1. Adsorption and Chromatographic Separation of Chain Molecules on Nanoporous Substrates
Alexander V. Neimark, Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ ,
Polymer separation: We aim at a fundamental understanding of the physico-chemical mechanisms of polymer adsorption in nanopores and the critical separation conditions based on the development of new methods of multiscale molecular simulations of equilibrium and dynamics of chain molecule in nanopores.
Size exclusion
Critical condition
Adsorption regime
Transition from size exclusion (left, long chains are eluted first) to adsorption (right, short chains are eluted first) regimes with the increase of adsorption potential. Critical regime (center, chain length independent separation). SCFT modeling.
The work in being performed in three directions: Monte Carlo (MC) simulation, Self Consistent Field Theory (SCFT), and stochastic Fokker-Plank (FP) formalism for modeling chain translocation in nanopores. The strategy is to calculate the variation of the free energy of polymer chain in the process of adsorption, then to determine the equilibrium partition coefficient, and the distribution of the elution times depending on the pore size and the magnitude of adsorption potential.
Dependence of the excess free energy of adsorbed chains of different length on the adsorption potential. The critical point, when the excess free energy does not depend on the chain length exists for ideal chains (left) and does not exist for real chains with exclusionvolume e (right). SCFT modeling.
Time distribution functions for successful (black) and unsuccessful (red) translocation events. SCFT and FP modeling.