Artículos de revistas
Distinct features of organosilyl-grafted pendant groups attached in the RUB-18 interlayer space
Registro en:
Dalton Transactions. Royal Soc Chemistry, n. 36, n. 7402, n. 7409, 2009.
1477-9226
WOS:000269493900014
10.1039/b908857a
Autor
Macedo, TR
Airoldi, C
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Two distinct methods to graft the silylating agent 3-cyanopropyltriclorosilane (CN) in the interlayer space of the layered silicate Na-RUB-18, with composition Na(2)Si(8)O(17)center dot nH(2)O, are described. The organosilylation was carried out by reflux and solvent evaporation methodologies, using the intercalated surfactant cetyltrimethylammonium after sodium exchange as one intermediate (CTA-RUB-18) and the acidic form (H-RUB-18) as the other intermediate. The resulting silylated derivatives obtained by both methods possessed basal spacings of 1.19 and 1.54 nm, and 1.26 and 1.16 nm, starting from CTA-RUB-18 and H-RUB-18, with the reflux and solvent evaporation methods, respectively. A favourable condition for this immobilization methodology is the use of small amounts of the silylating agent, with six times less than the previous procedure. The maximum amount of the silane attached to the RUB-18 surface, based on analytical results considering the nitrogen content, gave the values 5.64, 4.16, 4.37 and 4.05 mmol g(-1), respectively. All preparation processes were followed by elemental analyses and X-ray diffraction and the organofunctionalizations were confirmed through chemical and thermogravimetric data. The presence of pendant chains covalently bonded to the inorganic RUB-18 layers was confirmed by (13)C and (29)Si NMR spectroscopy. The inorganic-organic hybrids have the ability for divalent cation removal from aqueous solutions at the solid/liquid interface. The series of adsorption isotherms were favourably adjusted to the Freundlich equation, demonstrating the applicability of these synthesized chemically modified layered materials. o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015. 36 7402 7409 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)