Accession Number:

ADA282322

Title:

Self Assembly of n-Alkanethiolate Monolayers on Silver Nano-Structures: Determination of the Apparent Thickness of the Monolayer by Scanning Tunneling Microscopy

Descriptive Note:

Technical rept.

Corporate Author:

CALIFORNIA UNIV IRVINE DEPT OF CHEMISTRY

Report Date:

1994-07-12

Pagination or Media Count:

24.0

Abstract:

The STM is employed to monitor the effect of adsorption of an n-alkanethiolate monolayer, from an aqueous solution of the thiol, on the apparent topography of nanoscopic silver adsorption sites. Silver nano-disk structures were electrochemically deposited on graphite surfaces using the STM. The topography of these adsorption sites was then determined in-situ by STM imaging prior to the exposure of the nano-structure to an aqueous solution of an n- alkane thiol. The apparent thickness of the self-assembled monolayer SAM, estimated from the difference in the nano-structure height measured before and after adsorption of the monolayer, increased linearly with the alkyl chain length for five n-alkane thiols i.e., CnH2n1SH having even numbered chain lengths from n10 to 18. For SAMs of tetradecane thiol, hexadecane thiol, and octadecane thiol, the average height increments equaled the expected all-trans chain length of these molecules indicating that little penetration of the STM tip into the surface of the monolayer occurs during the STM imaging experiment. STM, N-alkane thiols, Biological, Lithography, Passivation.

Subject Categories:

  • Organic Chemistry
  • Physical Chemistry
  • Electricity and Magnetism
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE