Deformation and adhesion of viscoelastic particles: Theory and experiment

A summary is given of the authors' recent research on viscoelastic theory and its application to colloid probe atomic force microscopy. A general computational approach for the interaction of viscoelastic colloids interacting with realistic surface forces of extended range is outlined, and the origins of velocity- and time-dependent effects including hysteresis are discussed. A general method for establishing the zero of separation in atomic force microscopy of deformable bodies is described and utilized in force measurements made on viscoelastic poly( dimethylsiloxane) colloid particles. A quantitative analysis of the velocity and load dependence of the hysteresis in the measurements yields the viscoelastic parameters of the colloid.