Determination of Critical Aggregation Concentrations of Self-Assembling Lipids in Nonpolar Organic Media Using Spiropyrans as Photochromic Probes

Critical aggregation concentrations of organic gel-forming lipids in nonpolar organic media such as benzene were found to be determined by measuring the first-order rate constants of merocyanine-to-spiropyran thermal isomerizations for spiropyrans added as probes.