Nanocomposite materials are widespread in biological systems. Perhaps the most studied is the nacre of abalone shell, an orientated coating composed of alternating layers of aragonite (CaCO 3 ) and a biopolymer. Its laminated structure simultaneously provides strength, hardness and toughness: containing about 1 vol. % polymer, nacre is twice as hard and 1,000 times as tough as its constituent phases 1 . Such remarkable properties have inspired chemists and materials scientists to develop synthetic, 'biomimetic' nanocomposite assemblies 2-5 . Nonetheless, the efficient processing of layered organic-inorganic composites remains an elusive goal. Here we report a rapid, efficient selfassembly process for preparing nanolaminated coatings that mimic the structure of nacre. Beginning with a solution of silica, surfactant and organic monomers, we rely on evaporation during dip-coating to induce the formation of micelles and partitioning of the organic constituents into the micellar interiors 6 . Subsequent self-assembly of the silica-surfactant-monomer micellar species into lyotropic mesophases 7 simultaneously organizes the organic and inorganic precursors into the desired nanolaminated form. Polymerization fixes this structure, completing the nanocomposite assembly process. This approach may be generalized both to other composite architectures and to other materials combinations.Natural nanocomposites are formed by biomineralization 5 , a templated self-assembly process in which pre-organized organic surfaces regulate the nucleation, growth, morphology and orientation of inorganic crystals. Related synthetic, so-called 'biomimetic', approaches include crystallization beneath Langmuir monolayers 8 , crystallization on self-assembled monolayers 3,9 , supramolecular self-assembly 2,6,10 and sequential deposition 11 . Of these, only the last two offer the ability to introduce periodic microstructural and compositional changes needed for nanocomposite assembly. With regard to nanolaminated structures, supramolecular self-assembly has resulted in the formation of lamellar (silica/surfactant) films 12 or letters to nature 256

After over a decade of research, the efficient synthesis and processing of layered organic/inorganic nanocomposites that mimic bone and shell structures remains an elusive goal of the materials chemist. We report on a rapid, efficient, continuous method to form layered nanocomposites via evaporation induced supramolecular self-assembly (SSA). During dip coating of a homogeneous sol containing alcohol or ether solvents, silica precursors, organic monomers, initiators and surfactant (at an initial concentration below cmc), solvent evaporation induces the formation of micellar structures that co-organize with silica to form cubic, hexagonal or lamellar mesophases. The organic monomers and initiators are solvated within the hydrophobic micellar interiors. Subsequent photo or thermal polymerization and washing results in a silica/polymer thin film nanocomposite. The microstructural and physical characteristics of these materials will be discussed in the context of potential applications as abrasion resistant coatings and optical hosts.