| 초록 |
Colloidal crystals show structural colors through selective reflection of light at stopband. We can fabricate photonic capsules with colloidal crystals by microfluidic devices. When polymer chains and particles are present in the medium, the polymer chains induce depletion-attraction between particles. Even charged colloidal particles are crystallized in the medium by depletion-attraction force. Here, photonic capsules which display mixed structural color is achieved by independent crystallization of polystyrene (PS) nanoparticles with different sizes via depletion-induced phase separation. Crystallization of colloids occurs during the concentration process of capsules that contain PS nanoparticles and depletant. We crystallize two types of particles in groups by controlling the attraction force. In addition, the degree of color mixing is controlled by the sizes of each crystallite, which are controllable with the rate of concentration. |
