2P-31: Microfluidic fabrication of colloidal photonic crystal particles with various surfactants

Structural color results from optical phenomena such as interference and diffraction of light has been investigated as a good alternative to conventional light-absorbing dyes due to their lots of advantages including non-fading, low toxic and environmentally benign characteristics. In particular, colloidal photonic crystals (CPCs) have been widely studied because of angle-independent optical properties. To fabricate CPC structures, we generated double emulsions using a microfluidic device and subsequently induce dewetting of CPC cores with mechanical stimuli. The stability of the generated double emulsions can be controlled by interfacial tensions of fluids. We found that PVA surfactant contributes the stability of CPC core particles and another type of surfactant, PEG-PPG-PEG triblock copolymer can make double emulsions stable. As a result, we can control the stability of CPC core particles by optimizing the microfluidic condition of using surfactants.