Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites
Abstract Polymer nanocrystal composites were fabricated by embedding polyvinylidene fluoride (PVDF) with K0.5Na0.5NbO3 (KNN) nanocrystallites of different volume fraction using the hot-pressing technique. For comparison, PVDF–KNN microcrystal composites of the same compositions were also fabricated...
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| Format: | Article |
| Language: | English |
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Tsinghua University Press
2016-12-01
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| Series: | Journal of Advanced Ceramics |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1007/s40145-016-0204-2 |
| _version_ | 1797711146617143296 |
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| author | Bharathi Ponraj Rajasekhar Bhimireddi K. B. R. Varma |
| author_facet | Bharathi Ponraj Rajasekhar Bhimireddi K. B. R. Varma |
| author_sort | Bharathi Ponraj |
| collection | DOAJ |
| description | Abstract Polymer nanocrystal composites were fabricated by embedding polyvinylidene fluoride (PVDF) with K0.5Na0.5NbO3 (KNN) nanocrystallites of different volume fraction using the hot-pressing technique. For comparison, PVDF–KNN microcrystal composites of the same compositions were also fabricated which facilitated the studies of the crystallite size (wide range) effect on the dielectric and piezoelectric properties. The structural, morphological, dielectric, and piezoelectric properties of these nano and micro crystal composites were investigated. The incorporation of KNN fillers in PVDF at both nanometer and micron scales above 10 vol% resulted in the formation of polar β-form of PVDF. The room temperature dielectric constant as high as 3273 at 100 Hz was obtained for the PVDF comprising 40 vol% KNN nanocrystallites due to dipole–dipole interactions (as the presence of β-PVDF is prominent), whereas it was only 236 for the PVDF containing the same amount (40 vol%) of micron-sized crystallites of KNN at the same frequency. Various theoretical models were employed to predict the dielectric constants of the PVDF–KNN nano and micro crystal composites. The PVDF comprising 70 vol% micron-sized crystallites of KNN exhibited a d 33 value of 35 pC/N, while the nanocrystal composites of PVDF–KNN did not exhibit any piezoelectric response perhaps due to the unrelieved internal stress within each grain, besides the fact that they have less domain walls. |
| first_indexed | 2024-03-12T07:02:46Z |
| format | Article |
| id | doaj.art-07182bef47504924921f97b92ae06631 |
| institution | Directory Open Access Journal |
| issn | 2226-4108 2227-8508 |
| language | English |
| last_indexed | 2024-03-12T07:02:46Z |
| publishDate | 2016-12-01 |
| publisher | Tsinghua University Press |
| record_format | Article |
| series | Journal of Advanced Ceramics |
| spelling | doaj.art-07182bef47504924921f97b92ae066312023-09-02T23:38:07ZengTsinghua University PressJournal of Advanced Ceramics2226-41082227-85082016-12-015430832010.1007/s40145-016-0204-2Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF compositesBharathi Ponraj0Rajasekhar Bhimireddi1K. B. R. Varma2Materials Research Centre, Indian Institute of ScienceMaterials Research Centre, Indian Institute of ScienceMaterials Research Centre, Indian Institute of ScienceAbstract Polymer nanocrystal composites were fabricated by embedding polyvinylidene fluoride (PVDF) with K0.5Na0.5NbO3 (KNN) nanocrystallites of different volume fraction using the hot-pressing technique. For comparison, PVDF–KNN microcrystal composites of the same compositions were also fabricated which facilitated the studies of the crystallite size (wide range) effect on the dielectric and piezoelectric properties. The structural, morphological, dielectric, and piezoelectric properties of these nano and micro crystal composites were investigated. The incorporation of KNN fillers in PVDF at both nanometer and micron scales above 10 vol% resulted in the formation of polar β-form of PVDF. The room temperature dielectric constant as high as 3273 at 100 Hz was obtained for the PVDF comprising 40 vol% KNN nanocrystallites due to dipole–dipole interactions (as the presence of β-PVDF is prominent), whereas it was only 236 for the PVDF containing the same amount (40 vol%) of micron-sized crystallites of KNN at the same frequency. Various theoretical models were employed to predict the dielectric constants of the PVDF–KNN nano and micro crystal composites. The PVDF comprising 70 vol% micron-sized crystallites of KNN exhibited a d 33 value of 35 pC/N, while the nanocrystal composites of PVDF–KNN did not exhibit any piezoelectric response perhaps due to the unrelieved internal stress within each grain, besides the fact that they have less domain walls.http://link.springer.com/article/10.1007/s40145-016-0204-2polyvinylidene fluoride (PVDF)K0.5Na0.5NbO3 (KNN)compositesβ-PVDFnanocrystallites |
| spellingShingle | Bharathi Ponraj Rajasekhar Bhimireddi K. B. R. Varma Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites Journal of Advanced Ceramics polyvinylidene fluoride (PVDF) K0.5Na0.5NbO3 (KNN) composites β-PVDF nanocrystallites |
| title | Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites |
| title_full | Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites |
| title_fullStr | Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites |
| title_full_unstemmed | Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites |
| title_short | Effect of nano- and micron-sized K0.5Na0.5NbO3 fillers on the dielectric and piezoelectric properties of PVDF composites |
| title_sort | effect of nano and micron sized k0 5na0 5nbo3 fillers on the dielectric and piezoelectric properties of pvdf composites |
| topic | polyvinylidene fluoride (PVDF) K0.5Na0.5NbO3 (KNN) composites β-PVDF nanocrystallites |
| url | http://link.springer.com/article/10.1007/s40145-016-0204-2 |
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