Title of article :
Synthesis of cross-linked poly(4-vinylpyridine) and its copolymer microgels using supercritical carbon dioxide: Application in the adsorption of copper(II)
Author/Authors :
Cao، نويسنده , , Liqin and Hu، نويسنده , , Yaodong and Zhang، نويسنده , , Lijuan and Ma، نويسنده , , Chuang and Wang، نويسنده , , Xiaohu and Wang، نويسنده , , Jide، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2011
Abstract :
Compared with conventional precipitation polymerization method, cross-linked poly(4-vinylpyridine) (P4VP) and its microgels copolymerized with α-methacrylic acid (MAA) were synthesized through a new route of stabilizer-free polymerization in supercritical fluids. The yellow, dry, fine powders were directly obtained from precipitation polymerization of 4-vinylpyridine in supercritical carbon dioxide (scCO2) at pressures ranging from 70.0 to 230 bar, using N,N′-methylenebisacrylamide as cross-linker. The effects of the reaction pressure, cross-linker ratio, initiator concentration, and reaction time were investigated. The capacity of this microgel for adsorption of copper(II) was also studied. At higher cross-linker concentrations, a high yield of the cross-linked P4VP microgel was generated in scCO2, and its particle size was less than 300 nm. Polymerization of cross-linked P4VP in scCO2 was extremely sensitive to the density of the continuous phase. The adsorption followed the Langmuir isotherm. The adsorption capacities of cross-linked P(4VP-co-MAA) and cross-linked P4VP were 47.2 and 26.9 mg g−1, respectively.
Keywords :
Supercritical carbon dioxide , 4-Vinylpyridine , Adsorption , Copper(II) , Precipitation polymerization
Journal title :
Journal of Supercritical Fluids
Journal title :
Journal of Supercritical Fluids