| 초록 |
The structural color of colloidal photonic crystals can be easily tuned by changing the spacing between colloid particles in a polymer by applying external stimuli such as humidity, temperature and pH condition. In this study, we design the hydrogel photonic film by dispersing monodispersed silica particles in a water-sensitive polymer. When the silica particles are chemically etched, the film has a pore structure. When the cross-linked density of the polymer is low, the pore structure is collapsed and the film appears transparent in the dry state. However, when the film absorbs water, the polymer is swelled and the pore structure is restored, resulting in exhibiting vivid structural color. The structural color can be tuned by adjusting the degree of swelling of the polymer by applying different external stimuli such as ethanol or pH condition. Thus, the encrypted pattern, fabricated using hydrogel materials, can be used to sensors or user-interactive anti-counterfeiting patches. |
