(bron: wikipedia)Foams are two-phase material systems where a gas is disbursed in a second, non-gaseous material, specifically, in which gas cells are enclosed by a distinct liquid or solid material.[ Note, this source focuses only on liquid foams.][ Note, this source also focuses on liquid foams.] The foam "may contain more or less liquid [or solid] according to circumstances",[ although in the case of gas-liquid foams, the gas occupies most... meer]
