Finite element analysis of the Poisson–Boltzmann equation coupled with chemical equilibriums: redistribution and transport of protons in nanophase separated polymeric acid–base proton exchange membranes

<p>The finite element analysis is applied to the study of the redistribution and transport of protons in model nanophase separated polymeric acid–base composite membranes by the Poisson–Boltzmann equation coupled with the acid and base dissociation equilibriums for the first time. Space charge redistribution in terms of proton and hydroxide redistributions is observed at the interfaces of acidic and basic domains. The space charge redistribution causes internal electrostatic potential, and thus, promotes the macroscopic transport of protons in the acid–base composite membranes.</p

Hydrogen Transfer Reaction in Polycyclic Aromatic Hydrocarbon Radicals

Density functional theory calculations have been successfully applied to investigate the formation of hydrocarbon radicals and hydrogen transfer pathways related to the chemical vapor infiltration process based on model molecules of phenanthrene, anthra­[2,1,9,8-<i>opqra</i>]­tetracene, dibenzo­[<i>a</i>,<i>ghi</i>]­perylene, benzo­[<i>uv</i>]­naphtho­[2,1,8,7-<i>defg</i>]­pentaphene, and dibenzo­[<i>bc</i>,<i>ef</i>]­ovalene. The hydrogen transfer reaction rate constants are calculated within the framework of the Rice–Ramsperger–Kassel–Marcus theory and the transition state theory by use of the density functional theory calculation results as input. From these calculations, it is concluded that the hydrogen transfer reaction between two bay sites can happen almost spontaneously with energy barrier as low as about 4.0 kcal mol^–1, and the hydrogen transfer reactions between two armchair sites possess lower energy barrier than those between two zigzag sites