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Papers by Thomas Alnasser
Social Science Research Network, 2022
Proceedings of the International Conference on Hybrid and Organic Photovoltaics, Apr 20, 2022
Advances in Ultrafast Condensed Phase Physics III
Langmuir : the ACS journal of surfaces and colloids, Jan 8, 2017
Anionic and cationic (N-isopropylacrylamide derivatives) active colloidal hydrogel nanoparticles,... more Anionic and cationic (N-isopropylacrylamide derivatives) active colloidal hydrogel nanoparticles, i.e., nanogels, are electrostatically assembled on surfaces to form microscale patterns with complex geometries. While using mixed dispersions of these two kinds of nanogels, we demonstrate the capability of sorting the nanogels in one step to form separated binary nanogel patterns on a surface. These patterns appear independently or simultaneously depending on the relative proportion of each nanogel type in the mixture. Hence, the resulting nanogel patterns provide quantitative information regarding the dispersion composition and can be used to achieve smart concentration-dependent nanogel encryption. Moreover, AFM characterization measurements performed in liquid prove that the assembled nanogels maintain their uptake/release properties once attached to the surface. Consequently, this method paves the way for applying such active nanogel patterns to produce smart coatings and sensors.
The Journal of Physical Chemistry C, 2016
Http Www Theses Fr, Oct 21, 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Langmuir, 2015
The preparation of magnetic inks stable over time made of L1 0-ordered FePt nanoparticles, thiol-... more The preparation of magnetic inks stable over time made of L1 0-ordered FePt nanoparticles, thiol-ended poly-(ethylene glycol) methyl ether (mPEO-SH) compatibilizing macromolecules and asymmetric polystyrene-block-poly-(ethylene oxide) copolymers (BCP) as a subsequent selforganizing medium was optimized. It was demonstrated that the use of sacrificial MgO shells as physical barriers during the annealing stage for getting the L1 0-ordered state makes easier and more efficient the anchoring of compatibilizing PEO macromolecules onto the nanoparticles surface. L1 0-FePt grafted nanoparticles have shown a good colloidal stability and affinity with the PEO domains of the BCP leading to L1 0-FePt/BCP composite thin layers with individual magnetic dots dispersed in the BCP matrix.
Journal of Materials Chemistry C, 2013
En raison de leur constante d’anisotropie magnétocristalline particulièrement élevée,les nanopart... more En raison de leur constante d’anisotropie magnétocristalline particulièrement élevée,les nanoparticules de FePt cristallisant dans la phase « chimiquement » ordonnée L10présentent un grand intérêt pour la réalisation de média magnétiques discrets à très hautedensité (>1 Tb/in2) jusqu’à un diamètre limite de 3,5 nm. Nos travaux portent sur la synthèsepar voie chimique (thermolyse) de nanoparticules de FePt-ɣ, calibrées en taille (4 ≤ Ø ≤ 8 nm)et de composition chimique proche de Fe50Pt50. Par la suite, leur transition vers la variété L10est réalisée afin de leur assurer un comportement ferromagnétique fort à 300 K. En dépitd’une composition non homogène en fer au sein de chaque nanoparticule (coeur riche enplatine et surface davantage riche en fer), la phase L10 est obtenue après un recuit sousatmosphère réductrice (Ar/H2 5%) à des températures supérieures à 650°C. Par ailleurs, afinde prévenir la coalescence des nanoparticules lors du recuit, trois méthodes de protectionsdistinct...
JACS Au
Most photovoltaic (PV) technologies are opaque to maximize visible light absorption. However, see... more Most photovoltaic (PV) technologies are opaque to maximize visible light absorption. However, see-through solar cells open additional perspectives for PV integration. Looking beyond maximizing visible light harvesting, this work considers the human eye photopic response to optimize a selective near-infrared sensitizer based on a polymethine cyanine structure (VG20-C x) to render dye-sensitized solar cells (DSSCs) fully transparent and colorless. This peculiarity was achieved by conferring to the dye the ability to strongly and sharply absorb beyond 800 nm (S 0 −S 1 transition) while rejecting the upper S 0 −S n contributions far in the blue where the human retina is poorly sensitive. When associated with an aggregation-free anatase TiO 2 photoanode, the selective NIR-DSSC can display 3.1% power conversion efficiency, up to 76% average visible transmittance (AVT), a value approaching the 78% AVT value of a standard double glazing window while reaching a color rendering index (CRI) of 92.1%. The ultrafast and fast charge transfer processes are herein discussed, clarifying the different relaxation channels from the dye monomer excited states and highlighting the limiting steps to provide future directions to enhance the performances of this nonintrusive NIR-DSSC technology.
Advanced Energy Materials
ACS Applied Nano Materials
Advanced Energy Materials
Social Science Research Network, 2022
Proceedings of the International Conference on Hybrid and Organic Photovoltaics, Apr 20, 2022
Advances in Ultrafast Condensed Phase Physics III
Langmuir : the ACS journal of surfaces and colloids, Jan 8, 2017
Anionic and cationic (N-isopropylacrylamide derivatives) active colloidal hydrogel nanoparticles,... more Anionic and cationic (N-isopropylacrylamide derivatives) active colloidal hydrogel nanoparticles, i.e., nanogels, are electrostatically assembled on surfaces to form microscale patterns with complex geometries. While using mixed dispersions of these two kinds of nanogels, we demonstrate the capability of sorting the nanogels in one step to form separated binary nanogel patterns on a surface. These patterns appear independently or simultaneously depending on the relative proportion of each nanogel type in the mixture. Hence, the resulting nanogel patterns provide quantitative information regarding the dispersion composition and can be used to achieve smart concentration-dependent nanogel encryption. Moreover, AFM characterization measurements performed in liquid prove that the assembled nanogels maintain their uptake/release properties once attached to the surface. Consequently, this method paves the way for applying such active nanogel patterns to produce smart coatings and sensors.
The Journal of Physical Chemistry C, 2016
Http Www Theses Fr, Oct 21, 2013
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Langmuir, 2015
The preparation of magnetic inks stable over time made of L1 0-ordered FePt nanoparticles, thiol-... more The preparation of magnetic inks stable over time made of L1 0-ordered FePt nanoparticles, thiol-ended poly-(ethylene glycol) methyl ether (mPEO-SH) compatibilizing macromolecules and asymmetric polystyrene-block-poly-(ethylene oxide) copolymers (BCP) as a subsequent selforganizing medium was optimized. It was demonstrated that the use of sacrificial MgO shells as physical barriers during the annealing stage for getting the L1 0-ordered state makes easier and more efficient the anchoring of compatibilizing PEO macromolecules onto the nanoparticles surface. L1 0-FePt grafted nanoparticles have shown a good colloidal stability and affinity with the PEO domains of the BCP leading to L1 0-FePt/BCP composite thin layers with individual magnetic dots dispersed in the BCP matrix.
Journal of Materials Chemistry C, 2013
En raison de leur constante d’anisotropie magnétocristalline particulièrement élevée,les nanopart... more En raison de leur constante d’anisotropie magnétocristalline particulièrement élevée,les nanoparticules de FePt cristallisant dans la phase « chimiquement » ordonnée L10présentent un grand intérêt pour la réalisation de média magnétiques discrets à très hautedensité (>1 Tb/in2) jusqu’à un diamètre limite de 3,5 nm. Nos travaux portent sur la synthèsepar voie chimique (thermolyse) de nanoparticules de FePt-ɣ, calibrées en taille (4 ≤ Ø ≤ 8 nm)et de composition chimique proche de Fe50Pt50. Par la suite, leur transition vers la variété L10est réalisée afin de leur assurer un comportement ferromagnétique fort à 300 K. En dépitd’une composition non homogène en fer au sein de chaque nanoparticule (coeur riche enplatine et surface davantage riche en fer), la phase L10 est obtenue après un recuit sousatmosphère réductrice (Ar/H2 5%) à des températures supérieures à 650°C. Par ailleurs, afinde prévenir la coalescence des nanoparticules lors du recuit, trois méthodes de protectionsdistinct...
JACS Au
Most photovoltaic (PV) technologies are opaque to maximize visible light absorption. However, see... more Most photovoltaic (PV) technologies are opaque to maximize visible light absorption. However, see-through solar cells open additional perspectives for PV integration. Looking beyond maximizing visible light harvesting, this work considers the human eye photopic response to optimize a selective near-infrared sensitizer based on a polymethine cyanine structure (VG20-C x) to render dye-sensitized solar cells (DSSCs) fully transparent and colorless. This peculiarity was achieved by conferring to the dye the ability to strongly and sharply absorb beyond 800 nm (S 0 −S 1 transition) while rejecting the upper S 0 −S n contributions far in the blue where the human retina is poorly sensitive. When associated with an aggregation-free anatase TiO 2 photoanode, the selective NIR-DSSC can display 3.1% power conversion efficiency, up to 76% average visible transmittance (AVT), a value approaching the 78% AVT value of a standard double glazing window while reaching a color rendering index (CRI) of 92.1%. The ultrafast and fast charge transfer processes are herein discussed, clarifying the different relaxation channels from the dye monomer excited states and highlighting the limiting steps to provide future directions to enhance the performances of this nonintrusive NIR-DSSC technology.
Advanced Energy Materials
ACS Applied Nano Materials
Advanced Energy Materials