Effect of Particle Size on Rate of Coalescence of Silica Nanoparticles
โ Scribed by Sheryl H. Ehrman
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 51 KB
- Volume
- 213
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
โฆ Synopsis
In high temperature processes, at high concentrations, aerosol particles grow by collisions and coalescence. The rate of coalescence is an important parameter for predicting the final primary particle size. For some materials, particularly silica, predictions of final primary particle size using coalescence rates based upon bulk material properties are not in agreement with experimental results. One explanation may be that the high internal pressure in very small particles (less than 10 nm in diameter) affects the mobility of material within the particles and hence the coalescence rate. In this Note, a new approach for estimating rates of coalescence of particles in the initial stages of growth is presented. Coalescence of liquid particles is assumed to be rate-limited by atomic mobility, and the effect of internal pressure on diffusivity is considered.
๐ SIMILAR VOLUMES
Compressed tablets were prepared on a hydraulic press at several different compaction pressures by a standardized technique, using aspirin, dicalcium phosphate dihydrate, calcium phosphato-carbonate, alumina, and microcrystalline cellulose. All tablets except microcrystalline cellulose contained a c
Fumed silica is a synthetic amorphous silicon dioxide produced by burning silicon tetrachloride in an oxygen-hydrogen flame. Surface areas range from 50ยฑ400 m 2 /g. Using particle sizing techniques, fumed silica shows micron sized particles leading to surface areas markedly lower than expected. Fume
## The determination of standard deviation requires size The size-dependence of growth rate of monodisperse silica partimeasurement of a large number of particles, and the standard cles was investigated by analyzing the competitive growth of a deviation of monosize particles is small, so that foll
11), hydrophobic interaction (12, 13), secondary minimum The influence of particle size on the kinetics of slow Brownian coagulation (6-8, 14-16), slow equilibration of the surface coagulation is studied. Colloidal gold was chosen as a model syscharge during the collisions (17, 18), etc.-into tradit