Nano-engineering of zirconia–noble metals composites

Nano-explosion synthesis of multi-component ceramic nano-composites

“…A typical prior art synthesis procedure involves several sequential steps: cination; and (F) synthesis of the end-product powder via calcinations, i.e., thermal decomposition of the intermediate products. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Due to the high surface energy and chemical activity of nanoparticles, aggregation and subsequent or simultaneous hard agglomeration are the main problems encountered in the preparation of such powders. Despite these difficulties, several aqueous solution-based precipitation techniques have been employed to synthesize nanosize ceramic powders.…”

“…These include the use of ammonia, oxalic acid, urea, ammonium carbonate and hexamethylenetetramine precipitants. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Preparation techniques have included approaches based on sol-gel processing, reverse-micellar nanoreactor, 3,4 hydrothermal synthesis, [13][14][15] sonochemically and/or microwave-assisted decomposition of various aqueous (or non-aqueous) precursor solutions, 15 salt-assisted aerosol decomposition and combustion synthesis. [19][20][21][22][23][24][25][26] However, processing multi-component fine powders has proven to be extremely challenging and usually results in a non-homogeneous multiphase compound with poor morphology.…”

Nanoblast synthesis and SPS of nanostructured oxides for SOFC

“…Ceramic nanopowders are usually synthesized by several aqueous-solution-based precipitation techniques [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] which have included approaches based on sol-gel processing , a reverse-micellar nanoreactor [3,4], hydrothermal synthesis [13][14][15], sonochemically and/or microwave-assisted decomposition of various aqueous (or non-aqueous) precursor solutions [15], salt-assisted aerosol decomposition and combustion synthesis [16][17]. However, due to the differences in the synthesis kinetic, high surface energy of the nanoparticles, and its chemical activity, hard agglomeration and the compositional inhomogeneity are the main problems encountered in nanosynthesis [1,[6][7][8][9][10][11][12][13][14][15][18][19][20][21][22][23][24][25]…”

“…However, due to the differences in the synthesis kinetic, high surface energy of the nanoparticles, and its chemical activity, hard agglomeration and the compositional inhomogeneity are the main problems encountered in nanosynthesis [1,[6][7][8][9][10][11][12][13][14][15][18][19][20][21][22][23][24][25][26].…”

“…The preparation conditions of the 8Y-SZ nanopowder were well described in earlier papers [14,15]. Urea (NH 2 CONH 2 99% pure and produced by Wako Pure Chemicals Co., Japan) was used as a precipitation agent in the present study.…”