Dong Z.R.,Xiamen University |
Li Y.Y.,Xiamen University |
Yu S.L.,Xiamen University |
Sun G.S.,Guangxi Research Institute of Chemical Industry |
Gao J.X.,Xiamen University
Chinese Chemical Letters | Year: 2012
The new polydentate mixed-N, P, O chiral ligands have been synthesized by the condensation of bis(o-formylphenyl)-phenylphosphane and R-phenylglycinol in CHCl 3, and fully characterized by IR, NMR and EIMS spectra. These ligands were employed with a simple Ni complex Ni(PPh s) 2Cl 2 in situ as catalytic systems for asymmetric transfer hydrogenation of ketones, and the corresponding optical alcohols were obtained with up to 84% ee under mild conditions. © 2012 Zhen Rong Dong.
Liang L.,Guangxi University |
Zhao W.,Guangxi Research Institute of Chemical Industry |
Meng F.,Guangxi University |
Liu L.,Guangxi University |
Lin C.,Guangxi University
Spectroscopy Letters | Year: 2013
In this work, three new amide compounds of ferulic acid (FA) were synthesized. The fluorescence and ultraviolet spectroscopy were explored to study the interactions between three amide compounds of FA and bovine serum albumin (BSA) under imitated physiological conditions. The experimental results showed that the fluorescence quenching mechanism between BSA and three amide compounds of FA were mainly static quenching and nonradiation energy transfer at 25°C, 30°C, and 37°C. The Stern-Volmer quenching constants, the binding constants, and the number of binding sites and corresponding thermodynamic parameters ΔH, ΔG, and ΔS were calculated at different temperatures. From the thermodynamic parameters, we concluded that the action force was mainly a hydrophobic interaction. According to the Forster theory of nonradiation energy transfer, the binding distances (r) between BSA and amide compounds are less than 7 nm. Furthermore, the effects of amide compounds on the conformation of BSA were analyzed using synchronous fluorescence spectroscopy. © 2013 Copyright Taylor and Francis Group, LLC.
Liang X.,Guangxi University |
Liang X.,Qinzhou University |
Huang Z.,Guangxi University |
Zhang Y.,Guangxi University |
And 3 more authors.
Polymer Bulletin | Year: 2013
The aim of this study was to develop a sugarcane bagasse (SCB)-based biodegradable superabsorbent hydrogels (SAH) with a good swelling. To this end, SCB was firstly mechanically activated by home-made high efficiency stirring mill to enhance its reactivity by breaking the lignin seal and decreasing crystallinity of cellulose in SCB. Then, the SAH were synthesized by graft copolymerization of acrylic acid (AA) onto SCB with different mechanical activation times (tM) by using ammonium persulfate/sodium sulfite redox pair as an initiator in the presence of a crosslinker (N,N0-methylenebisacrylamide, MBAAm). The effect of tM on the equilibrium swelling capacity (Qeq), swelling kinetics of the SAH in deionized water, as well as the influences of pH, electrolytic media, and temperature on Qeq were studied. In addition, the products were characterized by scanning electron microscopy and differential scanning calorimetry. The results showed that mechanical activation promoted the graft copolymerization and thereby altered the Qeq of the SAH. The swelling process of the SAH exhibited anomalous swelling behavior and first-order dynamics, and the Qeq of the SAH was pH, salt, and temperature dependent. © Springer-Verlag Berlin Heidelberg 2013.
Li X.-H.,Guangxi University |
Zhang Y.-J.,Guangxi Research Institute of Chemical Industry |
Pan L.-P.,Guangxi University |
Wei Y.-S.,Hechi College
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2013
Neutral leach residue of zinc calcine (NLRZC) was mechanically activated by a stirring ball mill. Subsequently, the changes in physicochemical properties and dissolution kinetics in sulphuric acid were studied. The crystalline structure, morphology, particle size and specific surface area of the non-activated and mechanically activated NLRZC were characterized by X-ray diffraction, scanning electron microscope, particle size analyzer and volumetric adsorption analyzer, respectively. The characterization results indicate that mechanical activation (MA) induced remarkable changes in the physicochemical properties of NLRZC. The leaching experiments show that MA significantly enhances the leaching reactivity of NLRZC using the zinc extraction as evaluating index. After NLRZC is mechanically activated for 30 min and 60 min, the activation energy decreases from 56.6 kJ/mol of non-activated NLRZC to 36.1 kJ/mol and 29.9 kJ/mol, respectively. The reaction orders of the non-activated, 30 and 60 min activated NLRZC dissolution with respect to H2SO 4 concentration were found to be 0.34, 0.30, and 0.29, respectively. © 2013 The Nonferrous Metals Society of China.
Huang Z.,Guangxi University |
Wang N.,Guangxi University |
Zhang Y.,Guangxi University |
Zhang Y.,Guangxi Research Institute of Chemical Industry |
And 2 more authors.
Composites Part A: Applied Science and Manufacturing | Year: 2012
This current work is concerned with the pretreatment of sugarcane bagasse (SCB) by mechanical activation (MA) using a self-designed stirring ball mill and surface modification of SCB using aluminate coupling agent (ACA). The untreated and differently treated SCBs were used to produce composites with poly(vinyl chloride) (PVC) as polymer matrix. The activation grade (Ag) measurement and Fourier transform infrared (FTIR) analysis of SCB showed that MA enhanced the condensation reaction between ACA and hydroxyl groups of the SCB fibres, which obviously increased the hydrophobicity of SCB. It was found that the mechanical properties of both the PVC composites reinforced by SCB with and without ACA modification increased with increasing milling time (tM). Scanning electron microscopy (SEM) analysis showed that MA pretreatment significantly improved the dispersion of SCB in the composites and interfacial adhesion between SCB and PVC matrix, resulting in better mechanical properties of the composites. © 2011 Elsevier Ltd. All rights reserved.