苯丙氨酸改性树枝状聚赖氨酸的合成及表征

以双芴甲氧羰基赖氨酸(Di- Fmoc -Lysine)为支化单元采用固相多肽合成技术制备了一种树枝状聚赖氨酸.该聚合物表面活性氨基通过与芴甲氧羰基苯丙氨酸(Fmoc- Phe)反应获得表面完全替代的苯丙氨酸改性树枝状聚赖氨酸.产物的分子量和结构经MS和NMR进行了表征.研究结果表明,利用该方法得到的产物分子量单一,是一种潜在的理想非病毒治疗载体.     

水相湿法改性纳米碳酸钙表面性质的研究

用特定的表面改性剂在水相中对纳米碳酸钙的悬浮液进行了湿法改性。红外光谱和热失重分析证明,改性剂与碳酸钙之间以化学键结合;沉降体积和接触角的测定结果说明改性粒子在液体石蜡中的润湿性和疏水性得到了提高;透射电子显微镜照片显示改性粒子在液体石蜡中有更好的分散性;体系粘度实验表明改性粒子与液体石蜡之间有较好的相容性。     

Donor-acceptor properties, catalytic activity, and negative charge exoemission from the alumina surface modified with lithium cations

Donor-acceptor properties of alumina modified with lithium cations were studied by ESR of paramagnetic complexes of adsorbed anthraquinone. The results were compared with the data on negative ion emission (exoemission) accompanying the decomposition of isopropyl alcohol in the adsorption layer. The data on the activity measured by the pulse microcatalytic technique in isopropyl alcohol decomposition are discussed. Small additives of lithium were found to promote catalytic activity of the samples. The role of acid and basic sites in isopropyl alcohol decomposition was discussed. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 616–621, April, 2006.     

Synthesis of polypiperazine-amide thin-film membrane on PPESK hollow fiber UF membrane

A new interfacial polymerization (IP) procedure is developed in order to synthesize polypiperazine-amide thin-film membrane on the inner surface of poly(phthalazinone ether sulfone ketone) (PPESK) hollow fiber ultrafiltration (UF) membrane.A hollow fiber composite membrane with good performance was prepared and studied by FT-IR and scanning electron microscopy.     

表面包覆改性对纳米CeO2分散性的影响

了改善纳米CeO2在Zn-Al类共晶合金中的分散性,采用超声液相包覆法对纳米CeO2进行表面活性剂表面包覆改性,并用AES测定了包覆层的厚度,用TEM研究了CeO2的团聚状况,用TGA分析了有机物包覆层的炭化温度范围,最后用FE-SEM观察了CeO2在复合材料中的分散情况。结果表明,包覆在纳米CeO2表面的厚度约为20 nm的表面活性剂层提高了微粒的分散性,而且该包覆层在495℃时已经炭化。热力学计算的结果也表明,炭化层能与氧化膜反应,该反应提高了CeO2与基体间的润湿性,并使其均匀分布在基体合金中。     

粘土矿物的结构特征及其应用研究

阐述了贮量巨大、用途广泛的粘土矿物，其充分开发应用的关键，在于根据其结构特征，并通过适当的物理、化学方法加以改造、以适应各种不同工业应用的要求。并以我们对粘土矿物进行活化、改性、层间插入及其工业应用产品开发的初步研究成果，阐明利用粘土硅酸盐多层次结构的可变性，开拓新的应用性能的可能性及粘土矿物充分开发应用的途径。     

Analysis of dielectric relaxations of w/o emulsions in the light of theories of interfacial polarization

An attempt is made to apply dielectric theories of interfacial polarization to observations of dielectric relaxations for W/O emulsions. Approximate formulas for disperse systems in a W/O type were derived from the two theories: one proposed by Maxwell and Wagner for dilute disperse systems of spherical particles, and the other developed by Hanai for concentrated disperse systems. Dielectric measurements were carried out on concentrated W/O emulsions prepared from kerosene and distilled water or KCl aqueous solutions by minimal use of emulsifiers. Marked dielectric relaxations were observed with the emulsions, the dielectric parameters having been determined to characterize the relaxation data. Phase parameters such as relative permittivity, electric conductivity and volume fraction of the disperse phase were evaluated from the dielectric parameters by use of the approximate formulas of the respective theories. The phase parameters evaluated and the frequency dependence of complex permittivity of the W/O emulsions deduced from the theory for concentrated disperse systems are in excellent agreement with the observed data in comparison to that for dilute disperse systems. It is concluded that the dielectric relaxations due to the interfacial polarization of disperse systems of spheres are explained satisfactorily by the theory for concentrated disperse systems.     

铜离子交换改性的沸石催化剂上甲烷的非氧芳构化

已有研究表明，ＭｏＯ３／ＨＺＳＭ５是甲烷非氧芳构化的优良催化剂，在９７３Ｋ下甲烷转化率达６％～８％，苯选择性高于８０％，这为非氧气氛下甲烷的芳构化反应展示了非常诱人的前景［１～１２］．但是，该催化剂的活性和稳定性尚有待进一步提高，目前已有使用Ｐｔ，...     

Surface modification of imide containing polymers I: Catalytic groups

This paper describes basic studies of the surface modification of polyimide covered wires for insulation of electrical machines. Drain-off of the impregnating resin during production should be reduced by introduction of surface catalytic groups. ¹H NMR kinetic analysis of aminolytic ring opening reaction of low molecular model compounds for polyimides showed very fast modification reactions. The catalytic effect of various functional groups on unsaturated polyester imide, acrylate and epoxy resins was investigated by DSC. Co(II)-catalysts and tertiary aliphatic amines proved highest activity for double bond containing systems and epoxy resins, respectively. Aminolytic treatment of Kapton^® slides was followed by ATR-IR spectroscopy. Plate-plate rheometer measurements of epoxy resins employing tertiary amine-treated Kapton^® slides proved significantly reduced gelling temperature.     

Complete Oxidation of Methane over Palladium Supported on Alumina Modified with Calcium,Lanthanum,and Cerium Ions

The activity and thermal stability of Pd/Al_2O_3 and Pd/(Al_2O_3 MO_x)(M=Ca,La,Ce) palladium catalysts in the reaction of complete oxidation of methane are presented in this study.The catalyst supports were prepared by sol-gel method and they were dried either conventionally or with supercritical carbon dioxide.Then they were impregnated with palladium nitrate solution.The catalysts with unmodified alumina had a high surface area.The activity and thermal stability of the alumina- supported catalyst was also very high.The introduction of calcium,lanthanum,or cerium oxide into alumina support caused a decrease of the surface area in the way dependent on the support precursor drying method.These modifiers decreased the activity of palladium catalysts,and they required higher temperatures for the complete oxidation of methane than unmodified Pd/Al_2O_3.The improvement of the palladium activity by lanthanum and cerium support modifier was observed only at low temperatures of the reaction.