Synthesis, characterization and application of new adsorbents materials obtained from chemically modified mesoporous silicas

Author(s)

Natália Fattori

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2011-07-21

Examining board members

Yoshitaka Gushikem; Ana Maria da Costa Ferreira; Inez Valéria Pagotto Yoshida

• Advisor: Yoshitaka Gushikem

Abstract

This work describes the preparation and characterization of new adsorbent materials obtained from two different chemically modified substrates: i) a mesoporous silica constituted by a highly ordered and uniform porous framework, with parallel cylindrical pore channels packed in a hexagonal array (SBA-15), ii) a mesoporous silica characterized by a disordered porous framework, with non-uniform size and shape, distributed and interconnected randomly throughout the porous structure (Disordered Mesoporous Silica, DMS). The two mesoporous substrates were chemically modified with two different silylating agents, derived from the organic molecule 4,4'-bipyridine, immobilized on the surface of the silica in the monosubstituted form (Bipy), as well as in the disubstituted form (Bipy). The materials obtained were tested as practical adsorbents for cooper ions from ethanol solution, aiming their use in the purification of ethanol fuel. The effective sorption capacities and the heterogeneous equilibrium constants were obtained. The adsorption process of CuCl2 occurs in the solid/solution interface, through the formation of anionic copper complexes (CuCl4 and CuCl3), that act as counter-ions of the bipyridinium cations (Bipy e Bipy). The heterogeneous equilibrium constants values obtained express the ability of the materials to retain the anionic copper complexes on the adsorbent surface, through electrostatic interactions with the organic molecule 4,4'-bipyridine (AU)

• FAPESP's process: 09/12189-5 - Synthesis, characterization and application of new adsorbents obtained from mesoporous silica
• Grantee: Natália Fattori
• Support Opportunities: Scholarships in Brazil - Master