Search

Abstract: Nanometer-sized particles (1–100nm) are of considerable interest for a wide variety of applications, ranking from catalyst to luminescence ceramics, due to their unique and improved properties primarily determined by size, composition and structure. In this study, we report a simple, rapid aerosol decomposition process for the continuous synthesis of nanoparticles with adjustable sizes, narrow size distribution, high crystallinity and good stoichiometry. This paper presents the preparation and characterization of nanostructured spherical alumina particles (<500nm sized) by low temperature aerosol synthesis for the application in MMCs reinforcement. Synthesis procedure includes aerosol formation ultrasonically from alumina nitrate water solution and its decomposition into a tubular flow reactor at 400°C. Consequently, as-obtained particles are spherical, smooth, amorphous and in non-agglomerated state. The phase crystallization, either into γ-Al2O3 or α-Al2O3 is promoted by additional thermal treatment ranging between 700°C and 1300°C. Detailed phase and structural analyses were carried out using X-ray powder diffraction (XRD), scanning electron microscopy (SEM/EDS) and analytical and high-resolution transmission electron microscopy (TEM/HRTEM). [Copyright &y& Elsevier]

Abstract: In the field of materials for lithium ion batteries, the lithium iron phosphate LiFePO4 has been proven for use as a positive electrode due to its good resistance to thermal degradation and overcharge, safety and low cost. The use of nanostructured materials would improve its efficiency. This work shows the results of the synthesis of nanostructured materials with functional properties for lithium batteries through aerosol techniques. The Spray Pyrolysis method allows synthesizing nanostructured particles with spherical geometry, not agglomerates, with narrow distribution of particle size and homogeneous composition in respect to a precursor solution. Experimental techniques were focused on the morphological (SEM and TEM), structural (XRD and HRTEM-SAED), chemical (EDS) and electrochemical characterization. [Copyright &y& Elsevier]