Article Title: Preparation of D-tartaric Acid Modified Multi-walled Carbon Nanotubes for Resolution of Propranolol Enantiomers
Author(s): Dong-Ming Peng, Lin-Yan Yu, Jin-Gang Yu, Fei-Peng Jiao, Zhi-Guang Peng and Ting Zhang
Abstract:In this paper, multi-walled carbon nanotubes (MWCNTs) were oxidized by 30 w% hydrogen peroxide to introduce hydroxyl groups and carboxyl groups on it. Catalyzed by p-toluenesulfonic acid, D-tartaric acid (DTA) was grafted onto MWCNTs by an esterification reaction. Fourier transform infrared spectroscopy and high resolution transmission electron microscopy were used to elucidate the introduced groups and the morphologies changes of the MWCNTs samples. The D-tartaric acid modified MWCNTs were used as chiral im pregnating reagents for thin-layer chromatography for enantioseparation of propranolol enantiomers, and the chiral separation factor was achieved over 7.23 by a mixed solvent of acetonitrile-tert-butanol-acetic acid (volume ratio is 49:49:2) as developing solvent.
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Article Title: Investigation on Interfacial Characteristics of W/Al Nanostructure
Author(s): Ping Yang, Dongjing Liu, Yunqing Tang, Jie Gong, Yu Liu and Haiying Yang
Abstract:The objective of this paper is to provide a systematic investigation on design or evaluation for W/Al interface structure in micro/ nano electronic manufacturing. To understand the basic mechanical properties of the W/Al interface structure, the elastic modulus and the hardness of the sample were investigated by nanoindentation. To investigate the integrating characteristics of the sample in progress, the effect of thermal loading and no-thermal loading on the integrating force of the W/Al interface is tested by nanoscratch. The interfacial bonding force between the films can be obtained for understanding the integrating characteristics. The results show that the interfacial bonding force can be improved by thermal loading, which means the mechanical properties of W/Al interface can be modulated and modified by using thermal loading. It is significant for design and industrial manufacturing process of W/Al interface structure.
Abstract: By using oxidized multi-walled carbon nanotubes and β-cyclodextrin derivatives (methyl-β-cyclodextrin or hydroxypropyl-β- cyclodextrin) as impregnating reagents, high efficiently resolution of (±)-propranolol, a kind of commonly used β-blockers, has been achieved on abovementioned reagents impregnated silica gel GF254 layers. The solvent system tert-butanol-acetonitrile with various volume ratios was further investigated. By detecting the spots at 254 nm with a UV lamp, the obtained chiral separation factors indicated oxidized multi-walled carbon nanotubes and β-cyclodextrin derivatives impregnated TLC plates could be used for effectively chiral recognition of racemic compounds.
For more details, visit: http://benthamscience.com/journal/abstracts.php?journalID=cnano&articleID=109011
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