Theoretical study on structure and sum-frequency generation (SFG) spectroscopy of styrene-graphene adsorption system
Journal
Journal of Physical Chemistry C
Journal Volume
117
Journal Issue
4
Pages
1754-1760
Date Issued
2013
Author(s)
Abstract
In this theoretical study, we aimed to simulate the sum-frequency generation (SFG) spectroscopy of a thin polystyrene layer physically adsorbed on the graphene sheet and to figure out the orientation distribution of the phenyl units. To simplify the problem, we started the investigation by constructing molecular models with styrene and ethylbenzene monomers and styrene oligomers up to four units adsorbed on a finite-sized graphene hexagon. Geometric optimization results showed that the phenyl rings of the adsorbate always orientate close to the surface normal with a small tilt angle. The adsorption is weak but not negligible. SFG spectra have been simulated based on these calculated structures, vibrational frequencies, and dipole and polarizability derivatives to compare with experimental reports of polystyrene adsorbed on other surfaces. ? 2013 American Chemical Society.
Other Subjects
Adsorption system; Geometric optimization; Graphene sheets; Orientation distributions; Phenyl rings; Phenyl units; Polarizabilities; Sum-frequency generation spectroscopy; Surface normals; Theoretical study; Tilt angle; Adsorption; Ethylbenzene; Interferometry; Oligomers; Polystyrenes; Styrene; Graphene
Type
journal article