Fabrication and investigation of two-dimensional photonic colloid crystal structures

Photonic crystals are structures that guide the light. When a laser light is reflected onto micrometer sized colloid particles forming 2 dimensional hexagonal structure, Bragg scattering occurs and the scattering pattern reveals a Debye ring which is easily observed on the screen. The size of the Debye ring is related to the distance between the colloidal particles. In this thesis, temperature responsive material of NIPAM (N-isopropylacrylamide) monomers have been polymerized onto the 2-dimensional hexagonal photonic colloidal crystals, and this procedure has emerged a new hybrid system as temperature sensitive photonic colloidal crystals. This hybrid system shrinks above a certain temperature and the distance between underlying colloidal particles decreases as the temperature increases. In this thesis, by using different amounts of NIPAM, acrylic acid, acrylamide and crosslinker, the change in the distance between particles due to temperature has been observed for the first time using colloid photonic crystals with 2-dimensional hexagonal array. A basic Bragg diffraction experimental setup is built in the laboratoy and Debye rings are recorded by a digital camera to measure the distance between the particles before and after volume phase transition occurs at different temperatures. The decreasing distance between the particles are observed which is predicted by the theory and the previous studies. The detailed studies on the effect of the components of the hydrogel system have been performed for the first time on this system.