(70o) Colloidal Crystals of Polystyrene with High Surface Charge in Dilute Aqueous Suspension

Colloidal Crystals of Polystyrene with High Surface Charge in Dilute
Aqueous Suspension

Colloidal
crystals with high quality mentioned in numerous literatures were obtained
mostly under the condition of high concentration suspension of colloidal
spheres, our group has acquired polystyrene colloidal crystals with high
concentration of colloidal particle, PS diameters range from 120nm to 250nm,
the concentration of suspensions are about 6~10wt%. While colloidal crystal
with low suspension concentration has been wined, lower than 2wt%, which
irradiated flowery colors under sunshine in the proceeding of crystalline, once
the colloidal crystal arrange into single crystalline, the irradiated light
will be single color in one direction. The reason that dilute concentration
suspension can form colloidal crystal is that the PS colloidal particles had
high surface charge density, so the particle had strong repelling interaction
each another affording the longer range crystal lattice.