949 resultados para Variations


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Chinese Academy of Sciences [KZCX2-YW-315-2]; National Natural Science Foundation of China [40701021, 40625002]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The phase and morphology variations of titania prepared in ethanol/acetic acid mixture solvents have been systematically investigated. X-ray diffraction results and microscopy observations reveal that pure anatase aggregates consisted of small nanoparticles, pure rutile microspheres comprised of nanofibers, and their mixtures could be obtained by varying ratios of ethanol to acetic acid under solvothermal conditions. The contents of anatase and rutile in the mixed phases also vary with the ratios of ethanol to acetic acid. Field emission scanning electron microscopy and high resolution transmission electron microscopy results show that the two phases are separated from each other in final products and form aggregates with morphologies resembling to their pure phase products obtained under favorable conditions. The as-produced rutile nanofibers, either in pure phase or in mixed phases, tend to grow into hollow microspheres.