According to the present disclosure, a method of forming an exfoliated or intercalated filler material is provided, wherein the said method comprises the steps of mixing particles of filler material such as montmorillonite (MMT), mica, layered double hydroxide (LDH), and attapulgite (AT) dispersed in an aqueous medium with cationic acrylate monomers to form modified particles comprising positively charged ions, dispersing the modified particles in organic medium to form a dispersion, contacting said dispersion with an organo-silicate such as tetraethyl orthosilicate (TEOS) and a functionalizing agent comprising an organo-silane such as aminopropyltrimethoxysilane (APTMS), in the presence of a basic catalyst to form a layer of silica on the modified particles. The present disclosure also relates to an exfoliated or intercalated filler material obtained by the said method as well as a method of forming a resin/clay nanocomposite.