Foam films stabilized with lysophosphatidylglycerol in the presence of Na + and Ca 2+

S Alexandrov, R Todorov, A Jordanova, Z Lalchev, D Exerowa
2016 Bulgarian Chemical Communications   unpublished
This work presents investigation of foam films stabilized with soluble phospholipid palmitoyl lysophosphatidylglycerol (LPG). The films have been studied by measuring the thickness/electrolyte concentration and disjoining pressure/thickness isotherms in the presence of Na + and Ca 2+ in the solution. At low NaCl we have obtained formation of thick silver-colored films with equilibrium thickness. With the increase of the concentration of Na + the films became thinner and at 0.5 mol dm-3 their
more » ... 5 mol dm-3 their equilibrium thickness was ~9 nm (common black films). Foam films in the presence of Ca 2+ followed the same dependence, but at concentration of electrolyte 5×10-2 mol dm-3 and higher, Newton black films were formed. The formation of equilibrium Newton black films happened with "jump" from silver films during the thinning process. The isotherms of disjoining pressure for both electrolytes had shown lightly decrease for the thickness of the films, without any transitions.