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

The paper focusses on molecular aggregation in the binary system soybean ph osphatidylcholine (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 shif t. Rheometry and P-31 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 P-31 NMR measurements are discussed and compared with the data from the pulsed field gradient NMR with primary att ention being paid to the second and third c.m.c.