In a metal-free procedure, chelating thiol groups and an electrophile react to assemble a robust, conjugated porous polymer with pendant aldehyde functionalities. These groups are able to reduce Ag(i) ions to generate, in situ, Ag(0) nanoparticles evenly dispersed in the polymer matrix. The Ag(0)-polymer composite enables selective reduction of aromatic nitro compounds as a heterogeneous cataly...

A novel strategy was developed to synthesize polymer-coated metal nanoparticles (NPs) through reduction of metal cations with 3,4-dihydroxyphenylalanine (DOPA)-containing polyethylene glycol (PEG) polymers. Catechol redox chemistry was used to both synthesize metal NPs and simultaneously form a cross-linked shell of PEG polymers on their surfaces. DOPA reduced gold and silver cations into neutr...

A simple and modular synthetic approach, based on miniemulsion polymerization, has been developed for the fabrication of composite polymer-metal nanoparticle materials. The procedure produces well-defined composite structures consisting of gold, silver or MnFe(2)O(4) nanoparticles (∼10 nm in diameter) encapsulated within larger spherical nanoparticles of poly(divinylbenzene) (∼100 nm in diamete...

Microporous poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) membranes were prepared using the phase-separation method. Then, the membranes were immersed in liquid electrolyte to form polymer electrolytes. The effects of PMMA on the morphology, degree of crystallinity, porosity, and electrolyte uptake of the PVDF membrane were studied. The addition of PMMA increased the pore size...

The optical absorption, ionic conductivity, electronic conductivity, and gas separation properties have been evaluated for flexible composite films of ionically conductive polymers that contain partially embedded arrays of ordered, crystalline, p-type Si microwires. The cation exchange ionomer Nafion, and a recently developed anion exchange ionomer, poly(arylene ether sulfone) that contains qua...

The structural performance, reliability and durability of polymer composites can now be correlated with three generic classes of internal defects. The _first generic class of chemical structure defects (size 10-lOOA) that control critical design properties such as glass transition T 0 , moisture absorption, and dimensional changes can be controlled by chemical analysis of raw materials prior to...