We have studied the adsorption of thymol derivatives on AlP-nanotube surface by using density functional calculations in gas phase. Also the antioxidant activity of thymol was investigated in gas phase and ethanol. Th...We have studied the adsorption of thymol derivatives on AlP-nanotube surface by using density functional calculations in gas phase. Also the antioxidant activity of thymol was investigated in gas phase and ethanol. The effects of NMe2, OEthyl and Me substituents on the antioxidant activity and adsorption ability of thymol on AlP-nanotube were investigated. Results show that AlP-nanotube can effectively interact with substituted thymols, so their adsorptions are exothermic and experimentally possible from the energetic viewpoint. Results also show that, replacing NMe2 group in the x position of thymol may be a good strategy to improve the sensitivity of thymol toward AlP-nanotube surface. The NMe2 and OEthyl substitutions decrease the BDE and IP values and increase the antioxidant activity of thymol. The BDE and IP values of thymols have linear dependencies with corresponding Ead values. These can be utilized to select novel thymol derivatives with higher antioxidant activity and drug delivery ability.展开更多
Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy（XRD） and transmissi...Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy（XRD） and transmission electron microscopy（TEM）. The electrooxidation behaviors of ethanol on the Pd/C electrode in alkaline media were investigated using cyclic voltammetry（CV）, chronoamperometry（CA）, electrochemical impedance spectroscopy（EIS） and single cell performance methods. Pd/C electrode for ethanol oxidation showed high electro-catalytic activity and long term stability. However, it is observed that the current density decreases with the increasing of the potential and negative impedance presents in the potential from-0.1 to0.1 V. The decreasing current density and the negative impedance could be due to the adsorbed intermediates species that inhibited the further oxidation of ethanol. Based on the chemical reaction analysis and EIS spectra, equivalent circuits relating to various potential zones have been obtained. These results reveal the dynamic adsorption of intermediates species on Pd surfaces. Significantly, it is clarified that the adsorption behavior begins from the maximum catalysis of electro-catalysis and ends in the formation of the palladium（II） oxide layer on the electrode surface.展开更多
A new method for evaluating the compactness of rust layers on steels has been proposed in the present study. The method includes adsorption and dehydration process of anhydrous ethanol. The protective ability of rust ...A new method for evaluating the compactness of rust layers on steels has been proposed in the present study. The method includes adsorption and dehydration process of anhydrous ethanol. The protective ability of rust layers can be qualitatively reflected by the adsorption/dehydration rates. The specific surface area and porosity of rust layers can be calculated by a quantitative model. The results from the present method are consistent with electrochemical tests, N2 adsorption and X-ray diffraction analysis. The method characterizes the compactness of rust layers rather than that of corrosion products removed from the metal surfaces, which is generally practiced in classic N2 adsorption method. Furthermore, the method can reflect the compactness of inner rust layers, to which N2 adsorption is unavailable. The method provides a new approach for the study of rust layers.展开更多
Organic matters（OMs） and their oxidization products often influence the fate and transport of heavy metals in the subsurface aqueous systems through interaction with the mineral surfaces. This study investigates the...Organic matters（OMs） and their oxidization products often influence the fate and transport of heavy metals in the subsurface aqueous systems through interaction with the mineral surfaces. This study investigates the ethanol（EtO H）-mediated As（Ⅲ） adsorption onto Zn-loaded pinecone（PC） biochar through batch experiments conducted under Box–Behnken design. The effect of EtO H on As（Ⅲ） adsorption mechanism was quantitatively elucidated by fitting the experimental data using artificial neural network and quadratic modeling approaches. The quadratic model could describe the limiting nature of EtO H and pH on As（Ⅲ） adsorption,whereas neural network revealed the stronger influence of Et OH（64.5%） followed by pH（20.75%）and As（Ⅲ） concentration（14.75%） on the adsorption phenomena. Besides, the interaction among process variables indicated that Et OH enhances As（Ⅲ） adsorption over a pH range of2 to 7, possibly due to facilitation of ligand–metal（Zn） binding complexation mechanism.Eventually, hybrid response surface model–genetic algorithm（RSM–GA） approach predicted a better optimal solution than RSM, i.e., the adsorptive removal of As（Ⅲ）（10.47 μg/g） is facilitated at 30.22 mg C/L of Et OH with initial As（Ⅲ） concentration of 196.77 μg/L at pH 5.8. The implication of this investigation might help in understanding the application of biochar for removal of various As（Ⅲ） species in the presence of OM.展开更多
文摘We have studied the adsorption of thymol derivatives on AlP-nanotube surface by using density functional calculations in gas phase. Also the antioxidant activity of thymol was investigated in gas phase and ethanol. The effects of NMe2, OEthyl and Me substituents on the antioxidant activity and adsorption ability of thymol on AlP-nanotube were investigated. Results show that AlP-nanotube can effectively interact with substituted thymols, so their adsorptions are exothermic and experimentally possible from the energetic viewpoint. Results also show that, replacing NMe2 group in the x position of thymol may be a good strategy to improve the sensitivity of thymol toward AlP-nanotube surface. The NMe2 and OEthyl substitutions decrease the BDE and IP values and increase the antioxidant activity of thymol. The BDE and IP values of thymols have linear dependencies with corresponding Ead values. These can be utilized to select novel thymol derivatives with higher antioxidant activity and drug delivery ability.
文摘Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy（XRD） and transmission electron microscopy（TEM）. The electrooxidation behaviors of ethanol on the Pd/C electrode in alkaline media were investigated using cyclic voltammetry（CV）, chronoamperometry（CA）, electrochemical impedance spectroscopy（EIS） and single cell performance methods. Pd/C electrode for ethanol oxidation showed high electro-catalytic activity and long term stability. However, it is observed that the current density decreases with the increasing of the potential and negative impedance presents in the potential from-0.1 to0.1 V. The decreasing current density and the negative impedance could be due to the adsorbed intermediates species that inhibited the further oxidation of ethanol. Based on the chemical reaction analysis and EIS spectra, equivalent circuits relating to various potential zones have been obtained. These results reveal the dynamic adsorption of intermediates species on Pd surfaces. Significantly, it is clarified that the adsorption behavior begins from the maximum catalysis of electro-catalysis and ends in the formation of the palladium（II） oxide layer on the electrode surface.
基金the National Natural Science Foundation of China(No.51571026)。
文摘A new method for evaluating the compactness of rust layers on steels has been proposed in the present study. The method includes adsorption and dehydration process of anhydrous ethanol. The protective ability of rust layers can be qualitatively reflected by the adsorption/dehydration rates. The specific surface area and porosity of rust layers can be calculated by a quantitative model. The results from the present method are consistent with electrochemical tests, N2 adsorption and X-ray diffraction analysis. The method characterizes the compactness of rust layers rather than that of corrosion products removed from the metal surfaces, which is generally practiced in classic N2 adsorption method. Furthermore, the method can reflect the compactness of inner rust layers, to which N2 adsorption is unavailable. The method provides a new approach for the study of rust layers.
基金supported by the research funds from the University of Ulsan in South Korea during the financial year 2012–2013
文摘Organic matters（OMs） and their oxidization products often influence the fate and transport of heavy metals in the subsurface aqueous systems through interaction with the mineral surfaces. This study investigates the ethanol（EtO H）-mediated As（Ⅲ） adsorption onto Zn-loaded pinecone（PC） biochar through batch experiments conducted under Box–Behnken design. The effect of EtO H on As（Ⅲ） adsorption mechanism was quantitatively elucidated by fitting the experimental data using artificial neural network and quadratic modeling approaches. The quadratic model could describe the limiting nature of EtO H and pH on As（Ⅲ） adsorption,whereas neural network revealed the stronger influence of Et OH（64.5%） followed by pH（20.75%）and As（Ⅲ） concentration（14.75%） on the adsorption phenomena. Besides, the interaction among process variables indicated that Et OH enhances As（Ⅲ） adsorption over a pH range of2 to 7, possibly due to facilitation of ligand–metal（Zn） binding complexation mechanism.Eventually, hybrid response surface model–genetic algorithm（RSM–GA） approach predicted a better optimal solution than RSM, i.e., the adsorptive removal of As（Ⅲ）（10.47 μg/g） is facilitated at 30.22 mg C/L of Et OH with initial As（Ⅲ） concentration of 196.77 μg/L at pH 5.8. The implication of this investigation might help in understanding the application of biochar for removal of various As（Ⅲ） species in the presence of OM.
