Assembly of nanorods into designer superstructures: The role of templating, capillary forces, adhesion, and polymer hydration

Jacob W. Ciszek, Ling Huang, Stefan Tsonchev, Yu Huang Wang, Kenneth R. Shull, Mark A. Ratner, George C. Schatz, Chad A. Mirkin

Research output: Contribution to journalArticle

37 Citations (Scopus)


The assembly mechanism by which hundreds of thousands of two-segment gold-polypyrrole nanorods are assembled into kinetically controlled shape-directed superstructures is examined to predict the range of nanoparticle sizes and materials that can be utilized in their formation. Four processes are responsible for assembly: templating, capillary force assembly, adhesion, and polymer hydration. It is shown that templating, where rods are prepositioned for assembly, is scale invariant and that the energy-minimized state after this step is highly disordered. In addition, we predict that superstructures can be made independently from patterns of rods separated by a distance as small as six times the inter-rod spacing. Both modeling and experiment show that adhesion and polymer dehydration, which induces curvature in the superstructures, are applicable to other materials. However, the high surface energy and low elastic modulus of polypyrrole are advantageous toward generating three-dimensional structures, inducing curvature at gold/polypyrrole length ratios as large as 7:1.

Original languageEnglish
Pages (from-to)259-266
Number of pages8
JournalACS nano
Issue number1
Publication statusPublished - Jan 26 2010



  • Adhesion
  • Capillary force assembly
  • Nanorods
  • Self-assembly
  • Templating

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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