Supported gold (Au) nanocatalysts hold great promise for heterogeneous catalysis; however, their practical application is greatly hampered by poor thermodynamic stability. Herein, a general synthetic strategy is reported where discrete metal nanoparticles are made resistant to sintering, preserving their catalytic activities in high-temperature oxidation processes. Taking advantage of the uniqu...

The material bone consists of a biopolymer matrix (collagen) reinforced with mineral nanoparticles (carbonated hydroxylapatite), forming a natural composite which builds up a dense shell on the exterior and a network of struts with a mean diameter of 200μm in the core of many bones. The architecture of the foamy inner part of bones (spongiosa) is determined by loading conditions. The architectu...

The kinetics of hot-pressing for undoped and donor-doped BaTiO3 of high purity have been studied at 1050~ and at 2.3 to 27.6 MPa in an oxidizing atmosphere. The stress exponent and grain size exponent of the densification rate are indicative of control of densification by a grain boundary diffusion mechanism. The activation enthalpy (,~ 400 kJ mo1-1 ) for the densification process has been meas...

Transparent Pb(Zn1/3Nb2/3)O3–(Pb1-xLax)(Zr1-yTiy)O3 (PZN–PLZT) ferroelectric ceramics have successfully been prepared by hot-pressed sintering in oxygen atmosphere. Uniform cylindrical samples with diameter as large as 50 mm can readily be obtained. X-ray analysis and scanning electron microscopy experiments showed a pure perovskite phase, thin grain boundaries, and uniform dense microstructure...

We combine optical absorption spectroscopy, ex situ transmission electron microscopy (TEM) imaging, and variable-temperature measurements to study the effect of ultraviolet (UV) light and heat treatments on ethanedithiol-treated PbS quantum dot (QD) films as a function of ambient atmosphere, temperature, and QD size. Film aging occurs mainly by oxidation or ripening and sintering depending on Q...

In this study, we tailor the microstructure of hydroxyapatite/zirconia nanocrystalline composites by optimizing processing parameters, namely, introducing an atmosphere of water vapor during sintering in order to control the thermal stability of hydroxyapatite, and a modified sol-gel process that yields to an excellent intergranular distribution of zirconia phase dispersed intergranularly withi...

This work deals with the design, the characterization and testing of a novel glass-ceramic to be used as sealant for planar solid oxide fuel cells and its compatibility with Mn1.5Co1.5O4 coated Crofer22APU. Thermal, sintering and crystallization behaviour and thermo mechanical properties of the sealant are reviewed and discussed, indicating therefore that these compositions can be deposited at ...