Water sorption density distribution function

A spatial dispersion in the distribution of wall charges is accounted for by introducing a density distribution function n ((Tq), defined as the number of pores per infinitesimal interval of gq. Knowledge of n (ao) is a prerequisite for predicting the water sorption behavior of a PEM. The following integral expressions relate n (ao) to the number of unit cells Nuc in a sample of total dry volume Vo ... 

A necessary consistency check of a water sorption model is the calculation of vapor sorption isotherms. Equation 2.49 gives A V/Vb as a function of oo.c- The input for the calculation includes the environmental parameters T, P, P"), materials parameters (sr, G, PsQ-) probability density distribution n (ao). The value of t]c can be... 

Chapter 2 dwells on all aspects of the structure and functioning of polymer electrolyte membranes. The detailed treatment is limited to water-based proton conductors, as, arguably, water is nature s favorite medium for the purpose. A central concept in this chapter is the spontaneous formation of ionomer bundles. It is a linchpin between polymer physics, macromolecular self-assembly, phase separation, elasticity of ionomer walls, water sorption behavior, proton density distribution, coupled transport of protons and water, and membrane performance. 

Figure 2. Distribution of DNOC (open symbols), and TNT (filled symbols) between aqueous and solid phases of typical aquifer and soil materials. Shown is the fraction of sorbed species as a function of pH and K" -saturation of the clay minerals. The relative importance of the two dominating sorption mechanisms are compared hydrophobic partitioning into sediment organic matter (O, ) and specific EDA-complex formation with clay mineral surfaces (O, ) triangles (A, A) represent the overall speciation for DNOC and TNT respectively. Sediment parameters were chosen as follows fraction of organic carbon 4. (soil) = 0.05 f (aquifer) = 0.001 fraction of clay minerals f igy (soil) = 0.35 fciay (aquifer) = 0.05 porosity e(soil) = 0.4 (aquifer) = 0.3 bulk density p(soil) = p(aquifer) = 2.5 kg L water saturation 0(soil) = 0.5 0(aquifer) = 1 fraction of K -saturation of clay minerals = 0.001 (when pH was used as system variable) pH = 7.0 (when f(, +, was used as system variable). Linear adsorption isotherms of TNT and... 

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