Enhanced Molecular Diffusivity through Destructive Interference between Electrostatic and Osmotic Forces

Tuhin Samanta, Setare Mostajabi Sarhangi, Dmitry V. Matyushov

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Molecular charge asymmetrically distributed in a diffusing tagged particle causes a nonzero electrostatic force balanced by an opposing van der Waals (vdW) force. Fluctuations of electrostatic and vdW forces are highly correlated, and they destructively interfere in the force variance. This phenomenology is caused by the formation of a structurally frozen hydration layer for a particle diffusing in water and is responsible for a substantial speedup of translational diffusion compared to traditional theories of dielectric friction. Diffusion of proteins is insensitive to charge mutations, while smaller particles with asymmetric charge distribution can show a strong dependence of translational and rotational diffusion on molecular charge. Dielectric calculations of the electrostatic force require low values of ≃5 for the effective dielectric constant of interfacial water to be consistent with simulations.

Original languageEnglish (US)
Pages (from-to)6648-6653
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume12
Issue number28
DOIs
StatePublished - Jul 22 2021
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

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