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ABSTRACT: Two hypercrosslinked polymeric adsorbents (ZH-01 and Amberlite XAD-4 resin) were employed to remove three kinds of phenolic
compounds including phenol, 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions. The study was focused on the static
equilibrium adsorption behavior, the column dynamic adsorption and desorption profiles. The Freundlich model gave a perfect
fitting to the isotherm data. The adsorbing capacities for these three compounds on ZH-01 were higher than those on Amberlite
XAD-4 within the temperature range 288–318 K, which was attributed to the large micropore area and 2-carboxybenzoyl functional
groups on the network of ZH-01 resin. The adsorption for phenol and 4-nitrophenol on ZH-01 was a physical adsorption process,
while for 2,4-dinitrophenol it was a coexistence process of physical adsorption and chemisorption’s transitions. The column
test showed the advantages of ZH-01 in the dynamic adsorption processes of phenolic compounds. Being used as the desorption
reagent, sodium hydroxide solution showed an excellent performance.
Chinese Journal of Polymer Science 04/2012; 28(2):241-248. · 0.92 Impact Factor
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ABSTRACT: The features of brucine (BC) binding to two blood proteins, bovine hemoglobin (BHb), and bovine serum albumin (BSA), were investigated via fluorescence, circular dichroism and UV/Vis absorption spectroscopy. The results revealed that BC caused the fluorescence quenching of blood proteins by the formation of BC-protein complex. The corresponding thermodynamic parameters were measured at different temperatures. The process of binding BC molecule on protein was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic and electrostatic interactions play a major role in stabilizing the complex. The molecular docking has been employed to explore the binding site of the BC in BHb and BSA on the Autodock 4.2. The distances r between BC and protein were calculated to be 4.93 and 5.08 nm for BHb, and BSA, respectively. The effect of BC on the conformation of blood proteins was analyzed using CD, synchronous fluorescence and three-dimensional fluorescence spectra.
Molecular Biology Reports 12/2011; 39(4):4937-47. · 2.93 Impact Factor
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ABSTRACT: The interaction between paraquat (PQ) and bovine hemoglobin (BHb) was investigated using fluorescence and UV/vis absorption spectroscopy. The reactivity of the heme centers with superoxide anions formed by PQ was judged on the basis of the decrease of the Soret band. The experimental results showed that the fluorescence quenching of BHb by PQ was a result of the formation of PQ-BHb complex; static quenching was confirmed to result in the fluorescence quenching. The binding site number n, apparent binding constant K(A) and corresponding thermodynamic parameters were measured at different temperatures. The process of binding PQ molecule on BHb was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic and electrostatic interactions played a major role in stabilizing the complex. The effect of PQ on the conformation of BHb was analyzed using synchronous fluorescence spectroscopy.
International Journal of Biological Macromolecules 08/2007; 41(3):243-50. · 2.45 Impact Factor
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ABSTRACT: The interaction between silicotungstic acid and bovine serum albumin (BSA) was investigated using fluorescence and UV/vis. The experimental results showed that the fluorescence quenching of BSA by silicotungstic acid is a result of the formation of SiW-BSA complex; static quenching and non-radiative energy transferring were confirmed to result in the fluorescence quenching. The binding site number n, apparent binding constant K(A) and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BSA was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Hydrophobic interaction force plays a major role in stabilizing the complex. The effect of silicotungstic acid on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.
Journal of Pharmaceutical and Biomedical Analysis 05/2007; 43(5):1869-75. · 2.97 Impact Factor
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ABSTRACT: The adsorption behavior of p-aminobenzoic acid and o-aminobenzoic acid onto the different polymeric adsorbents was systematically investigated as a function of the solution concentration and temperature. Experimental results indicated that the equilibrium adsorption data of the four polymeric adsorbents fitted well in the Freundlich isotherm. The adsorption capacity of multi-functional polymeric adsorbent NJ-99 was the highest, which might be attributed to the strong hydrogen-bonding interaction between the amino groups on the resin and the carboxyl group of aminobenzoic acid. The adsorption capacity of o-aminobenzoic acid onto any adsorbent was higher than p-aminobenzoic acid. Thermodynamic studies suggested the exothermic, spontaneous physical adsorption process. Adsorption kinetics results showed that the adsorption followed the pseudo-second-order kinetics model and the intraparticle mass transfer process was the rate-controlling step.
Journal of Environmental Sciences 02/2007; 19(11):1298-304. · 1.66 Impact Factor
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Adsorption Science & Technology - ADSORPT SCI TECHNOL. 01/2003; 21(10):921-933.
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ABSTRACT: Adsorption equilibrium isotherms of phenolic compounds, phenol, p-cresol, p-chlorophenol and p-nitrophenol, from aqueous solutions by Amberlite XAD-4 polymeric adsorbent and its acetylized derivative MX-4 within temperature range of 283-323K were obtained and fitted to the Freundlich isotherms. The capacities of equilibrium adsorption for all four phenolic compounds from their aqueous solutions increased around 20% on the acetylized resin, which may be contributed to the specific surface area and the partial polarity on the network. Estimations of the isosteric enthalpy, free energy, and entropy for the adsorption process were reported.
Journal of Environmental Sciences 11/2002; 14(4):457-63. · 1.66 Impact Factor
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ABSTRACT: The interaction of benzidinne (BZ) with bovine hemoglobin (BHb) under physilolgical condition was studied by fluorescence spectrum. Fluorescence data revealed that the fluorescence quenching of BHb by BZ was the result of the formed complex of BZ–BHb, The quenching and energy transfer mechanisms were discussed, respectively. The binding constants and thermodynamic parameters at three different temperatures, the binding locality, and the binding power were obtained. The hydrophobic and hydrogen bonds interactions were the predominant intermolecular forces to stabilize the complex. The conformation of BHb was discussed by synchronous and three-dimensional fluorescence techniques.
Journal of Molecular Structure.
