Rheological properties in solutions of wormlike micelle composed of lysophosphatidylcholine/phosphatidylcholine mixture

Abstract

We have elucidated the heat induced formation of wormlike micelles in the mixture solutions containing two different geometric amphiphiles of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC), where LPC and PC have one and two alkyl chains as hydrophobic groups, respectively. The mixture solutions showed the increases in viscosity and transparency by heating, and showed the highest viscosity at the ratio of LPC/PC = 1.67, suggesting the formation of long wormlike micelles attained by the average cpp around 0.5 favorable. From the dynamic rheological measurements, it was found that the elasticity was proportional to the square of total concentration of LPC and PC, indicating the existence of entanglement among long wormlike micelles. Other mixture solutions seem to be mixtures of spherical, lamellar and wormlike micelles with different sizes judging from the viscoelastic behavior and transparency, where the sizes changed reversibly with the temperature changes.