Shear response of molecularly thin liquid films to an applied air stress

An experimental technique for shearing liquid films on a single solid surface at shear rates typically found in surface force apparatus (SFA) experiments is presented. The technique employs a flowing stream of nitrogen gas to apply a shear stress to the top surface of the liquid film. For demonstration purposes, two liquids are considered: perfluoropolyether polymer (PFPE) and a branched alkane (squalene).