymer blend compositions and additive concentrations. Results from scanning electron microscopy provided qualitative evidence for the trends observed for the pore statistics and MWCO results. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 430–444, 2002; DOI 10.1002/app.10414     

醋酸纤维素—纤维素增强膜的结构特征和分离性能

本文描述了醋酸纤维素－纤维素大孔增强超滤膜的结构特征一分离性能之间的关系。详细论述了膜材料含量和粘连剂含量及其分子量对膜结构和性能的影响。论述了不同配方铸膜液的膜，其孔径，水通量和截留率随操作压力的变化规律。实验证明这种高强度的ＣＡＣ膜经多次重复使用后，其结构性能保持完好。