Stability of Polytetrafluoroethylene, Polyethylene, and Polystyrene Pellets as a Matrix for Analytical Terahertz Spectroscopy

Results are reported for a detailed examination of polytetrafluoroethylene (PTFE), polyethylene (PE) and polystyrene (PS) as polymeric matrixes for preparing sample pellets for analytical terahertz (THz) spectroscopy. Individual pellets were prepared from each material by compression at five tons of pressure under ambient temperatures. Mass, diameter, thickness, porosity and THz spectra were measured daily for each pellet over a period of four days. Pellets were stored in a desiccator under ambient temperatures between measurements. The thickness of each pellet was determined in a non-contact manner by analysis of each time-domain THz spectrum.