81
reads

Jinn-Liang Liu

2013-12-25
15:30:00 - 16:20:00

101 , Mathematics Research Center Building (ori. New Math. Bldg.)

A Poisson-Fermi theory that includes both steric and correlation effects is presented for electrolytic systems. The steric effect is described by a Fermi like distribution, which is derived from the configuration entropy of spherical ions and water molecules with different sizes and valences. The correlation effect is described by a dielectric coefficient function from a decomposition of the Coulomb interaction into short and long components. The maximum allowable close packing (saturation) condition at high fields and the variation of dielectric coefficient from low to high concentration area are two of the most important features of the theory. The classical Poisson-Boltzmann theory generally fails to provide these features. Geometric singularities of molecular surfaces, strong nonlinearity of model systems, and the wide range of bath concentrations (up to 108 order variation in magnitude) in channel experiments pose severe challenges for theoretical investigations. We shall also present several numerical methods to tackle these problems. Numerical results in 3D for electric double layers, Born ion model, gramicidin A channel, and L-type calcium channel will be given to demonstrate the novelty of the theory and the effectiveness of numerical methods. All results are verified with either those of exact solutions, Monte Carlo, or molecular dynamics.

For material related to this talk, click here.