Insights into SO_2 and H_2O co-adsorption on Cu(100) surface with calculations of density functional theory

The co-adsorption behaviors of SO2 and H2 O on face-centered cubic Cu（100） ideal surface were studied using the GGA-r PBE method of density functional theory（DFT） with slab models. The optimized structures of single H2 O and SO2 on Cu（100） surface were calculated at the coverage of 0.25 ML（molecular layer） and 0.5 ML. The results show that there was no obvious chemical adsorption of them on Cu（100） surface. The adsorbed structures, adsorption energy and electronic properties including difference charge density, valence charge density, Bader charge analysis and partial density of states（PDOS） of co-adsorbed structures of H2 O and SO2 were investigated to illustrate the interaction between adsorbates and surface. H2 O and SO2 can adsorb on surface of Cu atoms chemically via molecule form at the coverage of 0.25 ML, while H2 O dissociated into OH adsorbed on surface and H bonded with SO2 which keeps away from surface at the coverage of 0.5 ML.

Prediction of structural and electronic properties of Cl2 adsorbed on TiO2(100)surface with C or CO in fluidized chlorination process:A first-principles study

Based on the first-principles calculations of density functional theory,co-adsorption models of C or CO with Cl2 on rutile TiO2(100)surface were established.The adsorption structures and electronic properties during chlorination process were predicted.Then,the adsorption energy,charge density,electron density difference and density of state of the adsorption structures were calculated and analyzed.The stabilities of the adsorption structures and the charge distributions between atoms were studied.It was found that both C and CO could promote the adsorption reactions of Cl2 on TiO2(100)surface,and C was more favorable to the adsorption process.The results show that the adsorption process of Cl2 on TiO2(100)surface was physisorption,and the co-adsorption processes of C or CO with Cl2 on TiO2(100)surface were chemisorptions.

The Adsorption of Copper from Aqueous Solutions Using Acrylamide-Grafted Cellulose

In the present study, the aptitudes of acrylamide grafted cellulose to remove Cu（Ⅱ） ions from aqueous solutions were investigated. The preparation process was carried out through graft copolymerization of acrylamide onto cellulose, using ceric ammonium nitrate as an initiator. Fourier transform Infrared spectroscopy was used to confirm and characterization poly acrylamide-grafted cellulose formation. Batch experiments of Cu（Ⅱ） ions adsorption on the grafted cellulose adsorbent were performed. Effects of initial pH of the solution, contact time and initial Cu（Ⅱ） concentration on the adsorption of Cu（Ⅱ） were studied. The maximum adsorption of Cu（Ⅱ） ion on grafted cellulose is observed 90 mg/g at the initial pH of 6. Equilibrium time was reached within 3h. Kinetic data were analyzed using the pseudo-first-order, pseudo-second-order equations. The data fitted very well to the pseudo-second-order rate expression. The equilibrium data for adsorption isotherms of these metal ions on grafted cellulose were obtained using the Langmuir and Freundlich models and the Langmuir model was obtained to be in better correlation with the experimental data. The results showed that acrylamide-g-cellulose developed in this study could be an economical and effective adsorbent for application in removal of copper ion from water and waste waters.

Moisture Sorption Isotherms of Soy Protein IsolatelCarboxymethyl Chitosan Blend Films

Soy protein isolate/carboxymethyl chitosan （SPI/CMCH） blended films incorporated with glycerol were prepared using solution casting to investigate the effects of the SPI and CMCH ratios （100：0, 88：12, 67：33, 50：50, 33：67, 12：88, 0：100） on the water sorption isotherm. The moisture sorption isotherm of the SPI/CMCH blended films was determined using various relative humidity＇s （16%, 35%, 55% and 76% RH） at 25 ± 1℃. The isotherms showed that the equilibrium moisture content （EMC） of the films increased with increasing CMCH content and the EMC value sharply increased above aw = 0.55. Understanding of sorption isotherms is important for prediction of moisture sorption properties of films via moisture sorption empirical models. The Guggenheim-Oswin, Brunauer-Emmett-Teller （BET）, and Anderson-de Boer （GAB） sorption model predictions were tested against the experimental data. The root mean square （RMS） values from the Oswin, BET, and GAB models respectively ranged from 698.54 to 1,557.54, 38.85 to 58.30, and 52.52 to 95.95. Therefore, the BET model was found to be the best-fit model for SPI/CMCH blended films at 25 ± 1 ℃.