RTE calibration model
It is important to extract pore size information from PALS spectra. However, there is no well-defined quantum mechanical model that works for both sub-nanometer voids and big mesopores. We have developed rectangular extension of the existing Tao-Eldrup model, to fully extend the quantum mechanical model to the classical, large-pore limit.
Our rectangular Tao-Eldrup model (RTE) model
At a given temperature, a lifetime vs. pore dimension curve can then be calculated. Details of this calculation can be found in our paper on Journal of Physical Chemistry B [Dull, 2001].
Figure 1. Pore-size calibration calculated at different temperatures using a cubical pore shape model. The 0K (ground state) curve given by the Tao-Eldrup model and the dashed curve given by the classical model are presented for comparison.
Figure 2 . A comparison of the RTE model with experimental data acquired in bulk materials.
Figure 3. Ps lifetimes measured in a low-k porous silica film (NanoglassTM A10B) as a function of film temperature and calculation according to the 3-dimentional rectangular Tao-Eldrup model.