Single bubble and drop techniques for characterizing foams and emulsions

TL;DR

This review discusses the emerging single bubble and drop techniques for studying foams and emulsions, highlighting their experimental methods, recent scientific insights, and future research directions.

Contribution

It provides a comprehensive overview of single bubble/drop platforms, measurement protocols, and recent advances in foam and emulsion science using these techniques.

Findings

Single bubble/drop methods reveal rheology and stabilization mechanisms.

Visualization techniques improve understanding of film rupture dynamics.

Recent studies enhance knowledge of interfacial properties in foams and emulsions.

Abstract

The physics of foams and emulsions has traditionally been studied using bulk foam/emulsion tests and single film platforms such as the Scheludko cell. Recently there has been a renewed interest in a third class of techniques that we term as single bubble/drop tests, which employ isolated whole bubbles and drops to probe the characteristics of foams and emulsions. Single bubble and drop techniques provide a convenient framework for investigating a number of important characteristics of foams and emulsions, including the rheology, stabilization mechanisms, and rupture dynamics. In this review we provide a comprehensive discussion of the various single bubble/drop platforms and the associated experimental measurement protocols including the construction of coalescence time distributions, visualization of the thin film profiles and characterization of the interfacial rheological properties. Subsequently, we summarize the recent developments in foam and emulsion science with a focus on the results obtained through single bubble/drop techniques. We conclude the review by presenting important venues for future research.