Assembly of reconfigurable one-dimensional colloidal superlattices due to a synergy of fundamental nanoscale forces.
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.
Department of Chemistry, and International Institute for Nanotechnology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
Kaylie L
KL
Young
Matthew R
MR
Jones
Jian
J
Zhang
Robert J
RJ
Macfarlane
Raul
R
Esquivel-Sirvent
Rikkert J
RJ
Nap
Jinsong
J
Wu
George C
GC
Schatz
Byeongdu
B
Lee
Chad A
CA
Mirkin