Cell wall Donnan potential

While the lipid bilayer has a very low water content, and therefore behaves quite hydrophobically, especially in its core (see Chapter 2 of this volume), the cell wall is rather hydrophilic, with some 90% of water. Physicochemically, the cell wall is particularly relevant because of its high ion binding capacity and the ensuing impact on the biointerphasial electric double layer. Due to the presence of such an electric double layer, the cell wall possesses Donnan-like features, leaving only a limited part of the interphasial potential decay in the diffuse double layer in the adjacent medium. For a detailed outline, the reader is referred to recent overviews of the subject matter [1,2]. 

Figure 1. Potential profile ij/(x) across the cell wall (x < 0) according to the simplified expression (6) from the Ohshima and Kondo model [15]. The profile within the solution (x > 0) is assumed to follow the usual GC decay expression ij/ = ij/Dm exp ( — kx) (equation (2)). Parameters T — 298 K, z—+1, = 78.5, thickness of the Donnan layer = 10 nm, p — 1447Cdm Curves correspond with c — 0.2, 0.1, 0.05, 0.02 and...

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