COMPLIANCE MEASUREMENTS OF CONFINED POLYSTYRENE SOLUTIONS BY ATOMIC-FORCE MICROSCOPY

The use of the atomic force microscope (AFM) as a local probe for elas tohydrodynamic lubrication is discussed. Compliances are measured with a modified AFM that allows application of ac and de force-displacemen t curves on end-grafted poly(styrene) chains in good (toluene) and poo r (water) solvents. In toluene, the chains form a stretched brush whos e elastic modulus is an order of magnitude larger than that of the col lapsed layer in water. The de force-displacement curves are compared t o those previously obtained on similar systems with the surface forces apparatus.