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2024-11-23 18:32

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Conference: Bucharest University Faculty of Physics 2023 Meeting

Section: Solid State Physics and Materials Science, Optics, Spectroscopy, Plasma and Lasers

Title:

Nanocomposite layers based on tungsten oxide/polymer processed by laser methods

Authors:

Stefan DOBRESCU (1,2), Adrian BERCEA (1), Simona BRAJNICOV (1), Iulian BOERASU (1), Anca BONCIU (1), Cristina CRACIUN (1), Mihaela FILIPESCU (1), Maria DINESCU (1)

Affiliation:

1) National Institute for Laser, Plasma and Radiation Physics, 077125 Magurele, Romania

2) Faculty of Physics, University of Bucharest, 077125 Magurele, Romania

E-mail

stefan.dobrescu@inflpr.ro

Keywords:

composites, mesoporous, tungsten oxide/polymer, sensor

Abstract:

Nanostructured composites based on tungsten oxide (WO3) and polymer (polyaniline or polypyrrole) were obtained as active membranes (thin films) for gas sensor applications. Pulsed laser deposition (PLD) and/or matrix-assisted pulsed laser evaporation (MAPLE) techniques were used to fabricate these membranes. Morphological and chemical characterizations were carried out on the resulting thin films. In the case of WO3/PPy and WO3/PANI composites obtained as thin films by MAPLE, it was observed that an increase of WO3 concentration in the polymeric matrix induced an increase in the density and roughness of the surface. Another way to obtain these composites as films was to grow WO3 thin films using PLD, which were “decorated” with polymer using MAPLE. The morphological investigations on WO3 thin films obtained by PLD revealed a “cloudlike” mesoporous surface with a relatively large specific surface area. After decoration of WO3 with polymers by MAPLE, the morphological investigations showed that PPy completely covered the mesoporous surface, leaving the “cloudlike” WO3 relatively intact. When PANI was deposited on the WO3 structures, a “crushing” of the WO3 structures was observed at the nanoscale. The “decoration” of the “cloudlike” structures of WO3 was not observed like in the case of PPy. At a micrometric level, the surface of the WO3/PANI films exhibited a porosity which induced a high specific surface area.

References:

1. Atanasova, G., Og. Dikovska, A., Dilova, T., Georgieva, B., Avdeev, G. V., Stefanov, P., & Nedyalkov, N. N. (2018). Metal-oxide nanostructures produced by PLD in open air for gas sensor applications. Applied Surface Science. doi:10.1016/j.apsusc.2018.11.178

2. Boyadjiev, S. I., Stefan, N., Szilágyi, I. M., Mihailescu, N., Visan, A., Mihailescu, I. N., … Gesheva, K. A. (2017). Characterization of MAPLE deposited WO3thin films for electrochromic applications. Journal of Physics: Conference Series, 780, 012013. doi:10.1088/1742-6596/780/1/012013

3. Papavlu, A. P., Dinca, V., Filipescu, M., & Dinescu, M. (2017). Matrix-Assisted Pulsed Laser Evaporation of Organic Thin Films: Applications in Biology and Chemical Sensors. Laser Ablation - From Fundamentals to Applications. doi:10.5772/intechopen.70676

Acknowledgement:

This work was supported by a grant of the Ministry of Research, Innovation and Digitization, CNCS - UEFISCDI, project number PN-III-P1-1.1-TE-2021-0219 (CO-POLYSENS), within PNCDI III.