Novel nanosized lead tungstate (PbWO4) hollow spindles were successfully synthesized, for the first time, via a Pluronic P123- (EO20PO70EO20-) assisted sonochemical process. The triblock copolymer acted as a structure-directing agent and played a key role in the formation of the hollow spindles. An in situ micelle templating mechanism has been proposed for the possible formation mechanism of the hollow nanostructure. The optical properties of the final products were investigated. It is exciting that the as-prepared PbWO4 hollow structure shows extraordinarily high room-temperature photoluminescence intensity compared to the solid structures.

Lead tungstate single crystals with dendritic, flowery and star-like structures have been prepared via a facile, ethylene glycol (EG)-assisted sonochemical method. The concentrations of EG and ultrasound irradiation were found to play crucial roles in the morphology control of the final products. The growth process was investigated by carefully following time-dependent experiments, and the oriented attachment process accompanying Ostwald ripening was proposed for the possible formation mechanism. The optical properties, such as the Raman spectra and photoluminescence (PL) spectra, of the obtained PbWO(4) crystals were studied.

Sb(III)-doped lead tungstate single crystals with controlled shapes and enhanced green emission have been synthesized via a facile, Pluronic P123 (EO(20)PO(70)EO(20))-assisted, sonochemical method. The surfactant Pluronic P123 was found to play a crucial role in the morphology control of the final products. The growth process was investigated by carefully following time-dependent experiments, and the oriented attachment process accompanying Ostwald ripening was proposed for the possible formation mechanism. The optical properties, such as the Raman spectra and PL spectra, of doped PbWO(4) were studied. Room-temperature photoluminescence of doped PbWO(4) samples with different morphologies at desired Sb doping concentrations showed greatly enhanced luminescence intensity compared to the undoped PbWO(4).

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Epitaxial lateral overgrowth (ELO) of GaN on SiO 2 -masked (0001) GaN substrates has been investigated by using chloride-based growth chemistries via hydride vapor phase epitaxy (HVPE) and metal organic vapor phase epitaxy (MOVPE). Diethyl gallium chloride, (C 2 H 5 ) 2 GaCl, was used in as the MOVPE Ga precursor. The lateral and vertical growth rates as well as the overgrowth morphology of ELO GaN structures are dependent on growth temperature, V/III ratio and the in-plane orientation of the mask opening. A high growth temperature and low V/III ratio increase the lateral growth rate and produce ELO structures with a planar surface to the GaN prisms. High-quality coalesced and planar ELO GaN has been fabricated by both growth chemistries. The use of the diethyl gallium chloride source allows for the benefits of HVPE growth to be realized within the MOVPE growth environment.

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We determined the distribution coefficients of solutes between a polymer film phase (polyvinyl chloride (PVC) with 67% (w/w) dioctyl sebacate (DOS)) and an aqueous phase in a 96-well format. The parallel measurement approach is efficient and uses very little material. Polymer-water distribution coefficients (Dpw) at different pH values yield the pKa and polymer-water partition coefficient values (Ppw) of the solutes. Log Ppw of a prominent drug-like compound, 2H-1, 2, 6-thiadiazine, 3-methyl-5-phenyl-, 1, 1-dioxide, is in good agreement with cLogP, while the pKa value is substantially different from calculated values. This method has been also successfully applied to a library of novel drug-like compounds. Log Dpw values (at pH 4.0, 7.0, 10.0) of 24 novel drug-like compounds have been determined with good reproducibility with the 96-well plate approach. Differences between experimental values and a variety of available calculated values are significant. This emphasizes the need for laboratory separations-based measurements of logD.