Photoacoustic infrared spectroscopy of polymer beads.
Photoacoustic (PA) spectra of four types of polymer resin beads, ranging in size from 35 to 150 microm, were acquired using a Fourier transform infrared spectrometer capable of both rapid- and step-scan mirror movement. Thermal diffusion lengths were on the order of the particle sizes of the beads. The PA magnitude spectra were similar to absorption spectra; both positive- and negative-going features occurred in the phase spectra. The frequency dependences of the total PA intensities of the polymer resins and carbon black differed by a factor of about f(-0.30). The intensities of the weak bands in the ratioed spectra (resin beads/carbon black) displayed a similar dependence. Partial saturation caused a more gradual variation for the stronger bands, where the intensity is proportional to approximately f(-0.1)-f(-0.2).
Wen
Qing
Q
CanmetENERGY, Natural Resources Canada, 1 Oil Patch Drive, Devon, Alberta T9G 1A8, Canada. Qing.Wen@NRCan.gc.ca
Michaelian
Kirk H
KH
D000162:Acoustics; D017953:Isocyanates / Q000032:analysis*; D015394:Molecular Structure; D010316:Particle Size; D011137:Polystyrenes / Q000032:analysis*; D013055:Spectrophotometry, Infrared / Q000379:methods*
D017953:Isocyanates; D011137:Polystyrenes; C101297:Tentagel resin