D. Hibberd et al., ULTRASONIC MONITORING OF OIL-IN-WATER EMULSIONS UNDERGOING DEPLETION FLOCCULATION, Journal of colloid and interface science, 193(1), 1997, pp. 77-87
The paper describes a three-part experiment on flocculating emulsions
in order to determine whether ultrasonic spectroscopy could be used to
detect and characterize the flocculation process. Three emulsions whi
ch represented unflocculated, partially flocculated, and fully floccul
ated systems were prepared, They were characterized independently usin
g direct microscopic examination and their creaming behavior. Ultrason
ic spectroscopic measurements of the flocculating emulsions showed lar
ge changes during the flocculation process, which were not readily mod
eled using single particle scattering theory, The ultrasonic propertie
s of the unflocculated emulsion did not change during the measurement
period. The results demonstrate that ultrasonic techniques are capable
of detecting the flocculation process. There is clear potential to us
e ultrasonic techniques to characterize flocculated structures, but mo
re work is needed on the theoretical analysis of the interaction of ul
trasound with particle aggregates. (C) 1997 Academic Press.