Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of methanol was found to be 4 × 10−6 cm2 s−10−6
dependence of peak potential on scan rate and peak width measurements, resulted in the estimation of apparent diffusion coefficient of methanol and the anodic transfer coefficient of the electrode reaction.
The proton permselectivity of the PEM, which is defined as the ratio of the proton conductivity to the permeability coefficient of methanol, gave a maximum value of 66 × 103 S cm−3 s.
The limiting effective diffusion coefficient of methanol (in a C4 mixture of isobutene and 1-butene) in an Amberylst 15 resin was used as an adjustable parameter and found to be 3.5 × 10−9 m2/s at 333 K.
The permeability coefficient of methanol through the PEM prepared under the conditions of CAMPS = 2.7 mol% and CGA = 0.35 vol% was about 30 times lower than that of Nafion®117 under the same measurement conditions.
We present here a measure of the mass transport represented by the self-diffusion coefficients (D) of methanol, and two alternative fuels ethylene glycol (EG) and dimethyl oxalate (DMO) in new low-cost nanoporous (NP PCMM's.
Pulse Field Gradient (PFG) NMR spectroscopy was used to get a direct measurement of the diffusion coefficients of water and methanol through the membranes.
Comparison (Table 1) of values of Δ δ isolvent and values of Δ δ iclassic determined from our CLASSIC NMR study of crystallization of m-ABA from DMSO gives a very high correlation coefficient for water, a moderately high correlation coefficient for methanol and a very low correlation coefficient for 1,4-dioxane.
While the metabolite profiles of ethanol and methanol extractions were quite similar, the coefficients of variation for metabolites from methanol extractions were relatively high (Figure 1C, left).
The methanol diffusion coefficients of membranes are much lower than that of Nafion (2×10−6 cm2/s).
