Fourier Transform Infrared Photoacoustic Spectroscopy of Surface-Treated Wool

Infrared photoacoustic spectroscopy (PAS) is a useful technique for examining sur face-treated wool samples. Sample preparation is simple, and reproducible spectra of adequate signal-to-noise ratio are obtained in a few minutes. The ability of PAS to vary the penetration depth by varying the optical path difference velocity is used to obtain spectra of the near surface region of the samples. These spectra are compared with those taken with a greater penetration depth, which therefore represent more of the bulk wool sample. Samples are chlorinated and chlorinated/neutralized wool from a shrinkproofing process, and wool treated with a proprietary fluoropolymer.