Superfluid ultra-dense deuterium D(-1) on polymer surfaces: Structure and density changes at a polymer-metal boundary

Ultra-dense deuterium D(-) with D-D bond distance 2.3 pm is the first ultra-dense material studied. It is a superfluid quantum material and may also be superconductive. Its interaction with metal and polymer surfaces is of immediate interest. D(-) exists on organic polymer surfaces like (poly(methyl methacrylate)) PMMA even at a distance of a few millimeter from a metal in contact with the polymer. The density of D(-) decreases from the metal surface to the open polymer surface, and is to some extent replaced by D(1) on the polymer surface. At low surface density of D(-), the long chain-clusters appear to lie parallel the surface, while at large densities the clusters stand vertical to the surface. Various polymers give different structures of D(-1), for example fewer non-superfluid clusters D-4 are observed on fluorocarbon surfaces relative to hydrogen containing polymers. Isotope exchange reactions in four-atom clusters are probably observed between deuterium in D(-1) and protium atoms in the hydrogenated polymer surface. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729078]