Diffraction Color Developed by Self-Assembly of Silica Particle Arrays

Abstract

Thin films of ordered arrays were fabricated with size-controlled silica spheres by solvent evaporation method. The ordered arrays could transmit a light of specific wavelength, which was significantly dependent on the particle size and confirmed using UV transmission spectroscopy. The stop band in UV spectrum was blue-shifted with a decrease in particle size, which can be explained by Bragg's diffraction law. By theoretical calculation, the colloidal crystal prepared with silica particles of 480 nm should show maximum transmission at 1056 nm and the self-assembled multilayer prepared with 560 nm-sized particles should exhibit stop band at 1390 nm, which, however, showed deviations of stop band between theoretical and experimental values. The deviation between theoretical and experimental values can be regarded as a result from the defects and disordered area in the colloidal crystal.

Keywords:

• colloidal crystal
• ordered array
• silica spheres

Acknowledgments

Financial support from Regional Technology Innovation Program of the Ministry of Commerce, Industry, and Energy (MOCIE) is gratefully acknowledged (Grant No. RTI04-01-04).