Biomateriales Sol-gel: Híbridos SiO2-biopolímeros; Aplicaciones en remediación de aguas

G. J. COPELLO; M. RAINERI; A. M. MEBERT; M. P. PESENTI; F. VARELA; L. E. DÍAZ

Rosario, Santa Fe, Argentina

Taller; I Taller Argentino en Ciencia Medio Ambiental; 2009

 The sol-gel chemistry is widely used for obtaining inorganic matrices from silicon dioxide precursors. Nowadays, its combination with biomolecules allows the generation of biomimetic hybrid materials. The advantages of the matrices obtained by the sol-gel process are due to the soft conditions involved in their synthesis (biocompatible pH, room temperature, absence of toxic reagents). The materials obtained this way have high mechanic resistance, high porosity and thermal and chemical stability. The versatility of sol-gel polymeric precursors allows the generation of materials in a wide range of geometries same as surface coatings. The precursors, initially in liquid state, could gel and polymerize in a support with a desired geometry or over a surface. Thus, once the matrix is aged, a rigid material of a thin film is obtained. The objective of the group’s project is the preparation of hybrid materials combining organic components along with silicon dioxide inorganic matrices and the study of their interaction with chemical compounds of environmental interest. In order to formulate new hybrid materials it was studied the incorporation of polymers from natural origin within the polymeric silicon dioxide matrices. The immobilization of biosorbents has two major advantages. First the polymer could be immobilized in an extended conformation which would let the maximum binding site availability for adsorption. Second, immobilization provides a solid support that allows the adsorption of the pollutant in aqueous media and an easy recovery of the material after the process is completed. This facilitates the scaling of the remediation procedure. Our research group developments related to water remediation are basically three types of hybrid materials: 1-A metal quelating surface obtained by immobilization of chitosan within silicate layers, which demonstrated the capability of adsorbing Cd(II), Cr(III) and Cr(VI). 2-A hybrid material which adsorbs textile and toxic dyes obtained by immobilizing chitosan or chitin in a tetraetoxy silane network, which demonstrated the capability of adsorbing Remazol Black B, Neutral Red, Erythrosine B, Gentian Violet, Methylene Blue and Eosyne Y. 3-A metal quelating hybrid material obtained by immobilizing yerba mate polyphenols (Ilex paraguariensis) in a tetraetoxy silane network, which demonstrated the capability of adsorbing lead and chromium.