Convective Depletion During The Fast Propagation Of A Nanosphere Through A Polymer Solution

TL;DR

This paper develops a nonlinear convective depletion theory for nanospheres moving rapidly through polymer solutions, with potential applications in protein separation techniques.

Contribution

It introduces a self-consistent field theory and self-similar solutions for convective depletion at high velocities, advancing understanding of particle-polymer interactions.

Findings

Velocity of charged proteins scales with the fifth power of electric field.

A self-similar solution for convective depletion is feasible at high velocities.

The theory aids in interpreting protein separation by electrophoresis.

Abstract

A theory of nonlinear convective depletion is set up as a nanosphere translates fast through a semidilute polymer solution. For nanospheres a self-consistent field theory in the Rouse approximation is often legitimate. A self-similar solution of the convective depletion equation is argued to be feasible at high velocities. The nature of the thin boundary layer in front of the propagating particle is analyzed. One example of convective depletion is when a charged protein moves through a semidilute polymer under the influence of a high electric field. The protein velocity is then proportional to the fifth power of the field. The theory could be useful in interpreting the separation of protein mixtures by microchip electrophoresis.