Dates for described

The most complete model to date for describing Case II diffusion is that of Thomas and Windle (13-16). They envision the process as a coupled swelling-diffusion problem in which the swelling rate is treated as a linear viscoelastic deformation driven by osmotic pressure. This model leads to the idea of a precursor phase propagating ahead of a moving boundary, as we have depicted in Figure 4. While Thomas and Windle have used numerical methods to examine in detail the predictions of their model, this model is difficult to test with the data obtained here. 

The model of two different OH groups is a simplified one. A discussion whether water is a continuum or a system of two species is misdirected. A model has to fit experimental data and to predict unknown properties of nature in the simplest way. This is fulfilled with our water model. The continuum theory may be correct as object in view of future research but has been inefficient to date for describing properties of water quantitatively. 

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