Assembly of reconfigurable one-dimensional colloidal superlattices due to a synergy of fundamental nanoscale forces

TitleAssembly of reconfigurable one-dimensional colloidal superlattices due to a synergy of fundamental nanoscale forces
Publication TypeJournal Article
Year of Publication2012
AuthorsYoung, KL, Jones, MR, Zhang, J, Macfarlane, RJ, Esquivel-Sirvent, R, Nap, RJ, Wu, J, Schatz, GC, Lee, B, Mirkin, CA
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue7
Pagination2240 - 2245
Date Published2012/02/14/
ISBN Number0027-8424
Abstract

We report that triangular gold nanoprisms in the presence of attractive depletion forces and repulsive electrostatic forces assemble into equilibrium one-dimensional lamellar crystals in solution with interparticle spacings greater than four times the thickness of the nanoprisms. Experimental and theoretical studies reveal that the anomalously large d spacings of the lamellar superlattices are due to a balance between depletion and electrostatic interactions, both of which arise from the surfactant cetyltrimethylammonium bromide. The effects of surfactant concentration, temperature, ionic strength of the solution, and prism edge length on the lattice parameters have been investigated and provide a variety of tools for in situ modulation of these colloidal superstructures. Additionally, we demonstrate a purification procedure based on our observations that can be used to efficiently separate triangular nanoprisms from spherical nanoparticles formed concomitantly during their synthesis.