title: Nanocomposites of phosphonic-acid-functionalized polyethylenes with inorganic quantum dots.
abstract: Insertion of diethyl vinyl phosphonates and free vinyl phosphonic acid, respectively, into [(P^O)Pd(Me)(dmso)] ((P^O) = κ(2)-P,O-Ar2PC6H4SO2O with Ar = 2-MeOC6H4) (1-dmso) occurs in a 2,1- as well as 1,2-fashion, to form a four-and a five-membered chelate [(P^O)Pd{κ(2)-C,O-CH(P(O)(OR)2)CH2CH3}] and [(P^O)Pd{κ(2)-C,O-CH2CH(P(O)(OR)2)CH3}] (R = H, Et). No decomposition or other reactions of 1 by free phosphonic acid moieties occur. Copolymerization in a pressure reactor by 1-dmso yields linear random poly(ethylene-co-diethyl vinyl phosphonate) and poly(ethylene-co-vinyl phosphonic acid). In these copolymerizations, reversible coordination of the phosphonate moieties of free monomer as well as chelate formation by incorporated monomer retards chain growth as also evidenced by relative binding studies of diethyl phosphonate towards 1. Post-polymerization emulsification of poly(ethylene-co-vinyl phosphonic acid) together with CdSe/CdS quantum dots (QDs) yields submicron (ca. 50 nm from dynamic light scattering (DLS) and transmission electron microscopy (TEM)) polymer particles with the QDs embedded in the functionalized polyethylene in a nonaggregated fashion. This embedding benefits the fluorescence behavior in terms of continuous emission and life-time as revealed by wide-field fluorescence measurements. These composite particle dispersions are employed as a ″masterbatch" together with an aqueous high density polyethylene (HDPE) dispersion to generate thin films (by spin-coating) and bulk materials (from the melt), respectively, in which the inorganic nanoparticles remain highly disperse.
authors.affiliation: Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rünzi
authors.forename: Moritz C
authors.initials: MC
authors.lastname: Baier
authors.forename: Carla
authors.initials: C
authors.lastname: Negele
authors.forename: Marina
authors.initials: M
authors.lastname: Krumova
authors.forename: Stefan
authors.initials: S
authors.lastname: Mecking
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D015394:Molecular Structure; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D010757:Phosphorous Acids / Q000737:chemistry*; D011095:Polyethylenes / Q000138:chemical synthesis / Q000737:chemistry*; D058105:Polymerization; D045663:Quantum Dots
chemical_list: D010757:Phosphorous Acids; D011095:Polyethylenes; C570063:phosphonic acid
keywords: composite materials; functionalized polyethylenes; insertion phosphonic; phosphonates; polymerization; quantum dots