Detection of X-Ray Doses with Color-Changing Hackmanites: Mechanism and Application

Hackmanites, a variety of sodalite with the general formula Na$_{8}$Al$_{6}$Si$_{6}$O$_{24}$(Cl,S)$_{2}$, are a family of nature-based smart materials having the ability for reversible photochromism upon UV or X-ray exposure. Being nontoxic, cheap, and durable, hackmanite would be an optimal material for the visual detection of the presence of X-rays in simple portable systems. However, its X-ray-induced coloring abilities are so far known only qualitatively. In this work, a combination of experimental and computational methods is used to reveal the mechanism of X-ray-induced color changing in these materials. Finally, their use is demonstrated both in color intensity-based X-ray dosimetry and photochromic X-ray imaging

Detection of X-Ray Doses with Color-Changing Hackmanites: Mechanism and Application

Hackmanites, a variety of sodalite with the general formula Na8Al6Si6O24(Cl,S)(2), are a family of nature-based smart materials having the ability for reversible photochromism upon UV or X-ray exposure. Being nontoxic, cheap, and durable, hackmanite would be an optimal material for the visual detection of the presence of X-rays in simple portable systems. However, its X-ray-induced coloring abilities are so far known only qualitatively. In this work, a combination of experimental and computational methods is used to reveal the mechanism of X-ray-induced color changing in these materials. Finally, their use is demonstrated both in color intensity-based X-ray dosimetry and photochromic X-ray imaging

Arqus Openness Position Paper

The Openness Position Paper published by the Arqus European University Alliance emphasises that Arqus institutions, in line with the policies, roadmaps and strategies of the EU and a wide range of stakeholders, are striving jointly to make further progress towards realising Open Science. The Position Paper identifies and acknowledges aims and values of Open Science and relates them to values, principles, and standards shared by the Arqus Alliance, followed by a vision for a future with Open Science. In the interest of a nuanced picture, the Position Paper discusses not only desired effects, but also possible areas of tension related to Open Science. It presents a wide range of specific aims and recommendations for each of the eleven elements of Open Science defined by the Arqus Openness Task Force: Governance Publications (including Open Access) Data (including research data management, FAIR and Open Data) Infrastructures (including support staff, Open Science software and tools, repositories, Open Labs) Methods (including source code, preregistration, materials, workflows, protocols, lab notes) Awareness and training (including education of early-stage researchers) Evaluation (including Open Metrics, research assessment, Open Peer Review, rewards and incentives) Communication (including multilingualism) Citizen Science Open Education Open Innovation The Position Paper concludes with an annex that highlights the progress already made in the implementation and support of Open Science practices at Arqus institutions.Cofunded by the Erasmus+Programme of the European Unio

Combined Theoretical and Exprimental Chracterization of Semicondcutors for Photoelectrocatalytic Applications

International audienc

Modelling the S-Doped Sodalites Using DFT, TD-DFT and SAC-CI Methods

International audienc

Optimisation des cellules solaires à colorants à base de ZnO par une approche combinée théorie/expérience

Cette dernière décennie a montré que les cellules solaires à colorants étaient une technologie photovoltaïque économiquement viable. Malgré les nombreuses études réalisées dans ce domaine, force est de constater que les rendements de photoconversion n ont toujours pas dépassé 12% avec ce type de cellule. Les travaux réalisés au cours de cette thèse s inscrivent dans une optique d optimisation des cellules solaires à colorants. Pour y parvenir, une approche joignant la théorie et l expérience a été développée. Par des calculs basés sur la Théorie de la Fonctionnelle de la Densité (DFT), une nouvelle famille de colorants, caractérisée par la présence d un groupement pyridinium, a été étudiée afin d en choisir les membres les plus aptes à générer un photocourant. En combinant une approche moléculaire et périodique, les calculs ont permis de comprendre différents mécanismes intervenant dans le fonctionnement de la cellule solaire conduisant à une optimisation théorique de certains constituants de la cellule comme la composition de l électrolyte ou le colorant. Parallèlement aux calculs, une méthodologie de construction et de caractérisation des cellules basée sur l utilisation de ZnO comme semiconducteur a été mise en place au sein du laboratoire. La synthèse de ces nouveaux colorants a aussi été réalisée au cours de ce travail de doctorat. La conception et la caractérisation expérimentales de cellules utilisant ces colorants a permis de valider le protocole théorique développé ouvrant la voie à une optimisation ab initio des cellules solaires à colorantsPARIS-BIUSJ-Biologie recherche (751052107) / SudocSudocFranceF

Ingénierie du photochromisme des aluminosilicates par chimie quantique

Sodalite-based photochromic minerals represent a potentially new family of inorganic photochromes. It was previously proven that the change in the color of these minerals is based on a photo-induced electron transfer from a sulfur-based impurity to a chlorine vacancy, leading to the formation of a trapped electron. In parallel, several groups have shown that it is possible to artificially synthesize these minerals and to tune the chemical composition from the native one (Na8[AlSiO4]6Cl2). In this study, we use an assessed quantum chemical method (based on periodic DFT calculations and TD-DFT calculations on an embedded cluster) to predict the influence of the chemical modification of sodalite on the photochromic properties of the material considering the general composition C8[ABO4]6X2 (A = Si, Ge; B = Al, Ga; C = Na, K; X = Cl, Br, I). The aim of this work is to pave the way for the design of artificial sodalites for specific applications

DFT investigation of tenebrescent natural minerals

International audienc

Investigation of electronic properties of photochromic sodalite by DFT/TD-DFT calculations.

International audienc