Existence of a Hydrophobic Gap at the Alkanethiol SAM–Water Interface: An Interfacial Capacitance Study
✍ Scribed by Ujjal Kumar Sur; V. Lakshminarayanan
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 109 KB
- Volume
- 254
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
The highly hydrophobic neat alkanethiol-coated SAM on evaporated gold shows an unusually low interfacial capacitance in aqueous media. This result cannot be explained by a simple parallel plate model of the double layer with the alkanethiol monolayer as a sole dielectric separator. Interestingly, a hydrophilic SAM prepared from a neat hydroxy thiol does not show any such capacitance lowering in aqueous media. Our results suggest the existence of a "hydrophobic gap" between the alkanethiol SAM-water interface. Such a model is also very much consistent with the predictions of Lum, Chandler, and Weeks theory of length scale dependent hydrophobicity.