AGGREGATION STRUCTURE AND SURFACE-PROPERTIES OF IMMOBILIZED ORGANOSILANE MONOLAYERS PREPARED BY THE UPWARD DRAWING METHOD

Octadecyltrichlorosilane [OTS, CH3(CH2)17SiCl3] and [2-(perfluorooctyl )ethyl] trichlorosilane [FOETS, CF3(CF2)7CH2CH2SiCl3] monolayers were prepared on a water surface. The monolayers of OTS and FOETS amphiphil es were polymerized to form a Si-O-Si linkage on the water subphase. T he polymerized monolayers were transferred onto a glass plate or silic on wafer surface by the upward drawing method and were covalently bond ed to the Si-OH groups of the glass or silicon wafer surface. Electron diffraction patterns revealed that the OTS monolayer was in a crystal line state, while the FOETS monolayer was in an amorphous state at 293 K. The bright field image showed homogeneous molecular aggregation in the OTS and FOETS monolayers. The atomic force microscopic and fricti onal force microscopic images of the OTS/FOETS mixed monolayers distin ctly showed a phase-separated structure. Deposition of the OTS, FOETS, and OTS/FOETS monolayers on the substrate was confirmed by attenuated total reflection Fourier transform infrared spectroscopy and x-ray ph otoelectron spectroscopy. A highly hydrophobic property was observed f or OTS, FOETS, and OTS/FOETS monolayer immobilized surfaces. Dynamic c ontact angle measurements indicated that the surface structure of thes e monolayers did not show reorganization upon environmental change bec ause of polymerization and the formation of a covalent bond between th e monolayer and the substrate surface.