Kinetics and Thermodynamics of Aniline Blue Adsorption Onto Cross-linked Gelatin/chitosan Polymer Blends

Okasha, Aly; Ghoneim, H. S.; Khalil, E.; Mohamed, S.

doi:10.21608/jtcps.2019.14878.1024

Kinetics and Thermodynamics of Aniline Blue Adsorption Onto Cross-linked Gelatin/chitosan Polymer Blends

Document Type : Original Article

Authors

¹ Spectroscopy Department, Physics Division, National Research Centre, 33 El Bohouth Street, Dokki-Giza P.O. 12622, Egypt

² Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Cairo, 11795, Egypt

10.21608/jtcps.2019.14878.1024

Abstract

Films of cross-linked gelatin/chitosan blends have been successfully synthesized using glutaraldehyde as a cross-linker. The synthesized samples were characterized using infrared Fourier transformation (FT-IR), and X-ray diffraction (XRD). The solubility in aqueous media, the pH-responsive swelling, and point of zero surface charge were explored. The adsorption efficiency of samples for the removal of the anionic dye aniline blue from aqueous media has been studied. The parameters that affect the adsorption efficiency as pH, initial dye concentration, contact time and temperature have been examined. Kinetics studies showed that the adsorption process was well described by the pseudo-second-order model and the equilibrium adsorption results fitted Freundlich model. Fitting the experimental data with the Dubinin-Radushkevich model indicated a predominant physisorption mechanism. The maximum dye removal achieved by 1:1 gelatin/chitosan at pH 5 and 35°C was 99.8%. The activation energy for the adsorption process increases as the chitosan content increases which indicating chemisorption behavior. Thermodynamic studies indicated that the adsorption is spontaneous, endothermic in nature and results in higher entropy.

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