SURFACE FORCE INDUCED DEFORMATIONS - A POST PARTICLE REMOVAL EXAMINATION OF THE SUBSTRATE

Micrometer size particles of tin and gold were deposited onto a polydi methylsiloxane/polyester alternating block copolymer substrate. After the adhesion induced deformations of the substrate equilibrated, the p articles were removed by amalgamation with mercury and the substrate w as examined using scanning electron microscopy. Craters having radii c omparable to those of the particle/substrate contact zones [L. P. DeMe jo, D. S. Rimai, J. Chen and R. C. Bowen, J. Adhesion 39, 61 (1992)] w ere observed. Elevated ridges around the craters were also observed, s uggestive of tensile interaction induced menisci. Similar ridges were previously observed between the particles and the substrate. The occur rence of craters long after the removal of the particles suggests that the deformations are plastic rather than elastic. This is consistent with results reported earlier.