ABSTRACT
The adhesion of fine particles to substrates is a complex, dynamic problem. The surface forces between the particles and the substrates can cause both materials to deform. In some instances the adhesion induced stresses are sufficiently large so as to result in plastic deformation of the materials. This chapter briefly reviews past research of surface force induced deformations. It shows direct evidence of such deformations between micrometer size particles and substrates, obtained using scanning electron microscopy at high tilt angles. The chapter presents evidence for the occurrence of both elastic and plastic response to the stresses generated by the adhesion forces. The thermodynamic work of adhesion between solids is calculated from the adhesion induced contact radius. The chapter presents evidence of hysteresis in the load-displacement relationship associated with adhering and removing a particle on a surface. Finally, it discusses the unexplained behavior such as the contact radius varying as the particle radius to the 3/4 power for polyurethane substrates.
