title: Time-resolved IR studies of monolayer self-assembly on a gold substrate using planar array infrared (PA-IR) spectroscopy.
abstract: Time-resolved and spatially resolved infrared spectra (line images) of self-assembled monolayers of octadecylthiol (ODT) on gold substrates were investigated by planar array infrared (PA-IR) spectroscopy, with a grazing incidence reflection attachment. It was observed that PA-IR spectra with a good signal-to-noise ratio that is comparable to those obtained from Fourier transform infrared spectroscopy could be acquired with a significantly shorter collection time. Focusing on the peak intensities and peak positions of the CH2 asymmetric stretch (approximately 2918 cm(-1)) and the CH3 symmetric stretch (approximately 2960 cm(-1)), respectively, the molecular orientation and organization of the monolayers were determined. The ODT formed a uniform monolayer on the surface of the gold whether it was deposited within 1-2 s or over a 40 h period. Disordered monolayers formed instantly, and with an increase in dipping time, the monolayer became more ordered, becoming highly ordered after dipping times of many ( > 24) hours.
authors.affiliation: University of Delaware, Department of Materials Science and Engineering, Newark, Delaware 19716, USA.
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Anand T
authors.initials: AT
authors.lastname: Kalambur
authors.forename: John F
authors.initials: JF
authors.lastname: Rabolt
authors.forename: D Bruce
authors.initials: DB
authors.lastname: Chase