title: Pyridine derivative covalently bonded on chitosan pendant chains for textile dye removal.
abstract: Chitosan was chemically modified through a sequence of four reactions with immobilized 2-aminomethylpyridine at the final stage, after prior protection of amino group with benzaldehyde. The characterized biopolymers containing free amino and hydroxyl active centers on the biopolymeric structure and pyridinic nitrogen on pendant chains showed combined hydrophobic properties that can potentially favor interactions. Reactive Yellow GR and Blue RN dyes gave the maximum sorption capacities of 2.13 and 1.61 mmol g(-1), which were performed as functions of contact time, concentration and dye structure. However, biopolymer/dye interactions are governed by effective hydrogen bond and van der Waals forces for such structural adjustments. The data obtained from the concentration isotherm were applied to non-linear regressions of the Langmuir, the Freundlich and the Sips models, with the best fit to the latter model. The kinetic data was fitted to non-linear regression of pseudo-second-order, indicating that the sorption phenomena are most likely to be controlled by chemisorption process.
authors: Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil.
authors: Cintia S
authors: CS
authors: Oliveira
authors: Institute of Chemistry, University of Campinas, UNICAMP, P.O. Box 6154, 13084-971 Campinas, SP, Brazil. Electronic address: airoldi@iqm.unicamp.br.
authors: Claudio
authors: C
authors: Airoldi
mesh_terms: D001704:Biopolymers / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D011725:Pyridines / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013784:Textiles; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D004396:Coloring Agents; D011725:Pyridines; D048271:Chitosan; C023666:pyridine
keywords: Chitosan; Dye; Non-linear regression; Pyridine derivative; Sorption