Tough and Hydrophilic Photonic Crystals Obtained from Direct UV Irradiation.

Tough and hydrophilic polystyrene (PS) photonic crystals (PCs) were obtained from direct UV irradiation. The irradiation procedure results in photochemical cross-linking of PS spheres, which leads to the enhanced mechanical strength of the PC films, without degrading the spectra quality of the PCs. Otherwise, the irradiation induces the formation of the carbonyl groups upon the latex surface, which changes the wettability of the films from hydrophobicity to high hydrophilicity. The results provide a facile and effective approach to fabricate functional PC films with high mechanical strength and special wettability, which will be of great importance for the practical application of PCs.