Advanced Materials Research Vol. 924

Abstract: Preface and Committees

Abstract: CdSe Quantum Dots (QDs) sensitized TiO₂ photocatylysts were synthesized by a facile sol-gel method at room temperature. The effects of CdSe QDs concentration on the properties of the photocatalysts were studied by XRD, BET, SEM, UV/vis. The photocatalytic performance was investigated by degrading methylene blue (MB) under halogen-tungsten lamp irradiation. The results revealed that the catalysts doped with CdSe QDs show large surface area, small crystal size and narrow band gap. The catalysts doped with 0.05% CdSe QDs possessed the best activity, and the degradation efficiency of methylene blue (MB) is up to 99.2% within 180 min.

Abstract: Oxidative damage is a public health issue in the modern world and promoting dietary anti-oxidants, such as curcumin, is a promising strategy. However, curcumin is unstable and poorly water-soluble and of poor bioavailability. This study constructed new curcumin-loaded O/W microemulsions using a pharmaceutically accepted Brij97 nonionic surfactant and evaluated several properties of curcumin encapsulated in the microemulsions. The pseudo-ternary phase diagram of Brij97/isopropyl alcohol/ethyl acetate/water system was determined and three microregions of the microemulsionsW/O, bicontinuous, and O/Ware identified by conductivity measurements, according to percolation theory. The properties investigation of a series of curcumin-loaded O/W microemulsions indicates: (1) The curcumin in such a situation performs sustained release following the first-order kinetics; (2) Better stability of curcumin to the sun light is observed over a time scale; (3) The curcumin presents relatively high anti-oxidant activity, with the IC₅₀ in between 31.5 and 17.2 μg/ml on scavenging the superoxide radicals. In addition, the structure difference in the homologues acetate seems having no effect on the stability and release behavior of curcumin, while the investigated properties clearly depend on the ME/acetate ratio in the microemulsions. This study might be a potential help to the protection and the delivery of curcumin.

Abstract: The pomponlike CaMoO4:Eu3+ red phosphors were synthesized via a ethylene glycol (EG)-mediated hydrothermal method in the presence of urea at 140 °C for 1 h. The structure, morphology and luminescent property were characterized and investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL). The results show that the Eu3+-doped CaMoO4 micropompons were well-crystallized and assembled by nanosheets. The products display a strong red emission under near ultraviolet (UV).

Abstract: Different doping concentration Al-doped ZnO nanofibers were synthesized by Atom Layer Deposition (ALD) using PVP fibers as template. The influence of Al doping concentration on the structure and optical properties of nanofibers was investigated. The samples were characterized by means of X-ray diffraction spectra, field emission scanning electron microscopy (FESEM). After doping, the morphologies were not changed, only the diameters of Al-doped ZnO nanofibers became larger. Compared with undoped ZnO, the intensity of diffractive peaks of Al-doped ZnO nanofibers became weak with the increasing of the doping concentration due to stress generation in the crystallization process. In raman spectra, Al₂O₃ peak related peaks were also observed. In addition, the intensity of UV emission decreased with increasing Al doping concentration and had a red shift.

Abstract: Abstract: As it's excellent mechanical and electrical conversion characteristics, Piezoelectric material has become an important material for capturing environmental mechanical energy to get electrical energy. In this paper, (100) oriented PZT piezoelectric thick film has been prepared on Pt/Cr/SiO2/Si substrate by sol-gel used PT as transition layer. The influences of preparation process on the (100) oriented degree, ferroelectric properties, dielectric properties and piezoelectric properties of PZT piezoelectric thick film were investigated. Experiment results show that, the increasing of annealing temperature and shortening annealing time can promote PZT piezoelectric thick film growing along (100) orientation. The increasing of annealing temperature results in the decreasing of remnant polarization intensity and increasing of coercive field. Under the frequency of 1 KHz, (100) oriented PZT piezoelectric thick film with thickness of 1.5 m has the dielectric constant ˰̶̿˰́̃̅̆˼˰̈̃́˰̴̱̾˰̇̈̀˰̱̈́˰̵̷̱̱̼̹̾̾̾˰̵̹̈́̽˰̶̿˰̹̅̽̾˼˰̹́̀̽̾˰̴̱̾˰̹́̅̽̾˼˰̴̱̾˰̴̵̵̹̼̳̹̳̈́͂˰̴̹̹̱̹̓̓̀̈́̿̾˰̱̈́̾ڄ˰̹̓˰̀˾̃́£¬0.20 and 0.22, respectively. (100) orientation of PZT piezoelectric thick film can effectively improve the piezoelectric properties of PZT piezoelectric thick film, PZT piezoelectric thick film with thickness of 1.5 m and annealing time of 5min has the better (100) orientation degree, has the piezoelectric constant d33 of 102.5 pC/N. Keywords: (100) orientation; PZT generation material; ferroelectric properties; dielectric properties; piezoelectric properties

Abstract: Silica microspheres coated by nanoZrO₂ were prepared by the sol-gel process using butoxidesolution (TBOZ) as precursor. The nanomicrospheres were formed via hydrolysis and condension reaction of metal alkoxides with the hydroxyl (-OH) of silica microspheres by form Zr-O-Si bonds. The samples were characterized by X-ray diffraction, FT-IR and SEM. Presence of the FT-IR bands with frequencies ranging from 800 to 900 cm-1 can be assigned to SiO vibration, and to ZrOSi stretching vibration. XRD analysis shows obviously the characteristic diffraction peaks of tetragonal (T-ZrO₂) in the sample by heat-treatment at 400°C. The SEM image showed that the surface layers of silica microspheres were coated by nanoparticles.

Abstract: Fe³⁺-TiO₂-CTAB nanostructured films were prepared by self-assembly technique, using surfactant cetyltrimethyl ammonium bromide (CTAB). The properties of the samples were examined by thermogravimetric analysis (TGA), X-ray diffraction (XRD) and UV-Vis spectrophotometry, respectively. The crystalline phase of the sample calcined at 450°C is mostly anatase-TiO₂ (A) accompanied by a small amount of rutile-TiO₂ (R). No significant characteristic peaks of iron oxide were detected in the XRD patterns, it suggested that Fe³⁺ ions incorporated into the TiO₂ skeleton and composed the mesoporous structures with TiO₂ uniformly. Fe³⁺-TiO₂-CTAB nanofilms exhibited higher photocatalytic activity under the effect Fe³⁺ of and CTAB.

Abstract: Graphite oxide (GO), prepared by modified Hummer’s method from graphite, was reduced by hydrazine hydrate in the presence of sodium dodecylbenzene sulfonate (SDBS), leading to a concentrated aqueous graphene dispersion which was stable for more than one month. The analyses of XRD, UV-vis and Raman spectroscopy indicate that the reduced graphene oxide (RGO) was formed after chemical reaction, where single or multiple graphene sheets were observed by TEM and AFM, indicating that the RGO is well-dispersed in water through the operation.

Abstract: Cd_1-xZn_xS thin films were deposited on soda-lime glass substrates with chemical-bath deposition (CBD) using cadmium acetate, zinc sulfate, thiourea, ammonia and ammonium acetate aqueous solution at different with stirring. All the samples were annealed at 200 °C for 60 min in the air. The crystal structure, surface morphology, thickness and optical properties of Cd_1-xZn_xS thin films with increasing ammonia concentration were studied with X-ray diffraction (XRD), scanning electron microscopy (SEM), step height measurement instrument and spectrophotometer respectively. The results revealed that Cd_1-xZn_xS thin films had cubic crystal structure and the intensity of the diffraction peak decreased gradually as reaction temperature rose and the average crystal size was from 7.0 nm to 8.9 nm. All of Cd_1-xZn_xS thin films had a granular surface with some smaller pores. The Cd_1-xZn_xS thin films band gap was from 2.68 eV to 2.83 eV. The transmission of film deposited at 80 °C was highest. The suitable reaction temperature was from 70 °C to 80 °C.