Translocation Of A Polymer Chain Through A Nanopore In A Membrane

Translocation of a polymer chain through a nanopore in a membrane is of great importance in biological field and has attracted intense attentions. As a result, the translocation process of polymer chains with different aggregated states through a nanopore in a membrane has been investigated from the aspects of experiment, theory and simulation. In this dissertation, at first we summarize the current experimental and theoretical progresses proposed by several groups, and then the translocation of diblock chain through a nanopore in a membrane is considered.The dissertation for M.S. degree is mainly composed of following three chapters:The first chapter: Introduction. Translocation of a polymer chain through a nanopore in a membrane has been outlined from recent experiments, theories and simulations, respectively.The second chapter: Theoretical investigations on the diblock copolymer chain translocation. In this chapter, based on the approximation of slow dynamics and the Fokker-Planck equation, the free energy of the translocating diblock chain and the mean first passage time (MFPT) are obtained. Meanwhile, the translocation order of diblock copolymer chain, solvent quality and rate constant of translocation are studied. The effects of these factors on the translocation are found to be significant.The last chapter: Theoretical investigations on the translocation of a blob polymer chain. The translocation of polymer chains with different aggregation structures is considered, and then the free energy of the translocating polymer chain is obtained and the mean first passage time is calculated under different conditions.