Self-diffusion of Rod-like Viruses Through Smectic Layer

TL;DR

This study visualizes how rod-like viruses move between smectic layers, revealing that diffusion occurs in quantized steps and matches theoretical predictions based on nematic diffusion models.

Contribution

It provides direct single-particle visualization of permeation in smectic layers and quantifies the diffusion mechanism in rod-like virus suspensions.

Findings

Diffusion occurs preferentially normal to smectic layers.

Particles move in quasi-quantized steps of one rod length.

Diffusion rate aligns with theoretical calculations from nematic diffusion models.

Abstract

We report the direct visualization at the scale of single particles of mass transport between smectic layers, also called permeation, in a suspension of rod-like viruses. Self-diffusion takes place preferentially in the direction normal to the smectic layers, and occurs by quasi-quantized steps of one rod length. The diffusion rate corresponds with the rate calculated from the diffusion in the nematic state with a lamellar periodic ordering potential that is obtained experimentally.