二氧化硅／环氧树脂复合涂层的制备及其疏水性能

采用喷涂技术,在马口铁表面喷涂环氧树脂和二氧化硅复合涂层,研究了二氧化硅的含量对表面疏水性的影响,复合涂层的疏水性随二氧化硅含量的增加而增加．当二氧化硅质量分数增大到40％时,所制备的复合涂层与水的接触角约为141°且具有较小的滚动角．     

新型疏水色谱填料--丁基交联壳聚糖的合成

合成了一种以壳聚糖为载体,以正丁基为配基,并以戊二醛交联提高其机械强度的新型疏水色谱填料－丁基交联壳聚糖,并对其合成条件的控制进行了研究。结果表明：交联剂用量、反应物比例以及反应物浓度决定了合成填料的疏水性能。为保证良好的听任性、实用性及较佳的分离效果,比较合适的合成条件是：戊二醛浓度0．1％（V／V）,正丁醛浓度0．13％－0．26％（V／V）,壳聚糖浓度2g/L-10g/L。不同条件下的合成的色谱填料对枯草杆菌α－淀粉酶粗品的分离提纯效果明显不同,进一步说明合成条件对色谱填料性能的影响。     

胍变及脲变α-淀粉酶的研究 Ⅰ.用高效疏水色谱法研究变性机理和复性效率

 用疏水性强弱不同的两种色谱柱对７．０ｍｏｌ／Ｌ盐酸胍及８．０ｍｏｌ／Ｌ脲变性的α－淀粉酶变体和在疏水色谱介质表面上折叠的中间体进行了分离和复性。通过研究和比较发现，两者的变性机理和形成折叠中间体的个数以及复性效率均不相同。在用疏水性较弱的疏水色谱柱对脲变α－淀粉酶的折叠中间体进行分离时，得到了疏水性接近连续的、数目很多的中间体。用疏水性较强的疏水色谱柱对胍变α－淀粉酶进行复性的效果较好。还研究了柱温变化对其折叠、分离效果和复性效率的影响。     

胍变及脲变α-淀粉酶的研究 Ⅰ.用高效疏水色谱法研究变性机理和复性效率

用疏水性强弱不同的两种色谱柱对７．０ｍｏｌ／Ｌ盐酸胍及８．０ｍｏｌ／Ｌ脲变性的α－淀粉酶变体和在疏水色谱介质表面上折叠的中间体进行了分离和复性。通过研究和比较发现，两者的变性机理和形成折叠中间体的个数以及复性效率均不相同。在用疏水性较弱的疏水色谱柱对脲变α－淀粉酶的折叠中间体进行分离时，得到了疏水性接近连续的、数目很多的中间体。用疏水性较强的疏水色谱柱对胍变α－淀粉酶进行复性的效果较好。还研究了柱温变化对其折叠、分离效果和复性效率的影响。     

丙烯酰胺和表面活性大单体共聚物的合成及其性能研究

首先合成表面活性大分子单体丙烯酸聚氧乙烯（２３）－十二烷基酯（ＡＡ－ＰＯＥＬＥ）,再通过与丙烯酰胺共聚合的方法得到在水溶性聚合物聚丙烯酰胺分子结构中引入疏水基团的共聚物改性ＰＡＭ。因ＡＡ－ＯＰＥＬＥ单体具有表面活性,所以共聚合时无需添加乳化剂。当改性ＰＡＭ中疏水基团含量为１．１０ｍｏｌ％时,其水溶液表现出独特的流变性和增稠性,着重讨论了改性ＰＡＭ作为乳胶增稠剂的性能。     

苄氧基甲基12—冠—3的合成与锂离子选择性电极研究

报道了苄氧基甲基－１２－冠－３－的合成，并以此化合物作载体研制成锂离子选择电极。用苄氧基甲基－１２冠－３－为载体的电极对锂离子响应拇性范围为１．０×１０＾－１－８．３×１０＾－５ｍｏｌ／Ｌ．检测限为４．２×１０＾－５ｍｏｌ／Ｌ，斜率为５７．４ｍＶ／ｐＬｉ。电极具有好的稳定性和重现性。     

间规聚苯乙烯的非等温结晶及其动力学

以Ｓｔ－ＭＭＡ－ＡＡ三元无皂共聚胶粒作载体,用物理吸附和共价偶联两方法固载日本血吸虫虫卵可溶性抗原（Ｓｊ－ＳＥＡ）。探讨了胶粒性质对Ｓｊ－ＳＥＡ固载量及活性的影响,研究结果表明,胶粒表面疏水性强或胶乳表面张力大,则物理吸附量大,但致敏胶乳的效价并不一定高;胶粒表面羧基密度大,共价偶联量多,但共价偶联量太大时,致敏乳效价低;在共价偶联量较小时,致敏胶乳的效价随固载的Ｓｉ－ＳＥＡ密度增大而提高。     

聚二甲基硅氧烷－氯磺化聚乙烯共混涂膜表面润湿性与表面结构的研究

研究了α，ω－二羟基聚二甲基硅氧烷（ＨＴＰＤＭＳ）－氯磺化聚乙烯（ＣＳＰ）非均相共混涂膜表面润湿性与表面结构的关系，发现膜表面疏水性随ＣＳＰ含量增加而出现突变点．ＸＰＳ分析证明，这是由于氯元素在表面含量呈突变性。阐明均一的疏水性共混涂膜形成的条件．     

聚酰亚胺微孔膜疏水化用于膜蒸馏

采用聚合物表面涂覆改性的方法，将疏水性聚合物硅橡胶涂覆在聚酰亚胺亲水微孔膜上，制得了具有良好膜蒸馏性能的聚酰亚胺疏水微孔复合膜。研究了涂覆工艺条件对所得聚酰亚胺疏水微孔复合膜的膜蒸馏性能的影响。结果表明，控制适当工艺条件可制得具有高膜蒸馏通量的聚酰亚胺微孔复合膜，其透过系数可达２．１７×１０－３ｋｇ／ｍ２·ｈ·Ｐａ。该改性聚酰亚胺疏水微孔复合膜使用３７ｄ后，截留率仍保持在９９．５％以上，具有较长使用寿命。     

Candida rugosa脂肪酶同工酶的选择固定化

采用DEAE－Sepharose CL-6B离子交换层析，将Candida rugosa脂肪酶（CRL）分成了含同工酶CRL A和CRL B的3个组份，CRL A和CRL B在低水－有机溶剂双液相体系中催化（R，S）－普生甲酯的不对称水解反应，具有不同的对映体选择性。SDS聚丙烯酰胺凝胶电泳分析发现，CRL A和CRL B的分子量几乎相同（约为62000－64000Da)。等电聚焦显示CRL A在等电点pI5.6处有单一条带，CRL B在等电点pI4.2附近有2条带。圆二色谱分析未发现明显结构差异，但在极低的离子强度下它们在疏水载体YWG－C6H5上的吸附速度明显不同。50％异丙醇处理发现，CRL B可解离为CRL A和小分子酸性化合物。据此认为CRL A和CRL B在结构组成上存在着轻微差别，CRL A的活性位点处疏水腔的开放程度较CRL B大，CRL B上非共价结合有一些小分子酸性化合物。据此，分别将其选择性地固定在了疏水性不同的载体YWG－C6H5和YWG－NH2上。本文通过一个简单易行的选择吸附步骤、同时达到了同工酶的分离纯化及固定化目的，提供了一种分离结构上相近的同工酶的便利方法。     

有机溶剂-水双液相体系脂肪酶不对称水解合成S-(+)-萘普生

采用有机溶剂－水双液相体系作为反应介质，并用键合有—Ｃ６Ｈ５的无定型多孔硅胶作为分散剂增大两相间的接触面，用圆柱状假丝酵母脂肪酶对萘普生甲酯进行不对称水解．考察了酶浓度、体系ｐＨ值、温度、分散剂对反应的影响．当转化率为２４．３％时，产品萘普生的对映体过量值（ｅｅ）为９４．９％，剩余底物萘普生甲酯的对映体过量值（ｅｅ）为３０．５％，当以异辛烷作为有机相时，该体系酶催化水解的对映体比率（Ｅ）约为５０．     

Lipase-catalyzed optical resolution of racemic naproxen in biphasic enzyme membrane reactors

A lipase-immobilized membrane reactor was applied for the optical resolution of racemic naproxen, and the effect of various operation conditions on reaction rate and enantio-selectivity was examined. The membrane reactor consisted of an organic phase dissolving naproxen ester, a lipase-immobilized polyamide membrane, and an aqueous phase to recover the reaction products. The lipase immobilized in the membrane reactor showed a stable activity for more than 200 h of continuous operation, while the native lipase in emulsioned stirred tank reactor quickly lost its activity showing an half-life time of about 2 h. When crude lipase was used, the biphasic enzyme membrane reactor gave smaller enantio-selectivity compared to the native lipase in the emulsioned tank reactor, whilst the use of pure lipase gave similar results to the native lipase. This paper discusses that other hydrolases present in the crude enzyme powder caused the decrease of enantio-selectivity. Enantio-selectivity depended on the substrate concentration, amount of enzyme loaded in the membrane and immobilization site. In fact, these parameters affect the organic/aqueous interface that plays an important role in the enhancement of enantio-selectivity.     

底物,水量对脂肪酶不对称拆分萘普生的影响

选择了一种便于底物－产物分离的微水－有机两相体系,将对Ｓ－（＋＿萘普生酯有高度对映体选择性的ＣＣＬ脂肪酶固定于硅藻土上。合成了了一种能提高酶催化反应速度的激活的酯－萘普生氯乙酯。     

膜反应器中萘普生甲酯的动态拆分

在碱催化连续原位消旋条件下,利用CRL脂肪酶（Candida rugosa lipase）催化的萘普生甲酯立体选择性水解反应。动态拆分制备（S）－普生。使用硫水硅橡胶膜隔离生物催化拆分反应和碱催化消旋反应,解决了常规动态拆分反应中生物催化剂难以承受原位化学消旋苛刻反应条件的难题。为了利于从水－有机溶剂乳化体系中分离产物和克服产物抑制,将亲水半透膜引入搅拌罐反应器,在该膜反应器中进行动态拆分反应。当转化率超过60％时,产物（S）－萘普生的对映体过量值（eep)仍在96％以上,在反应过程中还发现CRL脂肪酶同工酶的转化。     

游离和膜固定化脂肪酶在双液相介质中催化二肽合成的研究

以N－乙酰－L－苯丙氨酸乙酯和L－亮氨酰胺、L－丙氨酰胺、L－苯丙氨酰胺 、L－缬氨酰胺等L－氨基酰胺为底物，以游离或膜固定化脂肪酶为催化剂，在水、 有机溶剂单相和水－有机相双相体系反应介质中，合成了N－乙酰－L－苯丙氨酰基 －L－亮氨酰胺、N－乙酰－L－苯丙氨酰基－L－丙氨酰胺、N－乙酰－L－苯丙氨酰 基－L－苯丙氨酰胺、N－乙酰－L－苯丙氨酰基－L－缬氨酰胺等二肽。研究证明， 由于反应和纯化的同步进行，二肽可以在双液相酶膜反应器中达到高纯度和高收率 合成。     

Lipase-based HPLC stationary phase: enantioselective synthesis of 2-substituted 1,3-propanediol monoacetates

Pseudomonas cepacia lipase (PCL) has been immobilized by coating the enzyme on an epoxysilica HPLC column. The biocatalyst has been successfully used for the preparation of both the enantiomers of 3-acetoxy-2-benzyl-propan-1-ol and of 3-acetoxy-2-methylpropan-1-ol. The immobilized enzyme is active after months of use either in aqueous or in organic media.     

Adsorption and activity of lipase from Candida rugosa on the chitosan-modified poly(acrylonitrile-co-maleic acid) membrane surface

Efforts have recently been made to improve the biocompatibility of support surface for enzyme immobilization, which could create a specific microenvironment for the enzymes and thus benefit the enzyme activity. In this work, one natural macromolecule, chitosan, was tethered on the surface of poly(acrylonitrile-co-maleic acid) (PANCMA) membrane to prepare a dual-layer biomimetic support for enzyme immobilization. Lipase from Candida rugosa was immobilized on this dual-layer biomimetic support by adsorption. The properties of the immobilized enzyme were assayed and compared with those of the free one. It was found that the adsorption capacity of lipase on the chitosan-tethered PANCMA membrane increases with the decrease of ionic strength and there is an optimum pH value for the adsorption. The activity retention of the immobilized lipase on the chitosan-tethered membrane by adsorption (54.1%) is higher than that by chemical bonding (44.5%). In comparison with the immobilized lipase by chemical bonding, there is a decrease of the K(m) value and an increase of the V(max) value for the immobilized lipase by adsorption. Additionally, the experimental results of thermal stabilities indicate that the residual activity of the immobilized lipase at 50 degrees C is 38% by adsorption and 65% by chemical bonding.     

有机相中蚕丝固定化脂肪酶催化酯化反应性能研究

研究了有机相中蚕丝固定化脂肪酶催化酶化反应的催化活性。考究了有机溶剂,底物、反应温度,ＰＨ值和体系含水量等因素对固定化脂肪酶催化活性的影响。结果表明,以异辛烷为有机溶剂,在反应温度为５０℃ＰＨ值为７．４时,酶催化活性最好。     

Wood cellulignin as an alternative matrix for enzyme immobilization

The objective of this work was to select an efficient methodology for preparing active samples of Candida rugosa lipase immobilized in wood cellulignin, to be applied in hydrolysis and ester reactions. For this purpose, lipase was immobilized in the matrix by physical adsorption (pure cellulignin) and covalent binding (activated cellulignin with glutaraldeyde or carbonyldiimidazole [CDI]) in the presence or absence of polyethylene glycol (PEG) (Molecular mass of 1500 Daltons) as stabilizing agent. The activating agent and the presence of PEG-1500 in the immobilization procedure showed a strong influence on enzyme retention in the support. The values for enzyme retention ranged from 20 to 68%, and the highest yield was obtained when the enzyme was immobilized in cellulignin activated with CDI in the presence of PEG-1500. This immobilized derivative presented high hydrolytic (193.27 μM/[mg·min]) and synthetic (522.92 μM/[g·min]) activities when compared with those obtained by other techniques. The superiority of this immobilized system was confirmed by additional analyses, such as infrared spectroscopy and elemental analysis, which demonstrated an appropriate enzyme fixation and the highest level of protein incorporation in the support. Further information on the immobilized derivative was obtained by assessing the recycle potential in both aqueous and nonaqueous media.     

Immobilization of lipases on hydrophobilized zirconia nanoparticles: highly enantioselective and reusable biocatalysts

Our study has demonstrated for the first time that zirconia nanoparticles modified by a simple carboxylic surfactant of a very long alkyl chain can significantly enhance the activity of the immobilized lipases for asymmetric synthesis in organic media. Zirconia nanoparticles of ca. 20 nm diameter were grafted with carboxylic surfactant modifiers from Tween 85 and erucic acid. The surface of nanoparticles was successfully changed from hydrophilic to hydrophobic. Lipases from Candida rugosa and Pseudomonas cepacia were immobilized on the modified zirconia nanoparticles by adsorption in aqueous solution. The immobilized lipases were used for the resolution of ( R, S)-ibuprofen and ( R, S)-1-phenylethanol through esterification and acylation, respectively, in isooctane organic solvent. When immobilized on erucic acid-modified zirconia, both lipases gave significantly higher activity and enantioselectivity compared with those from their corresponding crude lipase powders. The nanohybrid biocatalysts are stable and can be reused for eight cycles without loss in activity and selectivity. The interaction between the hydrophobic surface of zirconia support and lipases probably induces the conformational rearrangement of lipases into an active, stable form.