Adhesion-induced deformations of polymeric substrates: Particle size dependence of the contact area

Abstract

Adhesion-induced deformations of a polyurethane substrate in contact with cross-linked polystyrene spheres, having diameters ranging from less than 2 μm to approximately 12.5 μm were observed using scanning electron microscopy. The diameters of the contact areas were measured from the micrographs. It was found that the contact radius varied as the particle radius raised to the 0.75±0.05 power. Experimental results are compared to the predictions of various adhesion models. The results are also discussed in terms of the Dupré work of adhesion.

Extension of the Two-Dimensional JKR Theory to the Case with a Large Contact Width

“…2.1a. However, many experiments have found that small particles could have a large contact radius in adhesive contact with elastic substrates, even under a zero external loading [14,15] as shown schematically in Fig. 2.1b.…”

Analysis of Contact Interactions between a Rough Deformable Colloid and a Smooth Substrate

“…Samples for contact area studies were prepared by a procedure described by Rimai et al (20,21). Samples for determining the roughness of the PSL were prepared two different ways, depending upon whether we were studying roughness of unused or used (in AFM removal force studies) PSL colloids.…”

“…To determine the maximum allowable contact area a procedure developed by Rimai was followed (16,21). This involved allowing PSL spheres to settle on a silicon substrate and then gold-coating the substrate.…”

“…Rimai et al have extensively studied the deformation of PSL spheres in contact with silicon and polyurethane substrates with a scanning electron microscope (SEM) (20)(21)(22)(23)(24)(25). They have experimentally determined the contact radius as a function of colloid radius, enabling the determination of the appropriate adhesion-induced deformation model.…”

Molecular dynamic modeling of interfacial energy

“…In addition, current theories do not always predict the correct power law dependence of the contact radius on particle radius. For example, it has been found that the contact radius of micrometer size particles in contact with elastomeric substrates can vary as the particle radius to the 3/4 power [28][29][30] rather than the 2/3 power, as predicted by the JKR theory. This paper reports results obtained from a first principles approach to the problem of particle adhesion.…”