Relationship between ultralow friction of mesogenic-like fluids and their lateral chain length

Mesogenic fluids (MFs) may have a great potential for technical applications to increase the energy efficiency and to prevent wear. Aim of the present work was to study a homologous series of mesogenic-like fluids to evaluate the influence of the chemical structure on the tribological behavior. Rheological measurements were additionally performed to correlate the tribological properties with the viscosity and flow behavior. Raman spectroscopy and differential scanning calorimetry measurements were used to characterize the MFs. Furthermore, the surface topography of the wear scar was studied by profilometry. The results were summarized and hence an approach was made to describe the several mechanisms which may lead to the observed tribological results. This work shows that a better understanding of the tribological behavior of these MFs is essential to develop new lubricants.