Conference Dates

November 8-12, 2015


Layer-by-layer (LbL) assembly is a conformal coating “platform” technology capable of imparting a multiplicity of functionalities on nearly any type of surface in a relatively environmentally friendly way. At its core, LbL is a solution deposition technique in which layers of cationic and anionic materials (e.g. nanoparticles, polymers and even biological molecules) are built up via electrostatic attractions in an alternating fashion, while controlling process variables such as pH, coating time, and concentration. Here we are producing nanocomposite multilayers (50 – 1000 nm thick), having 10 – 96 wt% clay, that are completely transparent and exhibit oxygen transmission rates below 0.005 cm3/m2•day. This exceptional oxygen barrier makes these coatings interesting for food, consumer products and flexible electronics packaging. These same ‘nanobrick wall’ assemblies are very conformal and able to impart flame resistance to highly flammable foam and fabric by uniformly coating the complex three-dimensional geometries. I’ll also describe how all-polymer thin films can separate H2 from N2 (or CO2) with selectivity greater than 2000, which exceeds other commonly used gas separation membranes (including zeolites). These films can also be produced with graphene oxide to generate high barrier and low sheet resistance. If there’s time, our work on antimicrobial and UV-resistant films will also be described. All of these nanocoatings are water-based and processing occurs under ambient conditions in most cases. Furthermore, these nanocoatings can be deposited in a commercially-feasible manner. Our work in these areas has been highlighted in C&EN, ScienceNews, Nature, Smithsonian Magazine, Chemistry World and various scientific news outlets worldwide. For more information, please visit my website: