Surface coverage groups

Utilization of resonance effects can facilitate unenhanced Raman measurement of surfaces and make the technique more versatile. For instance, a fluorescein derivative and another dye were used as resonantly Raman scattering labels for hydroxyl and carbonyl groups on glassy carbon surfaces. The labels were covalently bonded to the surface, their fluorescence was quenched by the carbon surface, and their resonance Raman spectra could be observed at surface coverages of approximately 1%. These labels enabled assess to changes in surface coverage by C-OH and C=0 with acidic or alkaline pretreatment [4.293]. 

The spectra shown m fig. 1 are for a meAyl surface coverage of about 0.1 ML. The results obtained at Ais coverage are m excellent agreement wiA earlier experiments involvmg decomposition of meAyl iodide to produce surface-bound meAyl groups.[l, 3,21]... 

Westermark, G. and Persson, 1. (1998) Chemisorption of tertiary phosphines on coinage and platinum group metal powders. An infrared reflectance absorption spectroscopic, enhanced Raman spectroscopic and surface coverage study. Colloids and Surfaces A -Physicochemical and Engineering Aspects, 144, 149-166. 

Analysis of the surface coverage revealed an average of 0.4 ionic liquid fragments nm 2, corresponding to the involvement of approximately 35% of all the hydroxyl groups of the pre-treated silica gel. 

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