Direct measurement of structural forces between two surfaces in a nonpolar liquid

摘要: The force as a function of separation has been measured between two molecularly smooth surfaces immersed in the liquid octamethylcyclotetrasiloxane (OMCTS) whose molecules are quasispherical diameter ∼1.0 nm. is an oscillatory distance, varying attraction and repulsion, with periodicity equal to size within experimental resolution ∼0.1 oscillations decay rapidly distance: their measurable range 6–10 molecular diameters magnitude exceeds that conventional van der Waals forces at small distances. insensitive changes temperature, but sensitive chemical nature surfaces, very presence water. results considered, qualitatively, context current theories state near solid interfaces, some implications for surface chemistry colloid science discussed.