title: Adsorption of metal halides from ethanol solutions by a 3-n-propylpyridiniumsilsesquioxane chloride-coated silica gel surface.
abstract: 3-n-propylpyridiniumsilsesquioxane chloride polymer, abbreviated as SiPy+Cl-, was used to coat a porous silica gel, SiO2, surface to form the chemically modified solid SiO2/SiPy+Cl-. The resulting polymer film was well adhered to the surface and presented an ion exchange capacity of 0.74 mmol g(-1). Metal halides, MClz [M=Fe(III), Cu(II), and Zn(II)], were adsorbed by the modified solid from ethanol solutions as neutral species by forming the surface anionic complexes described by the equation: mSiO2/SiPy+Cl-+ MClz <=> (SiO2/SiPy+)m[MCl(z+m)]m-, where the [MCl(z+m)]m- species adsorbed on the surface are FeCl4-, ZnCl4(2-), and CuCl4(2-). Accurate estimates of the specific sorption capacities and the heterogeneous stability constants of the immobilized metal complexes were determined with the aid of computational procedures.
authors.affiliation: Instituto de Química-Universidade Estadual de Campinas, Unicamp, CP 6154, 13084-971 Campinas, São Paulo, Brazil.
authors.forename: Rení V S
authors.initials: RV
authors.lastname: Alfaya
authors.forename: Sérgio T
authors.initials: ST
authors.lastname: Fujiwara
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Gushikem
authors.forename: Yuriy V
authors.initials: YV
authors.lastname: Kholin