Fabrication And Application Of Inverse-opal Hydrogel Photonic Crystal Microparticles

Photonic crystals(PCs) are optical materials with periodic distribution of different refractive index. The light can not travel in the photonic band gap of PCs and has bragg diffraction, it can thus be tuned. Photonic crystals have attracted much attention because of their potential applications in display, multiplex detection, sensor, optical fiber and so on. At present, mechanochromic responsive PC have some problems: angle dependence and slow response rate, therefore,it can not used in rapid and precise naked-eye detection; Photonic crystal micropaticles can overcome the problem of angle dependence, but the photonic crystal microparticles is mainly hard sphere, and there is small response to outside stimuli.Firstly, silica photonic crystal microparticles(SPCM) can be obtained by the selfassemble of silica nanoparticles. Secondly, we use the silica photonic crystal microparticles as template to prepare inverse-opal hydrogel photonic crystal microparticles(IOHPCM), this kind of IOHPCM is compose of polyacrylamide-acrylic acid(PAM-AA), and it can response to pH and organic solvent and glucose. When the pH of the solution increases, the carboxyl on hydrogel transform into carboxylate which make the osmotic pressure increases, and leading to hydrogel microparticle swell and the diffraction wavelength redshift. The hydrogel microspheres has a single structure color, and it can achieve full color change under different pH value. Hydrogel microparticle was further modified to incorporate 3-acrylamidophenylboronic acid into the hydrogel matrix. When 3-acrylamidophenylboronic acid combined with glucose, there form a donnan potential in hydrogels surface and showed swelling response in glucose aqueous solution, and the diffraction wavelength redshift. The hydrogel microspheres is angle-independent. Because hydrogel microspheres containing ordered porous, the small molecule can be quickly spread into inside. Conclusively we get fast response and angle-independent inverse-opal hydrogel photonic crystal microspheres.