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Silylated and acetylated β-cyclodextrins for gas chromatographic stationary phases

Journal of Central South University of Technology 2001年第4期8卷 239-243页

作者： TANG Ke wen 1,2 ,YI Jian ming 2,ZHOU Chun shan 1,ZHONG Shi an 1 (1. College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China 2. College of Chemistry and Chemical Engineering, Yueyang Normal University College of Chemistry and Chemical Engineering Central South University Changsha China College of Chemistry and Chemical Engineering Yueyang Normal University Yueyang China

Two new chiral stationary phases, 2,3 di O acetyl 6 O trimethylsilyl β cyclodextrin (DATBCD) and 2,6 di O trimethylsilyl 3 O acetyl β cyclodextrin(DTABCD), were synthesized, their structures were identified by means of infrared and NMR spectra. Capillary columns were coated with the two stationary phases by dynamic method. The chromatographic properties, and enantiomers separation, such as ketone, esters, alcohols and olefines, were investigated on the silylated and acetylated β cyclodextrin stationary phases. The experimental results show that the silylated and acetylated β cyclodextrins are suitable to be used as capillary gas chromatographic stationary phases, the relative polarity of DATBCD and DTABCD stationary phases is respectively 4143 and 3928, the column efficiencies are respectively 3084 and 4198, and DATBCD is of stronger enantioselectivity than DTABCD, capacity factor of the first eluted enantiomer ( k 1) and separation factor(α)of α phenylethanol on DATBCD stationary phase are respectively 8.23 and 1.019.

关键词： capillary gas chromatography silylated and acetylated β-cyclodextrins enantiomeric separation

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Molecular recognition study on a supramolecular system (ⅩⅤ)──Molecular recognition of aliphatic alcohols by some phenyl-selenium modified β-cyclodextrins

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Chinese Science Bulletin 1998年第12期43卷 1011-1015页

作者： LIU Yu, LI Bin, LI Ziyun and CHEN Rongti Department of Chemistry, Nankai University, Tianjin 300071, China

The spectrophotometric titrations have been performed at 298.15 K in buffered aqueous solution （pH 7.20） to give the stability constants （logK-s） for the supramolecular system formed by mono-[6-（phenylseleno）-6-deoxy]-β-cyclodextrin （2）, mono-[6-（p-tolylseleno）-6-deoxy]-β-cyclodextrin （3）, mono-[6-（o-tolylseleno）-6-deoxy]-β-cyclodextrin （4）, mono-[6-（m-tolylseleno）-6-deoxy]-β-cyclodextrin （5） with a series of aliphatic alcohols. The results were compared with the data reported for the parent β-cyclodextrin. The molecular binding ability and selectivity for aliphatic alcohols of modified β-cyclodextrins （25） were discussed from the viewpoints of the induced-fit and geometrical complement. The results obtained indicate that the phenylseleno moiety of β-cyclodextrin derivatives （25） as a probe for spectrometry can enhance not only the molecular binding ability but also the molecular recognition ability.

关键词： molecular recognition modified β-cyclodextrins aliphatic alcohol supramolecule.

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Thermally and mechanically stableβ-cyclodextrin/cellulose acetate nanofibers synthesized using an environmentally benign procedure

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International Journal of Smart and Nano Materials 2017年第1期8卷 1-19页

作者： Lebea N.Nthunya Monaheng L.Masheane Soraya P.Malinga Edward N.Nxumalo Bhekie B.Mamba Sabelo D.Mhlanga Nanotechnology and Water Sustainability Research Unit College of ScienceEngineering and TechnologyUniversity of South AfricaJohannesburgSouth Africa Department of Applied Chemistry and the DST/Mintek Nanotechnology Innovation Centre-Water Research Node University of JohannesburgJohannesburgSouth Africa

Electrospun cyclodextrin(CD)-based nanofibers with capabilities to remove pollutants from water have been synthesized and *** high-quality nanofibers presented here were synthesized in two simple steps that involved in-situ electrospinning of the nanofibers and all nanocomponents,followed by the reduction of silver(Ag+)and iron(Fe3+)ions to nanoparticles using an environmentally benign process that involved irradiation of the electrospun fibers using a tailor-made UV-equipped furnace at low *** the previously reported study it was observed that Ag and Fe nanoparticles effectively removed a range of different strains of Gram-negative and Gram-positive bacteria from *** such,this study focused on improving the thermal and mechanical properties of the nanofibers prepared from polymer blends ofβ-CDs with cellulose acetate(CA)and small additions(2 wt%)of functionalized multiwalled carbon nanotubes(fMWCNTs).The electrospinning parameters were varied to determine the optimum conditions for preparation of uniform nonbeaded ***-free and uniform nanofibers were obtained at a polymer concentration of 32%at the ratio of 1:1β-CDs:CA,syringe injection flow rate of 0.7 mL h−1,15 cm between the tip of the spinneret and the collector,and a voltage of 16 *** addition of f-MWCNTs was found to improve the tensile strength of the nanofibers by twofold,relative to nanofibers with no *** thermal degradation of the nanofibers was improved by a magnitude of 50°*** study has shown that adding small amounts of f-MWCNTs improved the thermal stability and mechanical strength of the CD/CA nanofibers significantly.

关键词： β-cyclodextrins cellulose acetate mechanical strength nanofibers thermal stability

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