Proton transport mechanisms self-diffusion

Even if a proton jump along a bond is very rapid, the conductivity is explained by the Grotthuss mechanism (it is not the same proton that jumps). Please notice that this jump is not a rotation it takes place along the bond from one minimum of the potential to another, creating, for short time, an ion H30+ and a correspondent OH-. But, I insist, their concentration is very small. It is out of question to see such species, for example, in scattering experiments. Their impact on the transport properties (self-diffusion, molecular rotations) is totally negligible. 

The mechanism of proton diffusion, usually referred as the Grotthuss mechanism, differs from that of other ions. Instead of a self-diffusion process, where the mass and the charge are inseparable, the proton diffusion is the movement of the protonic charge independently from the transport of the particle. This mode of propagation leads to the diffusion of the proton 0 + = 9.3 x 10 cm s being faster than the diffusion of all other ions (D <2 x 10 cm s ), and of the selfdiffusion of the water molecules in water as a solvent (for details see Ref [40]). 

The presence of water in PVPA seems to contribute to the conductivity of PVPA, at a temperature below the boiling point of water, by proton transport in additional proton solvents. Hence, the proton movement in PVPA can be explained by rapid transfer of protons via hydrogen bond-forming and bondbreaking (hopping mechanism) and by self-diffusion (vehicle mechanism). Different conductivity values could be obtained due to a different water content. Also, recent studies have revealed that the behavior of PVPA as a polyelectrolyte is very similar to poly(actylic acid) in aqueous salt solution under identical conditions. ... 

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