| 초록 |
Inverse opal structure is the negative replica of the opal structure. Therefore, as opals are composed of the close-packed array of face-centered cubic crystals, Inverse opals also show the regular structures. Their periodic modulation of different materials, in case of inverse opals, the embedded air cavities and the solid matrix, can create the stop band wavelength. This reflection wavelength depends on their architecture and the refractive indexes of the repeating materials. Here, we create the inverse opals made of biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), to use them as the colorimetric indicators for drugs and cosmetics which can improve the existing problems on expiration dates. To make the structure, we self-assembled the silica nanospheres on the PLGA film by using the hydrophilic treated substrate, and to embed the silica particles into the film, temperature was elevated. Then, by selective removal of opal template from the PLGA film, it leaves the PLGA inverse opal structure having biodegradable properties. Its biodegrade rates can be controlled with the environmental conditions which can shows the controlled discoloration. |
