Formulation of ceramic foams: a new class of amphiphiles

In this work, amino acids are proposed and assessed as a new class of amphiphiles that is more environmentally benign and present a wider operational window than those reported in the literature. The effects of the amphiphile concentration and structure on the foam properties were investigated (e.g. porosity, bubble size distribution). These were classified depending on their different hydrophobicity by establishing a hydrophobicity index. Monotonic relationships between the hydrophobicity index and the foam structural properties (e.g. porosity, bubble size) were found. In addition, the more suitable amino acid to be used at larger scales was identified and it was used as a model amphiphile to have a deeper insight into the foaming process. In particular, the repartition of the amino acids among the different interfaces and the minimum amphiphile concentration to obtain stable foams were identified.