Microstructure and adhesion mechanism of mechanically prepared composite particles

Abstract A shear compression type of grinding machine was modified to obtain composite particles, where the host particles were coated with a layer comprising a number of smaller guest particles. The microstructure of the composite particles, particularly the host-guest boundary structure, was examined by electron microscopy and surface analyses. The mechanism of the host-guest adhesion and coghesion guest particles was discussed. Among the metals used as the guest materials, smaller and harder particles adhered more easily onto the poly(methylmethacrylate) (PMMA) host particles which were as small as 11 μm. TiO 2 was bound onto PMMA by a partly fused polymer, overlain by a consolidated layer. The latter part was detached by a mechanical action as well as chemical dissolution, whereas the former stayed firmly adhered to the surface of the polymer spheres. Some evidence of chemical or atomic interaction between host and guest species was observed.