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Enhanced airborne sound absorption effect in poly(vinylidene fluoride)/(K 0.5 Na 0.5 )NbO 3 ‐nanofiber composite foams
Author(s) -
Mohamed Ayman M.,
Yao Kui,
Yousry Yasmin M.,
Wang Junling,
Ramakrishna Seeram
Publication year - 2020
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49022
Subject(s) - materials science , nanofiber , piezoelectricity , composite material , composite number , absorption (acoustics) , piezoelectric coefficient , piezoelectric sensor , noise reduction coefficient , porosity
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)/(K 0.5 Na 0.5 )NbO 3 (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.