In situ growth and structure of fractal silica aggregates in a flame

Technical Report · Thu Oct 01 04:00:00 EDT 1987

OSTI ID:5893758

Hurd, A J; Flower, W L

We studied flame-generated (fumed) silica particles in situ by static and dynamic light scattering and ex situ by transmission electron microscopy. The growth and aggregation of the particles was followed as a function of height in the flame. The scattered intensity appeared to be consistent with a fractal aggregate structure having a fractal dimension of D = 1.49 (smaller than previously reported ex situ measurements of fumed silica) although the data are too limited to determine D with certainty. From the dynamic light scattering results, corrected for polydispersity, the growth trend appeared to deviate from free-molecular behavior for long residence times. From the electron microscopy, we noted a surprising tendency for the silica monomers to shrink with residence time. 32 refs., 1 fig., 2 tabs.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA); Sandia National Labs., Livermore, CA (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5893758
• Report Number(s): SAND-87-2372; ON: DE88003241
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
AGGLOMERATION
CHALCOGENIDES
ELECTRON MICROSCOPY
FLAMES
GROWTH
LIGHT SCATTERING
MICROSCOPY
MINERALS
MONOMERS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PARTICLES
SCATTERING
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SIZE
TRANSMISSION ELECTRON MICROSCOPY