在烷基聚葡糖苷W/O微乳液中Novozym 435脂肪酶催化酯合成反应动力学的研究

研究了Novozym435脂肪酶在烷基聚葡糖苷形成的W／O微乳液体系中,催化正丁醇与正己酸合成酯的反应动力学．反应初始速率V0与正丁醇（ROH）和正己酸（HA）摩尔浓度的比值（CROH^0／CHA^0）有关,在CROH^0／CHA^0=0．2-17范围内,随CROH^0／CHA^0比值减小,初始速率V0增大,尤其是当CROH^0／CHA^0〈3时,V0迅速增大．其原因可能是醇浓度较高时,醇与酶结合形成的死端复合物在较高浓度酸的作用下分解,重新析出游离态酶所致．脂肪酶加入量、水相介质组成和醇的种类等对反应速率有重要影响．     

微乳法制备W/O型Fe3O4磁流体及其清除水面浮油模拟研究

应用复合乳化剂和助表面活性剂制备出稳定的油包水(W／O)型微乳液,利用拟三元相图和体系电导随组成的变化,探明了一定条件下形成W／O型微乳液的最佳体系,进而利用W／O型微乳液作为“微反应器”合成Fe2O4磁流体,应用TEM对制备的磁流体进行了表征．初步模拟了用磁流体清除水面浮油的实验,获得令人满意的结果。     

Enzyme-Based Vinyl Polymerization

In vitro enzyme-mediated polymerization of vinyl monomers is reviewed. Oxidoreductase enzymes have been used for the polymerization of styrene, derivatives of styrene, acrylates, and acrylamide in water and water-miscible co-solvents. Kinetic and mechanistic studies revealed that a ternary system (horseradish peroxidase, H₂O₂, initiator, or -diketone) is required for efficient polymerization and the initiator controls the polymer characteristics.     

Degradation of Cellulosic Materials Under the Alkaline Conditions of a Cementitious Repository for Low- and Intermediate-Level Radioactive Waste. II. Degradation Kinetics

The degradation of cellulosic materials, differing mainly in the degree of polymerization and the number of reducing end groups, was studied under the alkaline conditions similar to those existing in a cementitious repository for low- and intermediate-level radioactive waste (pH 13.3, T = 25°C). The kinetics of alkaline degradation (peeling-off reaction) were studied and the data analyzed by the model of Haas et al. [13]. The observed kinetic parameters for the propagation reaction and overall stopping reaction were compared with literature data. Although measured under different experimental conditions, literature data and data from this study show a consistent picture. Differences in the extent of degradation observed for the different cellulosic materials could be satisfactorily explained by differences in reducing end group content and, consequently, by differences in the degrees of polymerization. Besides the number of reducing end groups, the degree of amorphousness also plays an important role. The main degradation products formed under the experimental conditions used are - and -(gluco)isosaccharinic acid. This is in agreement with many other studies on alkaline degradation of cellulose. The two isomers are formed in roughly equal amounts.     

基于电聚合作用的脂质体免疫传感器检测水体中毒莠定的实验研究

利用脂质体包埋亚铁氰化钾,通过戊二醛交联毒莠定兔抗制成免疫脂质体,开发快速检测水中毒莠定的夹心型免疫传感器.在修饰电极的成分等方面优化传感器的工作参数,确定了Nation、多壁碳纳米管(multiwalled carbon nanotubes, MWCNTs)和毒莠定兔抗浓度的最优值分别为0.5%、10mg·mL-1、50μg·mL-1.免疫传感器的制作及测定过程如下:采用循环伏安法促使3,4-乙烯二氧噻吩(3,4-ethylendioxythiophene, EDOT)发生电聚合作用,将毒莠定兔抗直接固定到被修饰的玻碳电极上,电极再依次与待测水样和毒莠定兔抗修饰的免疫脂质体培育一定时间,最后利用TfitonX-100溶解与抗原结合的免疫脂质体,采用方波伏安法检测还原电流以反映毒莠定浓度,整个检测过程可以在70rain内完成.在0.1 mol·-1,的H3PO4中浸泡5 rain,可实现该传感器的良好再生.结果表明,毒莠定的检测下限达到了10-10mol·L-1,线性区间为10-10～10-4mol·L-1,适合饮用水中毒莠定浓度的检测要求.     

刚果红分子印迹聚合物纳米微球的合成及吸附性能

本研究以刚果红为模板分子,α-甲基丙烯酸(MAA)为功能单体,二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,乙腈为致孔剂,2,2-偶氮二异丁腈(AIBN)为引发剂,采用沉淀聚合法制备了刚果红分子印迹聚合物纳米微球(MIP).通过扫描、透射电镜对聚合物的结构和形貌进行了表征,结果显示制备的MIP微球的粒径在90 nm左右,粒径较为均匀.利用氮气吸附脱附实验测定了聚合物颗粒的比表面积和孔容.并对诸多吸附影响因素以及分子印迹聚合物的吸附能力、选择性和重复利用率进行了分析.结果表明,MIP对刚果红表现出较好的选择性识别能力,可多次循环使用,能用于染料废水中刚果红的选择性吸附.     

PVDF ultrafiltration membranes of controlled performance via blending PVDF-g-PEGMA copolymer synthesized under different reaction times

PVDF blended different graft ratio of PVDF-g-PEGMA were systematically studied. Tuning the amphiphilic copolymer synthesis time to control membrane performance. The PVDF membrane with PVDF-g-PEGMA at 19 h possesses most surface oxygen content. The synthesis time of PVDF-g-PEGMA at 9 h is good for high flux UF membrane. Polyvinylidene fluoride grafted with poly(ethylene glycol) methyl ether methacrylate (PVDF-g-PEGMA) was synthesized using atomic transfer radical polymerization (ATRP) at different reaction times (9 h, 19 h, and 29 h). The corresponding conversion rates were 10%, 20% and 30%, respectively. PVDF was blended with the copolymer mixture containing PVDF-g-PEGMA, solvent and residual PEGMA under different reaction times. In this study, we explored the effect of the copolymer mixture additives with different synthesis times on cast membrane performance. Increasing the reaction time of PVDF-g-PEGMA causes more PVDF-g-PEGMA and less residual PEGMA to be found in the casting solution. Incremental PVDF-g-PEGMA can dramatically increase the viscosity of the casting solution. An overly high viscosity led to a delayed phase inversion, thus hindering PEGMA segments in PVDF-g-PEGMA from migrating to the membrane surface. However, more residual PEGMA contributed to helping more PEGMA segments migrate to the membrane surface. The pure water fluxes of the blended membrane with reaction times of 9 h, 19 h, and 29 h are 5445 L·m⁻²·h⁻¹, 1068 L·m⁻²·h⁻¹and 1179 L·m⁻²·h⁻¹, respectively, at 0.07 MPa. Delayed phase inversion can form smaller surface pore size distributions, thus decreasing the water flux for the membranes with PVDF-g-PEGMA at 19 h and 29 h. Therefore, we can control the membrane pore size distribution by decreasing the reaction time of PVDF-g-PEGMA to obtain a better flux performance. The membrane with PVDF-g-PEGMA at 19 h exhibits the best foulant rejection and cleaning recovery due to its narrow pore size distribution and high surface oxygen content.     

Brij35构筑原位微乳液对四氯乙烯的增溶及脱附效果

利用非离子表面活性剂Brij35与助溶剂正丁醇的二元溶液,与四氯乙烯(PCE)在含水层原位构筑微乳液.重点考察对PCE增溶性能和脱附能力以及在模拟含水层中的形成过程和对模拟含水层的修复效果.结果 表明,微乳液对PCE的最大溶解度达到61.1g/L,增溶能力是单一Brij35溶液和其常规复配组合的9.7和2.3倍,并且P...     

Anti-fouling ultrafiltration membrane prepared from polysulfone-graft-methyl acrylate copolymers by UV-induced grafting method

Membrane fouling is one of the most important challenges faced in membrane ultrafiltration operations. The copolymers of polysulfone-graft-methyl acrylate were synthesized by homogeneous photo-initiated graft copolymerization. The variables affecting the degree of grafting, such as the time of UV(Ultraviolet-visible)irradiation and the concentrations of the methyl acrylate and photoinitiator, were investigated. The graft copolymer membranes were prepared by the phase inversion method. The chemical and morphological changes were characterized by attenuated total reflection-Fourier transform infrared spectroscopy(ATR/FT-IR), scanning electron microscopy, and water contact angles measurements. Results revealed that methyl acrylate groups were present on the membranes and the graft degree of methyl acrylate had remarkable effect on the performance of membranes. Pure water contact allgle on the membrane surface decreases with the increase of methyl acrylate graftdegree. which indicated that the hydrophilicity of graft copolymer membranes Was improved. The permeation fluxes of pure water and bovine serum albumin solution were measured to evaluate the antifouling property of graft copolymer membranes, the results of which have shown an enhancement of antifouling property for graft copoly mermembranes.     

A/O生物膜法处理乳液聚合ABS树脂生产废水

采用混凝—A/O生物膜法处理乳液聚合ABS树脂生产废水,确定了混凝预处理工序PAC和PAM的投加量,考察了混合液回流比(R)和A/O段总水力停留时间(HRT)对废水中COD,NH_4~+-N,SS,TN等污染物去除效果的影响。实验结果表明,在HRT为18～24 h、R为2～3的工艺条件下,A/O生物膜法好氧段发生了同步硝化反硝化反应,废水经处理后,出水COD小于60.0 mg/L,ρ(NH_4~+-N)小于5.0 mg/L,TN小于15.0 mg/L,达到了GB 31570—2015《石油炼制工业污染物排放标准》的要求。