Suitable Conditions to prepare regular composite fine particles which
were comprised of organic and inorganic compounds were investigated us
ing polystyrene lattices (2a = 180 nm) and alpha-alumina powders with
different particle sizes (2a = 1100 nm, 850 nm, and 400 nm), based on
heterocoagulation theory. It is apparent that under suitable condition
s (medium pH = 3 approximately 4, particle number ratio of latex and a
lpha-alumina greater-than-or-equal-to 300/1), the heterocoagulates gen
erated from their mixtures were comprised of regular composite particl
es. These were made of latex particles adhering on alpha-alumina parti
cles in the core. The fraction coverage of lattices increased with dec
reasing the particles size of alumina. Further, the behavior was influ
enced dramatically by the concentration of alumina particles in the mi
xing process; a ragular composite can be generated only from the dilut
ed suspensions of ca 0.2 wt%.