Thoughts on the structure of alkylsilane monolayers

Journal Article · Tue Apr 13 04:00:00 EDT 1999 · Langmuir

DOI:https://doi.org/10.1021/la981064e· OSTI ID:350237

Stevens, M J ^[1]

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1. Sandia National Labs., Albuquerque, NM (United States)

Cross-polymerization in alkylsilane self-assembled monolayers (SAMs) has been thought to be an essential ingredient of their stability. For alkylsilane SAMS at full coverage, it is shown here that cross-polymerization cannot occur due to steric effects. Thus, to form dense, fully covered monolayers, cross-polymerization must be avoided. Such monolayers should be as stable as alkanethiol SAMs, which also do not cross-polymerize. The structure of the headgroup plays a limiting role in possible monolayer structures. Due to large steric hindrances, the dimethylmonochlorosilanes cannot cover a silica surface with a density equal to the density of surface hydroxyls. In contrast, the trichlorosilanes can achieve such densities. To satisfy the steric constraints, the aliphatic tails must form a herringbone structure.

• Research Organization: Sandia National Laboratory
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 350237
• Journal Information: Langmuir, Journal Name: Langmuir Journal Issue: 8 Vol. 15; ISSN 0743-7463; ISSN LANGD5
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
CROSS-LINKING
LUBRICANTS
MOLECULAR STRUCTURE
SILANES
STABILITY