Ayman Mahmoud Mohamed, Kui Yao, Yasmin Mohamed Yousry, Junling Wang, and Seeram Ramakrishna, “Enhanced Airborne Sound Absorption Effect in Poly(vinylidene fluoride)/(K0.5Na0.5)NbO3-nanofiber Composite Foams,” Journal of Applied Polymer Science, 49022, pp. 1-10. https://doi.org/10.1002/app.49022, online on 27 Jan 2020; Vol. 137, No. 35, September 2020.
Abstract:
Introducing electrical conductive function to discharge local piezoelectric effect is found effective for improving airborne sound absorption performance. In this work, instead of conductive fillers, a composite with two piezoelectric materials with opposite piezoelectric responses was explored aiming at enhanced sound absorption effect. Open-cell poly(vinylidene fluoride)(K0.5Na0.5)NbO3 (PVDF/KNN) nanofiber composite foams were proposed and investigated for airborne sound absorption purpose. Structural and thermal analyses showed that the KNN nanofibers were well dispersed in the PVDF matrix and enhanced the degree of crystallinity of polar phase of PVDF. Significantly enhanced airborne sound absorption over a broad frequency range was observed in the PVDF/KNN-nanofiber composite foams, with increasing KNN nanofibers. One possible mechanism for the improved sound absorption with the piezoelectric KNN nanofibers with positive piezoelectric coefficient added in the PVDF matrix with negative piezoelectric coefficient is that electrical discharge could be facilitated for energy dissipation with the opposite charges generated through the piezoelectric effects in the two phases with opposite polarity. The experimental results show that the open-cell PVDF/KNN-nanofiber composite foams are promising for broadband airborne sound absorption application, and our analysis shed a light on the strategy in designing piezoelectric composite foam with high sound absorption performance.
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Funding Info:
This project is partially supported by Singapore Maritime Institute under the Maritime Sustainability R&D Programme, Project ID: SMI-2015-MA-07 (IMRE/16-7P1125), and by the Singapore Ministry of National Development and National Research Foundation under L2NIC Award No. L2NICCFP1-2013-9 (IMRE/14-9P1112). The authors would like to acknowledge the discussions with Dr. Eleftherios Christos Statharas, Mr. Poh Chong Lim, and Dr. Shuting Chen from Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), Singapore.
Description:
"This is the peer reviewed version of the following article: [Ayman Mahmoud Mohamed, Kui Yao, Yasmin Mohamed Yousry, Junling Wang, and Seeram Ramakrishna, “Enhanced Airborne Sound Absorption Effect in Poly(vinylidene fluoride)/(K0.5Na0.5)NbO3-nanofiber Composite Foams,” Journal of Applied Polymer Science, 49022, pp. 1-10. Vol. 137, No. 35, September 2020.], which has been published in final form at [https://doi.org/10.1002/app.49022I]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions."