| 학회 |
한국화학공학회 |
| 학술대회 |
1998년 봄 (04/24 ~ 04/25, KOEX) |
| 권호 |
4권 1호, p.961 |
| 발표분야 |
재료 |
| 제목 |
기상에서 나노미터 크기의 티타니아 입자들로 구성된 응집체의 구조재배열 |
| 초록 |
The in situ restructuring of chain aggregates of titania nanoparticles by heating was investigated. Titania nanoparticles(dp 7nm) were prepared by thermal decomposition of titanium tetraisopropoxide vapor in a N2 carrier gas and allowed to form aggregates with a count mean mobility diameter of 110nm. The change in mobility diameter of the aggregates was measured to determine the fractal dimension, Df, using two differential mobility analysers and a condensation particle counter. The gas temperature was varied from about 20℃ to 1,000℃. Aggregates that restructured at 900℃ and a residence time of 5.10sec reached a close-packed structure as observed in the electron microscope. The value of the Df increased from 2.33 to 3.00 as the restructuring temperature increased. The activation energy for restructuring estimated from the Df and the coordination number was 2.28 x 10-19J, almost an order of magnitude higher than that of metal aggregates such as silver and copper.
|
| 저자 |
장희동, Sheldon K. Friedlander
|
| 소속 |
한국자원(연) |
| 키워드 |
resturcturing; aggregated titania; gas-phase
|
| E-Mail |
|
| 원문파일 |
초록 보기 |
