IQUIMEFA   05518
INSTITUTO QUIMICA Y METABOLISMO DEL FARMACO
Unidad Ejecutora - UE
artículos
Título:
Removal of dyes from water using Chitosan hydrogel/SiO2 and chitin hydrogel/SiO2 hybrid materials obtained by the sol-gel method.
Autor/es:
G. J. COPELLO; A. M. MEBERT; M. RAINERI; M. P. PESENTI; L. E. DIAZ
Revista:
JOURNAL OF HAZARDOUS MATERIALS.
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2011 p. 932 - 939
ISSN:
0304-3894
Resumen:
This work describes the synthesis of chitosan hydrogel/SiO(2) and chitin
hydrogel/SiO(2) hybrid mesoporous materials obtained by the sol-gel
method for their use as biosorbents. Their adsorption capabilities
against four dyes (Remazol Black B, Erythrosine B, Neutral Red and
Gentian Violet) were compared in order to evaluate chitin as a plausible
replacement for chitosan considering its efficiency and lower cost.
Both chitin and chitosan were used in the form of hydrogels. This
allowed full compatibility with the ethanol release from
tetraethoxysilane. The hybrid materials were characterized by Attenuated
Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR),
Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy
(EDS), Nitrogen Adsorption Isotherms and (13)C solid-state Nuclear
Magnetic Resonance. Adsorption experimental data were analyzed using
Langmuir, Freundlich and Dubinin-Radushkevich isotherm models along with
the evaluation of adsorption energy and standard free energy (ΔG(0)).
The adsorption was observed to be pH dependent. The main mechanism of
dye adsorption was found to be a spontaneous charge associated
interaction, except for EB adsorption on chitin/SiO(2) matrix, which
showed to involve a lower energy physical adsorption interaction. Aside
from highly charged dyes the chitin containing matrix has similar or
higher adsorption capacity than the chitosan one.