Er doped nanoparticles as upconversion thermometer probes in confined fluids.

Non-contact temperature measurement at the nanoscale by photoluminescence using a nano-sensor in a confined fluid has been performed in the present work. Upconversion lanthanide-doped nanoparticles applied to ratiometric thermometry could be considered as a self-referenced nanosensor. Gadolinium orthovanadate (GdVO) nanoparticles doped with Yb and Er were synthesized and then dispersed in an ester-based fluid.

Quantum dots to probe temperature and pressure in highly confined liquids.

A new technique for temperature and pressure measurement within dynamic thin-film flows of liquids is presented. The technique is based on the fluorescence emission sensitivity of CdSe/CdS/ZnS quantum dots to temperature and pressure variations. In this respect, the quantum dots were dispersed in squalane, and their emission energy dependence on temperature and pressure was calibrated under static conditions.

Tribochemical Competition within a MoS/Ti Dry Lubricated Macroscale Contact in Ultrahigh Vacuum: A Time-of-Flight Secondary Ion Mass Spectrometry Investigation.

Controlling and predicting the tribological behavior of dry lubricants is a necessity to ensure low friction, long life, and low particle generation. Understanding the tribochemistry of the materials as a function of the environment is of primary interest as synergistic effects exist between the mechanics, the physicochemistry, and the thermodynamics within a contact. However, in most studies the role of the coating internal contaminants in the process is often discarded to the benefit of a more common approach in which the performances of the materials are compared as a function of different atmospheric pressure environments.

Luminescence nanothermometry with alkyl-capped silicon nanoparticles dispersed in nonpolar liquids.

Silicon nanoparticles (Si NPs) with a diameter size ranging from 4 to 8 nm were successfully fabricated. They exhibit a visible photoluminescence (PL) due to the quantum confinement effect. Chemical functionalization of these Si NPs with alkyl groups allowed to homogeneously disperse them in nonpolar liquids (NPLs).