title: Structure and surface reactivity of novel nanoporous alumina fillers.
abstract: Recent studies have shown that the particle size of fillers used for the reinforcement of dental resin composites should be multimodally distributed, in which micron-sized fillers are mixed with nanoparticles so as to achieve a higher filler level in the resin, and should be kept well dispersed so as to be functionalized by a silane. In this study, porous alumina monoliths with high specific surface area, measured by the Brunauer-Emmett-Teller (BET) method, were obtained using a novel preparation method. Structure and surface reactivity have been investigated as functions of temperature and chemical treatments. The impregnation of the as-prepared material by triméthyletoxysilane (TMES) stabilized alumina with high specific surface area at higher temperature. FTIR study has described the effect of TMES treatment and temperature on the structure of the material. The use of allyldimethoxysilane (ADMS), as a probe molecule for measuring the surface reactivity, has allowed us to show that the treatment of samples with TMES and their reheating at 1300 degrees C results in adsorption sites which give stronger chemical bonds. This preliminary study has, therefore, allowed us to optimize the structural and surface treatment of experimental fillers before their use in the reinforcement of resin composites or resin-modified glass ionomer cements.
authors.affiliation: Department of Biomaterials, Faculty of Dental Surgery, University of Paris VII, 75006 Paris, France. ch.azevedo@yahoo.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Azevedo
authors.forename: Bruno
authors.initials: B
authors.lastname: Tavernier
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vignes
authors.forename: Pierre
authors.initials: P
authors.lastname: Cenedese
authors.forename: Pierre
authors.initials: P
authors.lastname: Dubot
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D004867:Equipment Design; D005899:Glass Ionomer Cements / Q000737:chemistry; D006358:Hot Temperature; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature
chemical_list: D003764:Dental Materials; D005899:Glass Ionomer Cements; D008689:Methacrylates; D011108:Polymers; D012821:Silanes; D000537:Aluminum Oxide