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Journal of Photochemistry and Photobiology A-chemistry, Dec 1, 2021
Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of i... more Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of interest for many applications. Nowadays, the widespread analysis methods to study photocatalytic self-cleaning comprise mainly indirect methods such as UV–VIS spectroscopy, chromatography or contact angles measurements. Quartz Crystal Microbalance is another appropriate way to study how the surface is decontaminated because it has the advantage to directly measure the reactant mass. In this study the latter was used to investigate various parameters such as mass loss kinetics, effect of photocatalyst or contaminant effective thicknesses, illumination flux … A special attention was paid to the effects of humidity and O2 on the photocatalytic removal of nanometric paraffin oil (hydrocarbons) films over TiO2. QCM measurements were carried out for several H2O and O2 relative contents in the exposure. Ultimately, water is not essential but acts as a reaction promoter while O2 tends to be essential without significantly affecting the photocatalytic rate provided it is present in sufficient amount. Considering these observations and potential degradation pathways of paraffin oil hydrocarbons, the role of H2O and O2 is discussed.
Journal of vacuum science & technology, Jun 2, 2020
Journal of Photochemistry and Photobiology A: Chemistry, 2021
Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of i... more Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of interest for many applications. Nowadays, the widespread analysis methods to study photocatalytic self-cleaning comprise mainly indirect methods such as UV–VIS spectroscopy, chromatography or contact angles measurements. Quartz Crystal Microbalance is another appropriate way to study how the surface is decontaminated because it has the advantage to directly measure the reactant mass. In this study the latter was used to investigate various parameters such as mass loss kinetics, effect of photocatalyst or contaminant effective thicknesses, illumination flux … A special attention was paid to the effects of humidity and O2 on the photocatalytic removal of nanometric paraffin oil (hydrocarbons) films over TiO2. QCM measurements were carried out for several H2O and O2 relative contents in the exposure. Ultimately, water is not essential but acts as a reaction promoter while O2 tends to be essential without significantly affecting the photocatalytic rate provided it is present in sufficient amount. Considering these observations and potential degradation pathways of paraffin oil hydrocarbons, the role of H2O and O2 is discussed.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2020
The self-cleaning properties emerging from photocatalytic effects consist in the elimination of a... more The self-cleaning properties emerging from photocatalytic effects consist in the elimination of an organic contamination layer by light-induced redox reactions. Quartz crystal microbalances (QCMs), monitoring the contaminant mass loss under UV illumination, were used to investigate this effect and its efficiency. A new setup dedicated to such purpose is introduced along with the results of a self-cleaning experiment performed with a 20-nm TiO2 thin film coated on a QCM by atomic layer deposition. In particular, a 10-nm paraffin oil thin film deposited under vacuum is shown to be degraded down to its complete removal according to a zeroth order photocatalytic reaction. Finally, the experimental opportunities offered by the new setup, such as a controlled environment composition, are presented.
The invention relates to a thermal interface device comprising a thermal grease film (13) intende... more The invention relates to a thermal interface device comprising a thermal grease film (13) intended to be interposed between a first object (11) and a second object (12), and a microporous seal (22) encircling the periphery thermal grease film (13). The invention also relates to a manufacturing method comprising the steps of: • deposition of microporous seal (22) on the first object (11) so as to form a closed frame of the first object (11), • deposition of fat heat (13) on the first object (11), inside the closed frame, • smoothing thermal grease (13) bearing on part of microporous seal (22), for forming the film of thermal grease ( 13) surrounded by the microporous gasket (22), • deposition of the second object (12) on the thermal grease film (13).
Journal of Photochemistry and Photobiology A-chemistry, Dec 1, 2021
Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of i... more Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of interest for many applications. Nowadays, the widespread analysis methods to study photocatalytic self-cleaning comprise mainly indirect methods such as UV–VIS spectroscopy, chromatography or contact angles measurements. Quartz Crystal Microbalance is another appropriate way to study how the surface is decontaminated because it has the advantage to directly measure the reactant mass. In this study the latter was used to investigate various parameters such as mass loss kinetics, effect of photocatalyst or contaminant effective thicknesses, illumination flux … A special attention was paid to the effects of humidity and O2 on the photocatalytic removal of nanometric paraffin oil (hydrocarbons) films over TiO2. QCM measurements were carried out for several H2O and O2 relative contents in the exposure. Ultimately, water is not essential but acts as a reaction promoter while O2 tends to be essential without significantly affecting the photocatalytic rate provided it is present in sufficient amount. Considering these observations and potential degradation pathways of paraffin oil hydrocarbons, the role of H2O and O2 is discussed.
Journal of vacuum science & technology, Jun 2, 2020
Journal of Photochemistry and Photobiology A: Chemistry, 2021
Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of i... more Abstract The self-cleaning properties provided by photocatalytic reactions have raised a lot of interest for many applications. Nowadays, the widespread analysis methods to study photocatalytic self-cleaning comprise mainly indirect methods such as UV–VIS spectroscopy, chromatography or contact angles measurements. Quartz Crystal Microbalance is another appropriate way to study how the surface is decontaminated because it has the advantage to directly measure the reactant mass. In this study the latter was used to investigate various parameters such as mass loss kinetics, effect of photocatalyst or contaminant effective thicknesses, illumination flux … A special attention was paid to the effects of humidity and O2 on the photocatalytic removal of nanometric paraffin oil (hydrocarbons) films over TiO2. QCM measurements were carried out for several H2O and O2 relative contents in the exposure. Ultimately, water is not essential but acts as a reaction promoter while O2 tends to be essential without significantly affecting the photocatalytic rate provided it is present in sufficient amount. Considering these observations and potential degradation pathways of paraffin oil hydrocarbons, the role of H2O and O2 is discussed.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2020
The self-cleaning properties emerging from photocatalytic effects consist in the elimination of a... more The self-cleaning properties emerging from photocatalytic effects consist in the elimination of an organic contamination layer by light-induced redox reactions. Quartz crystal microbalances (QCMs), monitoring the contaminant mass loss under UV illumination, were used to investigate this effect and its efficiency. A new setup dedicated to such purpose is introduced along with the results of a self-cleaning experiment performed with a 20-nm TiO2 thin film coated on a QCM by atomic layer deposition. In particular, a 10-nm paraffin oil thin film deposited under vacuum is shown to be degraded down to its complete removal according to a zeroth order photocatalytic reaction. Finally, the experimental opportunities offered by the new setup, such as a controlled environment composition, are presented.
The invention relates to a thermal interface device comprising a thermal grease film (13) intende... more The invention relates to a thermal interface device comprising a thermal grease film (13) intended to be interposed between a first object (11) and a second object (12), and a microporous seal (22) encircling the periphery thermal grease film (13). The invention also relates to a manufacturing method comprising the steps of: • deposition of microporous seal (22) on the first object (11) so as to form a closed frame of the first object (11), • deposition of fat heat (13) on the first object (11), inside the closed frame, • smoothing thermal grease (13) bearing on part of microporous seal (22), for forming the film of thermal grease ( 13) surrounded by the microporous gasket (22), • deposition of the second object (12) on the thermal grease film (13).