Recent advances in gas barrier thin films via layer-by-layer assembly of polymers and platelets

Abstract

Layer-by-layer (LbL) assembly has emerged as the leading non-vacuum technology for the fabrication of transparent, super gas barrier films. The super gas barrier performance of LbL deposited films has been demonstrated in numerous studies, with a variety of polyelectrolytes, to rival that of metal and metal oxide-based barrier films. This Feature Article is a minireview of LbL-based multilayer thin films with a 'nanobrick wall' microstructure comprising polymeric mortar and nanoplatelet bricks that impart high gas barrier to otherwise permeable polymer substrates. These transparent, waterbased thin films exhibit oxygen transmission rates below 5 × 10-3 cm3 m-2 day-1 atm-1 and lower permeability than any other barrier material reported. In an effort to put this technology in the proper context, incumbent technologies such as metallized plastics, metal oxides, and fl ake-filled poly mers are briefl y reviewed.