Structural Colored Gels for Tunable Soft Photonic Crystals

A periodically ordered interconnecting porous structure can be embodied in chemical gels by using closest-packed colloidal crystals as templates. The interconnecting porosity not only provides a quick response but also endows the porous gels with structural color arising from coherent Bragg optical diffraction. The structural colors revealed by porous gels can be regulated by several techniques, and thus, it is feasible to obtain desirable, smart, soft materials. A well-known thermosensitive monomer, N-isopropylacrylamide (NIPA), and other minor monomers were used to fabricate various structural colored gels. The selection of minor monomers depended on the targeted properties. This review focuses on the synthesis of templates, structural colored porous gels, and the applications of structural colored gel as smart soft materials for tunable photonic crystals. (D 2009 The Japan Chemical journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 87-105; 2009: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20169