Self pinning protein-laden drops

TL;DR

This paper investigates how proteins in drops influence contact line pinning, revealing two regimes where pinning behavior varies with protein content and surface tension, impacting drop stability on substrates.

Contribution

It introduces a detailed analysis of protein-induced pinning regimes and their dependence on contact angle hysteresis and surface tension.

Findings

Pinning increases with contact angle hysteresis at low protein content.

Pinning decreases with surface tension at high protein content.

Two distinct pinning regimes are identified based on protein concentration.

Abstract

Proteins dissolved in a drop induce and enhance the pinning of the drop contact line. This effect dramatically increases volume of drops that are vertically pinned on a flat siliconized substrate. The drop pinning behavior exhibits two regimes: for low protein content in a drop the pinning increases as the contact angle hysteresis increases, and for high protein content the pinning decreases as the surface tension of the protein solution decreases.