No abstract

To improve the interfacial adhesion between poly(vinyl chloride) (PVC) and bamboo flour in PVC/bamboo flour composites, a novel coupling agent, poly(styrene-co-maleic anhydride)-block-poly(styrene-coacrylonitrile) {P[(SMA)-b-(SAN)]}, was synthesized through living free-radical polymerization in a one-pot reaction. P[(SMA)-b-(SAN)] was synthesized by a nitroxide-mediated polymerization technique in the presence of 2,2,6,6-tetramethylpiperidin-l-oxyl with azobisisobutyronitrile. The conversion of maleic anhydride (>99%) and styrene (>65%) was relatively high and yielded P[(SMA)-b-(SAN)] with a narrow molecular weight distribution (weight-average molecular weight/number-average molecular weight <1.38). PVC was blended with bamboo flours in the presence of the synthesized coupling agent with a two-roll mill. P[(SMA)-b-(SAN)] was added to the PVC matrix at a concentration of 55 or 20 wt %. As the content of P[(SMA)-b-(SAN)] in the wood-polymer composite increased, improved morphological and mechanical behaviors were observed.

No abstract

We investigated the growth mechanism of amorphous silicon thin films by implementing hot-wire chemical vapor deposition and fabricated thin film solar cell devices. The fabricated cells showed efficiencies of 7.5 and 8.6% for the samples without and with the rear-reflector decomposed by sputtering, respectively. The rear-reflector enhances the quantum efficiency in the infrared spectral region from 550 to 750 nm. The more stable quantum efficiency of the sample with the inclusion of a rear-reflector than the sample without the rear-reflector due to the bias effect is related to the enhancement of the short circuit current.

We investigated solar cells containing temperature-dependent Ag nanodots embedded in an amorphous Si thin film layer by using hot-wire chemical vapor deposition in order to improve the properties of crystalline Si solar cells. An Ag thin film with a thickness of 10 nm was deposited by DC sputtering followed by annealing at various temperatures ranging from 250 to 850 degrees C for 15 min under N2 gas. As increasing the annealing temperature, the Ag nanodots were enlarged and the photoreflectances of the samples with Ag nanodots were lower than the reference samples in the spectral range of 200-600 nm, demonstrating the plasmon effect of Ag nanodots. The cell properties on photoluminescence spectra, quantum efficiency, and conversion efficiency were measured with the maximum values for the sample annealed at 450 degrees C, indicating that there exists an optimal size of the Ag nanodots about 15-35 nm to be effective on the enhancement of surface plasmon effect.