Abstract

Beatrice Anna Maria Boggio Robutti

Understanding surfactant behaviour to reduce friction in motor vehicles

Metal-metal contacts within engines experience high levels of friction and wear, which contribute to faster engine breakdown and to the production of harmful vehicle emissions. Organic friction modifiers (OFMs) are additives commonly utilised to minimise engine losses through the formation of planes of low shear resistance between contacting metallic surfaces. OFMs are dosed into additives packages and their role is to enhance vehicle fuel economy.

Stearyldiethanolamine (SdEA) is a successful aminic OFM , reported to also work favourably in tandem with common wear-reducing additive ZDDP . In this work, we utilise a combination of conventional techniques and neutron scattering to understand the fundamental relationship between its molecular structure, bulk structure, and surface structure. The effect of conventional biofuel-related impurities on SdEA behaviour is also investigated.

Sheila Bhatt

Why don’t we bleed to death? Morphology, gelation and drying in droplets of human blood: tracking advective evolution

An optical-absorbance technique has been used to observe the time-resolved formation of blood fraction droplet residue morphologies in drying human blood. A range of red blood cell volume fractions and plasma-dilutions has been studied in order to track the advection of red blood cells and the formation of residue morphology. Recognising that blood has a complex interplay of both active (cellular) and passive (plasma protein) components, we show that the plasma only drying morphology is modified by the presence of red blood cells, and that diluting the plasma leads to a systematic and predictable variation in the regions of the phase-diagram in which specific classes of morphological residues appear. Tracking the time-resolved peak formation and collapse leading to the observed final residue topology may shed new light on the basis for predicting cracks and craquelure patterns, and provide an avenue for point-of-care pre-diagnostics to classify blood behaviour