Fluid Gel Lubrication as a Function of Solvent Quality

Soft tribology is of increasing interest in biotribology applications to approximate skin/skin and oral contact environments. As such a number of studies explore the tribological behaviour of food and consumer product/model systems have been reported. This work builds on this understanding by examining soft surface lubrication of Agar fluid gel as a function of solvent quality. Firstly with alcohols at varying concentrations and secondly with salts, using the well-known lyotropic effect, which from previous studies is known to affect the properties of gels. Pure solvent systems showed patterns in friction reduction. Fluid gel lubrication behaviour was different when altering solvent quality and is suggested to be primarily an effect of changing gel structure, which is illustrated by approximate particle size distributions obtained for each sample. These effects can potentially be used to control food properties for enhanced behaviour in the mouth, or to better understand the structures that would form when using a fluid gel in more complex solvent containing products.