Near-Surface Analysis and Depth Profiling by FT-IR Photoacoustic Spectroscopy

Abstract

Fourier transform photoacoustic spectroscopy (FT-IR/PAS) has proven to be a powerful technique for the near-surface characterization of solid materials. The effective sampling depth of FT-IR/PAS can be varied by using different interferometer mirror velocities, so that nondestructive depth profiling can be performed. In this research, sized cotton yarns, treated glass fibers, chemically modified poly(ethylene terephthalate) fibers, and a naturally weathered poly(vinyl chloride) composite were investigated with the use of FT-IR/PAS at different mirror velocities. Penetration of the chemical additives in these materials was studied. It was demonstrated that FT-IR/PAS has the ability to investigate the changes in chemical nature within the detectable surface layers of solid samples.