The polymer-induced repulsive interactions between the surfaces of a liquid film are measured for two systems using two force measurement techniques, in the case where the polymer is in a good solvent and adsorbs at the liquid surface. The force decays exponentially with the film thickness with a decay length proportional to the radius of gyration. The data are compared with a recent theoretical work which predicts a repulsive exponentially decaying force at large thicknesses.

• Received 22 September 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.1778