Imperial College London


Faculty of EngineeringDepartment of Mechanical Engineering

Senior Lecturer



+44 (0)20 7594 8991j.wong




671City and Guilds BuildingSouth Kensington Campus






BibTex format

author = {Dench, J and Morgan, N and Wong, J},
doi = {10.1007/s11249-016-0807-3},
journal = {Tribology Letters},
title = {Quantitative viscosity mapping using fluorescence lifetime measurements},
url = {},
volume = {65},
year = {2016}

RIS format (EndNote, RefMan)

AB - Lubricant viscosity is a key driver in both the tribological performance and energy efficiency of a lubricated contact. Elastohydrodynamic (EHD) lubrication produces very high pressures and shear rates, conditions hard to replicate using conventional rheometry. In situ rheological measurements within a typical contact are therefore important to investigate how a fluid behaves under such conditions. Molecular rotors provide such an opportunity to extract the local viscosity of a fluid under EHD lubrication. The validity of such an application is shown by comparing local viscosity measurements obtained using molecular rotors and fluorescence lifetime measurements, in a model EHD lubricant, with reference measurements using conventional rheometry techniques. The appropriateness of standard methods used in tribology for high-pressure rheometry (combining friction and film thickness measurements) has been verified when the flow of EHD lubricant is homogeneous and linear. A simple procedure for calibrating the fluorescence lifetime of molecular rotors at elevated pressure for viscosity measurements is proposed.
AU - Dench,J
AU - Morgan,N
AU - Wong,J
DO - 10.1007/s11249-016-0807-3
PY - 2016///
SN - 1573-2711
TI - Quantitative viscosity mapping using fluorescence lifetime measurements
T2 - Tribology Letters
UR -
UR -
VL - 65
ER -