Category: EHD

Visualisation of Structured Lubricants in Tribological Contacts

The layered, lamellar phase of lyotropic liquid crystals display promising tribological properties possessing low shear strength between layers, solid like elasticity and high load carrying capacity perpendicular to their layered structure. Being able to visualise and study the behaviour of LLC in high pressure contacts at a range of speed, slide-roll ratio (SRR) and temperature conditions can facilitate the understanding of the mechanism of action behind their low friction properties.

A microscope setup has been developed that is capable of collecting real time, high contrast videos of film formation, bulk alignment, and flow of liquid crystal containing lubricants in an EHD ultra-thin film tribometer. This project aims to describe an economic set of methods to evaluate qualitatively the behaviour of liquid crystals in and around tribological contacts.

This is demonstrated with two types of liquid crystals; lamellar lyotropic Oleic Acid/Triethanolamine and smectic thermotropic 8CB.