Biomimetic Nanocomposites Fabricated by Controlled Assembly of Nanoplatelets

The nacreous layer of mollusk shells is both strong and stiff. This is attributed to the unique three-dimensional (3D) assembly of platelet-like ceramic building blocks which are embedded in a polymer matrix. Layer-by-layer (LBL) assembly of clay nanoplates and polyelectrolytes has been developed to make polymer nanocomposites that mimic the natural structures and mechanical properties of nacres. However, the LBL approach is tedious in assembling thick coating. Here we report the rapid fabrication of large-area nacreous coatings by utilizing capillary and electrical forces. Hexagonal gibbsite nanoplatelets with ~200 nm diameter and ~10 nm thickness can be assembled into ordered multilayers with controlled thickness. The interstitials between gibbsite particles can be filled up by polymers and metals. The resulting biomimetic nanocomposites exhibit notable stiffness and strength.