聚醚砜／壳聚糖共混耐污染超滤膜的研制

采用相转化法,以聚醚砜（PES）、壳聚糖、聚乙二醇400（PEG400）、吐温80和LiCl／N,N-二甲基乙酰胺（DMAo）混合溶剂为原料制备聚醚砜／壳聚糖共混耐污染超滤膜。并对影响超滤膜结构和性能的各个因素进行了研究。结果表明．在壳聚糖质量分数为0．3％、反应温度为80℃条件下制备的聚醚砜／壳聚糖共混耐污染超滤膜性能最优。在25℃、0．1MPa操作条件下,膜的纯水通量为745．22（L／m2·h）,牛血清白蛋白截留率为91．79％。改性后的超滤膜表面接触角为74．6°,阻力增大系数为0．54,通量衰减速度小于未改性超滤膜,亲水性能和耐污染性能得到很大提高。     

重催油浆磺化制磺化沥青工艺条件研究

本实验用重催油浆经磺化、中和反应合成磺化沥青类产品。考察、优化了油浆磺化的原料、工艺条件,用中国石油天然气总公司钻井工程局企业标准《钻井液用磺化沥青-FT1》分析方法,对各种工艺条件下的油浆磺化产品的磺酸钠含量、油溶物、水溶物含量进行了测定比较,找到了油浆磺化制磺化沥青类产品的最佳工艺条件。     

无热源法生产脂肪族高效减水剂的磺化剂研究

以七水亚硫酸钠、无水亚硫酸钠、亚硫酸氢钠、焦亚硫酸钠4种无机盐为磺化剂,采用无热源工艺合成了脂肪族高效减水剂,并以单因素方法研究了4种无机盐磺化剂对脂肪族高效减水剂性能的影响。结果表明,以七水亚硫酸钠为磺化剂合成的脂肪族高效减水剂具有较优的水泥净浆分散性和分散保持性。     

磺化丙酮-甲醛缩聚物的结构表征及其发色机理分析

采用对磺化丙酮-甲醛缩聚物的结构进行了表征,含有羰基、羟基、碳碳双键等基团。通过紫外光谱和碘量法发现,不饱和键被NaBH4还原,使SAF减水剂的吸光度降低。SAF减水剂的棕红色是由于含有较长的双键或共轭羰基链段和助色基团-SO3所致。     

Silicate-based polymer-nanocomposite membranes for polymer electrolyte membrane fuel cells

Proton-exchange membrane fuel cells have emerged as a promising emission free technology to fulfill the existing power requirements of the 21st century. Nafion^® is the most widely accepted and commercialized membrane to date and possesses excellent electrochemical properties below 80 °C, under highly humidified conditions. However, a decrease in the proton conductivity of Nafion^® above 80 °C and lower humidity along with high membrane cost has prompted the development of new membranes and techniques. Addition of inorganic fillers, especially silicate-based nanomaterials, to the polymer membrane was utilized to partially overcome the aforementioned limitations. This is because of the lower cost, easy availability, high hydrophilicity and higher thermal stability of the inorganic silicates. Addition of silicates to the polymer membrane has also improved the mechanical, thermal and barrier properties, along with water uptake of the composite membranes, resulting in superior performance at higher temperature compared to that of the virgin membrane. However, the degrees of dispersion and interaction between the organic polymer and inorganic silicates play vital roles in improving the key properties of the membranes. Hence, different techniques and solvent media were used to improve the degrees of nanofiller dispersion and the physico-chemical properties of the membranes. This review focuses mainly on the techniques of silicate-based nanocomposite fabrication and the resulting impact on the membrane properties.     

Poly(Acrylic Acid-co-Acrylonitrile) Copolymer Modified Polyethersulfone Hollow Fiber Membrane with pH-Sensitivity

In this study, functional polyethersulfone (PES) hollow fiber membranes with pH sensitivity were prepared by blending with poly(acrylic acid-co-acrylonitrile) (P(AA-AN)) copolymer. The copolymer was characterized by FTIR analysis, elemental analysis, and GPC measurement. Scanning electron microscopy (SEM) was used to investigate the morphology of the blended hollow fiber membranes. The modified hollow fiber membranes showed excellent pH sensitivity and pH reversibility and we confirmed that both the pore size change and the electroviscous effect had great effect on the pH sensitivity of the copolymer blended PES hollow fiber membranes.     

Ultrafiltration of Aqueous Solutions of PVA‐Cu(II) Macromolecular Complex

Abstract

The hydrodynamic behavior of aqueous solutions of poly(vinyl alcohol) and poly(vinyl alcohol)–cupric complex and its effect on the performance in the concentration of the macromolecular cupric complex by ultrafiltration is considered in this study which implements various synthetic membranes in polyethersulfone. The polyelectrolyte–like behavior of poly(vinyl alcohol) is highlighted. This behavior disappears in the case of the macromolecular complex. The disappearance of the polyelectrolyte–like effect is explained by the modification of the macromolecular conformation induced by the formation of the complex which takes up a tightly packed conformation. The study of the effect of the variation of the pH and the ionic strength made it possible to observe that the increase of the pH is accompanied by the reduction of the medium viscosity and the increase of the flux through the ultrafilters and the increase of the ionic strength of the medium is accompanied by the increase of the thickness of the adsorbed solute layer. The study of the effect of the nature of the ionic species in solution on the hydrodynamic behavior of the aqueous solutions of the macrocomplex leads to the conclusion that the use of the cupric chloride salt, instead of the nitrate or the sulphate salts, in the preparation of the macrocomplex improves the hydrodynamic properties of the solution and enhances the performance of its treatment by means of the ultrafiltration process.     

Optimization of Membrane Process for Methane Recovery from Biogas

Including biogas, methane (CH₄) could be used as one of the important energy sources. In this research, the membrane separation process took place to recover purified CH_4, such as hydrogen sulfide (H₂S). The Polyethersulfone (PES) Hollow Fiber Membranes (HFM) was prepared by the dry-wet phase inversion technique. The simulation program using MATLAB was evaluated by utilizing the information from experimental results of a well-designed process. From the simulation program, the process that meets the specified conditions was designed. The three-stage process that has a membrane area of 454.3 m² recovered 91.3% of CH₄ in the feed of 250 l/min at 5 kg_f/cm² and 30°C. The membrane area and the recovery of CH₄ decreases as the operating process increases.     

Molecularly Imprinted Electrospinning Polyethersulfone Nano-Scale Fibers for the Binding and Recognition of Bisphenol A

Molecularly imprinted polyethersulfone (PES) nano-scale fibers were prepared by using electrospinning technique, and then used for the recognition and binding of endocrine disrupter bisphenol A (BPA) from aqueous solutions. As an alternative to synthesizing molecularly imprinted nanofibers using ‘template-guided’ or molecular self-assembly method, the route has proven to be one of simplicity and convenience. The imprinted PES nano-scale fibers with the diameter ranged from 200 nm to 500 nm could be easily used for the binding and recognition of BPA as that by using PES microfibers and particles, and the nano-scale fibers showed good performance for specific recognition of BPA. Significantly higher binding amount and speed were observed compared to the imprinted PES particles and microfibers.     

Removal of Volatile Organic Compounds from Water by Pervaporation Using Polyetherimide-Polyethersulfone Blend Hollow Fiber Membranes

Abstract

Removal of volatile organic compounds (VOCs) such as 1,2-dichloroethane, trichloroethylene, chlorobenzene and toluene from water solutions through polyetherimide (PEI)-polyethersulfone (PES) blend hollow fiber membranes was investigated by pervaporation (PV) in this work. The separation performances of the membranes were researched by varying the spinning conditions (such as coagulation temperature and air gap distance) for the preparation of the hollow fibers and the operation conditions (such as velocity, concentration, and temperature of feed liquids). For the PEI-PES blend hollow fiber membrane prepared when the air gap was 7 cm and the temperature of coagulation bath was 45°C, it possessed high selectivity to the aqueous solutions containing 0.04 wt.% of VOCs at 20°C. The separation factors to 1,2-dichloroethane, trichloroethylene, chlorobenzene and toluene were 7069, 5759, 3952, and 3205, respectively. It was found that the pervaporation performance of the blend hollow fiber membrane was strongly related to the molecular size of the VOCs. The order of the selectivities was 1,2-dichloroethane > trichloroethylene > chlorobenzene > toluene.