Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ2Multifunctional PLA/PHA-Based films incorporating Moluccella spinosa extract for sustainable and antimicrobial food packaging applications
Selcuk Pekdemir, Sibel; Gurler, Nedim; Yilmaz Sancar, Pelin; Karagulle, Burcu; Kok, Mediha; Pekdemir, Mustafa Ersin; Qader, Ibrahim Nazem
In this study, a novel plant-based shape memory biocomposite was developed for sustainable food packaging applications. A poly(lactic acid)/poly(hydroxyalkanoate) (PLA/PHA) blend was reinforced with the ethanolic extract of Moluccella spinosa, a plant recognized for its bioactive constituents. Structural and thermal analyses confirmed the successful incorporation of the extract without compromising the polymer matrix integrity. The results demonstrated improved barrier performance, characterized by lower water vapor permeability, reduced moisture content, and slightly increased opacity with increasing concentrations of M. spinosa extract. In addition, the composite films exhibited enhanced shape memory behavior, which became more pronounced at higher extract concentrations. Antimicrobial assays revealed a limited and selective inhibitory effect, primarily against Gram-positive bacteria (Enterococcus faecalis and Clostridium perfringens), while no notable activity was observed against Escherichia coli and Staphylococcus aureus. These findings indicate a preliminary antimicrobial potential, likely associated with a sustained-release mechanism rather than strong bactericidal activity. Overall, the integration of M. spinosa extract into the PLA/PHA matrix offers a promising route to design multifunctional, biodegradable packaging materials with shape memory capability, where antimicrobial functionality serves as a complementary feature, contributing to the advancement of environmentally friendly and active food packaging technologies.
- MakaleAçık Erişim2026Scopus SJRQ2Radiation shielding performance of CeO2-reinforced ternary nanocomposites based on biodegradable polymers and waste-derived polystyrene
Pekdemir, Mustafa Ersin; Yilmaz, Demet; Selçuk Pekdemir, Sibel; Gülhan, Aleyna; Yalçin Kuzu, Serpil; Altun, Sedanur; Taşgin, Yahya
The development of sustainable polymer-based materials for radiation shielding has attracted increasing interest, particularly for lightweight and flexible applications. In this study, ternary nanocomposites based on poly (hydroxyalkanoate) (PHA), poly (ε-caprolactone) (PCL), and polystyrene (PS) were prepared and reinforced with cerium oxide (CeO2) nanoparticles (5–15 wt%) to enhance radiation shielding performance. Structural characterization confirmed the preservation of polymer chemical structures and the successful incorporation of crystalline CeO2, while SEM observations revealed a relatively homogeneous nanoparticle dispersion within the ternary matrix, particularly at intermediate filler loadings. Thermal analysis demonstrated enhanced thermal stability with increasing CeO2 content, as evidenced by an increase in residual mass from 0.42% for the neat blend to 11.21% for the nanocomposite containing 15 wt% CeO2, along with a shift of degradation onset temperatures toward higher values. Photon shielding performance was experimentally evaluated in the energy range of 13.37–59.54 keV. The incorporation of 15 wt% CeO2 increased the mass attenuation coefficient (MAC) from 1.277 to 12.366 cm2 g−1 at 13.37 keV, corresponding to an approximately ninefold enhancement, while significantly reducing the half-value layer (HVL) and mean free path (MFP). Neutron shielding analysis showed a slight decrease in thermal neutron attenuation due to hydrogen dilution within the polymer matrix, whereas fast neutron attenuation and neutron removal cross sections exhibited only minor variations; the fast neutron removal cross section increased modestly from 0.1014 to 0.1047 cm−1 with 15 wt% CeO2 addition. Overall, the results highlight clear structure–property–performance relationships in CeO2-reinforced PHA/PCL/PS nanocomposites, demonstrating their potential as lightweight radiation shielding materials for low energy protection with improved thermal stability and shielding efficiency.
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İncele - MakaleAçık Erişim2025Scopus SJRQ2PCL/chitosan composite films enhanced with Bi2O3 in nuclear shielding applications: Irradiation resistance, thermal and structural properties
Yılmaz, Demet; Pekdemir, Mustafa Ersin; Dik, Gamze; Selçuk Pekdemir, Sibel; Ulu, Ahmet; Taşgın, Yahya; Ateş, Burhan
In this work, irradiation resistance, thermal, and structural characteristics of Bi2O3-reinforced poly ε-caprolactone/chitosan composites for nuclear shielding applications were studied. PCL/CTS/Bi2O3 composite films were prepared by using different amounts of Bi2O3 (0.5%–4.0% (w/v)). The radiation shielding parameters of the synthesized composite films were both experimentally and theoretically measured at the high energy region. The equivalent dose rates of the prepared film samples were measured using a fast neutron source. Also, to determine the irradiation resistance, the samples were irradiated with Am-241 and Co-60 sources for 30 days. The MFP values at 80.99 keV changed by approximately 61% in samples PCL/CTS and PCL/CTS/4% Bi2O3. The results show that Bi2O3 content increases the gamma shielding abilities in PCL/CTS films. According to TGA results, the thermal stability of the polymer composite films is increased by the addition of Bi2O3 to the PCL/CTS blend film. The results show that PCL/CTS composite materials can be used as protective coating materials for nuclear shielding. Highlights: PCL/CTS/Bi2O3 composite films were prepared by the solvent casting method. The thermal stability of the composite films increased by increasing the Bi2O3 amount. Bi2O3 increased the LAC and MAC values of the composite films. PCL/CTS/Bi2O3 composite films have a neutron shielding effect.
AtıfScopus5WoS5İncele - MakaleAçık Erişim2025Scopus SJRQ2Tungsten carbide-based shape memory biopolymer nanocomposites as a promising new gamma radiation shielding material
Pekdemir, Mustafa Ersin; Yılmaz, Demet; Selçuk Pekdemir, Sibel; Taşgın, Yahya; Ekmen, Busenur
In this study, structural, thermal and radiation shielding properties of Polylactic acid (PLA)/polyhydroxyalkanoates (PHAs)/Tungsten Carbide (WC) nanocomposite films were investigated. PHA/PLA/WC composite films were prepared by using different amounts of WC (5%, 10%, 18%, 28%). Characterization of the composite films was carried out by Attenuated Total Reflection Infrared Spectroscopy (ATR-IR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The linear and mass attenuation coefficients (LAC and MAC), mean free path (MFP), Half-Value Layer (HVL), Tenth Value Layer (TVL), effective atomic numbers (Zeff), and effective electron densities (Nel) of the synthesized composite films were experimentally measured from 53.16 to 383.85 keV. Also, the neutron equivalent dose rates for the prepared film samples were determined. Exposure buildup factor (EBF) and fast neutron removal cross section (ΣR) were theoretically calculated. The particle shielding characteristics of the composite films were evaluated. The MFP values at 356.01 keV are 8.211 cm, 7.772 cm, 7.360 cm, 6.710 cm and 5.942 cm for PLA/PHA, PLA/PHA/5%WC, PLA/PHA/10%WC, PLA/PHA/18%WC and PLA/PHA/28%WC, respectively. It was observed that an increase in WC content enhances the gamma shielding abilities in PHA/PLA films. The results revealed that PHA/PLA/WC composite materials can be used as protective coating materials.
AtıfScopus5WoS5OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ2Physical and shielding properties of Er2O3 rare earth oxide compound content on PCL/PEG blend
Taşgin, Yahya; Pekdemir, Mustafa Ersin; Yilmaz, Mücahit; Kanca, Muhammed Sait; Kök, Mediha
Rare earth elements (RRE), due to their unique magnetic, electrical, and optical properties, are an important group of elements demanded in many application areas from machine technology to the health industry. In this study, new composites were obtained by mixing Erbium oxide (Er2O3), one of the rare earth element oxides, into PCL–PEG blend, which is also an important material group, in different ratios. The characteristic functional groups of the obtained polymer blend/Er2O3 nanocomposites were determined by the ATR-IR, and as the erbium oxide ratio increased, characteristic peaks of the polymers in the blend as well as characteristic signals of the Er–O–Er bond were found. When the thermal behavior of the obtained composites was examined, it was observed that the polymer blend exhibited miscible blend properties and the melting temperature of the polymer blend increased as the Er2O3 ratio increased. In addition, it was determined that the thermal stability of the composite increased significantly. X-ray measurements of composites at room temperature support other measurement results. It was determined that the presence of Er-RRE oxide increased the crystal structure feature in the polymer blend composite. Gamma radiation shielding capabilities of polymer materials containing different erbium ratios were investigated by calculating shielding parameters such as half value layer (HVL), radiation protection efficiency (RPE), and mean free path (MFP). Cs-137 and Co-60 radioactive sources were used as gamma sources. According to the obtained measurement results, Erbium oxide increased the absorption property of the polymer composite material. Graphical abstract: [Figure not available: see fulltext.].
AtıfScopus26WoS28OpenAlex29İncele - MakaleAçık Erişim2023Scopus SJRQ2B2O3 reinforced polylactic acid/thermoplastic polyethylene glycol shape memory composites
Pekdemir, Mustafa Ersin; Kök, Mediha; Kanca, Muhammed Sait; Özen Öner, Ecem; Pekdemir, Sibel; Inci, Şule; Kirbağ, Sevda; Tatar, Beyhan
Recently, there has been a great demand for boron-containing compounds (BCCs) with unique biological properties. The demand for the use of these compounds not alone but as additives in composite materials is increasing day by day. In this study, the effect of adding B2O3 compound to the blend of PLA and PEG polymers, which is an important biocompatible shape memory polymer, was investigated. In order to examine the effect of increasing B2O3 additive on the thermal properties of PLA-PEG blend, it was determined by using a Differential Scanning Calorimetry (DSC) and thermogravimetric analyzer (TGA), and it was seen that while the melting temperature of PEG decreased, the melting temperature of PLA increased. In addition, when the thermal stability of the composites was examined, increasing of thermal stability was observed with the addition of B2O3 and a three-step degradation occurred. It was determined that the B2O3/PLA-PEG composite was homogeneous by taking X-ray measurements and SEM measurements. The antimicrobial property of the PLA-PEG blend improved with the increasing B2O3 contribution were observed from the antimicrobial activity measurements of the composite against 4 different bacteria. However, it was determined that the PLA-PEG blend preserved its shape memory effect with increasing diboron trioxide contribution.
AtıfScopus13OpenAlex16İncele - MakaleAçık Erişim2023Scopus SJRQ2Binary PCL–waste photopolymer blends for biodegradable food packaging applications
Gürler, Nedim; Pekdemir, Mustafa Ersin; Torğut, Gülben; Kök, Mediha
The aim of this study is to prepare waste photopolymer (WPP) / poly ɛ-caprolactone (PCL) blends that can be used in food packaging with different ratios (5%, 10%, 20% and 30%) WPP. The structural properties of the blend films were characterized by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Opacity, surface color, water vapor permeability and shape memory properties of these films were examined. Pure PCL film exhibited more thermal stability compared to PCL/WPP blend films. Therewithal, the glass transition temperature of the pure PCL film showed a shift. Water vapor permeability improved with the addition of WPP. L*, a* and transmittance values reduced with increasing WPP, but b* value increased. It was thought that these polymer blends would enable to be used as packaging material in terms of compatibility and waste evaluation.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2023Scopus SJRQ2Shape Memory Polymer-Based Nanocomposites Magnetically Enhanced with Fe3O4 Nanoparticles
Pekdemir, Mustafa Ersin; Aydin, Derya; Selçuk Pekdemir, Sibel; Erecevit Sönmez, Pınar; Aksoy, Edanur
This work aimed to investigate the effect of magnetic Fe3O4 nanoparticles (MNP), which are known to have a wide range of applications in recent years, on nanocomposite films prepared with shape memory polymers. Herein, PLA–PEG blend nanocomposite films were prepared by solution casting method using MNP at different ratios. PLA–PEG Blend/MNP nanocomposite films were characterized with Attenuated total reflection infrared spectroscopy (ATR-IR) to determine the –C=O stretching of PLA and Fe–O stretching signals of Fe3O4. The thermal stability, morphology, and magnetic behavior were studied by comparing the results among PLA–PEG blend, PLA–PEG blend/MNP nanocomposite with thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and a vibrating sample magnetometer (VSM), respectively. The effect of MNP on the shape memory properties of PLA/PEG blend was investigated. Moreover, the comparison of antimicrobial activity between PLA/PEG blend and PLA–PEG blend/MNP nanocomposite films were conducted by the disk diffusion method. The results showed that MNP increased the thermal stability of the PLA/PEG blend and the nanocomposites inhibited the growth of C.albicans microorganism. Graphical Abstract: [Figure not available: see fulltext.].
AtıfScopus41WoS39OpenAlex42İncele - MakaleAçık Erişim2022Scopus SJRQ1Novel of (PLA/PCL blend)/Gd2O3 rare earth oxide nanocomposites: Shape memory effect, thermal, magnetic, and mechanical properties
Özen Öner, Ecem; Pekdemir, Mustafa Ersin; Ercan, Ercan; Say, Yakup; Kök, Mediha; Aydoğdu, Yıldırım
Poly ɛ-caprolactone (PCL) and poly lactic acid (PLA) stand out as biocompatible polymers. In this study, PCL and PLA were blended in 40:60 ratio, respectively, and then the Gd2O3 compound, which is an important earth element oxide, was mixed in PLA–PCL shape memory polymer (SMP) blend at different rates and polymer blend nanocomposites were obtained. First of all, the effects of Gd2O3 oxide on the thermal properties of the SMP blend were determined with a differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA), and it was determined that Gd2O3 did not have a significant effect on the melting temperature of the blend, while it significantly increased its thermal stability. As a result of the XRD (X-ray diffraction) analysis of the composites at room temperature, it was determined that the semicrystalline blend, with the addition of Gd2O3, increased its crystalline property. When the shape memory effect was examined, it was understood that the additive did not eliminate the shape memory effect. When the magnetic property of the gadolinium oxide-doped composite, which is magnetocaloric oxide, was examined, the magnetic property of the composite changed from diamagnetic to paramagnetic with increasing additives. Finally, the mechanical properties of the shape memory blend composite were investigated and no regular changes were observed in the mechanical properties with increasing Gd2O3.
AtıfScopus38OpenAlex42İncele - MakaleAçık Erişim2022Scopus SJRQ2Biocompatible PLA/PCL blends nanocomposites doped with nanographite: Physico-chemical, and thermal behaviour
Qader, Ibrahim Nazem; Pekdemir, Mustafa Ersin; Coşkun, Meltem; Kanca, Muhammed Sait; Kök, Mediha; Dağdelen, Fethi
There is a great interest in nano-graphite due to its wide application in nanotechnology and important physical properties. Nanocomposites based on polymers and blends are important in the development of traditional polymers and in improving their usage areas. The aim of this study is to improve physico-chemical, and thermal behavior of poly(lactic acid) / poly(ε-caprolactone) (PLA/ PCL) blend by doping nano-graphite (NG) with different amounts and make the characterization of these nano-composites. It was observed that NG affected the temperature at which nanocomposites decompose. Also, the nanoparticles incorporated in the polymer blend become locked between the polymer filaments, speeding up the composites' decomposition. NG has significantly higher melting and evaporation temperature than PLA and PCL, so more residues were left as the quantity of NG rose. There was no significant change in the Tg and Tm peaks in the DSC experiment due to the inclusion of NG. While the NG particles raised the enthalpy of phase transition in general. The sharpness of the XRD peaks and the crystallinity of the nanocomposites both enhanced as the amount of NG in the blend was increased. Shape memory has been demonstrated to be a remarkable characteristic of thermos-sensitive PLA / PCL blend. Although the trained nanocomposite recovered most of its predetermined shape, increasing NG concentration in the composite may diminish its recovery behavior because.
AtıfScopus22WoS22OpenAlex25İncele - MakaleAçık Erişim2022Scopus SJRQ4Molecular Structure, Vibrational, Spectral Investigation and Quantum Chemical DFT Calculations of Poly(N-isopropyl acrylamide-co-nbutyl methacrylate)
Pihtili, Güzin; Hekim, Seda; Pekdemir, Mustafa Ersin
A new copolymer poly(N-isopropylacrylamide-co-nbutylmethacrylate) was synthesized by free radical solution polymerization process using 2,2′-Azobis(2-methylpropionitrile) as an initiator in 1,4-dioxane at 70 °C. The structure of the copolymer was characterized by Fourier Transform Infrared Spectrometer (FTIR), the proton nuclear magnetic resonance (1H NMR), and the ultraviolet-visible spectroscopy (UV-vis) method. Theoretically, density functional theory (DFT) (B3LYP) was utilized to identify the molecular geometry and then examine the vibrational frequencies and electrical characteristics of this molecule, with the 6-31G basis set in the ground state. In dichloromethane solution, UV-vis spectra of the molecule were calculated using the Time-Dependent DFT method. 1H NMR chemical shifts have been calculated with GIAO approximation, and the calculated results show good agreement with experimental chemical shifts.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2022Scopus SJRQ1Preparation of ε-Caprolactone/Fe3O4 Magnetic Nanocomposite and Its Application to the Remazol Brilliant Violet 5R Dye Adsorption from Wastewaters by Using RSM
Pekdemir, Mustafa Ersin; Tanyol, Mehtap; Torğut, Gülben
In this study, poly (ε-caprolactone)/Fe3O4 magnetic nanocomposite (PCL/Fe3O4 MNC) was synthesized by ring-opening polymerization. Then, PCL/Fe3O4 MNC was used as a novel adsorbent to remove remazol brilliant violet 5R (RBV 5R) from the aqueous media. The effects of PCL/Fe3O4 MNC dosage, process time, and initial RBV 5R concentration on the removal of RBV 5R were studied using the central composite design (CCD) method. The adsorption process was optimized using the response surface methodology, and the optimum conditions were defined. Optimum RBV 5R removal of 95.40% was obtained at a contact time of 167.98 min, PCL/Fe3O4 MNC dosage of 0.40 g, and RBV 5R concentration of 7.18 mg L−1. The process was also designed using the adsorption kinetic models and isotherm. The experimental data of RBV 5R adsorption on PCL/Fe3O4 MNC followed the Langmuir isotherm and pseudo-second-order kinetic models than the other models. Morphological and chemical properties of the adsorbent-adsorbate system indicated the high adsorption yield of RBV 5R on PCL/Fe3O4 MNC was achieved. The structural characteristics of the PCL/Fe3O4 MNC were analyzed by Fourier-transform infrared, attenuated total-reflectance (ATR), and X-ray diffraction. ATR tests showed that no significant change in chemical bond is found in PCL/Fe3O4 MNC before and after the adsorption process. The morphology of composites was investigated by scanning electron microscopy. A vibrating sample magnetometer (VSM) was used for the measurement of the magnetic property. Thermal analysis of MNC was studied using thermogravimetric analysis and differential scanning calorimetry instruments.
AtıfScopus6WoS5OpenAlex6İncele