Photoluminescent CdSe/CdS/ZnS Quantum Dots for Temperature and Pressure Sensing in Elastohydrodynamic Contacts - S. M. B. Albahrani

S. M. B. Albahrani, LaMCoS, Université de Lyon, INSA-Lyon, CNRS

Mardi 28 juin 2016 à 14 h

IMPMC - Université P. et M. Curie - 4, Place Jussieu - 75005 Paris

Salle de Conférence - Barre 22-23 - 4e étage - Salle 401

Abstract

Temperature and pressure are two relevant parameters for the optimization of
lubrication performance in the elastohydrodynamic lubrication (EHL) regime. To date,
various experimental methods have been developed to measure these two parameters
with more or less success.
In a continuation of these efforts, some investigations are presented in the current
work in view of developing a new in situ technique which allows measuring locally these
two parameters throughout elastohydrodynamic (EHD) contacts. This technique exploits
the photoluminescence (PL) sensitivity of CdSe/CdS/ZnS quantum dots (QDs) to
variations in temperature and pressure. In this respect, calibrations were performed using
a diamond anvil cell in order to establish the temperature/pressure sensitivity of the QDs.
Although these calibrations demonstrated the potential of these QDs, they revealed the
existence of some interaction-related parameters affecting their response, in addition to
the temperature and the pressure.
A comprehensive study was thus conducted in order to elucidate the mechanisms
behind these findings. More importantly, a methodology was defined in order to minimize
these undesired influences and, in fine, enable these QDs to be used as reliable
nanosensors. The application of these nanosensors was validated by (i) evaluating the
self-heating induced by viscous resistance of the lubricant under shearing within an optical
rheometer, and (ii) performing in situ pressure measurements in isothermal EHD contacts.

Contact : Christian Brouder (christian.brouder @ upmc.fr)