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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   

  • fits Tao-Eldrup model in the sub-nanometer pore regime (Figure 1)

  • fits precision measurement data in the classical pore regime (Figure 1)

  • fits experimental data in the intermediate regime (Figure 2)

  • valid for all temperatures (Figure 3)

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.