Flow-Induced Translocation of Star Polymers through a Nanopore

The flow-induced translocation of star polymers through a cylindrical nanopore has been studied using dissipative particle dynamics (DPD) simulations. The number of arms, f, was varied with the total number of monomers, N, kept constant. The effect of simulating the capture of the polymer into the pore upon the mean translocation time, <τt>, has been investigated by varying the chain's initial location. The results indicate that the incorporation of the capture process results in a reduction of <τt> by up to 15%. This is because the chain's initial location affects the extent of its stretching along the flow direction during translocation. <τt> exhibits nonmonotonic variation with f, in agreement with recently reported results for electric field-driven translocation of star polymers. Its value is larger and shows greater variation with f when the solvent quality is better. For the same value of f, the capture occurs faster in a good solvent. In addition, <τt> is greater for a semiflexible chain than its flexible counterpart as the time required for the branch point to enter the nanopore is longer in the former case.