title: Novel magnetic chitosan/poly(vinyl alcohol) hydrogel beads: preparation, characterization and application for adsorption of dye from aqueous solution.
abstract: Novel magnetic chitosan/poly(vinyl alcohol) hydrogel beads (m-CS/PVA HBs) were prepared by an instantaneous gelation method and characterized by X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). Results of characterization indicated that m-CS/PVA HBs have been prepared successfully without damaging the crystal structure of Fe(3)O(4) and their saturation magnetization were about 21.96 emu g(-1). The adsorption capacity of Congo Red on the m-CS/PVA HBs was 470.1 mg g(-1). The adsorption was well described by pseudo-second-order kinetics and Langmuir equation. Positive value of enthalpy change (ΔH(∘)) (13.32 kJ mol(-1)) showed that the adsorption was endothermic and physical in nature. The values of Gibbs free energy change (ΔG(∘)) were found to be -3.321 kJ mol(-1) at 298 K for m-CS/PVA HBs, indicating the spontaneity of Congo Red adsorption. Therefore, the m-CS/PVA HBs could be employed as a low-cost alternative to other adsorbents in the removal of dyes from aqueous solution.
authors.affiliation: College of Life Science, Taizhou University, Linhai 317000, Zhejiang, PR China.
authors.forename: H-Y
authors.initials: HY
authors.lastname: Zhu
authors.forename: Y-Q
authors.initials: YQ
authors.lastname: Fu
authors.forename: R
authors.initials: R
authors.lastname: Jiang
authors.forename: J
authors.initials: J
authors.lastname: Yao
authors.forename: L
authors.initials: L
authors.lastname: Xiao
authors.forename: G-M
authors.initials: GM
authors.lastname: Zeng
mesh_terms: D000327:Adsorption; D001709:Biotechnology / Q000379:methods*; D048271:Chitosan / Q000737:chemistry*; D004396:Coloring Agents / Q000032:analysis*; D006358:Hot Temperature; D020100:Hydrogels / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D008280:Magnetics; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012996:Solutions; D013818:Thermogravimetry / Q000379:methods; D014867:Water / Q000737:chemistry; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D004396:Coloring Agents; D020100:Hydrogels; D012996:Solutions; D014867:Water; D011142:Polyvinyl Alcohol; D048271:Chitosan; D007501:Iron