Linking polymer hydrophobicity and molecular interactions to rheology and tribology in phospholipid-containing complex gels.

Hypothesis: The rheological behavior and frictional properties (macroscopic level) of systems containing a hydrophobically modified polymer and phospholipids depend on the hydrophobic association that occur between the hydrophobic moiety of the polymer and the phospholipid tails (molecular level). The hydrophobicity of the polymer can thus be used to control its interactions with phospholipids, and manipulate complex gel macroscopic behavior.

Experiments: By using systems composed of a crosslinked hydrophobically modified polyacrylic acid (HMPAA) or a crosslinked polyacrylic acid polymer (PAA) and phospholipids, we examine the underlying mechanisms through which the components interact using isothermal titration calorimetry (ITC) and their effect on rheological and tribological characteristics of complex gels.