This Debye Colloquium, Colloidal Crystallization: from Structural Color to Encryption to Catalysis, will be given by Debye Visiting Chair Joanna Aizenberg from Harvard University.
This lecture will introduce a reproducible, one-pot sol-gel colloidal co-assembly approach that results in large-scale, highly ordered inverse opal films with embedded, uniformly distributed, and accessible nanoparticles. The unique coloration of these inverse opals combines iridescence with plasmonic effects. When locally functionalized, these films exhibit a sharply defined threshold wettability for infiltration that couples to macroscopic color changes. This approach may find applications in a broad range of technologies, including a convenient and direct method for liquid detection and encryption, or as a tag for low-cost monitoring of tampering or material aging. Extension of this methodology to create a new class of highly stable heterogeneous catalysts will also be discussed.