Effects of pore surface silylation and cesium doping on the siloxane bonding structure of mesoporous silica (MPS) film were analyzed using infrared spectroscopy MPS film was derived by sol-gel method and self-assembling technology of non-ionic surfactant template Cesium (Cs) catalyst was doped to the precursor solution with the amounts of 0 5 and 15 wt-ppm Vapor phase silylation was performed by transporting tetramethylcyclotetrasiloxane (TMCTS) or hexamethyldisilazane (HMDS) From dispersion analysis of the infrared spectrum transverse optical (TO) function and longitudinal optical (LO) function of silica skeleton which concern the ionic vibration of siloxane bonding at similar to 1000-1300 cm(-1) were determined In terms of LO-TO splitting width of the disorder-Induced oxygen vibration (AS(2)) mode siloxane network connectivity was discussed Oscillator strength of ionic vibration was also calculated quantitatively It was found that TMCTS treated MPS had highly cross linked siloxane network with Increased oscillator strength compared to those of HMDS treated MPS Cs doping promoted siloxane network connectivity while the oscillator strength was negligibly changed The connectivity and oscillator strength were almost equal to those of 1000 degrees C annealed gel silica Mechanical enhancement associated with the TMCTS treatment and Cs doping was presumably due to increased degree of the siloxane network (C) 2010 Elsevier B V All rights reserved