TY  - JOUR
AU  - Pavlović, Vera P.
AU  - Tošić, Dragana
AU  - Dojčilović, Radovan
AU  - Dudić, Duško
AU  - Dramićanin, Miroslav D.
AU  - Medić, Mina
AU  - McPherson, Michael M.
AU  - Pavlović, Vladimir B.
AU  - Vlahović, Branislav
AU  - Đoković, Vladimir
PY  - 2021
UR  - https://dais.sanu.ac.rs/123456789/10535
AB  - Na0.25K0.25Bi0.5TiO3 (NKBT) perovskite particles are synthesized by solid-state method and used as a filler for polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) co-polymer. X-ray diffraction analysis of NKBT powders shows that the particles have a rhombohedral perovskite crystal structure (R3c symmetry). Raman spectroscopy reveals that the co-polymer crystallizes predominantly into the mixture of polar β- and γ-crystals, while there is also a contribution of the non-polar α-crystal phase. The introduction of the NKBT into the PVDF-HFP results with an increase in effective dielectric permittivity and this effect depends on the inorganic content in the composite. The most interesting result of the present study is that the introduction of NKBT particles induces the appearance of an additional transition peak in the dielectric spectra of the co-polymer matrix. At the fixed frequency of ~2 kHz, the observed process appears at ~10 °C (about 45° above the glass transition temperature) and its magnitude strongly depends on the amount of the NKBT in the composite. Dielectric spectroscopy measurements of the composites are carried out in the wide range of frequencies (from 0.1 Hz to 1 MHz) and temperatures (from −100 to 100 °C). They reveal that the novel process can be clearly distinguished in the frequency range between 160 Hz and ~50 kHz.
PB  - Elsevier BV
T2  - Polymer Testing
T1  - PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix
SP  - 107093
VL  - 96
DO  - 10.1016/j.polymertesting.2021.107093
UR  - https://hdl.handle.net/21.15107/rcub_dais_10535
ER  - 

@article{
author = "Pavlović, Vera P. and Tošić, Dragana and Dojčilović, Radovan and Dudić, Duško and Dramićanin, Miroslav D. and Medić, Mina and McPherson, Michael M. and Pavlović, Vladimir B. and Vlahović, Branislav and Đoković, Vladimir",
year = "2021",
abstract = "Na0.25K0.25Bi0.5TiO3 (NKBT) perovskite particles are synthesized by solid-state method and used as a filler for polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) co-polymer. X-ray diffraction analysis of NKBT powders shows that the particles have a rhombohedral perovskite crystal structure (R3c symmetry). Raman spectroscopy reveals that the co-polymer crystallizes predominantly into the mixture of polar β- and γ-crystals, while there is also a contribution of the non-polar α-crystal phase. The introduction of the NKBT into the PVDF-HFP results with an increase in effective dielectric permittivity and this effect depends on the inorganic content in the composite. The most interesting result of the present study is that the introduction of NKBT particles induces the appearance of an additional transition peak in the dielectric spectra of the co-polymer matrix. At the fixed frequency of ~2 kHz, the observed process appears at ~10 °C (about 45° above the glass transition temperature) and its magnitude strongly depends on the amount of the NKBT in the composite. Dielectric spectroscopy measurements of the composites are carried out in the wide range of frequencies (from 0.1 Hz to 1 MHz) and temperatures (from −100 to 100 °C). They reveal that the novel process can be clearly distinguished in the frequency range between 160 Hz and ~50 kHz.",
publisher = "Elsevier BV",
journal = "Polymer Testing",
title = "PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix",
pages = "107093",
volume = "96",
doi = "10.1016/j.polymertesting.2021.107093",
url = "https://hdl.handle.net/21.15107/rcub_dais_10535"
}

Pavlović, V. P., Tošić, D., Dojčilović, R., Dudić, D., Dramićanin, M. D., Medić, M., McPherson, M. M., Pavlović, V. B., Vlahović, B.,& Đoković, V.. (2021). PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix. in Polymer Testing
Elsevier BV., 96, 107093.
https://doi.org/10.1016/j.polymertesting.2021.107093
https://hdl.handle.net/21.15107/rcub_dais_10535

Pavlović VP, Tošić D, Dojčilović R, Dudić D, Dramićanin MD, Medić M, McPherson MM, Pavlović VB, Vlahović B, Đoković V. PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix. in Polymer Testing. 2021;96:107093.
doi:10.1016/j.polymertesting.2021.107093
https://hdl.handle.net/21.15107/rcub_dais_10535 .

Pavlović, Vera P., Tošić, Dragana, Dojčilović, Radovan, Dudić, Duško, Dramićanin, Miroslav D., Medić, Mina, McPherson, Michael M., Pavlović, Vladimir B., Vlahović, Branislav, Đoković, Vladimir, "PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix" in Polymer Testing, 96 (2021):107093,
https://doi.org/10.1016/j.polymertesting.2021.107093 .,
https://hdl.handle.net/21.15107/rcub_dais_10535 .

TY  - JOUR
AU  - Mofokeng, Tladi G.
AU  - Luyt, Adriaan S.
AU  - Pavlović, Vera P.
AU  - Pavlović, Vladimir B.
AU  - Dudić, Duško
AU  - Vlahović, Branislav
AU  - Đoković, Vladimir
PY  - 2014
UR  - https://dais.sanu.ac.rs/123456789/660
AB  - Nanocomposites of polyvinylidene fluoride/polymethyl methacrylate (PVDF/PMMA) blend and mechanically activated barium titanate (BaTiO3) particles were prepared by melt mixing. Modification of filler by means of mechanical activation has a profound effect on the crystallization of PVDF in the blend matrix. Raman analysis showed that the modified BaTiO3 particles, due to higher specific surfaces, induce, predominantly, the crystallization of the electrically active β-phase of PVDF, while the initial micron size particles induce the formation of the most common but non-polar α-crystal form. The introduction of activated particles reduces the overall crystallinity but slightly affects the crystallization and melting temperatures of the matrix. Dielectric spectroscopy revealed that at fixed filler content the dielectric constant of the blend increases with decreasing of the particle size (increasing of the activation time). A similar trend was observed for the storage moduli in dynamic mechanical analysis; the stiffness of the composite was higher when mechanically activated particles were used.
PB  - AIP Publishing
T2  - Journal of Applied Physics
T1  - Ferroelectric nanocomposites of polyvinylidene fluoride/polymethyl methacrylate blend and BaTiO3 particles: Fabrication of β-crystal polymorph rich matrix through mechanical activation of the filler
SP  - 084109
VL  - 115
DO  - 10.1063/1.4866694
UR  - https://hdl.handle.net/21.15107/rcub_dais_660
ER  - 

@article{
author = "Mofokeng, Tladi G. and Luyt, Adriaan S. and Pavlović, Vera P. and Pavlović, Vladimir B. and Dudić, Duško and Vlahović, Branislav and Đoković, Vladimir",
year = "2014",
abstract = "Nanocomposites of polyvinylidene fluoride/polymethyl methacrylate (PVDF/PMMA) blend and mechanically activated barium titanate (BaTiO3) particles were prepared by melt mixing. Modification of filler by means of mechanical activation has a profound effect on the crystallization of PVDF in the blend matrix. Raman analysis showed that the modified BaTiO3 particles, due to higher specific surfaces, induce, predominantly, the crystallization of the electrically active β-phase of PVDF, while the initial micron size particles induce the formation of the most common but non-polar α-crystal form. The introduction of activated particles reduces the overall crystallinity but slightly affects the crystallization and melting temperatures of the matrix. Dielectric spectroscopy revealed that at fixed filler content the dielectric constant of the blend increases with decreasing of the particle size (increasing of the activation time). A similar trend was observed for the storage moduli in dynamic mechanical analysis; the stiffness of the composite was higher when mechanically activated particles were used.",
publisher = "AIP Publishing",
journal = "Journal of Applied Physics",
title = "Ferroelectric nanocomposites of polyvinylidene fluoride/polymethyl methacrylate blend and BaTiO3 particles: Fabrication of β-crystal polymorph rich matrix through mechanical activation of the filler",
pages = "084109",
volume = "115",
doi = "10.1063/1.4866694",
url = "https://hdl.handle.net/21.15107/rcub_dais_660"
}

Mofokeng, T. G., Luyt, A. S., Pavlović, V. P., Pavlović, V. B., Dudić, D., Vlahović, B.,& Đoković, V.. (2014). Ferroelectric nanocomposites of polyvinylidene fluoride/polymethyl methacrylate blend and BaTiO3 particles: Fabrication of β-crystal polymorph rich matrix through mechanical activation of the filler. in Journal of Applied Physics
AIP Publishing., 115, 084109.
https://doi.org/10.1063/1.4866694
https://hdl.handle.net/21.15107/rcub_dais_660

Mofokeng TG, Luyt AS, Pavlović VP, Pavlović VB, Dudić D, Vlahović B, Đoković V. Ferroelectric nanocomposites of polyvinylidene fluoride/polymethyl methacrylate blend and BaTiO3 particles: Fabrication of β-crystal polymorph rich matrix through mechanical activation of the filler. in Journal of Applied Physics. 2014;115:084109.
doi:10.1063/1.4866694
https://hdl.handle.net/21.15107/rcub_dais_660 .

Mofokeng, Tladi G., Luyt, Adriaan S., Pavlović, Vera P., Pavlović, Vladimir B., Dudić, Duško, Vlahović, Branislav, Đoković, Vladimir, "Ferroelectric nanocomposites of polyvinylidene fluoride/polymethyl methacrylate blend and BaTiO3 particles: Fabrication of β-crystal polymorph rich matrix through mechanical activation of the filler" in Journal of Applied Physics, 115 (2014):084109,
https://doi.org/10.1063/1.4866694 .,
https://hdl.handle.net/21.15107/rcub_dais_660 .