title: Polymer translocation through a gradient channel.
abstract: The translocation of polymer through a channel with a gradient interaction between the polymer and the channel is studied. The interaction is expressed by E = E0 + kx, where E0 is the initial potential energy at the entrance, x is the position of the monomer inside the channel, and k is the energy gradient. The mean first passage time τ is calculated by using Fokker-Planck equation for two cases (1) N > L and (2) N < L under the assumption that the diffusion rate D is a constant, here N is the polymer length and L is the length of channel. Results show that there is a minimum of τ at k = k(c) for both cases, and the value kc is dependent on E0 and driving force f. At large f, the scaling relation τ ∼ N is observed for long polymer chains. But the scaling relation is dependent on the energy gradient k for an unforced driving translocation.
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou 310027, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Li-Zhen
authors.initials: LZ
authors.lastname: Sun
authors.forename: Chao-Yang
authors.initials: CY
authors.lastname: Li
authors.forename: Meng-Bo
authors.initials: MB
authors.lastname: Luo
mesh_terms: D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D011108:Polymers / Q000737:chemistry*; D016062:Porosity
chemical_list: D011108:Polymers