High Ionic Conductivity of Transparent Film of Hydroxyapatite and Poly(vinyl alcohol) Nanocomposite

Summary: Hydroxyapatite (HAp)-polyvinyl alcohol (PVA) nanocomposite film containing Li⁺ was designed as a solid polymer electrolyte. A composite was prepared by reacting Ca(OH)₂ with H₃PO₄ in the presence of PVA which is denatured in order to have the carboxyl group, and a LiN(CF₃SO₂)₂ was added. HAp particles were commonly formed in the shape of spindles (long axis ca. 80 nm and short axis ca. 25 nm). The obtained nanocomposite film, in which HAp particles were dispersed uniformly, is transparent, flexible and drawable. Its ionic conductivity is about 10⁻³ S/m at room temperature. This value is very large. This high ionic conductivity is considerable on the basis of the dynamic percolation theory.     

Hydrosilylation of olefins and dehydrogenative double silylation of conjugated dienes catalyzed by lanthanide–imine complexes

Divalent lanthanide–imine complexes and a related species catalyzed the hydrosilylation of olefins with phenyl- and diphenylsilane. On the other hand, conjugated dienes were converted to 1,4-bissilyl-2-butenes and 3-silacyclopentenes, accompanied with hydrogen evolution, under similar conditions.     

Experimental heat and mass transfer of the separated and coupled rotating desiccant wheel and heat wheel

The experimental evaluation of the separated and coupled rotating desiccant wheel and heat wheel is reported. The study aims to investigate the performance of the desiccant wheel and of the heat wheel both when operated separately and jointly. The performance evaluation of the desiccant wheel is based on its moisture removal capacity (MRC), moisture removal regeneration (MRR), and moisture mass balance (MMB). In addition, the study used the total energy balance (TEB), sensible coefficient of performance (COP_Sensible), latent coefficient of performance (COP_Latent) and, total coefficient of performance (COP_Total). The performance of the heat wheel is based on its effectiveness. The COP_Sensible, COP_Latent and, COP_Total are used in the performance evaluation of the coupled desiccant wheel and heat wheel. The general results of the study show that the MRC, MRR and MMB coupled with the TEB, COP_Latent, COP_Sensible and COP_Total predict adequately the performance of the desiccant wheel. In addition, the coupled operation of the desiccant wheel and heat wheel, contributed to the reduction of the external thermal energy requirement for the regeneration of the desiccant wheel. This study can be applied in other researches seeking evaluation of the desiccant wheel, heat wheel, and their combined operation. Moreover, the data presented here are significant for the desiccant wheel benchmarking and for evaluation of the desiccant wheel models.     

Palladium‐catalyzed modification of poly(p‐bromostyrene) with carbazole and related heteroarenes containing an N?H bond and their properties

Palladium‐catalyzed polymer reactions of poly(p‐bromostyrene) with carbazole and related heteroarenes containing an N H bond (phenothiazine, phenoxazine, and iminostilbene) afforded polystyrene derivatives with heteroaromatic groups in the side chains with high conversions and recoveries. Characterization and chemical oxidation properties of the polymers also were examined. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 28–34, 2000