Melnikov, P.Santagnelli, S. B.dos Santos, F. J.Delben, A.Delben, JRTeixeira, ALRRommel, B. R.2014-05-202014-05-202003-02-28Materials Chemistry and Physics. Lausanne: Elsevier B.V. Sa, v. 78, n. 3, p. 835-839, 2003.0254-0584http://hdl.handle.net/11449/33626The physicochemical properties and morphology of spongolite, a fibrous hollow material from Mato Grosso do Sul State (Brazil) have been studied. The results of thermal analysis, scanning electron microscopy (SEM), X-ray diffraction and NMR spectroscopy indicated that external and internal surfaces of silica spicules are covered by silica gel layers. The water evolved in the range 120-350degreesC is the result of silanol groups condensation to siloxane bonds. Total homogenization of the needles is achieved by heating spongolite over 900degreesC. This mineral may be considered as a natural composite material containing surface-immobilized reactive species. The presence of active silica gel layers opens the possibilities of attaching functional groups to spongolite surface. (C) 2002 Elsevier B.V. B.V. All rights reserved.835-839engspongolitesilicacomposite materialspongioliteArtigo10.1016/S0254-0584(02)00452-2WOS:000179839900040Acesso restrito