Withdrawing a solid from a bath: how much liquid is coated?

TL;DR

This review examines how various complexities like interface properties, rheology, and solid characteristics influence the film thickness when a solid is withdrawn from a liquid bath, extending beyond ideal Newtonian assumptions.

Contribution

It systematically analyzes deviations from ideal predictions by exploring the effects of interface, rheology, and solid properties on film coating.

Findings

Significant effects of interface properties on film thickness.

Rheological complexities alter coating outcomes.

Theoretical models attempt to explain experimental deviations.

Abstract

A solid withdrawn from a liquid bath entrains a film. In this review, after recalling the predictions and results for pure Newtonian liquids coated on simple solids, we analyze the deviations to this ideal case exploring successively three potential sources of complexity: the liquid-air interface, the bulk rheological properties of the liquid and the mechanical or chemical properties of the solid. For these different complexities, we show that significant effects on the film thickness are observed experimentally and we summarize the theoretical analysis presented in the literature, which attempt to rationalize these measurements.