Hybrid organosilica are recency type of membranes derived from Ethyl Silicate 40 (ES40) and pluronic triblock copolymer (P123) precursors. These attributes make them defeat pure silica membranes performance on water desalination. This work aims to functionalize of hybrid organosilica (ES40 - P123) membranes for water desalination. Silica sols are produced by combining ES40 and P123 by sol–gel method through hydrolysis and condensation reactions with acid-base catalysts. P123 added together with base catalyst in sols mixture to form hybrid silica P123 structure then coated on membrane support α-Al2O3 and calcined at 450 oC by Rapid Thermal Processing (RTP) technique in air condition. RTP involves a rapid heating rate and a short period of high temperature exposure up to 1 hour without dwelling time and possibility replacing the conventional silica precursor tetraethyl orthosilicate (TEOS) with an industrial precursor ethyl silicate 40 (ES40). The characteristic results of organosilica (ES40-P123) xerogels by FTIR wavelength at 1063 cm-1 detected by siloxane (Si-O-Si) group and 796 cm-1 detected by Si-C. The presence of silica-carbon is indicating the organosilica structure become enhance and more stable toward water. Further, ES40 with RTP technique could save time, energy and cost during membrane fabrication. Keywords: Water Desalination, ES40-P123, hybrid organosilica membrane, interlayer-free, RTP, sol-gel method, TEOS,