Effects of compression and shearing on the microstructure of polymer-immobilized non-close-packed colloidal crystalline arrays

We have examined the changes in the optical properties and microstructure of polymer-immobilized non-close-packed colloidal crystalline arrays with compression and shearing stress. The optical properties and microstructures of the arrays were measured by angle-resolved reflection spectroscopy. The spectra indicate an increase in the refractive index and a decrease in the interplane spacing with compression, however, indicating an increase in the interplane spacing with shearing stress. These results show that compression decreases the interplane spacing without moving the inner-plane position, while shearing stress increases the interplane spacing by moving the position of the spheres in the same plane.