Mechanisms Grotthuss mechanism

The diffusion coefficients of H and OH ions are much larger than other ions because their movement in solution involves a kind of hopping mechanism (Grotthuss mechanism) related to the very fast dissociation and re-association of water molecules (Cukierman, 2006 Tuckerman et al., 2002). 

Agmon, N. 1995. The Grotthuss mechanism. Chemical Physics Letters 244 456—462. 

Structure diffusion (i.e., the Grotthuss mechanism) of protons in bulk water requires formation and cleavage of hydrogen bonds of water molecules in the second hydration shell of the hydrated proton (see Section 3.1) therefore, any constraint to the dynamics of the water molecules will decrease the mobility of the protons. Thus, knowledge of the state or nature of the water in the membrane is critical to understanding the mechanisms of proton transfer and transport in PEMs. 

COMRUTER ALGORITHMS SOFTWARE GROTTHUSS CHAINS GROTTHUSS-DRAPER LAW GROTTHUSS MECHANISM... 

Ab initio methods provide elegant solutions to the problem of simulating proton diffusion and conduction with the vehicular and Grotthuss mechanism. Modeling of water and representative Nation clusters has been readily performed. Notable findings include the formation of a defect structure in the ordered liquid water cluster. The activation energy for the defect formation is similar to that for conduction of proton in Nafion membrane. Classical MD methods can only account for physical diffusion of proton but can create very realistic model... 

Grotthuss mechanism — Classical mechanism proposed by - Grotthuss [i] to explain the transport of elec-... 

See also -> Eigen complex, -> water, - prototropic charge transport, -> Grotthuss mechanism. 

Figure 16.1 Models of proton transfer process via (a) Grotthuss mechanism and (b) Vehicle mechanism.

Similar thermal effects have also been noted in hydroxide water clusters [54]. While proton transfer is widely accepted to follow the "Grotthuss" mechanism... 

Figure 10 Proton conductivity according to the Grotthuss mechanism. (Reprinted from Ref. 131 2003, with permission from Elsevier)...

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