Department News
Evaluation of Sintering of Nanoparticles by Aerosol Method
Seminar Date
2000-06-15
Author
관리자
Date
2000-06-15
Views
861
1. 제 목 : Evaluation of Sintering of Nanoparticles by Aerosol Method
2. 연 사 : Dr. Takafumi Seto
Mechanical Engineering Lab,
Ministry of International Trade and Industry, JAPAN
3. 일 시 : 1999년 9월 16일 (목) 17:00 - 18:00
4. 장 소 : 301동 1409-1호
5. 내 용 :
In gas phase particle synthesis processes, the control of particle morphology is important because it can affect the properties of particles generated. Sintering of an agglomerated particle is especially important since it tends to determine the structure and size of the final particles.
In this study, the sintering of polydisperse agglomerates composed of nm-sized primary particles is investigated both experimentally and theoretically.
The metal oxide agglomerates are produced by thermal decomposition of the alchoxide vapor and have an agglomerate size of 100 nm with a primary particle size of 6 nm. To evaluate changes in the size distribution due to further heating, the particles are introduced directly into a second furnace. Size distributions of the agglomerates and primary particles are measured using a differential mobility analyzer (DMA, TSI model 3071) with a condensation nucleus counter (CNC, TSI model 3022) and transmission electron microscopy (TEM), respectively. From the surface area, volume and primary particle diameter distributions, the structure of the agglomerate particles can be determined. When the agglomerates are heated further in the tube furnace, the average size of agglomerates start to decreases at 1273 K. From the TEM picture at this temperature, the neck between the primary particle start to grow rapidly as do the primary particles themselves. By 1773 K, the agglomerates have become spherical particles and the diameters obtained by mobility measurements agree with the TEM values. The experiments were modeled using a two dimensional sectional representation of the population balance equations to characterize the agglomerate surface area and volume distributions (Koch and Friedlander, 1990, Xiong et al., 1993). The numerical simulation showed good agreement with the experimentally observed changes in the size distributions of both the primary particles and the agglomerates.
6. 문 의 : 최만수 교수 (☏ 880-7128)
2. 연 사 : Dr. Takafumi Seto
Mechanical Engineering Lab,
Ministry of International Trade and Industry, JAPAN
3. 일 시 : 1999년 9월 16일 (목) 17:00 - 18:00
4. 장 소 : 301동 1409-1호
5. 내 용 :
In gas phase particle synthesis processes, the control of particle morphology is important because it can affect the properties of particles generated. Sintering of an agglomerated particle is especially important since it tends to determine the structure and size of the final particles.
In this study, the sintering of polydisperse agglomerates composed of nm-sized primary particles is investigated both experimentally and theoretically.
The metal oxide agglomerates are produced by thermal decomposition of the alchoxide vapor and have an agglomerate size of 100 nm with a primary particle size of 6 nm. To evaluate changes in the size distribution due to further heating, the particles are introduced directly into a second furnace. Size distributions of the agglomerates and primary particles are measured using a differential mobility analyzer (DMA, TSI model 3071) with a condensation nucleus counter (CNC, TSI model 3022) and transmission electron microscopy (TEM), respectively. From the surface area, volume and primary particle diameter distributions, the structure of the agglomerate particles can be determined. When the agglomerates are heated further in the tube furnace, the average size of agglomerates start to decreases at 1273 K. From the TEM picture at this temperature, the neck between the primary particle start to grow rapidly as do the primary particles themselves. By 1773 K, the agglomerates have become spherical particles and the diameters obtained by mobility measurements agree with the TEM values. The experiments were modeled using a two dimensional sectional representation of the population balance equations to characterize the agglomerate surface area and volume distributions (Koch and Friedlander, 1990, Xiong et al., 1993). The numerical simulation showed good agreement with the experimentally observed changes in the size distributions of both the primary particles and the agglomerates.
6. 문 의 : 최만수 교수 (☏ 880-7128)
