Protein and ionic surfactants - promoters and inhibitors of contact line pinning

TL;DR

This paper investigates how different surfactants, specifically lysozyme and lauryl sulfate, influence the pinning of a drop's contact line, revealing that proteins promote and surfactants inhibit pinning through wetting behavior differences.

Contribution

It introduces a novel understanding of how proteins and surfactants differently affect contact line pinning based on wetting properties.

Findings

Lysozyme promotes contact line pinning.

Lauryl sulfate inhibits contact line pinning.

Wetting behavior explains the disparity in pinning effects.

Abstract

We report a new effect of surfactants in pinning a drop contact line, specifically that lysozyme promotes while lauryl sulfate inhibits pinning. We explain the pinning disparity assuming difference in wetting: the protein-laden drop wets a "clean" surface and the surfactant-laden drop wets an auto-precursored surface.