Loading...
Search for:
polyelectrolyte-brushes
0.005 seconds
Electrical Gating of Nanochannels of Polyelectrolyte Brushes
, M.Sc. Thesis Sharif University of Technology ; Ejtehadi, Mohammad Reza (Supervisor)
Abstract
The nuclear pore complex mediates all transport between the cell cytoplasm and the nucleus. Being inspired by this biological system, in this project we intended to design an artificial gate by using polyelectrolyte brushes in a cylindrical nanochannel, which will be opened by applying a tangent electrical field and will close by eliminating the field. Grafted polyelecrolyte brushes have the potential to be useful for the design of advanced gating systems for many applications like functional and conrolleble MEMS devices. In order to design the desired gating system we have employed the ESPResSo software to conduct a coarse-grained molecular dynamics simulation in NVT ensemble to simulate...
Tuning electrokinetic flow, ionic conductance, and selectivity in a solid-state nanopore modified with a pH-responsive polyelectrolyte brush: A molecular theory approach
, Article Journal of Physical Chemistry C ; Volume 124, Issue 34 , 2020 , Pages 18513-18531 ; Saidi, M. H ; Moosavi, A ; Kröger, M ; Sharif University of Technology
American Chemical Society
2020
Abstract
We use an efficient molecular theory approach to study electrokinetic flow within a pH-responsive nanopore grafted with a polyelectrolyte (PE) brush. The flow rate, migration and convective conductance, electric potential and velocity fields, species distributions and the degree of ionization of the weak PE functional groups and nanopore selectivity are obtained and interpreted while considering pH-induced surface charges. The theory is generally based on writing the overall free energy of the system including the entropies arising from the conformations of flexible, excluded volume chains, the mixing of mobile species, electrostatic contribution, and the free energy due to the chemical...
Stimuli-responsive polyelectrolyte brushes for regulating streaming current magnetic field and energy conversion efficiency in soft nanopores
, Article Physics of Fluids ; Volume 34, Issue 8 , 2022 ; 10706631 (ISSN) ; Saidi, M. H ; Kröger, M ; Tagliazucchi, M ; Sharif University of Technology
American Institute of Physics Inc
2022
Abstract
The electrokinetic energy conversion, electroviscous effect, and induced internal and external magnetic fields in a smart polyelectrolyte grafted "soft"nanopore with pH responsiveness are studied here using an efficient molecular theory approach. The analysis is based on writing the total free energy of the system, including the conformational entropy of the flexible, self-avoiding polymer chains and the translational entropy of the mobile species, the electrostatic interactions, and the free energy due to chemical equilibrium reactions. Then, the free energy is minimized, while satisfying the necessary constraints to find the equilibrium state of the system. The predictions of the model are...