Papers by Author: Sandrine Lucas

Abstract: Progress of fuse technology to reduce cost and to protect environment requires the understanding of physicochemical phenomena that govern the consolidation of the sand with alkaline silicate solution. In this context, this work concerns the agglomeration behaviours of sand with alkaline silicate solution. The effects of sand particles size and concentration of solutions are investigated at various temperatures. The main objective is to understand the interactions between sand and this alkaline solution during the impregnation of sand with sodium silicate solution and the drying leading to the consolidated materials. Various investigations were performed, thermogravimetrical and differential thermal analysis (TG/DTA), gravimetric analysis of wet sample, scanning electron microscopy (SEM) and compressive strength test on dry samples. The results show that agglomeration is affected by silica grains size distribution and temperature. Bonds strength between the grains increase with decreasing grain size and increasing temperature.

Abstract: The purpose of this study was to develop bioceramics with a well-defined porous structure in order to control drug loading and release over time. Porous structures were obtained through colloidal processing, using polymethyl methacrylate (PMMA) microspheres as templates (core) and hydroxyapatite (HA) nanoparticles as inorganic building blocks (shell). Dispersed HA suspensions were prepared and their electrokinetic properties were studied to determine a dispersant giving a high positive zeta potential (opposite to the negative zeta potential of PMMA). Upon mixture of well-dispersed HA and PMMA suspensions of opposite charge, core-shell structures were formed via heterocoagulation. After consolidation, polymers were removed by calcination, resulting in a porous structure of controlled size and distribution.