A novel strategy for the synthesis of layered organosilica is demonstrated. The ionic interaction between the anionic group of a surfactant (sodium dodecyl sulfate) and the cationic organic group of an organosilane (3-aminopropyltrimethoxysilane, ATMS) under acidic conditions was utilized to create a layered organosilica at room temperature. The inorganic part of the organosilica layer was an Si-O hexagonal sheet, and organofunctional groups were alternately arranged on both sides of the sheet. The layered structure of the ATMS organosilica was retained after the removal of the surfactant with chloride anion. The properties of the layered ATMS organosilica were investigated. The layered ATMS-Cl organosilica is stable and possesses a definite layer structure in water or ethanol. Various kinds of anions can be intercalated in the interlayer space of the layered ATMS organosilicas and the layer was expanded dependent on the intercalated anions. The structure of the layered ATMS organosilica was well retained during the intercalation processes. (c) 2004 Published by Elsevier Inc.