芬顿试剂降解羧甲基纤维素钠的定量分析

为制备低黏度的羧甲基纤维素钠(CMC),采用芬顿(Fenton)试剂对CMC进行降解,并对降解后的产物进行定量分析。在整个反应体系中,考查了反应时间、溶液浓度、温度、p H值以及V(H2O2)/V(Fe2+)的比值对CMC降解效果的影响。试验结果表明:Fenton试剂对CMC的降解效果非常显著。由正交试验得出最佳的降解工艺条件,即在3 g/L的CMC溶液2 L、反应温度50℃、p H值为3.5、V(H2O2)∶V(Fe2+)=3∶1(0.9 m L∶0.3 m L)、反应时间为30 min时,CMC降解率达到96.05%。对降解后产物的各项性能进行定量分析,结果均符合食品添加剂的各项理化指标。     

葛根素的提取与膜分离研究

采用紫外—可见分光光度计测量葛根素的含量,采取乙醇回流水浴提取,通过单因素法和正交试验分别研究提取时间、提取温度、乙醇的浓度、料液比四个因素对葛根素提取的影响。纯化部分主要依靠膜分离技术对提取液进行微滤、超滤、纳滤处理,通过对通量与时间、压力等因素关系的研究,得到合适的膜分离操作工艺条件。     

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。     

高电密自然循环离子膜烧碱生产工艺优化

介绍高电密自然循环离子膜烧碱生产过程中的各种工艺优化,总结了通过实际运行后产生的经济效益、节能减排、安全运行等方面的成果,并提出离子膜法电解工艺改造的其他建议。     

膜法技术在甲醇弛放气回收氢气中的应用

针对新能凤凰(滕州)能源有限公司煤制甲醇生产中存在的弛放气放空问题,为回收弛放气中的氢气,引进了膜法氢气回收技术。介绍了膜法氢回收工艺及该技术的应用情况,对膜分离氢回收装置采取了增加尾气管线、改造氢压机负荷开关、更换氢压机后水冷器、富氢气同时进入两期合成系统等改进措施。改进后,优化了循环气组成,提高了甲醇产量,具有较好的经济效益。     

膜法污水回用过程中的膜污染防治技术研究

关于膜法污水回用过程中的膜污染的研究一直备受关注。膜污染限制了膜的渗透通量,使膜的使用寿命缩短,严重制约着膜技术的应用和发展。结合膜技术在石化污水回用方面的应用和本实验室的研究成果,主要从膜前预处理工艺、膜材料、膜孔径的选择方面介绍了膜污染的防治措施,旨在给膜技术处理领域研究人员的研究提供一个简单的参考。     

Unveiling the Mode of Action of Two Antibacterial Tanshinone Derivatives

In this study, 2-(N-pyrrolidine-alkyl) tanshinones bearing pyrrolidine groups were synthesized and the antibacterial mechanism was explored. These derivatives selectively elicited antibacterial activity against Gram-positive bacteria. Moreover, their antibacterial activities were time-, concentration-dependent and persistent. It appeared that Fenton-mediated hydroxyl radicals were involved, and the disruption of cell membranes was observed. This study indicates that 2-(N-pyrrolidine-alkyl) tanshinones might be potential candidates as antibacterial agents.     

Deoxycholate‐Based Glycosides (DCGs) for Membrane Protein Stabilisation

Detergents are an absolute requirement for studying the structure of membrane proteins. However, many conventional detergents fail to stabilise denaturation‐sensitive membrane proteins, such as eukaryotic proteins and membrane protein complexes. New amphipathic agents with enhanced efficacy in stabilising membrane proteins will be helpful in overcoming the barriers to studying membrane protein structures. We have prepared a number of deoxycholate‐based amphiphiles with carbohydrate head groups, designated deoxycholate‐based glycosides (DCGs). These DCGs are the hydrophilic variants of previously reported deoxycholate‐based N‐oxides (DCAOs). Membrane proteins in these agents, particularly the branched diglucoside‐bearing amphiphiles DCG‐1 and DCG‐2, displayed favourable behaviour compared to previously reported parent compounds (DCAOs) and conventional detergents (LDAO and DDM). Given their excellent properties, these agents should have significant potential for membrane protein studies.     

Preparation and Reinforcement of Dual‐Porous Biocompatible Cellulose Scaffolds for Tissue Engineering

Biocompatible cellulose‐based aerogels composed of nanoporous struts, which embed interconnected voids of controlled micron‐size, have been prepared employing temporary templates of fused porogens, reinforcement by interpenetrating PMMA networks and supercritical carbon dioxide drying. Different combinations of cellulose solvent (Ca(SCN)₂/H₂O/LiCl or [EMIm][OAc]/DMSO) and anti‐solvent (EtOH), porogen type (paraffin wax or PMMA spheres) and porogen size (various fractions in the range of 100–500 μm) as well as intensity of PMMA reinforcement have been investigated to tailor the materials for cell scaffolding applications. All aerogels exhibited an open and dual porosity (micronporosity >100 μm and nanoporosity extending to the low micrometer range). Mechanical properties of the dual‐porous aerogels under compressive stress were considerably improved by introduction of interpenetrating PMMA networks. The effect of the reinforcing polymer on attachment, spreading, and proliferation of NIH 3T3 fibroblast cells, cultivated on selected dual‐porous aerogels to pre‐evaluate their biocompatibility was similarly positive.     

羟丙甲基纤维素的合成工艺的改进研究

基于现有羟丙基甲基纤维素合成方法的研究,采用氮气保护碱化和分步醚化方法,制得具有较高黏度的羟丙基甲基纤维素。该方法合成的羟丙基甲基纤维素(HPMC)具有在冷水中分散性能好、黏度高、增稠保水性能好的优点,适合建筑用的胶水的生产,可用于砌墙、抹灰、粉刷、嵌缝等施工中,同时也适合用于干混凝砂浆。