N. Borochov et A. Peled, AGGREGATION KINETICS OF PHOTO-EXCITED COLLOID SOLUTIONS OBSERVED BY DYNAMIC PHOTON-CORRELATION SPECTROSCOPY (PCS), Applied surface science, 86(1-4), 1995, pp. 533-537
Citations number
17
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
Factors such as temperature, chemical activity, ionic strength and pH
changes are known to affect colloid stability. This investigation conc
entrates on the new method of destabilizing colloid hydrosols by photo
n irradiation, recognizing the possibility of thereby controlling nucl
eation, growth and aggregation. Several unique advantages are obtained
by photon activation of colloids, such as spatial localization, wavel
ength selectivity and irradiation dose control. Using PCS, the post-ir
radiation particle aggregation dynamics of a-Se colloid hydrosols was
monitored. The variation of the average colloid particle diameter phi(
t) and the average colloid particle number m(t) vs. time shows two zon
es of distinct power law behaviour. The first zone, typical for times
of t less than or equal to 10(3) s shows a monotonic growth while for
longer times, saturation equilibrium values of phi and m are obtained,
which also exhibit a dose-memory effect.