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Adsorption of Cr(VI) ions onto poly(ethylene glycol dimethacrylate‐1‐vinyl‐1,2,4‐triazole)
Author(s) -
Kara Ali
Publication year - 2009
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.29169
Subject(s) - ethylene glycol dimethacrylate , freundlich equation , adsorption , langmuir adsorption model , langmuir , enthalpy , ethylene glycol , nuclear chemistry , chemistry , gibbs free energy , polymer chemistry , materials science , polymerization , organic chemistry , polymer , thermodynamics , methacrylic acid , physics
Poly(ethylene glycol dimethacrylate‐1‐vinyl‐1,2,4‐triazole) [poly(EGDMA‐VTAZ)] beads (average diameter = 150–200 μm) were prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1‐vinyl‐1,2,4‐triazole (VTAZ). Poly(EGDMA‐VTAZ) beads were characterized by swelling studies and scanning electron microscope (SEM). The adsorption of Cr(VI) from solutions was carried at different contact times, Cr(VI) concentrations, pH, and temperatures. High adsorption rates were achieved in about 240 min. The amount of Cr(VI) adsorbed increased with increasing concentration and decreasing pH and temperature. The intraparticle diffusion rate constants at various temperatures were calculated. Adsorption isotherms of Cr(VI) onto poly(EGDMA‐VTAZ) have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The pseudo first‐order kinetic model was used to describe the kinetic data. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy changes. The dimensionless separation factor ( R L ) showed that the adsorption of metal ions onto poly(EGDMA‐VTAZ) was favorable. It was seen that values of distribution coefficient ( K D ) decreasing with Cr(VI) concentration in solution at equilibrium ( C e ) indicated that the occupation of activate surface sites of adsorbent increased with Cr(VI). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009