Fabrication of Three-Dimensional Photonic Structures Utilizing Composite Colloids
The 3D nanoporous structures of inverse opals (IO), synthesized from a sacrificial colloidal crystal template, are potential candidates for applications in photonics, sensing, and catalysis.1 In order to utilize these structures as functional materials, tuning the IO composition is extremely important. The incorporation of metal nanoparticles into IO results in coupling of photonic and plasmonic properties, as well as the additional introduction of catalytic properties, thus greatly expands the possible applications of these composite materials.2,3 Moreover, the precise control over metal nanoparticles distribution into inverse opals structures, in particular the controlled placement of such particles at the air/solid interface of the individual pores, results in a higher accessibility of nanoparticles. In this work we synthesized composite polystyrene (PS) colloids by covalent attachment of gold nanoparticles (AuNPs) to the chemically modified PS surface. These composite PS-AuNP colloids were subsequently used as colloidal templates for IO formation. The accessibility of AuNPs at the air/solid interface allowed further growth of nanoparticles at defined positions of the inverse opal structure. SEM and TEM measurements reveal the formation of ordered 3D porous structures with well controlled gold distribution. The use of these composite IO systems for catalytic applications will be demonstrated.
1. a) Freymann, G.; Kitaev, V.; Lotschzc, B. V.; Ozin, G. A. Chem. Soc. Rev., 2013, 42, 2528. b) Hatton, B.; Mishchenko, L.; Davis, S.; Sandhage, K. H.; Aizenberg, J. Proc. Nat. Acad. Sci., 2010, 107, 10354.
2. a) Tan, Y.; Qian, W.; Ding, S.; Wang, Y. Chem. Mater. 2006, 18, 3385. b) Yu, A.; Meiser, F.; Cassagneau, T.; Caruso, F. Nano Lett. 2003, 4, 177.
3. Y. Vasquez, M. Kolle, L. Mishchenko, B. D. Hatton, J. Aizenberg, ACS Photonics, 2014, 1, 53minus;60