title: Silylation of leached-vermiculites following reaction with imidazole and copper sorption behavior.
abstract: Organically modified vermiculites were synthesized by previous silylation of three leached vermiculites, V0.3Cl, V0.5Cl and V0.8Cl, under anhydrous conditions following reaction with imidazole (Im), which acted as chelating agent for copper retention. Elemental analysis, X-ray diffraction, infrared spectroscopy, scanning electronic microscopy, transmission electron microscopy, (29)Si and (13)C NMR and nitrogen adsorption/desorption measurements were used to characterize pristine, leached and organofunctionalized solids. X-ray photoelectron spectroscopy (XPS) was used to evaluate the surface after copper sorption. Parameters such as contact time, pH and initial cation concentration for the adsorption of Cu(II) ions were investigated. The adsorption equilibrium data were fitted using the Langmuir isotherm model and the monolayer adsorption capacities were 2.38, 2.52 and 2.69mmolg(-1) for V0.5Cl-Im, V0.3Cl-Im and V0.8Cl-Im, respectively, at pH 6.0 and 298K for a time reaction of 80min. The sorption rates were described by pseudo-second-order kinetics. The chloropropyl imidazole vermiculites are promising adsorbents for the rapid removal of Cu(II) ions from aqueous solution.
authors: Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba, Brazil.
authors: Saloana S G
authors: SSG
authors: Santos
authors: Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba, Brazil.
authors: Mariana B B
authors: MBB
authors: Pereira
authors: Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, 13083-970 Campinas, São Paulo, Brazil.
authors: Ramon K S
authors: RKS
authors: Almeida
authors: Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba, Brazil.
authors: Antônio G
authors: AG
authors: Souza
authors: Chemistry Department of Paraíba Federal University, João Pessoa, Paraíba, Brazil. Electronic address: mgardennia@quimica.ufpb.br.
authors: Maria G
authors: MG
authors: Fonseca
authors: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8220, Laboratoire d'archéologie moléculaire et structurale (LAMS), Boîte courrier 225, 4 place Jussieu, 75005 Paris, France.
authors: M
authors: M
authors: Jaber
keywords: Copper sorption; Hybrid material; Silylated clay; Vermiculite