CORRELATION BETWEEN ADHESION HYSTERESIS AND PHASE STATE OF MONOLAYER FILMS

Chemisorbed films of hydrolyzed hexadecyltrichlorosilane (Cl3Si(CH2)15CH3) on elastomeric poly(dimethylsiloxane)s (PDMS) were used as model systems to study adhesion between polymer surfaces. The adhesion energies of these chemically modified surfaces were estimated by measuring the deformations that resulted on contacting small semispherical lenses and flat sheets of the polymer under controlled loads. The adhesion energies of these chemically modified surfaces obtained from the compressive loads were not always the same as those obtained from the decompressive loads-there was generally a finite hysteresis in adhesion energies. The magnitude of the adhesion hysteresis depends on the physical states of the alkylsiloxane films.