Structural Distortion of Dendrimers on Gold Surfaces: A Tapping-Mode AFM Investigation

Abstract

Atomic force microscopy (AFM) investigations of polyamidoamine (PAMAM) Starburst (Trademark) dendrimers, generations 4 and 8 (G4, G8), absorbed on Au (111) surfaces were conducted. By controlling dendrimer concentration and exposure time during adsorption, coverages ranging from completely isolated molecules to a monolayer were prepared. The individual dendrimer molecules forming a monolayer were clearly imaged. Upon exposure to hexadecanethiol, the shapes of individual dendrimers change and they become taller and narrower as more stable thiol-Au bonds replace some of the amine-Au bonds. In the case of monolayers, exposure to hexadecanethiol causes the dendrimers to gradually agglomerate, forming dendrimer "pillars" up to 30 nm in height and freeing progressively more surface area for thiol adsorption.

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Document Details

Document Type
Technical Report
Publication Date
Jan 05, 1998
Accession Number
ADA333726

Entities

People

  • Andreas Hierlemann
  • Antonio J. Ricco
  • Joseph K. Campbell
  • Lane A Baker
  • Richard M Crooks

Organizations

  • Texas A&M University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Adsorption
  • Agglomerates (Rock)
  • Chemistry
  • Dendrimers
  • Diameters
  • Distortion
  • Electronic Mail
  • Engineering
  • Films
  • Macromolecules
  • Materials
  • Molecules
  • Monomolecular Films
  • Polymers
  • United States
  • United States Government
  • Universities

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  • Mathematics or Statistics
  • Nanocomposite Materials Science
  • Surface Coatings Technology.