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1. Nanoscale thermal conductivity of Kapton-derived carbonaceous materials.

Author

Kondratenko, K., Hourlier, D., Vuillaume, D., and Lenfant, S.

Subjects
*THERMAL conductivity, *THERMAL conductivity measurement, *THERMOPHYSICAL properties, *THERMAL diffusivity, *AIR flow, *SPATIAL resolution
Abstract

This study exploits the nanoscale resolution of scanning thermal microscopy (SThM) to reveal inhomogeneous nature of thermal properties of carbon-derived materials issued from thermal conversion of the most commonly known polyimide, Kapton®. This information is otherwise inaccessible if conventional thermal characterization techniques are used due to their limited spatial resolution. Kapton films were pyrolyzed in an inert atmosphere to produce carbon-based residues with varying degree of conversion to free sp2 disordered carbon. The thermal conductivity of carbon materials ranges from 0.2 to 2 W m−1 K−1, depending on the temperature of the carbonization process (varied between 500 and 1200 °C). For quantitative measurements of thermal conductivity, the Null Point SThM (NP-SThM) technique is used in order to avoid unwanted effects as the parasitic heat flows through the air and the probe cantilever. It was found that NP SThM data for bulk materials are in excellent agreement with results obtained through more traditional techniques, namely, photo-thermal radiometry, flash laser analysis, and micro-Raman thermometry. This allowed us to use the NP-SThM technique to differentiate structural heterogeneities or imperfections at the surface of the pyrolyzed Kapton on the basis of the measured local thermal conductivity. [ABSTRACT FROM AUTHOR]

Published
2022
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7. Multilayer modelling of thermoacoustic sound generation for carbon based nanomaterial thermophone

Author

Guiraud, P., Giordano, Stefano, Bou Matar, Olivier, Pernod, Philippe, Hourlier, D., Lardat, R., Coquet, P., Pouliguen, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS-IEMN), Institut d’Électronique, de Microélectronique et de Nanotechnologie - Département Opto-Acousto-Électronique - UMR 8520 (IEMN-DOAE), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France)-Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Laboratoire International associé sur les phénomènes Critiques et Supercritiques en électronique fonctionnelle, acoustique et fluidique (LIA LICS/LEMAC), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Thales Underwater Systems (Thales) (TUS), CINTRA CNRS/NTU/THALES, UMI 3288, Délégation générale de l'armement (DGA), Ministère de la Défense, Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)-Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Acoustique Impulsionnelle & Magnéto-Acoustique Non linéaire - Fluides, Interfaces Liquides & Micro-Systèmes - IEMN (AIMAN-FILMS - IEMN), EPItaxie et PHYsique des hétérostructures - IEMN (EPIPHY - IEMN), CNRS International - NTU - Thales Research Alliance (CINTRA), THALES [France]-Nanyang Technological University [Singapour]-Centre National de la Recherche Scientifique (CNRS), Bio-Micro-Electro-Mechanical Systems - IEMN (BIOMEMS - IEMN), and AcknowledgementsThe authors would like to thank the French DGA/MRIS for theirfinancial support. This study is part of a project developed incollaboration with Prof Edwin Teo and his team from NTU Singapore, inthe frame of CINTRA UMI 3288 CNRS/NTU/THALES.'

Subjects
[PHYS]Physics [physics], [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [PHYS.MECA]Physics [physics]/Mechanics [physics], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; The thermoacoustic effect is based on applying an alternative current to a material with a high thermal conductivity and a low thermal capacity. The heat profile of the material follows the current profile and the compression dilatation of the air on the surface of the material due to the fluctuating temperature generates an acoustic wave whose frequency is proportional to the input frequency of the current. Since no resonating part are involved in the process the generation is wideband.

Published
2018

10. Leak-free integrated microfluidic channel fabrication for surface plasmon resonance applications.

Author

Bakouche, M-T, Ganesan, S, Guérin, D, Hourlier, D, Bouazaoui, M, Vilcot, J-P, and Maricot, S

Subjects
SURFACE plasmon resonance, POLYDIMETHYLSILOXANE, FOURIER transform infrared spectroscopy, CHEMICAL bonds, CONTACT angle, BOND strengths
Abstract

In this paper, we describe a novel fabrication method of a microfluidic integrated surface plasmon resonance (SPR) gold chip based on a (3-mercaptopropyl) trimethoxy silane (MPTMS) self-assembled monolayer. This monolayer was formed at the surface of a microfluidic chip made of polydimethylsiloxane (PDMS). Its presence was confirmed by contact angle and Fourier transform infrared spectroscopy measurements on the modified PDMS surface. A basic, but nevertheless appropriate, 4-channel microfluidic system was made on PDMS and reported on a gold SPR sensor. Sealing tests were carried-out by injecting continuous flows of solutions under gradient pressure up to 1.8 bar. Bonding strength of chemical and corona binding were measured and compared. The test of the integrated microfluidic SPR sensor on an SPR bench validated its functionality and proved as well that no leakage is observed between the different microfluidic channels. [ABSTRACT FROM AUTHOR]

Published
2020
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13. PDC-carbon hybrids

Author

Blum, Y., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2013

14. Modeling the reflectance of polydisperse random arrays of Si nanowires

Author

Grzela, G., Hourlier, D., Rivas, J.G., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2011

15. Nanowires and nanocones for new nanostructured materials

Author

Hourlier, D., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2011

16. Size and shape effects on the melting properties of catalytic nanoparticles

Author

Guisbiers, G., Abudukelimu, G., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2011

17. Bottom-up approach to designing nanostructured materials for a variety of applications

Author

Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2010

18. Size-dependent properties of platinum-based bimetallic nanoparticles

Author

Guisbiers, G., Abudukelimu, G., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2010

19. Scanning confocal Raman spectroscopy of individual silicon nanowires

Author

Strelchuk, V.V., Nikolenko, A.S., Lytvyn, P.M., Klimovskaya, A.I., Pedchenko, Y.N., Voroschenko, A.T., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2010

20. Carbon and nanowires based devices for high frequencey and low power applications

Author

Happy, H., Nougaret, L., Meng, N., Dambrine, Gilles, Bollaert, S., Hourlier, D., Caroff, P., Vignaud, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2009

21. The interaction particularities of nanoobjects on a solid state surface

Author

Marczak, M., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2009

22. Modeling of silicon nanowire growth : shaping, doping, and self-arrangement

Author

Klimovskaya, A., Efremov, A., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2009

23. Raman Spectroscopy of boron-doped silicon nanowires

Author

Marczak, M., Pichonat, E., Gebicki, W., Melin, Thierry, Hourlier, D., Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 (LASIRE), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille Institut (CLIL), Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)

Published
2008

24. Characterization of the individual core/shell silicon nanowires

Author

Marczak, M., Judek, J., Kozak, A., Gebicki, W., Melin, Thierry, Hourlier, D., Luxembourg, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2008

25. Scanning-probe measurements on undoped silicon nanowires

Author

Borowik, L., Diesinger, H., Hourlier, D., Melin, Thierry, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
[SPI]Engineering Sciences [physics]
Abstract

International audience

Published
2008

26. The answer to the challenging question : is there any limit size of nanowires ?

Author

Hourlier, D., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2008

27. Comment la thermodynamique a-t-elle permis l'élaboration d'un nouveau processus de croissance de nanofils à base de germanium ?

Author

Hourlier, D., Lefebvre, P., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2007

28. Determination of stable and metastable diagrams involved in the development of semiconductor nanowhiskers

Author

Hourlier, D., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2007

29. Raman spectrosopy of individual cone shaped nanowires

Author

Marczak, M., Judek, J., Kozak, A., Gebicki, W., Zdrojek, M., Hourlier, D., Luxembourg, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2007

30. Kelvin force microscopy frequency response optimization and application to nanowire/nanotube devices under polarization

Author

Diesinger, H., Hourlier, D., Brunel, D., Deresmes, D., Nys, J.P., Melin, Thierry, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Subjects
[SPI]Engineering Sciences [physics]
Abstract

International audience

Published
2007

31. Catalytic growth of silicon nanowires supported on high surface oxide substrates

Author

Hourlier, D., Lefebvre, P., Addad, A., Vannier, R.N., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2006

32. Raman spectroscopy characterization of single Si-nanowires

Author

Marczak, M., Jastrzebski, C., Gebricki, W., Zdrojek, M., Melin, Thierry, Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2006

33. Raman spectroscopy and AFM characterization on individual Si-based nanowires

Author

Marczak, M., Zdrojek, M., Gebicki, W., Jastrzebski, C., Melin, Thierry, Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2006

34. The major role of thermodynamics in the comprehension of 1D structures growth

Author

Hourlier, D., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2006

35. Thermodynamic study of silicon nanowire growth mechanisms

Author

Hourlier, D., Perrot, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2006

36. Fabrication and creep behavior of SiCN(O) nanocomposites

Author

Amara, Mohamed, Dez, R., Foucaud, Sylvie, Bahloul-Hourlier, D., Goursat, P., Herlin-Boime, Nathalie, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2004

37. Nano-powder ceramics synthesis by laser pyrolysis : numerical investigation

Author

Amara, Mohamed, El Ganaoui, M., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2004

38. Polysilsesquioxane derived ceramic foams with a gradient porosity

Author

Zeschky, J., Höfner, T., Arnold, C., Bahloul-Hourlier, D., Greil, P., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2004

39. A computational model for the Si/C/N nanopowder

Author

Amara, Mohamed, El Ganaoui, M., Hourlier, D., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), and Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF)

Published
2004

40. The role of multicomponent surface diffusion in growth and doping of silicon nanowires.

Author

Efremov, A., Klimovskaya, A., and Hourlier, D.

Subjects
DIFFUSION processes, NANOWIRES, SILICON, SEMICONDUCTOR doping, MONTE Carlo method, PHYSICAL sciences research
Abstract

The metal-catalyzed chemical vapor deposition on silicon substrates remains one of the most promising technologies for growing the silicon nanowires up to now. The process involves a wide variety of elementary events (adsorption, desorption, and multicomponent atomic transport with strongly different local mobility, etc.) that take place on the same surface sites and proceed on isolated nano-scaled part of the surface belonging to different individual catalyst particle. In this work, the competition for unoccupied sites during atomic transport under growth doping and percolation-related phenomena on confined parts of surface was treated by the Monte-Carlo simulations. Atomistic simulations were compared with numerical kinetic modeling. Arising nonlinear effects that finally lead to specific modes of the nanoobject growth, shaping, and doping were analyzed. By combining different kinds of simulations and experimental results, the proposed strategy provides a better control at atomic scale of nanowire growth. Both atomistic and kinetic considerations supplementing each other reveal the importance of surface transport and the role of surface immobile contaminations in the nanowire growth. [ABSTRACT FROM AUTHOR]

Published
2007
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45. Thermal conductivity of Kapton-derived carbon.

Author

Venkatachalam, S., Depriester, M., Sahraoui, A. Hadj, Capoen, B., Ammar, M.R., and Hourlier, D.

Subjects
*THERMAL conductivity, *KAPTON (Trademark), *CARBON, *PHOTOTHERMAL radiometry, *THERMOMETRY
Abstract

Heat treatment of translucent Kapton ® HN polyimide films conducted in inert atmosphere yields black residues. Micro-Raman spectroscopy revealed that the residues obtained between 600°C and 1200 °C are mainly constituted of disordered carbon. Aside its standard application in the structural identification of carbon, the Raman technique has also been used as a means of evaluating the thermal conductivity of Kapton-derived carbon. The aim of this study is to know whether such a tool can also be appropriate for disordered carbon with coherent diameters lower than 2 nm and with variable quantities of heteroatoms (H, O, N). To achieve this aim, a comparative study was undertaken using two other conventional techniques, namely laser flash analysis and photothermal radiometry. It has been found that thermal conductivity increases linearly with the heat-treatment temperature of Kapton and reaches 1.905 Wm −1 K −1 for the film heat-treated at 1200 °C. The comparison of the experimental results shows that the Raman thermometry is particularly sensitive for sp 2 carbon and predicts quite well the general trend of thermal conductivity of materials. However, the precision is rarely better than 20%. [ABSTRACT FROM AUTHOR]

Published
2017
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46. Kapton-derived carbon as efficient terahertz absorbers.

Author

Venkatachalam, S., Bertin, D., Ducournau, G., Lampin, J.F., and Hourlier, D.

Subjects
*TERAHERTZ technology, *LIGHT absorption, *OPTICAL control, *POLYIMIDE films, *PYROLYSIS, *CARBON compounds
Abstract

The focus of this study is the preparation of carbon-based materials that satisfy the requirements of developing quasi-optic controllable absorbers for terahertz technology. These materials have been obtained from a commercially available organic polymer, Kapton ® HN polyimide, through a pyrolysis process conducted in an inert atmosphere at different temperatures. The pyrolysis of Kapton film up to 1200 °C left a black residue principally composed of graphitic-carbon with a yield of about 55%. The D.C. conductivity of materials measured at 295 K increases with increasing pyrolysis temperature. The starting organic polymer is turned from an insulator to conductor material when heat-treated at over 700 °C. Moreover, in the frequency range 220–500 GHz, the pyrolyzed materials show distinct optical properties, which have variant degrees of terahertz absorption. Kapton ® HN polyimide that is thermally converted into carbon-based materials may be used for the realization of calibrated terahertz absorbers, particularly for thermal transducers. [ABSTRACT FROM AUTHOR]

Published
2016
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47. On the influence of water on THz vibrational spectral features of molecular crystals.

Author

Mitryukovskiy S, Vanpoucke DEP, Bai Y, Hannotte T, Lavancier M, Hourlier D, Roos G, and Peretti R

Subjects
Molecular Conformation, Water chemistry, Terahertz Spectroscopy methods, Vibration
Abstract

The nanoscale structure of molecular assemblies plays a major role in many (μ)-biological mechanisms. Molecular crystals are one of the most simple of these assemblies and are widely used in a variety of applications from pharmaceuticals and agrochemicals, to nutraceuticals and cosmetics. The collective vibrations in such molecular crystals can be probed using terahertz spectroscopy, providing unique characteristic spectral fingerprints. However, the association of the spectral features to the crystal conformation, crystal phase and its environment is a difficult task. We present a combined computational-experimental study on the incorporation of water in lactose molecular crystals, and show how simulations can be used to associate spectral features in the THz region to crystal conformations and phases. Using periodic DFT simulations of lactose molecular crystals, the role of water in the observed lactose THz spectrum is clarified, presenting both direct and indirect contributions. A specific experimental setup is built to allow the controlled heating and corresponding dehydration of the sample, providing the monitoring of the crystal phase transformation dynamics. Besides the observation that lactose phases and phase transformation appear to be more complex than previously thought - including several crystal forms in a single phase and a non-negligible water content in the so-called anhydrous phase - we draw two main conclusions from this study. Firstly, THz modes are spread over more than one molecule and require periodic computation rather than a gas-phase one. Secondly, hydration water does not only play a perturbative role but also participates in the facilitation of the THz vibrations.

Published
2022
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48. Charge Blinking Statistics of Semiconductor Nanocrystals Revealed by Carbon Nanotube Single Charge Sensors.

Author

Zbydniewska E, Duzynska A, Popoff M, Hourlier D, Lenfant S, Judek J, Zdrojek M, and Mélin T

Abstract

We demonstrate the relation between the optical blinking of colloidal semiconductor nanocrystals (NCs) and their electrical charge blinking for which we provide the first experimental observation of power-law statistics. To show this, we harness the performance of CdSe/ZnS NCs coupled with carbon nanotube field-effect transistors (CNTFETs), which act as single charge-sensitive electrometers with submillisecond time resolution, at room temperature. A random telegraph signal (RTS) associated with the NC single-trap charging is observed and exhibits power-law temporal statistics (τ(-α), with α in the range of ∼1-3), and a Lorentzian current noise power spectrum with a well-defined 1/f(2) corner. The spectroscopic analysis of the NC-CNTFET devices is consistent with the charging of NC defect states with a charging energy of Ec ≥ 200 meV. These results pave the way for a deeper understanding of the physics and technology of nanocrystal-based optoelectronic devices.

Published
2015
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49. Size-dependent catalytic and melting properties of platinum-palladium nanoparticles.

Author

Guisbiers G, Abudukelimu G, and Hourlier D

Abstract

While nanocatalysis is a very active field, there have been very few studies in the size/shape-dependent catalytic properties of transition metals from a thermodynamical approach. Transition metal nanoparticles are very attractive due their high surface to volume ratio and their high surface energy. In particular, in this paper we focus on the Pt-Pd catalyst which is an important system in catalysis. The melting temperature, melting enthalpy, and catalytic activation energy were found to decrease with size. The face centered cubic crystal structure of platinum and palladium has been considered in the model. The shape stability has been discussed. The phase diagram of different polyhedral shapes has been plotted and the surface segregation has been considered. The model predicts a nanoparticle core rich in Pt surrounded by a layer enriched in Pd. The Pd segregation at the surface strongly modifies the catalytic activation energy compared to the non-segregated nanoparticle. The predictions were compared with the available experimental data in the literature. PACS: 65.80-g; 82.60.Qr; 64.75.Jk.

Published
2011
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