The acid catalyzed hydrolysis and condensation of octadecyltriethoxy silane (OTES) was examined at the air/water interface using Langmuir-Blodgett trough. The various studies include isotherm, isobar and transfer of OTES molecules in general and octadecyltrimethoxysilane molecules for comparison with some of the results. It was observed that harrier speed. initial surface area, time and pH influenced the final mean molecular area of the surface film. Finally the monolayer films obtained were transferred onto various Substrates like mica [J. Wood and R. Sharma. Langmuir, 10 (1994) 2307.], silicon and gallium nitride (GaN) [J.L. Rouviere. J.L. Weyher. M. Seelmann-Eggebert. S. Porowski, Appl. Phys. Lett. 73 (1998) 668, J.L. Weyher, S. Muller, 1. Grzegory, S. Porowski. J. Cryst. Growth 182 (1997) 17.]. The film on mica was prepared at two different barrier speeds and the evolution of film formation was examined by Atomic Force Microscopy The use of silicon and GaN. as substrates for film transfer is part of ongoing studies in as potential g-ate dielectrics for semi-conductor materials. (c) 2006 Elsevier B.V. All rights reserved.