琼脂糖性质对凝胶电泳法分离金属性和半导体性单壁碳纳米管的影响

利用琼脂糖凝胶电泳分离单壁碳纳米管(SWCNTs)技术, 考察了MB, Agarose, Agarose B和LRU 4种琼脂糖对SWCNTs分离效率的影响. 紫外-可见-近红外(UV-Vis-NIR)吸收光谱研究结果表明, 不同的琼脂糖对SWCNTs中s-SWCNTs的分离效率影响较小, 而对m-SWCNTs的分离效率影响较大. 分析4种琼脂糖凝胶的凝胶强度和凝胶网孔尺寸等发现, 影响SWCNTs中m-SWCNTs分离效率的主要因素是琼脂糖的凝胶强度和琼脂糖凝胶形成的网孔尺寸, 小的凝胶网孔尺寸有利于m-SWCNTs富集, 高凝胶强度则不利于其富集.     

化学改性琼脂糖凝胶的物化性能及其对重组人血白蛋白的纯化应用研究

考察了几种经过化学改性后带有离子交换配基的琼脂糖凝胶介质的理化性能.通过外形观察、元素及金属含量分析、柱效测定、耐压及流速测定、离子交换容量和蛋白吸附容量测定,从多方面对性能进行验证比较,并对其在分离纯化重组人血白蛋白的应用性能进行了初步研究.结果表明国产产品与进口产品理化性能相当.     

疏水层析蛋白质动力学与平衡过程的考察

疏水层析是分离生物大分子的常用技术之一，但对疏水层析中蛋白质吸附动力学和平衡过程的研究并不多见．本文对蛋白质疏水吸附动力学和平衡过程作了基本假设，并用实验进行了验证。制备了两种不同丁基密度的疏水琼脂糖介质，用其吸附牛血清白蛋白(BSA)以验证对疏水吸附动力学与平衡过程作的假设，考察了盐浓度及配基密度对蛋白质疏水吸附的影响．还对三种疏水性不同的蛋白质：核糖核酸酶、卵清蛋白和牛血清白蛋白的混合体系进行了分离性能的研究，获得了满意的分离效果．实验表明，蛋白质在疏水介质上的吸附动力学和平衡过程与所作假设相符，在实验条件下等温吸附线符合Langmuir吸附等温方程：研制的丁基琼脂糖疏水介质具有优良的使用性能。     

Na~+浓度对反应体系成胶特性及SiO_2凝胶粉末性能的影响

以水玻璃为原料，乙酸乙酯为潜伏酸试剂，采用溶胶—凝胶法制备超细二氧化硅凝胶粉末。研究了成胶反应过程中Ｎａ＋ 浓度对反应体系成胶特性及最终所得二氧化硅凝胶粉末性能的影响，并用透射电镜和氮气物理吸附实验手段对粉末的有关性能进行了测试表征     

DEAE-纤维素法从琼脂中分离制备琼脂糖工艺研究

采用DEAE-纤维素法静态和动态两种工艺从琼脂中分离制备琼脂糖,并考察了最佳工艺条件。静态吸附的最佳工艺条件为:在80℃下,浓度为40g/L的琼脂溶液与25g DEAE-52纤维素进行4h的离子交换,制得的琼脂糖凝胶强度为1028g/cm2,硫酸根含量为0.208%,透明度为64.0%,凝固温度为36.0℃,融化温度为90.2℃,得率为57.2%;动态吸附的最适工艺条件为:在80℃下,浓度为8g/L的琼脂溶液,以1.5m L/min的上样流速流经填充60g DEAE-52纤维素的层析柱,制得的琼脂糖凝胶强度为1040g/cm2,硫酸根含量为0.159%,透明度为65.8%,凝固温度为36.5℃,融化温度为89.8℃,得率为50.3%。DNA Marker电泳实验表明,自制琼脂糖具有优异的电泳性能,能满足生化实验要求。     

大豆分离蛋白/琼脂糖复合水凝胶

采用简单的物理共混方法,制备一种大豆分离蛋白/琼脂糖降温型复合水凝胶.即在高温下聚乙二醇改性的大豆分离蛋白/琼脂糖混合物呈溶液状态,降温至生理温度37℃或更低温度则形成水凝胶.表征了该复合凝胶的溶胀度、力学性能、细胞毒性和细胞迁移率.结果表明,改性大豆分离蛋白/琼脂糖复合水凝胶具有较高的溶胀度和力学性能,良好的生物相容性和细胞迁移率,在伤口敷料领域显示出潜在的应用.     

超高容量氧化石墨烯/碳纳米管气凝胶用于血红蛋白的吸附分离

采用冷冻干燥技术制备了三维氧化石墨烯/碳纳米管(GO/CNTs)气凝胶,在疏水作用下,该气凝胶对蛋白质表现出良好的吸附性能.在p H=8.0时,GO/CNTs气凝胶对血红蛋白的吸附效率很高,而对白蛋白基本不吸附,从而可实现血红蛋白的选择性吸附分离.在最佳吸附条件下,GO/CNTs气凝胶对血红蛋白的吸附容量高达3793.3 mg/g,是去除高丰度血红蛋白的高效材料.吸附后的血红蛋白可以使用p H=11.5的BrittonRobisin缓冲液有效洗脱,回收率为67%.圆二色光谱结果表明,GO/CNTs气凝胶具有良好的生物相容性,其表面发生的吸附/洗脱过程对血红蛋白的构象基本无影响.将GO/CNTs气凝胶用于人全血样品中血红蛋白的选择性分离,SDS-聚丙烯酰胺凝胶电泳结果表明得到了较高纯度的血红蛋白.     

果胶锆凝胶球对苯甲酸的吸附性能研究

用锆氧基离子与果胶反应制得果胶锆凝胶球,采用扫描电镜和红外光谱初步表征了凝胶球的结构,并测定了凝胶球的机械强度。研究了该凝胶球对苯甲酸的吸附性能。分别考察了果胶浓度、锆氧基离子浓度、吸附时间、p H值、温度及苯甲酸浓度对吸附性能的影响。结果表明,在298K下,果胶锆凝胶球对苯甲酸的吸附在4.5h左右达到平衡,当果胶的质量分数为3.0%,锆氧基离子质量分数为1.0%,苯甲酸初始浓度为500mg/L,吸附量可达73.89mg/g。所研究的吸附体系既适用于Freundlich方程,又适用于Langmuir方程;吸附过程为自发的放热、熵减过程,降低温度对吸附更有利。     

新型金属有机气凝胶的合成、 表征及气体吸附性能

利用高稳定性的UiO-66系列金属有机骨架多孔材料制备金属有机气凝胶材料, 制得的UiO-66系列金属有机气凝胶材料具有多级孔结构和较高的比表面积, 在气体吸附分离领域具有较大应用潜力. 气体吸附实验结果表明, UiO-66-NH₂金属有机气凝胶材料具有极佳的CO₂吸附性能和CO₂/CH₄分离性能, 通过理想吸附溶液理论计算得出其吸附选择性高达18.3.     

疏水膜色谱法对生物大分子的快速纯化

首次采用自制的分别级合了辛基、丁基、苯基及聚乙二醇-4000的4种常用疏水基团的纤维素疏水膜色谱柱,以键合了辛基、苯基的SepharoseCL－4B凝胶柱为对照,考察了疏水膜色谱柱对牛血清白蛋白（BSA）的动态吸附容量及流速对吸附容量的影响。疏水膜色谱柱对蛋白及酶具有较好的疏水吸附及纯化作用,但吸附容量比相应的琼脂糖凝胶柱低得多。增大流速及降低蛋白溶液质量浓度对疏水膜色谱柱的吸附容量影响较小,这些性能使膜色谱柱非常适合于大体积低质量浓度蛋白溶液（如基团工程培养液）的分离纯化。     

Quaternary ammonium substituted agarose as surface coating for capillary electrophoresis

A novel positively charged polymer of quaternary ammonium substituted agarose (Q-agarose) has been synthesized and explored for use as a coating in capillary electrophoresis. The fast and simple coating procedure is based on a multi-site electrostatic interaction between the polycationic agarose polymer and the negatively charged fused-silica surface. By simply flushing fused-silica capillaries with hot polymer solution a positively charged, hydrophilic deactivation layer is achieved. The polymer surface provides an intermediate electroosmotic flow of reversed direction, over a range of pH 2-11, compared to unmodified fused-silica. The coating procedure was highly reproducible with an RSD of 4%, evaluated as the electroosmotic flow mobility for 30 capillaries prepared at 10 different occasions. The application of Q-agarose coated capillaries in separation science was investigated using a set of basic drugs and model proteins and peptides. Due to the intermediate electroosmotic flow generated, the resolution of basic drugs could be increased, compared to using bare fused-silica capillaries. Moreover, the coating enabled separation of proteins and peptides with efficiencies up to 300.000 plates m(-1).     

Investigation of sol-gel matrices containing crude metallothionein from <Emphasis Type="Italic">Scchizosaccharomyces pombe</Emphasis> for water treatment applications

The application of silica sol–gel particles containing crude metallothionein (MT) was investigated for cadmium removal from water. The metallothionein was first extracted from the yeast Scchizosaccharomyces pombe, and entrapped in the sol–gel matrices. Then sol–gel particles with the different sizes (ranging from 45 to 225 μm) were made. The effect of different flow rates as well as different particle sizes on adsorption of cadmium was investigated. The particle size has a greater effect on Cd adsorption than flow rate in the system studied. The breakthrough curves in the column were modeled using an empirical two parameter fixed-bed adsorption model. The model relates the changes of cadmium concentration in effluent to the standard deviation (σ) and characteristic of time (t ₀).     

表面印迹法制备钴(Ⅱ)离子印迹硅胶及性能

采用表面印迹技术, 以Co(Ⅱ)离子作为印迹离子, 二乙烯三胺基丙基三甲氧基硅烷为功能分子, 硅胶为支撑物, 环氧氯丙烷为交联剂, 在硅胶表面制备Co(Ⅱ)离子印迹硅胶材料, 利用红外光谱仪、扫描电镜和热重分析仪等进行了表征, 采用平衡吸附法研究了印迹硅胶材料的吸附性能和选择识别能力. 结果表明, 印迹硅胶材料和非印迹硅胶材料的最大吸附量分别为35.2和6.5 mg/g; 印迹硅胶材料对Co(Ⅱ)离子的吸附行为符合Langmuir模型; 20 min即可达到吸附平衡; 当pH=3.9~7.8时, 印迹硅胶材料保持了较好的吸附容量; 印迹硅胶材料对Co(Ⅱ)离子具有较强的选择性识别能力; 重复使用时性能稳定.     

Suspension polymerization of poly(ethylene glycol) methacrylate: a route for swellable spherical gel beads with controlled hydrophilicity and functionality

 Spherical and swellable gel beads were obtained by the suspension polymerization of poly(ethylene glycol) methacrylate macromonomer (PEG-MA). The average size and size distribution properties, the equilibrium swelling behaviour and the protein adsorption characteristics of PEG-MA-based gel beads were determined. In the suspension polymerization system, the organic phase including monomer, cross-linker and diluent solution was dispersed in an aqueous medium by using poly(vinylpyrrolidone) as the stabilizer. The diluent solution was prepared by mixing cyclohexanol and octanol at different volume ratios. The suspension polymerization experiments were designed in two separate parts. In the first part, ethylene glycol dimethacrylate was selected as the cross-linker and swellable PEG-MA-based gel beads were obtained by changing the cross-linker concentration, the monomer/diluent ratio and the stirring rate. In the second part, a more hydrophobic structure, divinylbenzene (DVB) was tried as a cross-linker. In this part, PEG-MA-DVB copolymer beads were obtained by changing the DVB/PEG-MA feed ratio. Then, the hydrophicility of the resulting gel beads could be controlled by changing the feed ratio of hydrophilic macromonomer to hydrophobic cross-linker. This property was also used to control the extent of nonspecific protein adsorption onto the surface of the gel beads. The non specific albumin adsorption onto the gel beads decreased with increasing PEG-MA content. No significant nonspecific adsorption at the isoelectric point of albumin was detected onto the gel beads produced with the higher PEG-MA/DVB feed ratios. For specific albumin adsorption, a triazinyl dye (i.e., cibacron blue, CB F3G-A) was covalently attached onto the surface of the copolymer beads via terminal hydroxyl groups of PEG-MA. The results of albumin adsorption experiments with the CB F3G-A carrying beads indicated that an appreciable specific albumin adsorption capacity could be obtained with the gel beads produced with a PEG-MA/DVB feed ratio of 1.5/4.0. Received: 16 August 1999/Revised: 27 December 1999     

Body temperature-responsive gels derived from hydroxypropylcellulose bearing lignin II: adsorption and release behavior

The lower critical solution temperature (LCST) of hydroxypropylcellulose bearing lignin (HPC-L) prepared from unbleached pulp depends on the amount of residual lignin. An HPC-L gel having thermal properties reflective of original HPC-L was prepared using ethyleneglycol diglycidylether as a crosslinker, as previously reported [Uraki et al. (2004) Carbohydr. Polym. 58:123–130], and the volume transition temperature was detected as an endothermic peak by differential scanning calorimetry (DSC). The adsorption and release behavior of the guest molecules to/from this gel was then examined. When the adsorption of cationic and anionic guests was compared, cationic methylene blue (MB) was adsorbed in larger amounts than anionic methyl orange (MO). In addition, MB adsorption into the HPC-L gel was greater than MB adsorption into the HPC gel prepared from commercially available HPC. This suggests that residual lignin affects the adsorption of organic dyes. Significant differences were not observed with respect to the release of MB from HPC-L at 38 °C and lower temperatures. In the adsorption of surfactants, marked adsorption at around the critical micelle concentration of the ionic surfactants and gel swelling were observed. Such swelling did not occur in the aqueous nonionic surfactant solution, although the nonionic surfactant was adsorbed into the gel. Gel swelling may have been caused by the electrostatic repulsion of the ionic surfactants adsorbed onto the polymer chains within the gel structure.     

The Thermal Stability and Adsorbability of the Mechylated Silica Gel

The methylated silica gel has been produced by the reaction between the surface silanol groups and Clsi(CH3)3 vapor.The adsorption isotherms of acetic acid from carbon tetrachloride onto silica gel and emthylated silica gel heated at various temperatures have been determined at 25℃,and the above mentioned silica gels have been studied by TC and IR.The results indicate:(1) The adsorption of acetic acid from carbon tetrachloried onto methylated silica gel decreased greatly,probably because the concentration of the free hydroxyl groups for methylated silica gel decreased greatly as the IR shows.(2) As the methylated surface was destroyed at 450℃,the adsorption ability was restored when the methylated silica gel treated at>500℃.(3) So long as the methylated silica gel was treated at high temperature,the adsorption ability could be restored owing to that surface free hydroxyl groups were reproduced.     

以铜离子为模板的褐藻酸凝胶对铜离子的选择性富集研究

以铜离子为模板，制备了褐藻酸凝胶（Cu-alginate)，通过吸附实验及过柱渗滤实验，试验了该吸附剂对铜离子的选择性吸附性能，并且采用该吸附剂富集了自来水中微量的Cu^2 ，结合原子吸收法测定了水样中Cu^2 的含量。结果表明：该吸附剂对Cu^2 有较高的选择性吸附性能，显著优于一些化学合成铜离子模板缩聚物及非铜模板褐藻酸凝胶（如Ca-alginate),非重金属离子（如K^ 、Na^ 、Ca^2 ）及某些重金属离子（如Ni^2 、Cd^2 ）等对Cu^2 的吸附均不产生明显干扰。用该吸附剂富集水中的微量铜离子，回收率可达97.7%。     

改性固体表面的吸附作用——甲基化硅胶的热稳定性和吸附性能

本文利用三甲基氯硅烷与硅胶表面羟基反应的方法制备了甲基化硅胶。测定了亲水硅胶和甲基化硅胶的热处理对其自四氯化碳中吸附乙酸的等温线的影响,并配合有热重分析(TG)和红外光谱(IR)的测定。结果表明:(1)甲基化后的硅胶对乙酸的吸附能力大大下降;(2)甲基化硅胶的热处理温度达500℃时吸附能力完全恢复到甲基化前的硅胶的水平,甲基化层明显开始破坏的温度为450℃;(3)甲基化硅胶高温处理后吸附能力得以恢复的主要原因是重新形成表面自由羟基。     

CMC型高分子表面活性剂在固/液界面上的吸附

在润湿、乳化、洗涤、分散等应用领域中,表面活性剂分子在界面上的吸附状态对性能有重要影响.另一方面,在化学驱油过程中,表面活性剂分子在氧化物矿物上的吸附是引起表面活性剂损失的主要原因,表面活性剂的损耗量大,将降低采收率及经济效益[1].高分子表面活性剂作为一种多功能的新型表面活性剂在许多领域有广阔的应用前景,但对其性能研究尚处于起步阶段,特别是结构复杂的高分子双亲性共聚物,在吸附、乳化等方面研究尚少报导.羧甲基纤维素系列高分子表面活性剂是采用独特的超声波辐照技术合成的嵌段型共聚物,具有优良的表/界面活性[2],可望用…     

A Novel Thermosensitive Gel Adsorbent for Phosphate Ions

Summary: A novel thermosensitive gel adsorbent for phosphate ions was developed and its adsorption/desorption properties were investigated. The gel adsorbent was made by the copolymerization of N-isopropylacrylamide (NIPA) and N-[3-(dimethylamino)propyl]acrylamide (DMAPAA). The adsorbent has a volume phase transition temperature (VPTT), below which it becomes hydrophilic. The tertiary amino groups of DMAPAA were ionized and showed a cationic state when the gel swelled. Phosphate ions were adsorbed onto the ionized tertiary amino groups in the gel network below the VPTT and were desorbed above the VPTT because of the suppression of the ionization of the tertiary amino groups of gel and the shrinkage of the gel.