Programmed Self-Assembly of Branched Nanocrystals with an Amphiphilic Surface Pattern

Yuki Taniguchi, Muhammad Adli Bin Sazali, Yusei Kobayashi, Noriyoshi Arai, Tsuyoshi Kawai, Takuya Nakashima

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Site-selective surface modification on the shape-controlled nanocrystals is a key approach in the programmed self-assembly of inorganic colloidal materials. This study demonstrates a simple methodology to gain self-assemblies of semiconductor nanocrystals with branched shapes through tip-to-tip attachment. Short-chained water-soluble cationic thiols are employed as a surface ligand for CdSe tetrapods and CdSe/CdS core/shell octapods. Because of the less affinity of arm-tip to the surface ligands compared to the arm-side wall, the tip-surface becomes uncapped to give a hydrophobic nature, affording an amphiphilic surface pattern. The amphiphilic tetrapods aggregated into porous agglomerates through tip-to-tip connection in water, while they afforded a hexagonally arranged Kagome-like two-dimensional (2D) assembly by the simple casting of aqueous dispersion with the aid of a convective self-assembly mechanism. A 2D net-like assembly was similarly obtained from amphiphilic octapods. A dissipative particle dynamics simulation using a planar tripod model with an amphiphilic surface pattern reproduced the formation of the Kagome-like assembly in a 2D confined space, demonstrating that the lateral diffusion of nanoparticles and the firm contacts between the hydrophobic tips play crucial roles in the self-assembly.

Original languageEnglish
Pages (from-to)9312-9320
Number of pages9
JournalACS Nano
Volume11
Issue number9
DOIs
Publication statusPublished - 2017 Sep 26
Externally publishedYes

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Keywords

  • branched structures
  • dissipative particle dynamics
  • hydrophobic effect
  • nanocrystals
  • self-assembly

ASJC Scopus subject areas

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

Cite this

Taniguchi, Y., Sazali, M. A. B., Kobayashi, Y., Arai, N., Kawai, T., & Nakashima, T. (2017). Programmed Self-Assembly of Branched Nanocrystals with an Amphiphilic Surface Pattern. ACS Nano, 11(9), 9312-9320. https://doi.org/10.1021/acsnano.7b04719