Responsive Aqueous Foams
Résumé
Remarkable properties have emerged recently for aqueous foams including ultrastability and responsiveness. Responsive aqueous foams refer to foams for which the stability can be switched between stable and unstable states with a change in environment or with external stimuli. Responsive foams have been obtained from various foam stabilizers such as surfactants, proteins, polymers and particles and with various stimuli. Different strategies have been developed to design this type of soft materials. We briefly review the two main approaches used to obtain responsive foams. The first approach is based on the responsiveness of the interfacial layer surrounding the gas bubbles leading to responsive foams. The second one is based on the modifications occurring in the aqueous phase inside the foam liquid channels to tune the foam stability. We will highlight the most sophisticated approaches which use light, temperature and magnetic field leading to switchable foam stability.