The PVDF-35%HCl system was readily fitted in this way and the HCl diffusivities
obtained are given in Table 3.
of the desorption and reabsorption processes are the same, and both are higher than that of the absorption process (Table 1).
Using the transition point as the only tool for establishing the initial profile may result in an overestimation of diffusivities
, thus giving shorter predicted lifetimes.
Zero concentration diffusivities
for water are presented in Fig.
It is important to note that the diffusivities
for the outer pipe wall, when using 4516 h and 6260 h as the initial profiles, are reversed.
In sorption experiments, diffusivities
are most conveniently determined from the half-sorption time, [t.
As described in the Experimental section, the diffusivities
of polymer samples may be determined through absorption and desorption tests.
The desorption diffusivities
were about an order of magnitude higher than the sorption diffusivities
obtained from the immersion experiments with the thin films (Table 2).
The design of this equipment is based on the correct estimation of diffusivities
of the organic volatiles in the polymer phase, since most of the mass transfer resistance is located in the solid phase rather than in the gas phase.
The contributors compare and assess diffusion data from the literature for all elements in minerals and natural melts and provide equations to evaluate diffusivities
under different conditions.
The analytical gas transport equation (equation 8) results for radon, using specific diffusivities
Temperature gradient difference is created from the difference between the solid and fluid thermal diffusivities