摘要
Nanofiber membranes from the composite of cellulose acetate/polyvinylpyrrolidone were prepared using electrospinning technique. After treated with water and alcoholic KOH to remove partially polyvinylpyrrolidone and deacetylate the cellulose acetate, the membranes were further functionalized with thiol groups using thioglycolic acid. Related materials were characterized using infrared and thermogravimetric analysis. And the results showed that the membranes were success of functionalisation. Then the nanofiber membranes were used in the sorption-desorption process. The effects of pH, contacting time and adsorption capacity of nanofiber membranes were studied against Cu（II）, Cd（II） and Pb（II） ions. And the maximum adsorption capacities of Pb （II）, Cu （II）, and Cd （II） ions were estimated at 30.96, 19.63, 34.70 mg g-1. Our results suggested that the adsorption be- haviour of metal ions could be described using Langmuir model. Their adsorption kinetics was in agreement with the model of pseudo-second order, suggesting chemical adsorption as the rate-limiting step of the adsorption mechanism. The durability of the thiol-functionalized cellulose nanofiber membranes was also evaluated by repetitive adsorption-desorption.
Nanofiber membranes from the composite of cellulose acetate/polyvinylpyrrolidone were prepared using electrospinning technique. After treated with water and alcoholic KOH to remove partially polyvinylpyrrolidone and deacetylate the cellulose acetate, the membranes were further functionalized with thiol groups using thioglycolic acid. Related materials were characterized using infrared and thermogravimetric analysis. And the results showed that the membranes were success of functionalisation. Then the nanofiber membranes were used in the sorption-desorption process. The effects of pH, contacting time and adsorption capacity of nanofiber membranes were studied against Cu(Ⅱ), Cd(Ⅱ) and Pb(Ⅱ) ions. And the maximum adsorption capacities of Pb (Ⅱ), Cu (Ⅱ), and Cd (Ⅱ) ions were estimated at 30.96, 19.63, 34.70 mg g-1 . Our results suggested that the adsorption behaviour of metal ions could be described using Langmuir model. Their adsorption kinetics was in agreement with the model of pseudo-second order, suggesting chemical adsorption as the rate-limiting step of the adsorption mechanism. The durability of the thiol-functionalized cellulose nanofiber membranes was also evaluated by repetitive adsorption-desorption.
基金
the National Nature Science Foundation of China (21177049,51103063)
the Program of Science and Technology of Zhejiang Province (2011C22096, 2011C37033)
the Program for Science and Technology of Jiaxing (2011AY1027, 2011AY1007) for financial supports
