Surface analysis of silica gel particles after mechanical dry coating with magnesium stearate

Laurence Galet (1) , Yamina Ouabbas (2, 3, 4) , Alain Chamayou (1) , Philippe Grosseau (2, 3, 4) , Michel Baron (1) , Gérard Thomas (2, 3, 4)

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement
2 SPIN-ENSMSE - Centre Sciences des Processus Industriels et Naturels
3 LPMG-EMSE - Laboratoire des Procédés en Milieux Granulaires
4 P2MC-ENSMSE - Département Poudres et Matériaux Multi-Composants

A dry coating technique has been used to change the surface properties of silica gel particles (d50=55μm) by coating with different mass ratios of magnesium stearate - MgSt2 (d50=4.6μm): 1%, 5%, 15% and 30%. The dry coating experiments were performed using a “Hybridizer, a high-speed dry impact blending coater”, manufactured by Nara Machinery (Japan). The surface morphology of the uncoated and coated silica gel particles was observed by environmental scanning electron microscopy (ESEM). The images show that a greater MgSt2 coverage was observed on the surface of silica gel as the MgSt2 mass ratio is increased. In addition, atomic force microscopy (AFM) analysis revealed how this coating process makes possible a discrete and uniform dispersion of the MgSt2 particles. AFM studies were carried out with a scanning probe microscope Multimode Nanoscope IIIA (Digital Instruments /Veeco Metrology Group).

Mots clés: adhesion force; silica; AFM phase imaging; magnesium stearate; dry coating

Domaines: Génie des procédés

Laurence Galet, Yamina Ouabbas, Alain Chamayou, Philippe Grosseau, Michel Baron, et al.. Surface analysis of silica gel particles after mechanical dry coating with magnesium stearate. Kona, 2010, 28, pp.209-218. ⟨hal-00551907⟩