Tribological studies of PLL-g-PEG polyelectrolyte copolymers in aqueous glycerol mixtures

Aqueous tribology is becoming an important approach to the lubrication of contacting surfaces in the biomedical, pharmaceutical, and food industries. Poly (ethylene glycol)-based polyelectrolytes can form brush-like structures on several classes of surface in aqueous media and improve the lubrication properties of water. The use of aqueous glycerol solutions along with polymer brushes can further reduce the frictional forces at the contact when compared to non-viscous aqueous solutions. Though there was a collapse in the brush structure in aqueous glycerol solutions, the presence of polymer at the interface could still induce steric repulsion to reduce the friction. The increased pressure-viscosity coefficient of the glycerol-containing bulk solution enhanced the lubrication properties beyond the boundary regime. This is an abstract of a paper presented at the 2009 World Tribology Congress (Kyoto, Japan 9/6-11/2009).