Formation of Monolayer Films by the Spontaneous Assembly of Organic Thiols from Solution onto Gold
Abstract
Long-chain alkanethiols, HS(CH2)nX, adsorb from solution onto gold surfaces and form ordered, oriented monolayer films. The properties of the interfaces between the films and liquids are largely independent of chain length when n > 10; in particular, wetting is not directly influenced by the proximity of the underlying gold substrate. The specific interaction of gold with sulfur and other 'soft' nucleophiles and its low reactivity toward most 'hard' acids and bases make it possible to vary the structure of the terminal group, X, widely and thus permit the introduction of a great range of functional groups into a surface. Studies of wettability of these monolayers, and of their composition using X-ray photoelectron spectroscopy (XPS), indicate that the monolayers are oriented with the tail group, X, exposed at the monolayer-air or monolayer-liquid interface. The adsorption of simple n-alkanethiols generates hydrophobic surfaces whose free energy (19 mJ sq m) is the lowest of any hydrocarbon surface studied to date. (TTL)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1988
- Accession Number
- ADA229263
Entities
People
- Colin D. Bain
- E. B. Troughton
- George M. Whitesides
- Joseph Evall
- Yu-tai Tao
Organizations
- Harvard University