Solvent And Stress Response Of Polyacrylamide Hydrogel Photonic Crystals

Photonic crystals are synthetic materials patterned in three-dimensions with periodicity in dielectric constant. This material has some impressive characteristics such as photonic bandgap and photonic localization which could control the transmission of light. Photonic crystals have bright prospects in optoelectronic devices and communications area.Responsive photonic crystals are materials with photonic bandgap responding to external stimuli (such as pH, temperature, stress, specific chemicals). Photonic crystals are fabricated with responsive polymers, which could change on its volume under certain external stimulate, and the color and spectra change in macroscopy. The detail works of this dissertation are listed below:First, monodisperse polystyrene spheres with diameters from 180nm-300nm have been synthesized by emulsion polymerization.Second, single crystalline opal structural polystyrene template has been prepared by vertical deposition method. The deposition speed of colloid particles is determined by adjusting the deposition temperature and emulsion concentration. Single crystalline face centered cubic structure polystyrene template has been made in certain conditions.Third, the opal structure template is infiltrated by precursor solution (AM, AM/AA, AM/NSA) and then polymerized in room temperature by redox initiator. By immersing polymers in chloroform to remove the template, inverse opal structure hydrogel photonic crystal is fabricated. Well ordered three dimensional inverse opal structure could be analyzed by SEM and reflectance spectra.In the end, responsive abilities of the hydrogel have been measured, and the hydrogel is well responsive to organic solvent/water solution, BSA and external stress.