Self-aggregation of a native soybean phosphatidylcholine in n-butanol

The paper focusses on molecular aggregation in the binary system soybean phosphatidylcholine (SPC)/n-butanol. Critical micelle concentrations (c.m.c.) were determined from the inflection points in the concentration-dependent slopes for apparent and partial molal volumes, viscosity, and chemical shift. Rheometry and 31 P NMR results are in good agreement with these data. In the investigated system a first (7.5 %w/w SPC), second (35 %w/w SPC), and third (63 %w/w SPC) critical micelle concentration (c.m.c.) were detected. The results from the viscometry and 31 P NMR measurements are discussed and compared with the data from the pulsed field gradient NMR with primary attention being paid to the second and third c.m.c.