Brankica Gajić

Ms. Brankica Gajić

orcid

Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 June 2025 in Molecules
Verified
Journal Article
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BGBrankica Gajić
Brankica Gajić
MMMilica Milošević
Milica Milošević
Dejan KepićDejan Kepić
Dejan Kepić
GĆGordana Ćirić-Marjanović
Gordana Ćirić-Marjanović
ZŠZoran V. Šaponjić
Zoran V. Šaponjić
Marija B. RadoičićMarija B. Radoičić
Marija B. Radoičić
Nowadays, there is an urgent need for efficient photocatalysts and adsorbents for environmentally relevant applications. This study investigates the effect of polyaniline (PANI) on the structure and performance of carbonized nanocomposites composed of PANI and TiO2 nanotubes (NTs), focusing on their photocatalytic degradation efficiency and dye adsorption capacity. The hypothesis was that PANI forms conductive carbon domains and stabilizes the anatase phase during thermal treatment, enhancing the performance of TiO2-NTs as photocatalysts. Nanocomposites based on PANI and TiO2-NTs (TTP) were synthesized through chemical oxidative polymerization of aniline (ANI) in the presence of TiO2-NTs using two TiO2/ANI molar ratios of 50 and 150 and subsequently carbonized at 650 °C, yielding CTTP-50 and CTTP-150. The novel CTTP composites and carbonized pristine TiO2-NTs (CTNT) were characterized by various techniques, including TEM, UV-Vis diffuse reflectance, Raman spectroscopy, XRD, and TGA. Their performance regarding dye adsorption and photocatalytic degradation under visible light was evaluated with Acid Orange 7, Methylene Blue, and Rhodamine B. CTTP-150 exhibited the highest adsorption capacity and photodegradation rate, attributed to the synergistic effect of PANI, which stabilizes the TiO2 phase and enhances visible-light absorption and adsorption.

8 December 2025 in Molecules
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Journal Article
Open access
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BGBrankica Gajić
Brankica Gajić
Marija B. RadoičićMarija B. Radoičić
Marija B. Radoičić
Muhammad YasirMuhammad Yasir
Muhammad Yasir
WSWarda Saeed
Warda Saeed
SBSilvester Bolka
Silvester Bolka
Svetlana JovanovićSvetlana Jovanović
Svetlana Jovanović
The present study explores the comparative influence of reduced graphene oxide (rGO), silver nanowires (AgNWs), and their hybrid rGO–AgNWs on the electromagnetic interference (EMI) shielding performance of polyaniline (PANI)-based flexible films prepared using a polycaprolactone (PCL) matrix. The nanocomposites were synthesized through in situ oxidative polymerization of aniline in the presence of individual or hybrid fillers, followed by their dispersion in the PCL matrix and casting of the corresponding films. Morphological and structural characterization (SEM, Raman, and FTIR spectroscopy) confirmed a uniform PANI coating on both rGO sheets and AgNWs, forming hierarchical 3D conductive networks. Thermal (TGA) and thermomechanical (TMA) analyses revealed enhanced thermal stability and stiffness across all composite systems, driven by strong interfacial interactions and restricted polymer chain mobility. Tmax increased from 437.9 °C for neat PCL to 487.9 °C for PANI/PCL, 480.6 °C for PANI/rGO/PCL, 499.4 °C for PANI/AgNWs/PCL and 495.0 °C for the hybrid PANI/rGO–AgNWs/PCL film. The gradual decrease in contact angle following the order PANI/AgNWs/PCL < PANI/rGO–AgNWs/PCL < PANI/rGO/PCL < PANI/PCL < PCL clearly indicates a systematic increase in surface polarity and surface energy with the incorporation of conductive nanofillers. Electrical conductivity reached 60.8 S cm−1 for PANI/rGO/PCL, gradually decreasing to 27.4 S cm−1 for PANI/AgNWs/PCL and 22.1 S cm−1 for the quaternary hybrid film. The EMI shielding effectiveness (SET) measurements in the X-band (8–12 GHz) demonstrated that the PANI/rGO/PCL film exhibited the highest attenuation (~7.2 dB). In contrast, the incorporation of AgNWs partially disrupted the conductive network, reducing SE to ~5–6 dB. The findings highlight the distinct and synergistic roles of 1D and 2D fillers in modulating the electrical, thermal, and mechanical properties of biodegradable polymer films, offering a sustainable route toward lightweight, flexible EMI shielding materials.

29 October 2025 in Molecules
Verified
Journal Article
Open access
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BGBrankica Gajić
Brankica Gajić
Marija B. RadoičićMarija B. Radoičić
Marija B. Radoičić
Muhammad YasirMuhammad Yasir
Muhammad Yasir
WSWarda Saeed
Warda Saeed
SBSilvester Bolka
Silvester Bolka
Svetlana JovanovićSvetlana Jovanović
Svetlana Jovanović
The remarkable growth of high-frequency electronic systems has raised concerns about electromagnetic interference (EMI), emphasizing the need for lightweight and efficient shielding materials. In this study, ternary composites based on polypyrrole (PPy), graphene oxide (GO), and silver nanowires (AgNWs) were synthesized through chemical oxidative polymerization of pyrrole monomer and embedded into polycaprolactone (PCL) matrices to create flexible films. Structural and morphological analyses confirmed the successful incorporation of all components, with scanning electron microscopy showing granular PPy, sheet-like GO, and fibrous AgNWs, while spectroscopic studies indicated strong interfacial interactions without damaging the PPy backbone. Thermomechanical analysis revealed that GO increased stiffness and defined the glass transition, whereas AgNWs improved toughness and energy dissipation; their combined use resulted in balanced properties. EMI shielding effectiveness (SE) was tested in the X-band (8–12 GHz). Pure PPy exhibited poor shielding ability, while the addition of GO and AgNWs significantly enhanced performance. The highest EMI SE values were observed in PPy/GO–AgNWs composites, with an average SE of 16.05 dB at 20 wt% of the composite in the PCL matrix, equivalent to about 84.4% attenuation of incident waves. These results demonstrate that the synergistic integration of GO and AgNWs into PPy matrices enables the creation of lightweight, flexible films with advanced EMI shielding properties, showing great potential for next-generation electronic and aerospace applications.

8 July 2026 in Applied Surface Science
Verified
Journal Article
Closed access
BGBrankica Gajić
Brankica Gajić
NRNenad Radić
Nenad Radić
MIMila Ilić
Mila Ilić
JKJanez Kovač
Janez Kovač
GMGordana Ćirić Marjanović
Gordana Ćirić Marjanović
ZŠZoran V. Šaponjić
Zoran V. Šaponjić