The photocurrent in bilayer polymer photovoltaic cells is dominated by the exciton dissociation efficiency at donor/acceptor interface. An analytical model is developed for the photocurrent-voltage characteristics of the bilayer polymer/TiO2 photovoltaic cells. The model gives an analytical expression for the exciton dissociation efficiency at the interface, and explains the dependence of the p...

Gradient concentric rings of polymers, including (poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly(methyl methacrylate) (PMMA), with unprecedented regularity were formed by repeated "stick-slip" motion of the contact line in a sphere-on-flat geometry. Subsequently, polymer rings served as templates to direct the formation of concentric Au rings. Three methods were de...

The donor-acceptor ground-state charge-transfer complex (CTC) formed in solution between a conjugated polymer, poly[methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene-vinylene] (MEH-PPV), and a low-molecular-weight organic acceptor, 2,4,7-trinitrofluorenone (TNF), is studied by optical absorption and Raman spectroscopy. The CTC absorption as a function of TNF content shows a threshold increase that is ...

In a previous study on heparin biosynthesis, incubation of a mouse mastocytoma microsomal fraction with UDP-N-acetyl-D-glucosamine and UDP-D-glucuronic acid resulted in the formation of two nonsulfated polysaccharides, one of which was fully N-acetylated whereas the other contained about equal amounts of Nacetylated and N-unsubstituted glucosamine residues. In the presence of 3’-phosphoadenylyl...

In a previous study on heparin biosynthesis, incubation of a mouse mastocytoma microsomal fraction with UDP-N-acetyl-D-glucosamine and UDP-D-glucuronic acid resulted in the formation of two nonsulfated polysaccharides, one of which was fully N-acetylated whereas the other contained about equal amounts of Nacetylated and N-unsubstituted glucosamine residues. In the presence of 3’-phosphoadenylyl...

objective(s): particularly in developing countries, selenium and/or iodine deficiencies are encountered and use of pesticides in agriculture are not well-controlled. fenvalerate is a pyrethroid insectide used in agriculture and has applications against a wide range of pests. this study was designed to evaluate the effects of fenvalerate on hepatic and cerebral xenobiotic metabolizing enzyme act...

Single molecule confocal fluorescence microscopy was used to perform photoluminescence spectroscopy on single, isolated molecules of the conjugated polymer poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylene-vinylene] (MEH-PPV). We show that the fluorescence from single chains of this electroluminescent polymer depends strongly on chain conformation. The time evolution of the spectra, emission in...

We simultaneously measured the absorption and emission of single conjugated polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) molecules in a poly(methyl methacrylate) (PMMA) matrix using near-critical xenon to enhance the photothermal contrast for direct absorption measurements. We directly measured the number of monomers and the quantum yield of single conjugated poly...