Reversible long-range patterning of gold nanoparticles by smectic liquid crystals

Jonathan Milette, Sabrina Relaix, Cyrille Lavigne, Violeta Toader, Stephen J. Cowling, Isabel M. Saez, R. Bruce Lennox, John W. Goodby, Linda Reven

Research output: Contribution to journalArticlepeer-review

Abstract

4.7 nm Gold nanoparticles(AuNPs) capped with mesogenic ligands, dispersed in homeotropically aligned smectic A liquid crystal (LC), reversibly form arrays of aggregates with micron-scale periodicities over macroscopic areas at the nematic to smectic A phase transition (TN-SmA). AuNPs with a mixed capping layer of 4'-(n-mercaptododecyloxy)biphenyl-4-carbonitrile and hexanethiol in a 1 : 1 ratio were dispersed in 4'-octyl-4-cyanobiphenyl (8CB) and subjected to boundary conditions known to produce periodic edge dislocations. In a cavity cell with a meniscus, the arrays consisted of concentric circles. Linear arrays were produced by wedge cells and control over the periodicity was achieved through variation of the wedge angle. Based on the dependence of the geometry and periodicity of the arrays on boundary conditions, we propose that the AuNPs concentrate at edge dislocation defects of the smectic phase.

Original languageEnglish
Pages (from-to)6593-6598
Number of pages6
JournalSoft Matter
Volume8
Issue number24
Early online date18 May 2012
DOIs
Publication statusPublished - 28 Jun 2012

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