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Cloud point phenomenon in aqueous mixtures of cationic-anionic surfactants

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Chinese Journal of chemistry 1994年第6期12卷 552-554页

作者： XIAO, Jin-Xin ZHAO, Guo-XiDepartment of chemistry, peking university, {2., china Department of chemistry Peking University Beijing 100871 China Keywords Cloud point cation‐anionic surfactants.

It used to be held that the cloud point phenomenon was only a characteris-tic of nonionic surfactants alone. Such phenomenon is rarely observed in ionicsurfactants. The present study shows that the mixture of cationic-anionic surfac-tants not only has a krafft point which is the characteristic of an ionic surfactant,but also exhibits the cloud point phenomenon obviously at certain concentrations.

关键词： Cloud point cation-anionic surfactants.

PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON POLY (OXYETHYLENE-co-OXYTETRAMETHYLENE) DIOL

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Chinese Journal of Polymer Science 2001年第4期19卷 371-376页

作者： Chen-yu Su Guang-li Zhang Hong-zhi Zhang Department of Polymer Science and engineering College of chemistry and Molecular engineering peking university beijing 100871, china peking Univ Dept Polymer Sci & Engn Coll Chem & Mol Engn Beijing 100871 Peoples R China

Polyurethane elastomers derived from 4,4 ' -methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of -3 degreesC, while that of polyurethane based upon poly(tetramethylene ether) glycol of the 'same molecular weight, i.e. being 2.00, and molecular weight distribution, i.e, in the range of 1.4-1.5, starts to decrease dramatically at 5 degreesC.

关键词： polyurethane poly(oxyethylene-co-oxytetramethylene) diol low temperature resilience heteropolyacid-ethylene oxide initiator system

Applications of functionalized ionic liquids

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Science china chemistry 2006年第5期49卷 385-401页

作者： LI Xuehui1, ZHAO Dongbin2.3, FEI Zhaofu2.& WANG Lefu1 1. Department of Chemical engineering, Guangdong Provincial Laboratory of green Chemical Technology, South {2. Uni-versity of Technology, Guangzhou 510641, {2. 2. Swiss Federal Institute of Technology, Lausanne, EPFL, CH-1015 Lausanne, Switzerland 3. PKU green chemistry center, beijing National Laboratory for Molecular Sciences, College of chemistry and Molecular engineering, peking university, beijing 100871, {2. 1. Department of Chemical engineering Guangdong Provincial Laboratory of Green Chemical Technology South China University of Technology Guangzhou 510641 China 2. Lausanne EPFL Swiss Federal Institute of Technology CH-1015 Lausanne Switzerland 3. PKU green chemistry center Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

Recent developments of the synthesis and applications of functionalized ionic liquids (including dual-functionalized ionic liquids) have been highlighted in this review. Ionic liquids are at-tracting attention as alternative solvents in green chemistry, but as more functionalized ILs are pre-pared, a greater number of applications in increasingly diverse fields are found.

关键词： ionic liquids functionalized ionic liquids dual-functionallzed ionicliquids reaction media asymmetric synthesis nano-materials porous materials lubricants flue-gas desulfurization oil desul-furization

Synthesis,Structure and Antitumor Activities of Tridccapeptide PSPP3 from Papaver Somniferum Pollen

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Chinese Chemical Letters 1999年第2期10卷 115-116页

作者： Jia Xi XU Sheng JIN(College of chemistry and Molecular engineering, {2., beijing 100871) Coll. of Chem. and Molec. Eng. Peking University Beijing 100871 China

Five analogs and five segments of the Papavor Somniferum pollen tridecapeptidePSPP3 were designed and synthesized by using solid-phase peptide synthesis method. Theirinhibitive activities to human liver tumor cell Bel-7402.were assayed by MTT method and theirsecondary structures in solution were determined by CD spectra. The relationship of the structureand activity was discussed.

关键词： Pollen peptide anti-tumor activity structure and activity

Systematic study of the transfer of amino acids across the water/1,2.dichloroethane interface facilitated by dibenzo-18-crown-6

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Science china chemistry 2004年第1期47卷 24-33页

作者： CHEN Yong, YUAN Yi, ZHANG Meiqin, LI Fei, SUN Peng, GAO Zhao & SHAO YuanhuaState Key Laboratory of Electroanalytical chemistry, Changchun Institute of Applied chemistry, Chinese Academy of Sciences, Changchun 13002., {2. College of chemistry and Molecular engineering, peking university, beijing 100871, {2. Lab. of Electroanalytical Chem. Changchun Inst. of Appl. Chem. Chinese Acad. of Sci. Changchun 130022 China Coll. of Chem. and Molecular Eng. Peking Univ. Beijing 100871 China

Facilitated ion transfer reactions of 2. amino acids with dibenzo-18-crown-6 (DB18C6) at the water/1,2.dichloroethane (W/DCE) interfaces supported at the tips of micro- and nano-pipets were investigated systematically using cyclic voltammetry. It was found that there were only 10 amino acids, that is, Leu, Val, lie, Phe, Trp, Met, Ala, Gly, Cys, Gin (in brief), whose protonated forms as cations can give well-defined facilitated ion transfer voltammograms within the potential window, and the reaction pathway was proven to be consistent with the transfer by interfacial complexation/dissociation (TIC/TID) mechanisms. The association constants of DB 18C6 with different amino acids in the DCE (β0), and the kinetic parameters of reaction were evaluated based on the steady-state voltammetry of micro- or nano-pipets, respectively. The experimental results demonstrated that the selectivity of complexation of protonated amino acid by DB18C6 compared with that of alkali metal cations was low, which can be attributed to the vicinal effect arising from steric hindrance introduced by their side group and the steric bulk effect by lipophilic stabilization. Moreover, the association constants and the standard rate constants for different amino acids showed good correlations with their hydrophobicity (π), except Gly and Met, which inferred that the selectivity of such heterogeneous complex reaction for different amino acids with DB18C6, was not only affected by discrimination in binding these ions to the crown ether macro-cycle, but also significantly modified by the ion transfer Gibbs energy which was closely related to the structure of the transferred ions, protonated amino acids.

关键词： micro-/nano-pipet, water/1,2.dichloroethane interface, facilitated ion transfer, cyclic voltammetry, amino acid.

Antiviral compounds and one new iridoid glycoside from Cornus officinalis

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Progress in Natural Science:Materials International 2006年第2期16卷 142-146页

作者： WANG Yue, LI Zhengquan, CHEN Lirong and XU Xiaojie (College of chemistry and Molecular engineering, {2., beijing 100871, china) [a]College of chemistry and Molecular engineering Piking University Beijing China

From Cornus officinalis Sieb. et Zucc., bioassay-guided fractionation led to the isolation of four active tannin compounds with high effectiveness of inhibiting Hepatitis C virus NS3 serine protease in vitro. The compounds are: 1,2.3, 6-tetragalloyl-β-D-glucopyranose (1), 1,2.3,4,6- pentagalloyl-β-D-glucopyranose (2., Tellimagrandin I (3) and Tellimagrandin II(4). The four compounds could inhibit HCV NS3 protease in vitro with IC50 values of 6.98, 5.11, 7.0 and 4.8μmol/L respectively. In addition, a new iridoid glycoside (5) was also isolated from Cornus officinalis Sieb. et Zucc., which was assigned to be 7-O-butyl morroniside by spec-troscopic analysis.

关键词： inhibitor HCV NS3 protease iridoid glycoside Cornus officinalis Sieb. et Zucc.

SYNTHESIS AND BIOTECHNOLOGICAL APPLICATIONS OF VINYL POLYMERINORGANIC HYBRID AND MESOPOROUS MATERIALS

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Chinese Journal of Polymer Science 2000年第1期18卷 1-7页

作者： Yen Wei Kun-yuan Qiu Department of chemistry, Drexel university, Philadelphia, Pennsylvania 19104, USA Department of Polymer Science and {2., peking university, beijing 100871, china Drexel Univ Dept Chem Philadelphia PA 19104 USA peking Univ Dept Polymer Sci & Engn Beijing 100871 Peoples R China

We describe the sol-gel synthesis of a new family of organic-inorganic hybrid materials, in which various vinyl polymers are covalently bonded to and uniformly distributed in inorganic oxide matrices. The materials can be tailored to have both good toughness and hardness while maintaining excellent optical transparency. Doping the sol-gel metal oxides with optically active compounds such as D-glucose results in new optical rotatory composite materials. Removal of the dopant compounds from the composites affords mesoporous oxide materials; which represents a new, nonsurfactant-templated route to mesoporous molecular sieves. We have successfully immobilized a series of enzymes and other bioactive agents in mesoporous materials. Catalytical activities of the enzyme encapsulated in mesoporous materials were found to be much higher than those encapsulated in microporous materials.

关键词： vinyl polymer-inorganic hybrid materials mesoporous materials sol-gel process biotech-nological applications

A　CONVENIENT　METHOD　FOR　SYNTHESIZING　AND　CHARACTERIZATION　OF　（Z）－ALKENOLS　AND　THEIR　ACETATES

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Chinese Chemical Letters 1995年第11期6卷 943-944页

作者： Gu YUAN(Department of chemistry,peking university, {2.) beijing Univ Dept Chem Beijing 100871 Peoples R China

All double bond positional isomers of (Z)-dodecenol, (Z)-tetradecenol, (Z)hexadecenol and their acetates were synthesized by the Wittig reaction and the coupling reaction, and a novel procedure for the identification ...

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A NOVEL PHOTO-INITIATING SYSTEM FOR ATOM TRANSFER RADICAL POLYMERIZATION OF STYRENE

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Chinese Journal of Polymer Science 2001年第5期19卷 441-445页

作者： Shu-hui Qin Dong-qi Qin Kun-yuan Qiu Department of Polymer Science and engineering College of chemistry and Molecular engineering peking university beijing 100871, china beijing Univ Dept Polymer Sci & Engn Coll Chem & Mol Engn Beijing 100871 Peoples R China

A novel photo-induced initiating system, 2.2.dimethoxy-2.phenylacetophenone (DMPA)/ferric tri(NN-diethyldithiocarbamate) [Fe(DC)(3)], was developed and used for the atom transfer radical polymerization (ATRP) of styrene in toluene. The polymerization proceeds with DMPA as photo-initiator, Fe(DC)(3) as catalyst and DC as a reversible transfer group, while the halogen and ligands are free. Well-defined PSt was prepared and the polymerization mechanism revealed by end group analysis belongs to a reverse ATRP. Block copolymer was prepared by using thus obtained PSt as macroinitiator and Fe(DC)(2. as catalyst under UV light irradiation via a conventional ATRP process.

关键词： photo atom transfer radical polymerization living radical polymerization well-defined polystyrene block copolymer