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Pcl/Chitosan Blended Nanofibrous Tubes Made by Dual Syringe Electrospinning

Hild M., Al Rez M. F., Aibibu D., Toskas G., Cheng T., Laourine E., Cherif C.

Autex Research Journal

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2015

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Vol. 15, no. 1

54--59

EN

3D tubular scaffolds made from Poly-(Ɛ-caprolactone) (PCL)/chitosan (CS) nanofibres are very promising candidate as vascular grafts in the field of tissue engineering. In this work, the fabrication of PCL/CS-blended nanofibrous tubes with small diameters by electrospinning from separate PCL and CS solutions is studied. The influence of different CS solutions (CS/polyethylene glycol (PEO)/glacial acetic acid (AcOH), CS/trifluoroacetic acid (TFA), CS/ AcOH) on fibre formation and producibility of nanofibrous tubes is investigated. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) is used to verify the presence of CS in the blended samples. Tensile testing and pore size measurements are done to underline the good prerequisites of the fabricated blended PCL/ CS nanofibrous tubes as potential scaffolds for vascular grafts. Tubes fabricated from the combination of PCL and CS dissolved in AcOH possesses properties, which are favourable for future cell culture studies.

2

Pure chitosan and chitsoan/chitosan lactate blended nanofibres made by single step electrospinning

Cheng T., Hund R D, Aibibu D., Horakova J., Cherif C.

Autex Research Journal

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2013

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Vol. 13, no. 4

128--133

EN

A single step electrospinning of chitosan and chitosan derivative-chitosan lactate nanofibres was studied in this paper. Chitosan was dissolved into acetic acid to produce structure-stable nanofibres. The effect of chitosan concentration and the content of acetic acid on the fibre diameter and morphology of nanofibres were studied in detail. The dynamic viscosity and surface tension of the electrospinning chitosan solutions were systematically studied as well. Based on the fundamental study on electrospinning chitosan in acetic acid, a chitosan derivative, chitosan lactate, was added to produce nanofibre in a pH-friendly aqueous environment. Chemical and morphological analyses demonstrated that chitosan lactate will positively influence the formation of nanofibres in higher pH condition although the morphology should be improved.

3

Modification of the Acid-base and Catalytic Properties of CuCl2-KCl-LaCl3/-Al2O3 by MgAl2O4 in Ethane Oxychlorination

Liu J., Sui Y., Zhou G., Zhen K., Zhang X., Cheng T.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 1

95-101

EN

Effect of MgAl2O4 on the structure, acidity as well as catalytic activity of CuCl2-KCl-LaCl3/gamma-Al2O3 catalyst in ethane oxychlorination was studied. Impregnation of gamma-Al2O3 with Mg and Al nitrates formed magnesium aluminate spinel on the support. TPR results showed that Cu species were located on both -Al2O3 and MgA gamma2O4 phases. With modification of -Al2O3 by MgAl2O4, the interaction between Cu species and support weakened and the surface active species CuCl2 increased. Formation of MgA gamma2O4 leads to a decrease of strong acid sites and an increase of weak acid sites. Much larger quantities of coke were deposited on the CuCl2-KCl-LaCl3/gamma-Al2O3 than on the modified catalyst, which was attributed to its more strong acid sites. Based on these factors CuCl2-KCl-LaCl3/MgAl2O4-Al2O3 catalyst exhibits better catalytic activity and stability than gamma-Al2O3 supported catalyst, and the highest vinyl chloride selectivity reached 46.8% and was still 40.6% after 210 h reaction.

4

Estimation of Consecutive and Parallel Reactions During Dehydrogenation with Carbon Dioxide over Co-MCM-41

Li Y., Guo X., Zhou G., He X., Bi Y., Li W., Cheng T., Wu T., Zhen K.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 8

1357-1364

EN

The main reactions between C2H6 and CO2 and their thermodynamics were studied, which indicated that there exist very complicated reactions between them. CO2 can enhance the equilibrium conversion of C2H4 formationvia dehydrogenation of C2H6 and react with the surface deposited carbon, resulting in stabilization of the activity and the prolongation of lifetime of the catalyst. Thus, the exploration of catalyst with desired C2H4 selectivity from oxidative dehydrogenation of ethane (ODE) is most important. In this study, the possible reactions of ODE with CO2 on Co-MCM-41 catalyst are discussed.