An optimized recipe for making giant bubble

TL;DR

This paper identifies key physical ingredients and optimal conditions for creating stable, large soap bubbles, combining experimental measurements with a practical recipe for artistic and scientific applications.

Contribution

It provides a systematic experimental approach to optimize bubble stability and ease of generation, introducing a validated recipe based on surfactant, polymer, and glycerol concentrations.

Findings

Optimal surfactant concentration is not too high.

Long flexible polymers improve bubble formation.

Glycerol enhances bubble stability by reducing evaporation.

Abstract

Big bubbles are largely used in physics laboratories to study 2D turbulence, surface wavers, fundamental properties of soap systems... On a more artistic point of view, blowing big bubbles is part of many artistic shows. Both communities usually wan to get reasonably stable foam films. The purpose of this article is to propose the main physical ingredients allowing to identify a good recipe for making stable films and bubbles. We propose controlled experiments, to measure both the easiness to generate a bubble and its stability for different stabilizing solutions, which we choose by adding one by one the ingredients contained in an artist's recipe. The main results are that (i) the surfactant concentration must be not too high (ii) the solution must contain some long flexible polymer chains to allow an easy bubble generation and (iii) the addition of glycerol allows a better bubble stability by avoiding evaporation. We finally propose an efficient recipe, which takes into account all these considerations.