Chemical imaging of the surface of self-assembled polystyrene-b-poly(methyl methacrylate) diblock copolymer films using apertureless near-field IR microscopy.
The nanoscale chemical composition variations of the surfaces of thin films of polystyrene- b-poly(methyl methacrylate) (PS- b-PMMA) diblock copolymers are investigated using apertureless near-field IR microscopy. The scattering of the incident infrared beam from a modulated atomic force microscopy (AFM) tip is probed using homodyne detection and demodulation at the tip oscillation frequency. An increase in the IR attenuation is observed in the PMMA-rich domains with a wavenumber dependence that is consistent with the bulk absorption spectrum. The results indicate that even though a small topography-induced artifact can be observed in the near-field images, the chemical signature of the sample is detected clearly.
Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
Kerstin
K
Mueller
Xiujuan
X
Yang
Melissa
M
Paulite
Zahra
Z
Fakhraai
Nikhil
N
Gunari
Gilbert C
GC
Walker
D008689:Methacrylates / Q000737:chemistry*; D008853:Microscopy; D015394:Molecular Structure; D011137:Polystyrenes / Q000737:chemistry*; D013053:Spectrophotometry; D013499:Surface Properties
D008689:Methacrylates; D011137:Polystyrenes; C522509:polystyrene-block-poly(methyl methacrylate)