TY  - JOUR
AU  - Pavlović, Vera P.
AU  - Tošić, Dragana
AU  - Dojčilović, Radovan
AU  - Dudić, Duško
AU  - Dramićanin, Miroslav
AU  - Medić, Mina M.
AU  - McPherson, Michael M.
AU  - Pavlović, Vladimir B.
AU  - Vlahović, Branislav
AU  - Đoković, Vladimir
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9563
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. © 2021 The Authors
T2  - Polymer Testing
T1  - PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix
VL  - 96
SP  - 107093
DO  - 10.1016/j.polymertesting.2021.107093
ER  - 

@article{
author = "Pavlović, Vera P. and Tošić, Dragana and Dojčilović, Radovan and Dudić, Duško and Dramićanin, Miroslav and Medić, Mina M. 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. © 2021 The Authors",
journal = "Polymer Testing",
title = "PVDF-HFP/NKBT composite dielectrics: Perovskite particles induce the appearance of an additional dielectric relaxation process in ferroelectric polymer matrix",
volume = "96",
pages = "107093",
doi = "10.1016/j.polymertesting.2021.107093"
}

Pavlović, V. P., Tošić, D., Dojčilović, R., Dudić, D., Dramićanin, M., Medić, M. 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, 96, 107093.
https://doi.org/10.1016/j.polymertesting.2021.107093

Pavlović VP, Tošić D, Dojčilović R, Dudić D, Dramićanin M, Medić MM, 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 .

Pavlović, Vera P., Tošić, Dragana, Dojčilović, Radovan, Dudić, Duško, Dramićanin, Miroslav, Medić, Mina M., 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 . .

TY  - JOUR
AU  - Kisić, Danilo
AU  - Nenadović, Miloš
AU  - Potočnik, Jelena
AU  - Novaković, Mirjana M.
AU  - Noga, Pavol
AU  - Vaňa, Dušan
AU  - Závacká, Anna
AU  - Rakočević, Zlatko Lj.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8587
AB  - Fe/Polyethylene nanocomposite was synthesized by ion beam implantation of 56Fe+ into bulk high-density polyethylene. Nanoscale surface morphology along with magnetic and optical behavior was investigated. The aim of the research was to investigate changes of polyethylene's surface layer morphology with the change of Fe implantation fluence in the high fluence range and to find correlations with the magnetic and optical behavior. Four implantation fluences were applied: 5 × 1016, 1 × 1017, 2 × 1017 and 5 × 1017 cm−2, while the implantation energy was 95 keV. Concentration profiles of implanted Fe were analyzed by Rutherford backscattering spectrometry, showing Fe concentration profile maxima closer to the surface with increasing implantation fluence. Cross-sectional transmission electron microscopy showed the formation of metallic nanoparticles with sizes in a range from below 1 nm up to few tens of nanometers, depending on the fluence, and for the highest implantation fluence, a continuous layer was formed. Magneto-optic Kerr effect magnetometry demonstrates weak ferromagnetic behavior for the 2 higher fluences, and superparamagnetic for the 2 lower fluences. The UV-VIS remission function spectra show the peak in the UV region, which we attribute to iron nanoparticles.
T2  - Vacuum
T1  - Surface layer morphology of the high fluence Fe implanted polyethylene - Correlation with the magnetic and optical behavior
VL  - 171
SP  - 109016
DO  - 10.1016/j.vacuum.2019.109016
ER  - 

@article{
author = "Kisić, Danilo and Nenadović, Miloš and Potočnik, Jelena and Novaković, Mirjana M. and Noga, Pavol and Vaňa, Dušan and Závacká, Anna and Rakočević, Zlatko Lj.",
year = "2020",
abstract = "Fe/Polyethylene nanocomposite was synthesized by ion beam implantation of 56Fe+ into bulk high-density polyethylene. Nanoscale surface morphology along with magnetic and optical behavior was investigated. The aim of the research was to investigate changes of polyethylene's surface layer morphology with the change of Fe implantation fluence in the high fluence range and to find correlations with the magnetic and optical behavior. Four implantation fluences were applied: 5 × 1016, 1 × 1017, 2 × 1017 and 5 × 1017 cm−2, while the implantation energy was 95 keV. Concentration profiles of implanted Fe were analyzed by Rutherford backscattering spectrometry, showing Fe concentration profile maxima closer to the surface with increasing implantation fluence. Cross-sectional transmission electron microscopy showed the formation of metallic nanoparticles with sizes in a range from below 1 nm up to few tens of nanometers, depending on the fluence, and for the highest implantation fluence, a continuous layer was formed. Magneto-optic Kerr effect magnetometry demonstrates weak ferromagnetic behavior for the 2 higher fluences, and superparamagnetic for the 2 lower fluences. The UV-VIS remission function spectra show the peak in the UV region, which we attribute to iron nanoparticles.",
journal = "Vacuum",
title = "Surface layer morphology of the high fluence Fe implanted polyethylene - Correlation with the magnetic and optical behavior",
volume = "171",
pages = "109016",
doi = "10.1016/j.vacuum.2019.109016"
}

Kisić, D., Nenadović, M., Potočnik, J., Novaković, M. M., Noga, P., Vaňa, D., Závacká, A.,& Rakočević, Z. Lj.. (2020). Surface layer morphology of the high fluence Fe implanted polyethylene - Correlation with the magnetic and optical behavior. in Vacuum, 171, 109016.
https://doi.org/10.1016/j.vacuum.2019.109016

Kisić D, Nenadović M, Potočnik J, Novaković MM, Noga P, Vaňa D, Závacká A, Rakočević ZL. Surface layer morphology of the high fluence Fe implanted polyethylene - Correlation with the magnetic and optical behavior. in Vacuum. 2020;171:109016.
doi:10.1016/j.vacuum.2019.109016 .

Kisić, Danilo, Nenadović, Miloš, Potočnik, Jelena, Novaković, Mirjana M., Noga, Pavol, Vaňa, Dušan, Závacká, Anna, Rakočević, Zlatko Lj., "Surface layer morphology of the high fluence Fe implanted polyethylene - Correlation with the magnetic and optical behavior" in Vacuum, 171 (2020):109016,
https://doi.org/10.1016/j.vacuum.2019.109016 . .

TY  - JOUR
AU  - Dojčilović, Radovan
AU  - Pajović, Jelena D.
AU  - Božanić, Dušan K.
AU  - Jović, Nataša G.
AU  - Pavlović, Vera P.
AU  - Pavlović, Vladimir B.
AU  - Lenhardt Acković, Lea
AU  - Zeković, Ivana Lj.
AU  - Dramićanin, Miroslav
AU  - Kaščakova, Slavka
AU  - Refregiers, Matthieu
AU  - Rašić, Goran
AU  - Vlahović, Branislav
AU  - Đoković, Vladimir
PY  - 2018
UR  - http://stacks.iop.org/2053-1583/5/i=4/a=045019?key=crossref.f455f07bdfb3469c8077963ff0f38f95
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7909
AB  - The interaction of partially reduced graphene oxide (prGO) and Huh7.5.1 liver cancer cells was investigated by means of DUV fluorescence bioimaging. The prGO sample was obtained by the reduction (to a certain extent) of the initially prepared graphene oxide (GO) nanosheets with hydrazine. The fluorescence of the GO nanosheets increases with time of the reduction due to a change in ratio of the sp2 and sp3 carbon sites and the prGO sample was extracted from the dispersion after 6 min, when the intensity of the fluorescence reached its maximum. The reduction process was left to proceed further to saturation until highly reduced graphene oxide (denoted here as rGO) was obtained. GO, prGO and rGO samples were investigated by structural (scanning electron microscopy (SEM), scanning transmission electron microscopy coupled with energy dispersive spectrometry (STEM-EDS)) and spectroscopic (UV-vis, photoluminescence (PL), Raman) methods. After that, Huh7.5.1 cells were incubated with GO, prGO and rGO nanosheets and used in bioimaging studies, which were performed on DISCO beamline of synchrotron SOLEIL. It was found that the prGO significantly enhanced the fluorescence of the cells and increased the intensity of the signal by ~2.5 times. Time-lapse fluorescence microscopy experiments showed that fluorescence dynamics strongly depends on the type of nanosheets used. The obtained prGO nanostructure can be easily conjugated with aromatic ring containing drugs, which opens a possibility for its applications in fluorescence microscopy monitored drug delivery. © 2018 IOP Publishing Ltd.
T2  - 2D Materials
T1  - DUV fluorescence bioimaging study of the interaction of partially reduced graphene oxide and liver cancer cells
VL  - 5
IS  - 4
SP  - 045019
DO  - 10.1088/2053-1583/aad72b
ER  - 

@article{
author = "Dojčilović, Radovan and Pajović, Jelena D. and Božanić, Dušan K. and Jović, Nataša G. and Pavlović, Vera P. and Pavlović, Vladimir B. and Lenhardt Acković, Lea and Zeković, Ivana Lj. and Dramićanin, Miroslav and Kaščakova, Slavka and Refregiers, Matthieu and Rašić, Goran and Vlahović, Branislav and Đoković, Vladimir",
year = "2018",
abstract = "The interaction of partially reduced graphene oxide (prGO) and Huh7.5.1 liver cancer cells was investigated by means of DUV fluorescence bioimaging. The prGO sample was obtained by the reduction (to a certain extent) of the initially prepared graphene oxide (GO) nanosheets with hydrazine. The fluorescence of the GO nanosheets increases with time of the reduction due to a change in ratio of the sp2 and sp3 carbon sites and the prGO sample was extracted from the dispersion after 6 min, when the intensity of the fluorescence reached its maximum. The reduction process was left to proceed further to saturation until highly reduced graphene oxide (denoted here as rGO) was obtained. GO, prGO and rGO samples were investigated by structural (scanning electron microscopy (SEM), scanning transmission electron microscopy coupled with energy dispersive spectrometry (STEM-EDS)) and spectroscopic (UV-vis, photoluminescence (PL), Raman) methods. After that, Huh7.5.1 cells were incubated with GO, prGO and rGO nanosheets and used in bioimaging studies, which were performed on DISCO beamline of synchrotron SOLEIL. It was found that the prGO significantly enhanced the fluorescence of the cells and increased the intensity of the signal by ~2.5 times. Time-lapse fluorescence microscopy experiments showed that fluorescence dynamics strongly depends on the type of nanosheets used. The obtained prGO nanostructure can be easily conjugated with aromatic ring containing drugs, which opens a possibility for its applications in fluorescence microscopy monitored drug delivery. © 2018 IOP Publishing Ltd.",
journal = "2D Materials",
title = "DUV fluorescence bioimaging study of the interaction of partially reduced graphene oxide and liver cancer cells",
volume = "5",
number = "4",
pages = "045019",
doi = "10.1088/2053-1583/aad72b"
}

Dojčilović, R., Pajović, J. D., Božanić, D. K., Jović, N. G., Pavlović, V. P., Pavlović, V. B., Lenhardt Acković, L., Zeković, I. Lj., Dramićanin, M., Kaščakova, S., Refregiers, M., Rašić, G., Vlahović, B.,& Đoković, V.. (2018). DUV fluorescence bioimaging study of the interaction of partially reduced graphene oxide and liver cancer cells. in 2D Materials, 5(4), 045019.
https://doi.org/10.1088/2053-1583/aad72b

Dojčilović R, Pajović JD, Božanić DK, Jović NG, Pavlović VP, Pavlović VB, Lenhardt Acković L, Zeković IL, Dramićanin M, Kaščakova S, Refregiers M, Rašić G, Vlahović B, Đoković V. DUV fluorescence bioimaging study of the interaction of partially reduced graphene oxide and liver cancer cells. in 2D Materials. 2018;5(4):045019.
doi:10.1088/2053-1583/aad72b .

Dojčilović, Radovan, Pajović, Jelena D., Božanić, Dušan K., Jović, Nataša G., Pavlović, Vera P., Pavlović, Vladimir B., Lenhardt Acković, Lea, Zeković, Ivana Lj., Dramićanin, Miroslav, Kaščakova, Slavka, Refregiers, Matthieu, Rašić, Goran, Vlahović, Branislav, Đoković, Vladimir, "DUV fluorescence bioimaging study of the interaction of partially reduced graphene oxide and liver cancer cells" in 2D Materials, 5, no. 4 (2018):045019,
https://doi.org/10.1088/2053-1583/aad72b . .

TY  - JOUR
AU  - Hosakun, Worakan
AU  - Hosakun, Yanin
AU  - Dudić, Duško
AU  - Đoković, Vladimir
AU  - Csoka, Levente
PY  - 2018
UR  - https://linkinghub.elsevier.com/retrieve/pii/S0142941818311358
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7864
AB  - Flexible and transparent substrate materials were fabricated by using bacterial cellulose (BC), silk fibroin protein (SF) and/or polyvinyl alcohol (PVA). The BC-SF and BC-SF-PVA films obtained were further modified by impregnation with silver nanocubes (AgNC). The influences of the silver nanocubes and white light illumination on the electric and viscoelastic properties of the films were investigated. Complex conductivity measurements showed that the films with PVA component are more sensitive to light exposure and there is an increase in conductance when the sample is illuminated. The films that contained silver nanocubes showed higher values of specific susceptance than their unmodified counterparts. DMA analyses revealed that the storage shear moduli of the films increase with addition of silver nanocubes. It was also found that the relaxation transition observed at elevated temperatures in the BC-SF-PVA-AgNC films is highly sensitive to the light exposure. Above the glass transition of PVA, both storage- and loss-shear moduli change dramatically if the sample is illuminated during the measurements with respect to the case when it was kept in the dark. © 2018
T2  - Polymer Testing
T1  - Dependence of mechanical and electrical properties of silver nanocubes impregnated bacterial cellulose-silk fibroin-polyvinyl alcohol films on light exposure
VL  - 71
SP  - 110
EP  - 114
DO  - 10.1016/j.polymertesting.2018.08.031
ER  - 

@article{
author = "Hosakun, Worakan and Hosakun, Yanin and Dudić, Duško and Đoković, Vladimir and Csoka, Levente",
year = "2018",
abstract = "Flexible and transparent substrate materials were fabricated by using bacterial cellulose (BC), silk fibroin protein (SF) and/or polyvinyl alcohol (PVA). The BC-SF and BC-SF-PVA films obtained were further modified by impregnation with silver nanocubes (AgNC). The influences of the silver nanocubes and white light illumination on the electric and viscoelastic properties of the films were investigated. Complex conductivity measurements showed that the films with PVA component are more sensitive to light exposure and there is an increase in conductance when the sample is illuminated. The films that contained silver nanocubes showed higher values of specific susceptance than their unmodified counterparts. DMA analyses revealed that the storage shear moduli of the films increase with addition of silver nanocubes. It was also found that the relaxation transition observed at elevated temperatures in the BC-SF-PVA-AgNC films is highly sensitive to the light exposure. Above the glass transition of PVA, both storage- and loss-shear moduli change dramatically if the sample is illuminated during the measurements with respect to the case when it was kept in the dark. © 2018",
journal = "Polymer Testing",
title = "Dependence of mechanical and electrical properties of silver nanocubes impregnated bacterial cellulose-silk fibroin-polyvinyl alcohol films on light exposure",
volume = "71",
pages = "110-114",
doi = "10.1016/j.polymertesting.2018.08.031"
}

Hosakun, W., Hosakun, Y., Dudić, D., Đoković, V.,& Csoka, L.. (2018). Dependence of mechanical and electrical properties of silver nanocubes impregnated bacterial cellulose-silk fibroin-polyvinyl alcohol films on light exposure. in Polymer Testing, 71, 110-114.
https://doi.org/10.1016/j.polymertesting.2018.08.031

Hosakun W, Hosakun Y, Dudić D, Đoković V, Csoka L. Dependence of mechanical and electrical properties of silver nanocubes impregnated bacterial cellulose-silk fibroin-polyvinyl alcohol films on light exposure. in Polymer Testing. 2018;71:110-114.
doi:10.1016/j.polymertesting.2018.08.031 .

Hosakun, Worakan, Hosakun, Yanin, Dudić, Duško, Đoković, Vladimir, Csoka, Levente, "Dependence of mechanical and electrical properties of silver nanocubes impregnated bacterial cellulose-silk fibroin-polyvinyl alcohol films on light exposure" in Polymer Testing, 71 (2018):110-114,
https://doi.org/10.1016/j.polymertesting.2018.08.031 . .

TY  - JOUR
AU  - Petronijević, Ivan M.
AU  - Cerović, Dragana D.
AU  - Dudić, Duško
AU  - Dojčilović, Jablan R.
AU  - Dojčinović, Biljana P.
AU  - Pergal, Marija V.
PY  - 2018
UR  - http://doi.wiley.com/10.1002/pat.4289
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7708
AB  - In this paper, a new simple and environmentally friendly treatment technique for obtaining polymer nanocomposites with appropriate dielectric properties has been presented. Sheets of isotactic polypropylene and atactic polystyrene were immersed in 3 saturated water solutions of alkali metal salts (LiCl, NaCl, and KCl) at 2 fixed temperatures (23°C and 90°C), and 3 DC electrical potentials (+4 kV, −4 kV, and ground potential) were applied. A quantification of alkali metals in the polymer sheets was conducted by inductively coupled plasma optic emission spectrometry. The obtained concentration values were from 7.38·10−9 mol/cm3to 1.25·10−7 mol/cm3. The qualitative analysis of potassium distribution in the polymer matrix was conducted by time-of-flight secondary ion mass spectrometry cross-sectional record. The relative dielectric constant (ε′) of samples was investigated in the frequency range from 20 Hz to 9 MHz at the constant temperature of 22°C. Stable values of ε′ in fully measured frequency range were observed for both pure and treated samples. Next, the results of the dielectric spectroscopy measurements were compared and established the kind of treatment that provided the highest value of ε′. The relationship between the concentrations of alkali metals and the values of relative dielectric constant was determined for the samples obtained by a treatment at 90°C and +4 kV.
T2  - Polymers for Advanced Technologies
T1  - Dielectric spectroscopy of nanocomposites based on iPP and aPS treated in the water solutions of alkali metal salts
VL  - 29
IS  - 6
SP  - 1826
EP  - 1833
DO  - 10.1002/pat.4289
ER  - 

@article{
author = "Petronijević, Ivan M. and Cerović, Dragana D. and Dudić, Duško and Dojčilović, Jablan R. and Dojčinović, Biljana P. and Pergal, Marija V.",
year = "2018",
abstract = "In this paper, a new simple and environmentally friendly treatment technique for obtaining polymer nanocomposites with appropriate dielectric properties has been presented. Sheets of isotactic polypropylene and atactic polystyrene were immersed in 3 saturated water solutions of alkali metal salts (LiCl, NaCl, and KCl) at 2 fixed temperatures (23°C and 90°C), and 3 DC electrical potentials (+4 kV, −4 kV, and ground potential) were applied. A quantification of alkali metals in the polymer sheets was conducted by inductively coupled plasma optic emission spectrometry. The obtained concentration values were from 7.38·10−9 mol/cm3to 1.25·10−7 mol/cm3. The qualitative analysis of potassium distribution in the polymer matrix was conducted by time-of-flight secondary ion mass spectrometry cross-sectional record. The relative dielectric constant (ε′) of samples was investigated in the frequency range from 20 Hz to 9 MHz at the constant temperature of 22°C. Stable values of ε′ in fully measured frequency range were observed for both pure and treated samples. Next, the results of the dielectric spectroscopy measurements were compared and established the kind of treatment that provided the highest value of ε′. The relationship between the concentrations of alkali metals and the values of relative dielectric constant was determined for the samples obtained by a treatment at 90°C and +4 kV.",
journal = "Polymers for Advanced Technologies",
title = "Dielectric spectroscopy of nanocomposites based on iPP and aPS treated in the water solutions of alkali metal salts",
volume = "29",
number = "6",
pages = "1826-1833",
doi = "10.1002/pat.4289"
}

Petronijević, I. M., Cerović, D. D., Dudić, D., Dojčilović, J. R., Dojčinović, B. P.,& Pergal, M. V.. (2018). Dielectric spectroscopy of nanocomposites based on iPP and aPS treated in the water solutions of alkali metal salts. in Polymers for Advanced Technologies, 29(6), 1826-1833.
https://doi.org/10.1002/pat.4289

Petronijević IM, Cerović DD, Dudić D, Dojčilović JR, Dojčinović BP, Pergal MV. Dielectric spectroscopy of nanocomposites based on iPP and aPS treated in the water solutions of alkali metal salts. in Polymers for Advanced Technologies. 2018;29(6):1826-1833.
doi:10.1002/pat.4289 .

Petronijević, Ivan M., Cerović, Dragana D., Dudić, Duško, Dojčilović, Jablan R., Dojčinović, Biljana P., Pergal, Marija V., "Dielectric spectroscopy of nanocomposites based on iPP and aPS treated in the water solutions of alkali metal salts" in Polymers for Advanced Technologies, 29, no. 6 (2018):1826-1833,
https://doi.org/10.1002/pat.4289 . .

TY  - JOUR
AU  - Škipina, Blanka
AU  - Luyt, Adriaan S.
AU  - Csoka, Levente
AU  - Đoković, Vladimir
AU  - Dudić, Duško
PY  - 2018
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1922
AB  - The article describes the influence of humidity on the surface photodielectric properties of papers prepared from poly(ethyleneimine)-TiO2 hanoparticles-anthocyanin modified cellulose fibres. The anthocyanins were extracted from purple cabbage, beet-root, plum peel, red wine and red currant juice. The samples were conditioned to various relative humidities (from 9 to 100%) and illuminated with white visible light, lambda GT = 405 nm. The poly(ethyleneimine)-TiO2-anthocyanin modified samples showed similar photodielectric behaviour that can be clearly distinguished from the samples modified solely with poly(ethyleneimine)-TiO2. Generally, an increase in humidity enhances the conductivity of the samples and induces an increase in the amount of photo-induced charge. Also, at higher humidities (above 80%), the samples with anthocyanin showed significantly higher values of photo-induced charges with respect to anthocyanin free samples. The presented results suggest that the presence of water molecules promotes electron-injection processes from the anthocyanin to the semiconductor surface. (C) 2017 Elsevier Ltd. All rights reserved.
T2  - Dyes and Pigments
T1  - Generation of photo charge in poly(ethyleneimine)-TiO2-anthocyanin modified papers conditioned at different humidities
VL  - 149
SP  - 51
EP  - 58
DO  - 10.1016/j.dyepig.2017.08.064
ER  - 

@article{
author = "Škipina, Blanka and Luyt, Adriaan S. and Csoka, Levente and Đoković, Vladimir and Dudić, Duško",
year = "2018",
abstract = "The article describes the influence of humidity on the surface photodielectric properties of papers prepared from poly(ethyleneimine)-TiO2 hanoparticles-anthocyanin modified cellulose fibres. The anthocyanins were extracted from purple cabbage, beet-root, plum peel, red wine and red currant juice. The samples were conditioned to various relative humidities (from 9 to 100%) and illuminated with white visible light, lambda GT = 405 nm. The poly(ethyleneimine)-TiO2-anthocyanin modified samples showed similar photodielectric behaviour that can be clearly distinguished from the samples modified solely with poly(ethyleneimine)-TiO2. Generally, an increase in humidity enhances the conductivity of the samples and induces an increase in the amount of photo-induced charge. Also, at higher humidities (above 80%), the samples with anthocyanin showed significantly higher values of photo-induced charges with respect to anthocyanin free samples. The presented results suggest that the presence of water molecules promotes electron-injection processes from the anthocyanin to the semiconductor surface. (C) 2017 Elsevier Ltd. All rights reserved.",
journal = "Dyes and Pigments",
title = "Generation of photo charge in poly(ethyleneimine)-TiO2-anthocyanin modified papers conditioned at different humidities",
volume = "149",
pages = "51-58",
doi = "10.1016/j.dyepig.2017.08.064"
}

Škipina, B., Luyt, A. S., Csoka, L., Đoković, V.,& Dudić, D.. (2018). Generation of photo charge in poly(ethyleneimine)-TiO2-anthocyanin modified papers conditioned at different humidities. in Dyes and Pigments, 149, 51-58.
https://doi.org/10.1016/j.dyepig.2017.08.064

Škipina B, Luyt AS, Csoka L, Đoković V, Dudić D. Generation of photo charge in poly(ethyleneimine)-TiO2-anthocyanin modified papers conditioned at different humidities. in Dyes and Pigments. 2018;149:51-58.
doi:10.1016/j.dyepig.2017.08.064 .

Škipina, Blanka, Luyt, Adriaan S., Csoka, Levente, Đoković, Vladimir, Dudić, Duško, "Generation of photo charge in poly(ethyleneimine)-TiO2-anthocyanin modified papers conditioned at different humidities" in Dyes and Pigments, 149 (2018):51-58,
https://doi.org/10.1016/j.dyepig.2017.08.064 . .

TY  - JOUR
AU  - Luyt, Adriaan S.
AU  - Škipina, Blanka
AU  - Csoka, Levente
AU  - Dudić, Duško
PY  - 2018
UR  - http://link.springer.com/10.1007/s00226-018-0994-1
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7629
AB  - Modified cellulose materials are finding increasing application in electronics, because of the need for more environmental-friendly electronic circuits. The papers prepared from poly(ethyleneimine)-TiO2-anthocyanin-modified cellulose fibres are completely environmentally friendly and can be applied to the construction of photocells or photo-/humidity sensors. To better understand the mechanisms of electrical conductivity of the said cellulose composites, the effect of humidity (RH = 9% -> 100%) on its dielectric properties is presented in this article. The possibility of trapping the negative and positive charges in the composite under different humidity conditions is also examined. A large number of studies suggest that proton conductivity, stimulated by humidity, is the dominant mechanism of electrical conductivity in cellulose-based materials. The results presented in this paper indicate that the electronic conductivity mechanisms also play a significant role in papers prepared from poly(ethyleneimine)-TiO2-anthocyanin-modified cellulose fibres.
T2  - Wood Science and Technology
T1  - Charge-trapping capability and AC conductivity at different humidities of poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres
VL  - 52
IS  - 3
SP  - 637
EP  - 651
DO  - 10.1007/s00226-018-0994-1
ER  - 

@article{
author = "Luyt, Adriaan S. and Škipina, Blanka and Csoka, Levente and Dudić, Duško",
year = "2018",
abstract = "Modified cellulose materials are finding increasing application in electronics, because of the need for more environmental-friendly electronic circuits. The papers prepared from poly(ethyleneimine)-TiO2-anthocyanin-modified cellulose fibres are completely environmentally friendly and can be applied to the construction of photocells or photo-/humidity sensors. To better understand the mechanisms of electrical conductivity of the said cellulose composites, the effect of humidity (RH = 9% -> 100%) on its dielectric properties is presented in this article. The possibility of trapping the negative and positive charges in the composite under different humidity conditions is also examined. A large number of studies suggest that proton conductivity, stimulated by humidity, is the dominant mechanism of electrical conductivity in cellulose-based materials. The results presented in this paper indicate that the electronic conductivity mechanisms also play a significant role in papers prepared from poly(ethyleneimine)-TiO2-anthocyanin-modified cellulose fibres.",
journal = "Wood Science and Technology",
title = "Charge-trapping capability and AC conductivity at different humidities of poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres",
volume = "52",
number = "3",
pages = "637-651",
doi = "10.1007/s00226-018-0994-1"
}

Luyt, A. S., Škipina, B., Csoka, L.,& Dudić, D.. (2018). Charge-trapping capability and AC conductivity at different humidities of poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres. in Wood Science and Technology, 52(3), 637-651.
https://doi.org/10.1007/s00226-018-0994-1

Luyt AS, Škipina B, Csoka L, Dudić D. Charge-trapping capability and AC conductivity at different humidities of poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres. in Wood Science and Technology. 2018;52(3):637-651.
doi:10.1007/s00226-018-0994-1 .

Luyt, Adriaan S., Škipina, Blanka, Csoka, Levente, Dudić, Duško, "Charge-trapping capability and AC conductivity at different humidities of poly(ethyleneimine)–TiO2–anthocyanin-modified cellulose fibres" in Wood Science and Technology, 52, no. 3 (2018):637-651,
https://doi.org/10.1007/s00226-018-0994-1 . .

TY  - JOUR
AU  - Dojčilović, Radovan
AU  - Pajović, Jelena D.
AU  - Božanić, Dušan K.
AU  - Bogdanović, Una
AU  - Vodnik, Vesna
AU  - Dimitrijević-Branković, Suzana I.
AU  - Miljković, Miona G.
AU  - Kaščakova, Slavka
AU  - Refregiers, Matthieu
AU  - Đoković, Vladimir
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1608
AB  - The interaction of the tryptophan functionalized Ag nanoparticles and live Candida albicans cells was studied by synchrotron excitation deep-ultraviolet (DUV) fluorescence imaging at the DISCO beamline of Synchrotron SOLEIL. DUV imaging showed that incubation of the fungus with functionalized nanoparticles results in significant increase in the fluorescence signal. The analysis of the images revealed that the interaction of the nanoparticles with (pseudo)hyphae polymorphs of the diploid fungus was less pronounced than in the case of yeast cells or budding spores. The changes in the intensity of the fluorescence signals of the cells after incubation were followed in [327-353 nm] and [370-410 nm] spectral ranges that correspond to the fluorescence of tryptophan in non-polar and polar environment, respectively. As a consequence of the environmental sensitivity of the silver-tryptophan fluorescent nanoprobe, we were able to determine the possible accumulation sites of the nanoparticles. The analysis of the intensity decay kinetics showed that the photobleaching effects were more pronounced in the case of the functionalized nanoparticle treated cells. The results of time-integrated emission in the mentioned spectral ranges suggested that the nanoparticles penetrate the cells, but that the majority of the nanoparticles attach to the cells surfaces. (C) 2017 Elsevier B.V. All rights reserved.
T2  - Colloids and Surfaces. B: Biointerfaces
T1  - Interaction of amino acid-functionalized silver nanoparticles and Candida albicans polymorphs: A deep-UV fluorescence imaging study
VL  - 155
SP  - 341
EP  - 348
DO  - 10.1016/j.colsurfb.2017.04.044
ER  - 

@article{
author = "Dojčilović, Radovan and Pajović, Jelena D. and Božanić, Dušan K. and Bogdanović, Una and Vodnik, Vesna and Dimitrijević-Branković, Suzana I. and Miljković, Miona G. and Kaščakova, Slavka and Refregiers, Matthieu and Đoković, Vladimir",
year = "2017",
abstract = "The interaction of the tryptophan functionalized Ag nanoparticles and live Candida albicans cells was studied by synchrotron excitation deep-ultraviolet (DUV) fluorescence imaging at the DISCO beamline of Synchrotron SOLEIL. DUV imaging showed that incubation of the fungus with functionalized nanoparticles results in significant increase in the fluorescence signal. The analysis of the images revealed that the interaction of the nanoparticles with (pseudo)hyphae polymorphs of the diploid fungus was less pronounced than in the case of yeast cells or budding spores. The changes in the intensity of the fluorescence signals of the cells after incubation were followed in [327-353 nm] and [370-410 nm] spectral ranges that correspond to the fluorescence of tryptophan in non-polar and polar environment, respectively. As a consequence of the environmental sensitivity of the silver-tryptophan fluorescent nanoprobe, we were able to determine the possible accumulation sites of the nanoparticles. The analysis of the intensity decay kinetics showed that the photobleaching effects were more pronounced in the case of the functionalized nanoparticle treated cells. The results of time-integrated emission in the mentioned spectral ranges suggested that the nanoparticles penetrate the cells, but that the majority of the nanoparticles attach to the cells surfaces. (C) 2017 Elsevier B.V. All rights reserved.",
journal = "Colloids and Surfaces. B: Biointerfaces",
title = "Interaction of amino acid-functionalized silver nanoparticles and Candida albicans polymorphs: A deep-UV fluorescence imaging study",
volume = "155",
pages = "341-348",
doi = "10.1016/j.colsurfb.2017.04.044"
}

Dojčilović, R., Pajović, J. D., Božanić, D. K., Bogdanović, U., Vodnik, V., Dimitrijević-Branković, S. I., Miljković, M. G., Kaščakova, S., Refregiers, M.,& Đoković, V.. (2017). Interaction of amino acid-functionalized silver nanoparticles and Candida albicans polymorphs: A deep-UV fluorescence imaging study. in Colloids and Surfaces. B: Biointerfaces, 155, 341-348.
https://doi.org/10.1016/j.colsurfb.2017.04.044

Dojčilović R, Pajović JD, Božanić DK, Bogdanović U, Vodnik V, Dimitrijević-Branković SI, Miljković MG, Kaščakova S, Refregiers M, Đoković V. Interaction of amino acid-functionalized silver nanoparticles and Candida albicans polymorphs: A deep-UV fluorescence imaging study. in Colloids and Surfaces. B: Biointerfaces. 2017;155:341-348.
doi:10.1016/j.colsurfb.2017.04.044 .

Dojčilović, Radovan, Pajović, Jelena D., Božanić, Dušan K., Bogdanović, Una, Vodnik, Vesna, Dimitrijević-Branković, Suzana I., Miljković, Miona G., Kaščakova, Slavka, Refregiers, Matthieu, Đoković, Vladimir, "Interaction of amino acid-functionalized silver nanoparticles and Candida albicans polymorphs: A deep-UV fluorescence imaging study" in Colloids and Surfaces. B: Biointerfaces, 155 (2017):341-348,
https://doi.org/10.1016/j.colsurfb.2017.04.044 . .

TY  - JOUR
AU  - Motloung, Benison T.
AU  - Dudić, Duško
AU  - Mofokeng, Julia P.
AU  - Luyt, Adriaan S.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1486
AB  - This paper reports on the presence of wax and radiation-induced crosslinking on the morphology, thermal and mechanical properties, as well as electrical conductivity and thermo-switch properties of LDPE containing different amounts of carbon black (CB) or carbon black plus zinc metal as filler. Although the filler was generally well dispersed in the polymer or polymer/wax blend, there were clear indications of the formation of conductive pathways. Different combinations of polymer, wax, CB and zinc filler and radiation induced crosslinking gave rise to different extents of crystallinity and/or chain immobilization, which had an influence on the mechanical and thermo-mechanical properties, and on the electrical conductivity and thermo-switch behaviour. Most importantly, the presence of wax, and CB and CB/Zn fillers, gave rise to increased electrical conductivity. The thermal expansion in the composites did not seem to play a significant role in obtaining larger values of the positive temperature coefficient of resistivity (PTC). We found that the presence of a small amount of paraffin wax significantly increased the PTC coefficients of the LDPE based conductive composites, and that gamma-radiation induced crosslinking provided the thermo-mechanical stability of the amorphous regions in LDPE needed to obtain a high PTC intensity, which would provide a cheap material with good thermo-switch functionality, which is something not observed before.
T2  - Journal of Polymer Research
T1  - Properties and thermo-switch behaviour of LDPE mixed with carbon black, zinc metal and paraffin wax
VL  - 24
IS  - 3
DO  - 10.1007/s10965-017-1205-8
ER  - 

@article{
author = "Motloung, Benison T. and Dudić, Duško and Mofokeng, Julia P. and Luyt, Adriaan S.",
year = "2017",
abstract = "This paper reports on the presence of wax and radiation-induced crosslinking on the morphology, thermal and mechanical properties, as well as electrical conductivity and thermo-switch properties of LDPE containing different amounts of carbon black (CB) or carbon black plus zinc metal as filler. Although the filler was generally well dispersed in the polymer or polymer/wax blend, there were clear indications of the formation of conductive pathways. Different combinations of polymer, wax, CB and zinc filler and radiation induced crosslinking gave rise to different extents of crystallinity and/or chain immobilization, which had an influence on the mechanical and thermo-mechanical properties, and on the electrical conductivity and thermo-switch behaviour. Most importantly, the presence of wax, and CB and CB/Zn fillers, gave rise to increased electrical conductivity. The thermal expansion in the composites did not seem to play a significant role in obtaining larger values of the positive temperature coefficient of resistivity (PTC). We found that the presence of a small amount of paraffin wax significantly increased the PTC coefficients of the LDPE based conductive composites, and that gamma-radiation induced crosslinking provided the thermo-mechanical stability of the amorphous regions in LDPE needed to obtain a high PTC intensity, which would provide a cheap material with good thermo-switch functionality, which is something not observed before.",
journal = "Journal of Polymer Research",
title = "Properties and thermo-switch behaviour of LDPE mixed with carbon black, zinc metal and paraffin wax",
volume = "24",
number = "3",
doi = "10.1007/s10965-017-1205-8"
}

Motloung, B. T., Dudić, D., Mofokeng, J. P.,& Luyt, A. S.. (2017). Properties and thermo-switch behaviour of LDPE mixed with carbon black, zinc metal and paraffin wax. in Journal of Polymer Research, 24(3).
https://doi.org/10.1007/s10965-017-1205-8

Motloung BT, Dudić D, Mofokeng JP, Luyt AS. Properties and thermo-switch behaviour of LDPE mixed with carbon black, zinc metal and paraffin wax. in Journal of Polymer Research. 2017;24(3).
doi:10.1007/s10965-017-1205-8 .

Motloung, Benison T., Dudić, Duško, Mofokeng, Julia P., Luyt, Adriaan S., "Properties and thermo-switch behaviour of LDPE mixed with carbon black, zinc metal and paraffin wax" in Journal of Polymer Research, 24, no. 3 (2017),
https://doi.org/10.1007/s10965-017-1205-8 . .

TY  - JOUR
AU  - Pajović, Jelena D.
AU  - Dojčilović, Radovan
AU  - Božanić, Dušan K.
AU  - Vodnik, Vesna
AU  - Dimitrijević-Branković, Suzana I.
AU  - Kaščakova, Slavka
AU  - Refregiers, Matthieu
AU  - Markelić, Milica
AU  - Đoković, Vladimir
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1107
AB  - Fluorescent nanostructures were prepared by functionalization of gold nanoparticles with riboflavin molecules and used as probes for synchrotron radiation deep ultraviolet (SR-DUV) fluorescence imaging of gluteraldehyde-fixed Candida albicans cells. The nanoparticles were characterized by transmission electron microscopy (TEM) and optical spectroscopy techniques. The TEM analysis showed that the nanostructures were 6 nm in diameter, while the results of the fluorescence spectroscopies confirmed the photoluminescence of the nanoparticles. The SR-DUV imaging showed that it was possible to distinguish the fluorescence of the nanoparticles from the autofluorescence of the cells, as well as that the local maxima of the signal pertaining to the fluorescence of goldriboflavin nanostructures were mostly positioned on the surfaces of the C. albicans cells of spherical morphology.
T2  - Optical and Quantum Electronics
T1  - Deep UV fluorescence imaging study of Candida albicans cells treated with gold-riboflavin hydrocolloids
VL  - 48
IS  - 6
DO  - 10.1007/s11082-016-0578-y
ER  - 

@article{
author = "Pajović, Jelena D. and Dojčilović, Radovan and Božanić, Dušan K. and Vodnik, Vesna and Dimitrijević-Branković, Suzana I. and Kaščakova, Slavka and Refregiers, Matthieu and Markelić, Milica and Đoković, Vladimir",
year = "2016",
abstract = "Fluorescent nanostructures were prepared by functionalization of gold nanoparticles with riboflavin molecules and used as probes for synchrotron radiation deep ultraviolet (SR-DUV) fluorescence imaging of gluteraldehyde-fixed Candida albicans cells. The nanoparticles were characterized by transmission electron microscopy (TEM) and optical spectroscopy techniques. The TEM analysis showed that the nanostructures were 6 nm in diameter, while the results of the fluorescence spectroscopies confirmed the photoluminescence of the nanoparticles. The SR-DUV imaging showed that it was possible to distinguish the fluorescence of the nanoparticles from the autofluorescence of the cells, as well as that the local maxima of the signal pertaining to the fluorescence of goldriboflavin nanostructures were mostly positioned on the surfaces of the C. albicans cells of spherical morphology.",
journal = "Optical and Quantum Electronics",
title = "Deep UV fluorescence imaging study of Candida albicans cells treated with gold-riboflavin hydrocolloids",
volume = "48",
number = "6",
doi = "10.1007/s11082-016-0578-y"
}

Pajović, J. D., Dojčilović, R., Božanić, D. K., Vodnik, V., Dimitrijević-Branković, S. I., Kaščakova, S., Refregiers, M., Markelić, M.,& Đoković, V.. (2016). Deep UV fluorescence imaging study of Candida albicans cells treated with gold-riboflavin hydrocolloids. in Optical and Quantum Electronics, 48(6).
https://doi.org/10.1007/s11082-016-0578-y

Pajović JD, Dojčilović R, Božanić DK, Vodnik V, Dimitrijević-Branković SI, Kaščakova S, Refregiers M, Markelić M, Đoković V. Deep UV fluorescence imaging study of Candida albicans cells treated with gold-riboflavin hydrocolloids. in Optical and Quantum Electronics. 2016;48(6).
doi:10.1007/s11082-016-0578-y .

Pajović, Jelena D., Dojčilović, Radovan, Božanić, Dušan K., Vodnik, Vesna, Dimitrijević-Branković, Suzana I., Kaščakova, Slavka, Refregiers, Matthieu, Markelić, Milica, Đoković, Vladimir, "Deep UV fluorescence imaging study of Candida albicans cells treated with gold-riboflavin hydrocolloids" in Optical and Quantum Electronics, 48, no. 6 (2016),
https://doi.org/10.1007/s11082-016-0578-y . .

TY  - JOUR
AU  - Dudić, Duško
AU  - Luyt, Adriaan S.
AU  - Marinković, Filip S.
AU  - Petronijević, Ivan M.
AU  - Dojčilović, Jablan R.
AU  - Kostoski, Dušan
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/341
AB  - Electrical AC conductivity of semiconducting low-density polyethylene (LDPE)-carbon black (CB) composites has been studied in the frequency range between 24 Hz and 75 kHz and the temperature range from 295 to 355 K. The composites were gamma irradiated at room temperature to different absorbed doses up to 300 kGy. The effects of gamma irradiation on the AC conductivity at room temperature and the conductive temperature coefficients (CTC) were observed. It was found that the effect of gamma irradiation on the stability of AC conductivity at elevated temperature (355 K) is dependent on the carbon black content and the gamma irradiation dose. (C) 2014 Elsevier Ltd. All rights reserved.
T2  - Radiation Physics and Chemistry
T1  - The effect of gamma irradiation on the thermal behavior of dielectric properties of linear low-density/carbon black semiconductive composites
VL  - 107
SP  - 89
EP  - 94
DO  - 10.1016/j.radphyschem.2014.10.003
ER  - 

@article{
author = "Dudić, Duško and Luyt, Adriaan S. and Marinković, Filip S. and Petronijević, Ivan M. and Dojčilović, Jablan R. and Kostoski, Dušan",
year = "2015",
abstract = "Electrical AC conductivity of semiconducting low-density polyethylene (LDPE)-carbon black (CB) composites has been studied in the frequency range between 24 Hz and 75 kHz and the temperature range from 295 to 355 K. The composites were gamma irradiated at room temperature to different absorbed doses up to 300 kGy. The effects of gamma irradiation on the AC conductivity at room temperature and the conductive temperature coefficients (CTC) were observed. It was found that the effect of gamma irradiation on the stability of AC conductivity at elevated temperature (355 K) is dependent on the carbon black content and the gamma irradiation dose. (C) 2014 Elsevier Ltd. All rights reserved.",
journal = "Radiation Physics and Chemistry",
title = "The effect of gamma irradiation on the thermal behavior of dielectric properties of linear low-density/carbon black semiconductive composites",
volume = "107",
pages = "89-94",
doi = "10.1016/j.radphyschem.2014.10.003"
}

Dudić, D., Luyt, A. S., Marinković, F. S., Petronijević, I. M., Dojčilović, J. R.,& Kostoski, D.. (2015). The effect of gamma irradiation on the thermal behavior of dielectric properties of linear low-density/carbon black semiconductive composites. in Radiation Physics and Chemistry, 107, 89-94.
https://doi.org/10.1016/j.radphyschem.2014.10.003

Dudić D, Luyt AS, Marinković FS, Petronijević IM, Dojčilović JR, Kostoski D. The effect of gamma irradiation on the thermal behavior of dielectric properties of linear low-density/carbon black semiconductive composites. in Radiation Physics and Chemistry. 2015;107:89-94.
doi:10.1016/j.radphyschem.2014.10.003 .

Dudić, Duško, Luyt, Adriaan S., Marinković, Filip S., Petronijević, Ivan M., Dojčilović, Jablan R., Kostoski, Dušan, "The effect of gamma irradiation on the thermal behavior of dielectric properties of linear low-density/carbon black semiconductive composites" in Radiation Physics and Chemistry, 107 (2015):89-94,
https://doi.org/10.1016/j.radphyschem.2014.10.003 . .

TY  - JOUR
AU  - Csoka, Levente
AU  - Dudić, Duško
AU  - Petronijević, Ivan M.
AU  - Rozsa, C.
AU  - Halasz, K.
AU  - Đoković, Vladimir
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/439
AB  - Poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fiber sheets were prepared as a support material for dye-sensitized solar cells. The study is focused on the effects of different anthocyanins on the photo-induced changes and contact relaxation of the surface AC-conductivity of the papers. The anthocyanins were extracted from purple cabbage, beet-root, plum peel, red vine and red currant juice. The results showed that there were pronounced contact relaxation effects at the interfaces between alumina electrode and the papers, which were further affected by the presence of anthocyanins. The electrode effects are mainly manifested by a decrease in conductance, which falls by about 30 % from its initial value about 400 min after the beginning of the experiment carried out in the dark. The illumination of the samples induces an increase in the magnitude of the observed changes in conductance but does not affect the nature of the relaxation processes. By estimating the temperature coefficients of conductivity of the papers and the changes in temperature during the illumination of the samples, we succeeded to separate the effects of heating from the total effects of illumination on the conductance and susceptance of the papers.
T2  - Cellulose
T1  - Photo-induced changes and contact relaxation of the surface AC-conductivity of the paper prepared from poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fibers
VL  - 22
IS  - 1
SP  - 779
EP  - 788
DO  - 10.1007/s10570-014-0537-3
ER  - 

@article{
author = "Csoka, Levente and Dudić, Duško and Petronijević, Ivan M. and Rozsa, C. and Halasz, K. and Đoković, Vladimir",
year = "2015",
abstract = "Poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fiber sheets were prepared as a support material for dye-sensitized solar cells. The study is focused on the effects of different anthocyanins on the photo-induced changes and contact relaxation of the surface AC-conductivity of the papers. The anthocyanins were extracted from purple cabbage, beet-root, plum peel, red vine and red currant juice. The results showed that there were pronounced contact relaxation effects at the interfaces between alumina electrode and the papers, which were further affected by the presence of anthocyanins. The electrode effects are mainly manifested by a decrease in conductance, which falls by about 30 % from its initial value about 400 min after the beginning of the experiment carried out in the dark. The illumination of the samples induces an increase in the magnitude of the observed changes in conductance but does not affect the nature of the relaxation processes. By estimating the temperature coefficients of conductivity of the papers and the changes in temperature during the illumination of the samples, we succeeded to separate the effects of heating from the total effects of illumination on the conductance and susceptance of the papers.",
journal = "Cellulose",
title = "Photo-induced changes and contact relaxation of the surface AC-conductivity of the paper prepared from poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fibers",
volume = "22",
number = "1",
pages = "779-788",
doi = "10.1007/s10570-014-0537-3"
}

Csoka, L., Dudić, D., Petronijević, I. M., Rozsa, C., Halasz, K.,& Đoković, V.. (2015). Photo-induced changes and contact relaxation of the surface AC-conductivity of the paper prepared from poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fibers. in Cellulose, 22(1), 779-788.
https://doi.org/10.1007/s10570-014-0537-3

Csoka L, Dudić D, Petronijević IM, Rozsa C, Halasz K, Đoković V. Photo-induced changes and contact relaxation of the surface AC-conductivity of the paper prepared from poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fibers. in Cellulose. 2015;22(1):779-788.
doi:10.1007/s10570-014-0537-3 .

Csoka, Levente, Dudić, Duško, Petronijević, Ivan M., Rozsa, C., Halasz, K., Đoković, Vladimir, "Photo-induced changes and contact relaxation of the surface AC-conductivity of the paper prepared from poly(ethyleneimine)-TiO2-anthocyanin modified cellulose fibers" in Cellulose, 22, no. 1 (2015):779-788,
https://doi.org/10.1007/s10570-014-0537-3 . .

TY  - JOUR
AU  - Molaba, M. P.
AU  - Dudić, Duško
AU  - Luyt, Adriaan S.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/694
AB  - The aim of this study was to investigate the presence of wax, different Ag nanoparticle contents, and different cooling rates from the melt, on the morphology, thermal and electrical conductivity, and dynamic mechanical properties of iPP. The Ag particles were well dispersed in the polymer, and formed nucleation centres for the crystallization of iPP. They were also well dispersed in iPP/wax, but they were located in the wax phase which was dispersed between the iPP spherulites. Generally the extent of filler agglomeration increased with increasing filler content. The Ag particles, whether in the iPP or wax phase, had little influence on the crystallinities and melting temperatures of iPP. The presence of Ag particles in iPP had little influence on its modulus, but the presence of both wax and Ag particles significantly improved the modulus of these nanocomposites. The thermal and electrical conductivities of the samples more significantly improved when both wax and Ag were present. With increasing Ag particle contents in both iPP/Ag and iPP/wax/Ag, the thermal conductivities increased, but leveled off at higher filler contents, while the electrical conductivities continuously increased with increasing filler contents. The slowly cooled samples had higher crystallinities than the quenched samples and therefore they were more thermally conductive than the quenched samples.
T2  - Express Polymer Letters
T1  - Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites
VL  - 9
IS  - 10
SP  - 901
EP  - 915
DO  - 10.3144/expresspolymlett.2015.82
ER  - 

@article{
author = "Molaba, M. P. and Dudić, Duško and Luyt, Adriaan S.",
year = "2015",
abstract = "The aim of this study was to investigate the presence of wax, different Ag nanoparticle contents, and different cooling rates from the melt, on the morphology, thermal and electrical conductivity, and dynamic mechanical properties of iPP. The Ag particles were well dispersed in the polymer, and formed nucleation centres for the crystallization of iPP. They were also well dispersed in iPP/wax, but they were located in the wax phase which was dispersed between the iPP spherulites. Generally the extent of filler agglomeration increased with increasing filler content. The Ag particles, whether in the iPP or wax phase, had little influence on the crystallinities and melting temperatures of iPP. The presence of Ag particles in iPP had little influence on its modulus, but the presence of both wax and Ag particles significantly improved the modulus of these nanocomposites. The thermal and electrical conductivities of the samples more significantly improved when both wax and Ag were present. With increasing Ag particle contents in both iPP/Ag and iPP/wax/Ag, the thermal conductivities increased, but leveled off at higher filler contents, while the electrical conductivities continuously increased with increasing filler contents. The slowly cooled samples had higher crystallinities than the quenched samples and therefore they were more thermally conductive than the quenched samples.",
journal = "Express Polymer Letters",
title = "Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites",
volume = "9",
number = "10",
pages = "901-915",
doi = "10.3144/expresspolymlett.2015.82"
}

Molaba, M. P., Dudić, D.,& Luyt, A. S.. (2015). Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites. in Express Polymer Letters, 9(10), 901-915.
https://doi.org/10.3144/expresspolymlett.2015.82

Molaba MP, Dudić D, Luyt AS. Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites. in Express Polymer Letters. 2015;9(10):901-915.
doi:10.3144/expresspolymlett.2015.82 .

Molaba, M. P., Dudić, Duško, Luyt, Adriaan S., "Influence of the presence of medium-soft paraffin wax on the morphology and properties of iPP/silver nanocomposites" in Express Polymer Letters, 9, no. 10 (2015):901-915,
https://doi.org/10.3144/expresspolymlett.2015.82 . .

TY  - JOUR
AU  - Simonovic, Kosta
AU  - Petronijević, Ivan M.
AU  - Kostoski, Dušan
AU  - Dojčilović, Jablan R.
AU  - Luyt, Adriaan S.
AU  - Dudić, Duško
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/147
AB  - The surface dielectric properties of acid-etched low-density polyethylene (LDPE) were analysed in the frequency range from 20 Hz to 200 kHz. Samples were treated with various acids for a period of one hour, at temperatures ranging from 20 to 70 degrees C. After the treatment, the samples were analysed with Fourier transform infrared spectroscopy, revealing chemical and crystallinity changes on the surface, as a direct result of the treatment. The sample surfaces were analysed using atomic force microscopy. The micrographs show that the acid treatment increases the roughness of the samples. Compared to untreated LDPE, the etched samples may exhibit significantly different conductance values at low frequencies. It is also observed that an increase in the acid treatment temperature can result in lower values of conductance and susceptance compared to untreated samples. LDPE films with low value of surface AC conductivity after acid treatment are potentially useful substrates for high-speed electro-sensing applications. The presented results indicate that a suitable choice of acid treatment of LDPE can effect surface polarization while preserving low values of surface AC conductivity of the polymer. (c) 2014 Society of Chemical Industry
T2  - Polymer International
T1  - Effects of acid treatment at different temperatures on the surface dielectric properties of low-density polyethylene
VL  - 63
IS  - 11
SP  - 1924
EP  - 1929
DO  - 10.1002/pi.4731
ER  - 

@article{
author = "Simonovic, Kosta and Petronijević, Ivan M. and Kostoski, Dušan and Dojčilović, Jablan R. and Luyt, Adriaan S. and Dudić, Duško",
year = "2014",
abstract = "The surface dielectric properties of acid-etched low-density polyethylene (LDPE) were analysed in the frequency range from 20 Hz to 200 kHz. Samples were treated with various acids for a period of one hour, at temperatures ranging from 20 to 70 degrees C. After the treatment, the samples were analysed with Fourier transform infrared spectroscopy, revealing chemical and crystallinity changes on the surface, as a direct result of the treatment. The sample surfaces were analysed using atomic force microscopy. The micrographs show that the acid treatment increases the roughness of the samples. Compared to untreated LDPE, the etched samples may exhibit significantly different conductance values at low frequencies. It is also observed that an increase in the acid treatment temperature can result in lower values of conductance and susceptance compared to untreated samples. LDPE films with low value of surface AC conductivity after acid treatment are potentially useful substrates for high-speed electro-sensing applications. The presented results indicate that a suitable choice of acid treatment of LDPE can effect surface polarization while preserving low values of surface AC conductivity of the polymer. (c) 2014 Society of Chemical Industry",
journal = "Polymer International",
title = "Effects of acid treatment at different temperatures on the surface dielectric properties of low-density polyethylene",
volume = "63",
number = "11",
pages = "1924-1929",
doi = "10.1002/pi.4731"
}

Simonovic, K., Petronijević, I. M., Kostoski, D., Dojčilović, J. R., Luyt, A. S.,& Dudić, D.. (2014). Effects of acid treatment at different temperatures on the surface dielectric properties of low-density polyethylene. in Polymer International, 63(11), 1924-1929.
https://doi.org/10.1002/pi.4731

Simonovic K, Petronijević IM, Kostoski D, Dojčilović JR, Luyt AS, Dudić D. Effects of acid treatment at different temperatures on the surface dielectric properties of low-density polyethylene. in Polymer International. 2014;63(11):1924-1929.
doi:10.1002/pi.4731 .

Simonovic, Kosta, Petronijević, Ivan M., Kostoski, Dušan, Dojčilović, Jablan R., Luyt, Adriaan S., Dudić, Duško, "Effects of acid treatment at different temperatures on the surface dielectric properties of low-density polyethylene" in Polymer International, 63, no. 11 (2014):1924-1929,
https://doi.org/10.1002/pi.4731 . .

TY  - JOUR
AU  - Petronijević, Ivan M.
AU  - Simonovic, K.
AU  - Marinković, Filip S.
AU  - Dojčilović, Jablan R.
AU  - Luyt, Adriaan S.
AU  - Dudić, Duško
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/120
AB  - This study describes the possibility of dielectric characterization of the initial stages of ageing in an low-density polyethylene (LDPE) + graphite composite, which is not possible using the standard method of dielectric spectroscopy. It is shown that the differences between the delay angles, Delta phi = phi(TRI)-phi(SIN), obtained using triangular and sinusoidal excitations on the composite samples, shows a maximum, and at the same time the position of this maximum shows more sensitivity to changes in the electrical properties of the material caused by ageing than other dielectric parameters. In order to clarify the applied methodology, a comparative analysis of the dielectric properties of other polymers poly(vinyl chloride) (PVC) and poly(vinyl alcohol) (PVA) and a conductive polymer composite (LDPE + carbon black) with respect to the application of sinusoidal and triangular electrical signals was carried out. Based on the presented results, we believe that the position of the peak in the frequency spectra of the difference between the delay angles obtained by using triangular and sinusoidal signals may be a suitable parameter for the dielectric characterization of polymeric materials.
T2  - Express Polymer Letters
T1  - The detection of the early stages of ageing in an LDPE plus graphite composite by comparison of dielectric responses induced by sinusoidal and triangular signals
VL  - 8
IS  - 10
SP  - 733
EP  - 744
DO  - 10.3144/expresspolymlett.2014.76
ER  - 

@article{
author = "Petronijević, Ivan M. and Simonovic, K. and Marinković, Filip S. and Dojčilović, Jablan R. and Luyt, Adriaan S. and Dudić, Duško",
year = "2014",
abstract = "This study describes the possibility of dielectric characterization of the initial stages of ageing in an low-density polyethylene (LDPE) + graphite composite, which is not possible using the standard method of dielectric spectroscopy. It is shown that the differences between the delay angles, Delta phi = phi(TRI)-phi(SIN), obtained using triangular and sinusoidal excitations on the composite samples, shows a maximum, and at the same time the position of this maximum shows more sensitivity to changes in the electrical properties of the material caused by ageing than other dielectric parameters. In order to clarify the applied methodology, a comparative analysis of the dielectric properties of other polymers poly(vinyl chloride) (PVC) and poly(vinyl alcohol) (PVA) and a conductive polymer composite (LDPE + carbon black) with respect to the application of sinusoidal and triangular electrical signals was carried out. Based on the presented results, we believe that the position of the peak in the frequency spectra of the difference between the delay angles obtained by using triangular and sinusoidal signals may be a suitable parameter for the dielectric characterization of polymeric materials.",
journal = "Express Polymer Letters",
title = "The detection of the early stages of ageing in an LDPE plus graphite composite by comparison of dielectric responses induced by sinusoidal and triangular signals",
volume = "8",
number = "10",
pages = "733-744",
doi = "10.3144/expresspolymlett.2014.76"
}

Petronijević, I. M., Simonovic, K., Marinković, F. S., Dojčilović, J. R., Luyt, A. S.,& Dudić, D.. (2014). The detection of the early stages of ageing in an LDPE plus graphite composite by comparison of dielectric responses induced by sinusoidal and triangular signals. in Express Polymer Letters, 8(10), 733-744.
https://doi.org/10.3144/expresspolymlett.2014.76

Petronijević IM, Simonovic K, Marinković FS, Dojčilović JR, Luyt AS, Dudić D. The detection of the early stages of ageing in an LDPE plus graphite composite by comparison of dielectric responses induced by sinusoidal and triangular signals. in Express Polymer Letters. 2014;8(10):733-744.
doi:10.3144/expresspolymlett.2014.76 .

Petronijević, Ivan M., Simonovic, K., Marinković, Filip S., Dojčilović, Jablan R., Luyt, Adriaan S., Dudić, Duško, "The detection of the early stages of ageing in an LDPE plus graphite composite by comparison of dielectric responses induced by sinusoidal and triangular signals" in Express Polymer Letters, 8, no. 10 (2014):733-744,
https://doi.org/10.3144/expresspolymlett.2014.76 . .