Abstract
Infrared absorption measurements at normal incidence of radiation have been carried out on octadecanethiol (ODT) deposited from ethanol-water mixed solutions onto colloidal silver particles (ca. 30 nm diameter) on Si(111) substrates. The infrared absorption spectra taken as functions of silver mass thickness and ODT concentration show that the intensities of the CH2 asymmetric and symmetric stretch modes of ODT are twice enhanced in comparison to those observed in the absence of the particles. The spectra also reveal that at any ODT concentration the absorption intensities exhibit a maximum for a particular mass thickness of the particles, indicating that the enhancement is linked to the aggregation of the particles. Contribution of the surface plasmon resonance apparently does not play a major role in the present systems. Approximately the same magnitude of enhancement is obtained for silver hydrosol particles exposed to ODT from the solution followed by depositing on the substrates. Scanning electron morphological inspection has been done on the aggregates in relation to the enhancement.
Original language | English |
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Pages (from-to) | 86-91 |
Number of pages | 6 |
Journal | Materials Transactions |
Volume | 45 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2004 Jan |
Keywords
- Colloid
- Infrared absorption enhancement
- Octadecanethiol
- Plasma resonance
- Silver
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering