Synthesis and crystal chemical evolution of fresnoite powders

(Ba,Sr) 2TiSi 2O 8 fresnoite powders were prepared via a Pechini process in which citric acid and ethylene glycol were used as complexing agents. The resulting gel contained a homogeneous distribution of the metal ions that suppressed the formation of (Ba,Sr)TiO 3 perovskite as a secondary phase during calcination. Phase development was examined as by isochronal and isothermal reaction analysis. A combination of thermo- and differential gravimetric analysis (TGADGA), quantitative X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed that calcination at 900 °C/12 h yielded finely crystalline (∼70 nm) Ba 2TiSi 2O 8 (BTS) and Sr 2TiSi 2O 8 (STS). The endmembers and compositional intermediates crystallized directly from the Pechini resin and indirectly through reaction of (Ba,Sr)CO 3, (Ba,Sr)TiO 3 and a silica-rich glass intermediates. This new method for preparing fresnoite yields materials suitable for consolidation as dense monolithic dielectrics or for use as high surface area catalytic powders

PEG-POSS Assisted facile preparation of amphiphilic gold nanoparticles and interface formation of Janus nanoparticles

Chemical Communications472767-769CHCO

Synthesis and crystal chemical evolution of fresnoite powders

(Ba,Sr)2TiSi2O8 fresnoite powders were prepared via a Pechini process in which citric acid and ethylene glycol were used as complexing agents. The resulting gel contained a homogeneous distribution of the metal ions that suppressed the formation of (Ba,Sr)TiO3 perovskite as a secondary phase during calcination. Phase development was examined as by isochronal and isothermal reaction analysis. A combination of thermo- and differential gravimetric analysis (TGA–DGA), quantitative X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) confirmed that calcination at 900 °C/12 h yielded finely crystalline (∼70 nm) Ba2TiSi2O8 (BTS) and Sr2TiSi2O8 (STS). The endmembers and compositional intermediates crystallized directly from the Pechini resin and indirectly through reaction of (Ba,Sr)CO3, (Ba,Sr)TiO3 and a silica-rich glass intermediates. This new method for preparing fresnoite yields materials suitable for consolidation as dense monolithic dielectrics or for use as high surface area catalytic powders

Fabrication of CFRP from high performance clay/epoxy nanocomposite: Preparation conditions, thermal-mechanical properties and interlaminar fracture characteristics

10.1016/j.compositesa.2011.02.014Composites Part A: Applied Science and Manufacturing428881-887CASM

Synthesis of contiguous silica-gold core-shell structures: Critical parameters and processes

10.1021/la703580rLangmuir2495109-5112LANG

Synthesis of gold nanoshells based on the deposition-precipitation process

Gold Bulletin41123-3

Particle size effect of silver nanoparticles decorated single walled carbon nanotube electrode for supercapacitors

10.1149/1.3267874Journal of the Electrochemical Society1572A179-A184JESO

Property change in multifunctional TiCxOy thin films: Effect of the O/Ti ratio

TiCxOy films with various O/Ti ratios have been deposited by DC magnetron sputtering, using C pieces incrusted in a Ti target erosion area. Composition analysis revealed the existence of three different growth regimes: (i) zone I, corresponding to films with metallic-like appearance, and atomic ratios O/Ti below one; (ii) zone II, with films revealing interference-like colours, and atomic ratios O/Ti higher than 2. Between these two regions, there was a transition zone T, where the atomic ratio O/Ti is between one and two. The films within this zone revealed a brown colour. X-ray diffraction (XRD) structural characterization results showed an evolution from a mixed Ti(C,O) phase at lower O/Ti ratio, to a quasi-amorphous structure within zone T, and poorly crystallized rutile and anatase TiO2 at the highest O/Ti ratios (zone II). These different structural arrangements resulting from different film's compositions had clear effects on electrical resistivity, whose values increased from about 7 × 102 to 2 × 1011 [mu][Omega] cm with increase of the O/Ti ratio. Fourier-transform infrared spectroscopy (FTIR) was used to further confirm the different nature of films structure and, thus, to better understand their properties variation. The observed behaviour was found to be in straight correlation with those of XRD.http://www.sciencedirect.com/science/article/B6TW0-4KWK0WW-3/1/f0de0f5875ba8dd82aec3345e10bf93