Fluorohectorites were rendered organophilic through the cation exchange of sodium intergallery cations for protonated monoamine, diamine, and triamine oligopropyleneoxides and octadecylamine, benzylamine, and adducts of octadecylamine and benzylamine with diglycidyl ether of bisphenol A (DGEBA). The influence of the silicate surface modification and compatibility on the morphology and thermal and mechanical properties was examined. Surface modification with protonated octadecylamine and its adduct with DGEBA promoted the formation of microscale domains of silicate layers separated by more than 50 Angstrom, as evidenced by transmission electron microscopy and wide-angle X-ray scattering. Young's modulus of these two nanocomposites increased parabolically with the true silicate content, whereas conventionally filled composites exhibited a linear relationship. The highest fracture toughness was observed for conventionally filled composites.