Synthesis and stability of switchable CO2-responsive foaming coupled with nanoparticles

Summary: CO2-responsive foaming has been drawing huge attention due to its unique switching characteristics in academic research and industrial practices, whereas its stability remains questionable for further applications. In this paper, a new CO2-switchable foam was synthesized by adding the preferably selected hydrophilic nanoparticle N20 into the foaming agent C12A, through a series of analytical experiments. Overall, the synergy between cationic surfactants and nanoparticles with a contact angle of 37.83° is the best. More specifically, after adding 1.5 wt% N20, the half-life of foam is 14 times longer than that of pure C12A foam. What’s more, the C12A-N20 solution is validated to own distinctive CO2-N2 switching features because very slight foaming degradations are observed in terms of the foaming volume and half-life time even after three cycles of CO2-N2 injections. This study is of paramount importance pertaining to future CO2 foam research and applications in energy and environmental practices.