A method for the determination of trace amounts of La, Y and Eu, based on the formation of volatile chelates between rare earth elements and 1-phenyl-3-methyl-4-benzoyl-pyrazolone [5] (PMBP) in a graphite furnace, is described. PMBP was used as a chemical modifier for the volatilization of La, Y and Eu from the electrothermal vaporizer into the ICP. The factors affecting the chelating reaction between La, Y and Eu and PMBP were studied in detail, and the vaporization behavior of the chelates formed in the graphite furnace was also investigated. It was found that the presence of an excess of PMBP was necessary to prevent the thermal decomposition of the chelates during the volatilization and transportation processes. Under the optimized conditions, the limits of detection for La, Y and Eu are 8.0, 1.0 and 0.9 ng ml-1, respectively, and the relative standard deviations range from 3.3% (La) to 4.0% (Y). The linear ranges of the calibration graphs span three orders of magnitude. The method was applied to the analysis of an environmental reference material and the results obtained were in good agreement with the reference values.

Titania was synthesized from laurylamine hydrochloride (LAHC) and Ti(SO4)2 under different acidic conditions. The effect of acidity on the structural and textural evolution of titania has been investigated by X-ray diffraction (XRD), nitrogen adsorption-desorption, transmission electron micrographs (TEM), FTIR spectroscopy and thermogravimetric analysis (TGA). With increasing the pH value in the initial mixture, the obtained samples transformed from nanoparticles with intra-particle mesostructures (pH 0.6 and 2.0) to nanoparticles with nonporous structure (pH 3.7), and finally to worm-like porous materials with inter-particle mesostructures (pH 4.2)resulted from the aggregates of nanoparticles. The obtained mesoporous nanoparticles (pH 0.6 and 2.0) have mean diameter of ca. 25 nm, and the pore size distributions are bimodal with fine intra-particle pores and larger inter-particle pores. The intra-particle mesostructure not only retard the growth of nanocrystallites, but also prevent phase transition of anatase to rutile at high temperature. The BET surface area of the TiO2 calcined at 300 C decreased from 212 to 74 m2/g with pH increasing from 0.6 to 4.2.

Mesoporous titanium dioxide nanosized powder with high specific surface area and anatase wall was synthesized via hydrothermal process by using cetyltrimethylammonium bromide (CTAB) as surfactant-directing agent and pore-forming agent. The resulting materials were characterized by XRD, nitrogen adsorption, FESEM, TEM, and FT-IR spectroscopy. The as-synthesized mesoporous TiO2 nanoparticles have mean diameter of 17.6nm with mean pore size of 2.1nm. The specific surface area of the as-synthesized mesoporous nanosized TiO2 exceeded 430m2/g and that of the samples after calcination at 600℃ still have 221.9m2/g. The mesoporous TiO2 nanoparticles show significant activities on the oxidation of Rhodamine B (RB). The large surface area, small crystalline size, and well-crystallized anatase mesostructure can explain the high photocatalytic activity of mesoporous TiO2 nanoparticles calcined at 400℃.

Mesoporous titania nanoparticles with high specific surface area and thermal stable anatasewallwas synthesized from surfactant laurylamine hydrochloride (LAHC) and inorganic precursor Ti(SO4)2. The as-synthesized and calcined materials were characterized by X-ray diffraction, nitrogen adsorption-desorption, transmission electron micrographs, Fourier transform infrared spectroscopy and thermogravimetric analysis. The obtained mesoporous TiO2 nanoparticles have mean diameter of 25.5 nm. The specific surface area of the mesoporous nanosized TiO2 calcined at 400℃ exceeded 189m2 g−1, and that of the samples after calcinations at 500℃ still have 151m2 g−1. The obtained anatase mesoporous TiO2 nanoparticles show relative high thermal stability.

Eu2+, Dy3+ co-doped strontium aluminate (SrAl2O4) phosphor nanometer powders with high brightness and long afterglow were prepared by heating the precursor gel (resulted from sol-gel method) at 900℃ and a reductive atmosphere of active carbon. The average particle size of the SrAl2O4:Eu, Dy phosphor powders was 59±7nm and its optical properties have been studied systematically. The broad band UV excited luminescence of the SrAl2O4: Eu, Dy was observed at λmax=506nm due to transitions from the 4f65d1 to the 4f7 configuration of the Eu2+ ion. The results indicated that the main peaks in the emission and excitation spectrum shifted to the short wavelength compared with phosphor obtained by the solid-state reaction synthesis method. The decay speed of the afterglow for nanometer phosphors was faster than that obtained by the solid-state reaction method.