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749 results on '"Hadziioannou, Georges"'

4. Enhanced Pyroelectricity Over Extended Thermal Range in Flexible Polymer Thin Films.

Author

Xie, Kaili, Housseini, Joulia, Resende, Pedro M., Le Goupil, Florian, Isasa, Jean‐David, Tencé‐Girault, Sylvie, Fleury, Guillaume, Kellay, Hamid, and Hadziioannou, Georges

Subjects
POLYMER films, INFRARED detectors, CORE materials, CRYSTALLINE polymers, TRANSITION temperature, FERROELECTRIC polymers
Abstract

Polymer‐based pyroelectric thin films are crucial functional materials at the core of flexible and lightweight electronic devices, such as wearable monitoring sensors, energy harvesters, and infrared detectors. Nevertheless, the pyroelectric properties of the polymer films, such as poly(vinylidene fluoride‐trifluoroethylene) (P(VDF‐TrFE)), vanish when the surrounding temperature exceeds the ferroelectric‐to‐paraelectric transition temperature, and thus limits their pyroelectric performance to a low‐temperature range. Herein, to mitigate this issue by employing a new class of P(VDF‐TrFE) copolymer which has a low TrFE molar content is proposed. Fine‐tuning of the structure through thermal annealing in a vacuum environment significantly favors robust and highly polarized polymer films with a large area. Electric poling combined with an optimal annealing temperature (110–120 °C) gives highly ordered ferroelectric crystalline domains in the polymer films. Consequently, this remarkably broadens the temperature range (roughly up to 140 °C) for which the polymer film still presents high pyroelectric properties (pyroelectric coefficient 50 µC (m2K)−1). This study provides an alternative choice for pyroelectric polymer films with enhanced pyroelectricity in applications that require wider temperature ranges. [ABSTRACT FROM AUTHOR]

Published
2024
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7. Hierarchical self-assembly of nanoparticles for optical metamaterials

Author

Gomez-Graña, Sergio, Beulze, Aurélie Le, Treguer-Delapierre, Mona, Mornet, Stéphane, Duguet, Etienne, Grana, Eftychia, Cloutet, Eric, Hadziioannou, Georges, Leng, Jacques, Salmon, Jean-Baptiste, Kravets, Vasyl G., Grigorenko, Alexander N., Peyyety, Naga A., Ponsinet, Virginie, Richetti, Philippe, Baron, Alexandre, Torrent, Daniel, and Barois, Philippe

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Hierarchical self-assembly arranges nanostructures at different length scales. It gradually becomes an effective method of fabricating artificial metamaterials from composite nanostructures tailored for a particular response. Hierarchical self-assembly overcomes shortcomings of "top-down" methods by significantly reducing fabrication time and making it possible to form bulk materials. Here we report an application of hierarchical self-assembly of metal nanoparticles for the creation of the first isotropic optical metamaterial with strong artificial magnetism in blue light. We have used colloidal self-assembly to create artificial "nanomolecules" that generate the desired magnetic response and microfluidic self-assembly to produce a bulk metastructure. We demonstrate that the magnetic response of the final material is accurately described by an isotropic magnetic permeability that satisfies the principle of locality. Our approach unlocks the fabrication of large volumes of composite nanomaterials. Moreover, the spatial disorder inherent to this "bottom-up" method holds the key to solving the non-locality problem. The technique can be readily extended to the future generations of low-loss optical metamaterials made of dielectric nano-blocks to bypass the limitations of optical losses associated with plasmonic resonances in noble metals., Comment: Main article:10 pages, 4 figures. Supplementary information: 11 pages, 7 figures

Published
2016

14. Tuning the Aggregates of Thiophene‐based Trimers by Methyl Side‐chain Engineering for Photocatalytic Hydrogen Evolution

Author

Yuan, Xiaojiao, primary, Yang, Kunran, additional, Grazon, Chloé, additional, Wang, Cong, additional, Vallan, Lorenzo, additional, Resende, Pedro M, additional, Isasa, Jean-David, additional, Li, Fanxing, additional, Brochon, Cyril, additional, Remita, Hynd, additional, Hadziioannou, Georges, additional, Cloutet, Eric, additional, and Li, Jian, additional

Published
2023
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22. Chitosan-Modified Polyethyleneimine Nanoparticles for Enhancing the Carboxylation Reaction and Plants CO2 Uptake

Author

Routier, Cyril, Vallan, Lorenzo, Daguerre, Yohann, Juvany, Marta, Istif, Emin, Mantione, Daniele, Brochon, Cyril, Hadziioannou, Georges, Strand, Asa, Nasholm, Torgny N., Cloutet, Eric, Pavlopoulou, Eleni, Stavrinidou, Eleni, Routier, Cyril, Vallan, Lorenzo, Daguerre, Yohann, Juvany, Marta, Istif, Emin, Mantione, Daniele, Brochon, Cyril, Hadziioannou, Georges, Strand, Asa, Nasholm, Torgny N., Cloutet, Eric, Pavlopoulou, Eleni, and Stavrinidou, Eleni

Abstract

Increasing plants photosynthetic efficienc y is a major challenge that must be addressed in order to cover the food demands of the growing population in the changing climate. Photosynthes i s is greatly limited at the initial carboxylation reaction, where CO2 is converted to the organic acid 3-PGA, catalyzed by the RuBisCO enzyme. RuBisCO has poor affinity for CO2, but also the CO2 concentration at the RuBisCO site is limited by the diffusion of atmospheric CO2 through the various leaf compartments to the reaction site. Beyond genetic engineer-ing, nanotechnology can offer a materials-based approach for enhancing photosynthesis, and yet, it has mostly been explored for the light-dependent reactions. In this work, we developed polyethyleneimine-based nanoparticl e s for enhancing the carbox-ylation reaction. We demonstrate that the nanoparticles can capture CO2 in the form of bicarbonate and increase the CO2 that reacts with the RuBisCO enzyme, enhancing the 3-PGA production in in vitro assays by 20%. The nanoparticles can be introduced to the plant via leaf infiltration and, because of the functionalization with chitosan oligomers, they do not induce any toxic effect to the plant. In the leaves, the nanoparticles localize in the apoplastic space but also spontaneously reach the chloroplasts where photosynthetic activity takes place. Their CO2 loading-dependent fluorescence verifies that, in vivo, they maintain their abi l i t y to capture CO2 and can be therefore reloaded with atmospheric CO2 while in planta. Our results contribute to the development of a nanomaterials-based CO2-concentrating mechanism in plants t h a t can potentially increase photosynthetic efficiency and overall plants CO2 storage., Funding Agencies|European Union [800926, 101042148]; Swedish Research Council [VR-2017-04910]; Swedish Government Strategic Research Area in Materials Science on Advanced Functional Materials at Linkoping University [2009-00971]; MCIN/AEI [Ayuda RYC2021-031668-I]

Published
2023
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23. Tuning the Aggregates of Thiophene‐based Trimers by Methyl Side‐chain Engineering for Photocatalytic Hydrogen Evolution.

Author

Yuan, Xiaojiao, Yang, Kunran, Grazon, Chloé, Wang, Cong, Vallan, Lorenzo, Isasa, Jean‐David, Resende, Pedro M., Li, Fanxing, Brochon, Cyril, Remita, Hynd, Hadziioannou, Georges, Cloutet, Eric, and Li, Jian

Subjects
PHOTOCATALYSTS, ORGANIC semiconductors, CHARGE carriers, PHOTOCATALYSIS, HYDROGEN
Abstract

Organic π‐conjugated semiconductors (OCSs) have recently emerged as a promising alternative to traditional inorganic materials for photocatalysis. However, the aggregation of OCSs in photocatalytic aqueous solution caused by self‐assembly, which closely relates to the photocatalytic activity, has not yet been studied. Here, the relationship between the aggregation of 4,7‐Bis(thiophen‐2‐yl) benzothiadiazole (TBT) and the photocatalytic activity was systematically investigated by introducing and varying the position of methyl side chains on the two peripheral thiophene units. Experimental and theoretical results indicated that the introduction of ‐CH3 group at the 3‐position of TBT resulted in the smallest size and best crystallinity of aggregates compared to that of TBT, 4‐ and 5‐positions. As a result, TBT‐3 exhibited an excellent photocatalytic activity towards H2 evolution, ascribed to the shorten charge carrier transport distance and solid long‐range order. These results suggest the important role of aggregation behavior of OCSs for efficient photocatalysis. [ABSTRACT FROM AUTHOR]

Published
2024
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28. Chitosan-Modified Polyethyleneimine Nanoparticles for Enhancing the Carboxylation Reaction and Plants’ CO2Uptake

Author

Routier, Cyril, primary, Vallan, Lorenzo, additional, Daguerre, Yohann, additional, Juvany, Marta, additional, Istif, Emin, additional, Mantione, Daniele, additional, Brochon, Cyril, additional, Hadziioannou, Georges, additional, Strand, Åsa, additional, Näsholm, Torgny, additional, Cloutet, Eric, additional, Pavlopoulou, Eleni, additional, and Stavrinidou, Eleni, additional

Published
2023
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29. Organic Conjugated Trimers with Donor–Acceptor–Donor Structures for Photocatalytic Hydrogen Generation Application

Author

Yuan, Xiaojiao, primary, Wang, Cong, additional, Vallan, Lorenzo, additional, Bui, Anh Thy, additional, Jonusauskas, Gediminas, additional, McClenaghan, Nathan D., additional, Grazon, Chloé, additional, Lacomme, Sabrina, additional, Brochon, Cyril, additional, Remita, Hynd, additional, Hadziioannou, Georges, additional, and Cloutet, Eric, additional

Published
2023
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30. Conjugated polymer blends for faster organic mixed conductors

Author

Barker, Micah, primary, Nicolini, Tommaso, additional, Yaman, Yasmina Al, additional, Thuau, Damien, additional, Siscan, Olga, additional, Ramachandran, Sasikumar, additional, Cloutet, Eric, additional, Brochon, Cyril, additional, Richter, Lee J., additional, Dautel, Olivier J., additional, Hadziioannou, Georges, additional, and Stingelin, Natalie, additional

Published
2023
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38. Correction : Biohybrid plants with electronic roots via in vivo polymerization of conjugated oligomers (vol 8, pg 3295, 2021)

Author

Parker, Daniela, Daguerre, Yohann, Dufil, Gwennael, Mantione, Daniele, Solano, Eduardo, Cloutet, Eric, Hadziioannou, Georges, Näsholm, Torgny, Berggren, Magnus, Pavlopoulou, Eleni, Stavrinidou, Eleni, Parker, Daniela, Daguerre, Yohann, Dufil, Gwennael, Mantione, Daniele, Solano, Eduardo, Cloutet, Eric, Hadziioannou, Georges, Näsholm, Torgny, Berggren, Magnus, Pavlopoulou, Eleni, and Stavrinidou, Eleni

Abstract

n/a

Published
2022
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47. Top-coats for scalable nano-manufacturing with high-χ block copolymers in lithographic applications

Author

Chevalier, Xavier, Gomes correia, Cindy, POUND-LANA, Gwenaelle, Bézard, Philippe, SÉRÉGÉ, Matthieu, PETIT-ETIENNE, Camille, Gay, Guillaume, Cunge, Gilles, CABANNES-BOUÉ, Benjamin, Nicolet, Célia, Navarro, Christophe, Cayrefourcq, Ian, Müller, Marcus, Hadziioannou, Georges, Iliopoulos, Ilias, Fleury, Guillaume, Gomez Correia, Cindy, Zelsmann, M., Laboratoire des technologies de la microélectronique (LTM ), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Chimie des Polymères Organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC), and Université de Bordeaux (UB)-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, [PHYS]Physics [physics], Materials science, Silicon, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Planarity testing, chemistry, Stack (abstract data type), 0103 physical sciences, Scalability, Copolymer, Lamellar structure, 0210 nano-technology, Lithography, ComputingMilieux_MISCELLANEOUS, Nano manufacturing
Abstract

Results for the self-assembly of lamellar silicon-containing high-χ block copolymers (BCP) with innovative neutral top-coat design are presented. We demonstrate that these materials and associated processes are compatible with a standard lithographic process, and oriented toward a potential high volume manufacturing. We show that this dedicated technology is able to guarantee the stability and planarity of the stack even at elevated self-assembly bake temperatures, and opens new opportunity in the fields of 3D BCPs stacks. Finally, we show interesting results for the etch-transfer of a lamellar BCP in silicon.

Published
2021
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