2011年8月16日，羅格斯大學Aleksey Vishnyakov博士來訪并做學術報告。
Aleksey Vishnyakov上午9:30，在三樓講學廳做題為《Gauge cell method for calculation of the free energies of inhomogeneous systems》的報告，報告摘要如下：
The first part of the talk briefly describes the gauge cell approach to calculation of free energies of inhomogeneous and dense systems. We will review the foundation of the gauge cell method and its application to various phenomena, such as adsorption, wetting and nucleation. In the second part, we present a recently proposed extension of the gauge cell method to polymeric molecules. The new technique employs the “incremental chemical potential” concept, quanti
tatively reproduces the modified Widom particle insertion results of Kumar et al. (1991) and is by an order of magnitude more efficient for long chains in terms of the computational time required for the same accuracy of chemical potential calculations. We have applied the polymer gauge method to Lennard-Jones homopolymers of up to 500 monomers in length. First, we discuss coil globule transitions in the language of incremental chemical potentials, paying particul
ar attention to the chain increment ansatz, which suggests the monomer chemical potential independence of the chain length. Then, the new technique applied to polymer sorption into pores of different diameters. We study the effects of the magnitude of adsorption potential and temperature on the behavior of single chains in confinements that are comparable in size with the free chain radius of gyration. At sufficiently low temperatures, the dependence of the incremental chemical potential on the chain length in wetting pores is superficially similar to a capillary condensation isotherm, showing a resemblance of monolayer formation following by pore volume filling, as the chain length increases. We find that the incremental gauge cell method is an accurate and efficient technique to calculate the free energy of chain molecules that can be applied to bulk and confined systems, and may find practical application
s in modeling polymer partitioning on porous substrates. Finally, we make an attempt to relate the free energies of confined polymer to sorption dynamics using the Fokker-Plank equation. ，羅格斯大學Aleksey Vishnyakov博士來訪并做學術報告。
Aleksey Vishnyakov擬定于8月16日上午9:30，在三樓講學廳做題為《Gauge cell method for calculation of the free energies of inhomogeneous systems》的報告，報告摘要如下：
The first part of the talk briefly describes the gauge cell approach to calculation of free energies of inhomogeneous and dense systems. We will review the foundation of the gauge cell method and its application to various phenomena, such as adsorption, wetting and nucleation. In the second part, we present a recently proposed extension of the gauge cell method to polymeric molecules. The new technique employs the “incremental chemical potential” concept, quanti
tatively reproduces the modified Widom particle insertion results of Kumar et al. (1991) and is by an order of magnitude more efficient for long chains in terms of the computational time required for the same accuracy of chemical potential calculations. We have applied the polymer gauge method to Lennard-Jones homopolymers of up to 500 monomers in length. First, we discuss coil globule transitions in the language of incremental chemical potentials, paying particul
ar attention to the chain increment ansatz, which suggests the monomer chemical potential independence of the chain length. Then, the new technique applied to polymer sorption into pores of different diameters. We study the effects of the magnitude of adsorption potential and temperature on the behavior of single chains in confinements that are comparable in size with the free chain radius of gyration. At sufficiently low temperatures, the dependence of the incremental chemical potential on the chain length in wetting pores is superficially similar to a capillary condensation isotherm, showing a resemblance of monolayer formation following by pore volume filling, as the chain length increases. We find that the incremental gauge cell method is an accurate and efficient technique to calculate the free energy of chain molecules that can be applied to bulk and confined systems, and may find practical application
s in modeling polymer partitioning on porous substrates. Finally, we make an attempt to relate the free energies of confined polymer to sorption dynamics using the Fokker-Plank equation.