Cartilage-inspired, lipid-based boundary-lubricated hydrogels.

The lubrication of hydrogels arises from fluid or solvated surface phases. By contrast, the lubricity of articular cartilage, a complex biohydrogel, has been at least partially attributed to nonfluid, lipid-exposing boundary layers. We emulated this behavior in synthetic hydrogels by incorporating trace lipid concentrations to create a molecularly thin, lipid-based boundary layer that renews continuously.

Probing the Surface Properties of Gold at Low Electrolyte Concentration.

Using the surface force balance (SFB), we studied the surface properties of gold in aqueous solution with low electrolyte concentration (∼10(-5) M and pH = 5.8), i.e.