Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ2Development and Characterization of Starch/Microcrystalline Cellulose/Bentonite Intelligent Packaging Films Incorporated With Red Beet Peel Extract for Monitoring Chicken Freshness
Gürler, Nedim
This study presents the physical, mechanical, antioxidant, and application properties of films prepared by adding red beet peel extract to the starch/microcrystalline cellulose/bentonite clay polymer composites by casting method to monitor chicken breast freshness. The effects of bentonite in different proportions (0%, 1%, 5%, and 10%) were investigated. The structure of the films was elucidated by XRD, FTIR spectroscopy, and SEM for surface morphology of films. Regarding mechanical testing, the highest tensile strength starch/microcrystalline cellulose-1% bentonite film was 0.88 MPa. It was noticed that water vapor permeability (WVP) improved with the addition of bentonite. Films containing 10% bentonite clay showed a 27% decrease in water vapor permeability compared to films without clay. However, the swelling power of composites increased as the bentonite content increased. Additionally, with the addition of clay the films exhibited more opaque properties. Red beet peel extract was also incorporated to the polymer composite to monitor chicken breast freshness. The antioxidant properties of the films were accomplished using DPPH method. When red beet peel extract was incorporated into the polymer film, the highest DPPH scavenging activity increased by 50%. In summary, starch/microcrystalline cellulose/bentonite films can be used as pH-sensitive intelligent packaging for controlling the freshness of chicken breast.
- MakaleYalnız künye2025Scopus SJRQ2Evaluation of Nano-Zinc Borate Effects on Thermal Properties, Morphology, Antibacterial Activity, and Drug Release Behavior of Starch/Gelatin Hydrogel Films for Biomedical Applications
Koçak, Berna; Gürler, Nedim; İpek, Yeliz; Yazdıç, Ferit Can; Karaman, Altuğ
Starch and gelatin offer opportunities for use due to their non-toxicity, biocompatibility, physical and functional properties. In this study, different amounts of nano-zinc borate were added to starch/gelatin composition for biological applications and their properties were studied. The structure of the films was investigated by various techniques. Nanostructured zinc borate was synthesized using a chemical method and particle sizes were determined as 196 nm. The atenolol drug was doped into the polymer composite. The atenolol release was performed at pH 7.4 and in phosphate-buffered saline solution medium. Cumulative drug release was 76% with the inclusion of nano-zinc borate in the polymer mixture. The atenolol release was approximately 50%–70% in films with nano-zinc borate added after 300 min. Furthermore, thermal resistance of the films improved with the addition of nano-zinc borate. The investigated chemical compound exhibited pronounced antibacterial activity against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), with significantly greater potency compared to Gram-negative bacteria (E. coli and Pseudomonas aeruginosa). Notably, the formulation containing 1.5% starch, 0.5% gelatin, and 1% nano-zinc borate demonstrated broad-spectrum efficacy against all tested pathogens, highlighting its potential as a promising antibacterial agent. The observed differential activity against bacterial strains suggests that fine-tuning the concentrations of starch, gelatin, and nano-zinc borate may optimize antibacterial efficacy and broaden the spectrum. The results showed us that non-toxic and biocompatible polymer films can be realized in pharmaceutical industry systems and biomedical applications.
- MakaleYalnız künye2024Scopus SJRQ2Evaluation of effect of boric acid on thermoplastic starch: Morphological, mechanical, barrier, and optical properties
Yoğurtçu, Hakan; Gürler, Nedim
In this study, starch was modified with different amounts of boric acid, and the degree of substitution of the synthesized compounds at different temperatures and times was determined by Fourier transform infrared (FTIR) and titration methods. The degrees of substitution in both methods showed similar tendency. Optimum conditions were determined, and thermoplastic starch (TPS) and boric acid (B) films were prepared by casting method using glycerol as plasticizer. The morphological properties of the films were studied by scanning electron microscope-energy dispersive spectrometry (SEM-EDS). According to the FTIR results, it was observed that the B-O and B-O-C stretching vibrations increased when the amount of boric acid increased. The tensile strength, water barrier (swelling capacity, solubility, and water vapor permeability), and optical properties of samples were investigated. The swelling capacity, solubility, and water vapor permeability of the films decreased with the addition of 0.5% boric acid to the starch, but the highest tensile strength was achieved. The tensile strength for TPSB0.5% increased compared to control group TPS. In addition, the film showed the highest transparency. Thermoplastic film containing 0.5% boric acid can be used as a packaging material due to its improved mechanical and water barrier. Highlights: The thermoplastic starch and boric acid composite were successfully produced. The presence of boric acid was confirmed by energy dispersive spectrometry (EDS). The degree of substitution was determined by two different methods. Transparency increased with the addition of boric acid. Tensile strength improved with boric acid content.
AtıfScopus26WoS25OpenAlex27
İncele - MakaleYalnız künye2024Scopus SJRQ1Physical and biological characteristics of eco-friendly films added with Cinnamomum zeylanicum extract for packaging materials
Gürler, Nedim; Ertekin, Özlem
The effects of Cinnamomum zeylanicum extract (CZE) at different rations (0%, 1%, 3% and 5%) on gelatin (GL)–polyvinyl alcohol (PVA) blend films were evaluated in relation to the structural, tensile strength, physical, antimicrobial and antioxidant properties of the films in this study. The results showed that water barriers of the film samples decreased, but the UV-blocking property increased and became opaque at the highest GLPVA5 film. The tensile strengths of GLPVA, GLPVA1, GLPVA3 and GLPVA5 films were 1.21, 1.78, 1.62 and 1.95 MPa, respectively. The antimicrobial effect of these films was determined against Escherichia coli, Enterococcus faecalis, Salmonella typhimurium and Bacillus cereus according to the parallel stick method. Antioxidant properties of cinnamon extract were investigated using 2,2-diphenyl-1-picryl-hydrazil (DPPH) methods. The % inhibition of DPPH was found to be 82.00. No antibacterial effect was detected for B.cereus and E. faecalis at 0%, 1%, 3% and 5%. While no activity was observed in 0%, 1% and 3% cinnamon, 7.5 and 3.0 mm zones were detected in S. typhimirium and E. coli, respectively, in 5% cinnamon. The results suggest that the film samples could be used in a potential packaging with antioxidant and antibacterial properties.
AtıfScopus9WoS9OpenAlex7İncele - MakaleAçık Erişim2024Scopus SJRQ2Enhanced impedance, electrical conductivity, dielectric properties for colloidal starch-g-poly (methyl methacrylate) supported with semiconductor cadmium sulfide
Torğut, Gülben; Gürler, Nedim
In this study, starch-graft-poly (methyl methacrylate) (starch-g-PMMA) composites doped with different amounts (5, 10, and 15 wt%) of cadmium sulfide (CdS) particles were fabricated for electrical measurements using in-situ polymerization technique. The structural characterization of the samples was studied. The dielectric and conductivity properties of the composites were investigated using impedance analyzer depending on the frequency (100 Hz–20 kHz) at room temperature. Spectroscopy revealed that the dielectric constant (ε′), dielectric loss (ε′′), and real (Z) components of impedance are found to decrease with increasing frequency for both starch-g-PMMA and starch-g-PMMA (5, 10, and 15 wt%) composites. On the contrary, the AC conductivity (σac) of samples increased with increasing frequency. In addition, ε′ and ε′′ values of starch-g-PMMA were lower than composites that added CdS. When the CdS content increased from 0 to 15%, ε′ increased from 5.62 to 15.10 at 100 Hz. AC conductivity was improved after adding the CdS particles. The maximum conductivity value for starch-g-PMMA15%CdS is found to be 3.07 × 10–7 at 100 Hz. When the dielectric properties of composites are evaluated, it is concluded that it is an exciting material for electronic applications in technology.
AtıfScopus9WoS8OpenAlex10İncele - MakaleAçık Erişim20233-APTMS takviyeli kitosan-polivinil alkol harman filmlerinin fiziksel ve antibakteriyel aktiviteleri
Yazdıç, Ferit Can; Gürler, Nedim
Bu çalışmada kitosan (KT) ve polivinil alkol (PA) karışımına %0, %0.5, %1 ve %2 oranlarında 3-(aminopropil) trimetoksi silan (3-APTMS) ilave edilerek dökme metoduyla filmler hazırlanmıştır. Hazırlanan filmlerin FTIR, SEM, su buharı geçirgenliği, çözünürlük, opaklık ve renk özellikleri incelenmiştir. KT/PA, KT/PA-0.5, KT/PA-1 ve KT/PA-2 filmlerinin su buharı geçirgenliği sırasıyla 3.82×10⁻⁶ g m⁻¹ s⁻¹ Pa⁻¹, 3.14×10⁻⁶ g m⁻¹ s⁻¹ Pa⁻¹, 2.08×10⁻⁶ g m⁻¹ s⁻¹ Pa⁻¹ ve 1.59×10⁻⁶ g m⁻¹ s⁻¹ Pa-1 olarak gerçekleşti. Filmleri su içinde çözünürlüğü azaldı. Artan 3-APTMS içeriği ile filmler daha opak oldu ve UV ışık bariyer özellik gösterdi. Renk özellikleri ise a* değeri artarken b* değeri ise azalarak filmler sarımsı-yeşil oldu. Ayrıca filmlerin Gram negatif (E. coli ) ve gram pozitif (S. aureus subsp. aureus) bakterilere karşı antimikrobiyal aktiviteleri değerlendirildi. Elde edilen KT/PA tek başına S. aureus subsp. aureus (ATCC 25923) ve E. coli (ATCC 25922) ye karşı herhangi bir antimikrobiyal aktiviteyi göstermedi. Dikkat çeken nokta KT/PA'ya eklenen %2 3-APTMS antibakteriyel aktivitenin standart olarak kullanılan ampisilin ile aynı olmasıdır.
- MakaleYalnız künye2023Scopus SJRQ2Development of chitosan/gelatin/starch composite edible films incorporated with pineapple peel extract and aloe vera gel: Mechanical, physical, antibacterial, antioxidant, and sensorial analysis
Gürler, Nedim
In this study, chitosan (C)/gelatin(G)/starch(S) composites incorporated pineapple peel extract (PPE) and aloe vera gel (AVG) were prepared by the casting method as antioxidant agents. Mechanical, water vapor permeability (WVP), moisture content, solubility, opacity, and color properties of the effects of PPE and AVG at different concentrations (0%, 10%, and 30%) were investigated. The prepared films were characterized by Fourier transform infrared spectroscopy in attenuated total reflection (ATR-FTIR), X-ray diffraction (XRD), Thermal gravimetric analysis (TGA), Scanning electron microscope (SEM), mechanical, water barrier, opacity, and color. PPE and AVG extract incorporated edible films improved thermal stability of edible films. Tensile strength decreased with the addition of extracts; the maximum tensile strength was 8.15 MPa for CGS film. The WVP of the films increased with the increasing PPE and AVG concentration. As a biological activity, the films inhibited the growth of gram-positive (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). With the addition of PPE and AVG to the CGS film, its antioxidant properties were enhanced. In addition, the prepared films were applied for strawberry coating both in the refrigerator and at room temperature. Consequently, these edible-coated films can be used for active food packaging/coating to extend the shelf life of fruits.
AtıfScopus51WoS46OpenAlex49İncele - MakaleYalnız künye2023Scopus SJRQ2Physicochemical Properties for Food Packaging and Toxicity Behaviors Against Healthy Cells of Environmentally Friendly Biocompatible Starch/Citric Acid/Polyvinyl Alcohol Biocomposite Films
Gürler, Nedim; Paşa, Salih; Erdoğan, Ömer; Cevik, Ozge
The current study focuses on the fabrication, characterization, and cytotoxic effects of polymeric biocomposite films composed of starch, various concentrations of citric acid (3%, 6%, and 9%), and polyvinyl alcohol. The cross-linked corn starch (S)-polyvinyl alcohol (P) biocomposite films are prepared by casting technique using glucose (G) and fructose (F) as plasticizers. The chemical structure of obtained films is characterized by Fourier transform infrared and x-ray diffraction. Physicochemical parameters of the films such as solubility, swelling capacity, and water vapor permeability, optical and mechanical properties are investigated. Furthermore, the cytotoxicity is evaluated to determine the biocompatibility of samples. The physicochemical properties of S-P(Starch-Polyvinyl alcohol) films improve with the addition of citric acid during the esterification reaction. The tensile strength for Starch-Polyvinyl alcohol-Glucose blend composition with 3% citric acid (SPG3) and Starch-Polyvinyl alcohol-Fructose blend composition with 3% citric acid (SFG3) biocomposite films is determined as 10.17 and 8.24 MPa, respectively, compared to 8.16 and 7.94 MPa for without citric acid, respectively. The cell viability values of biocomposite films towards NIH-3T3 and L929 cells are calculated 90% compared to the control group. Thus, it demonstrates that they are also quite biocompatible materials.
AtıfScopus34WoS37OpenAlex37İncele - 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 - MakaleYalnız künye2022Scopus SJRQ2Physicomechanical, thermal and dielectric properties of eco-friendly starch-microcrystalline cellulose-clay nanocomposite films for food packaging and electrical applications
Gürler, Nedim; Torğut, Gülben
Potato starch (PS) films reinforced with microcrystalline cellulose (MCC) were prepared with casting solution, and the effect of montmorillonite (MMT) clay in different proportions (1, 3, 5 and 10 wt%) using nanofiller was established. The films were investigated by Fourier transform ınfrared (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), tensile strength, opacity, colour, water vapour permeability and solubility. Tensile strength for nanocomposite films depending on the clay content was increased significantly from 0.64 to 1.89 MPa. The water vapour permeability of nanocomposite films was improved compared to the PSMCC blend without MMT. Also, dielectric properties and electrical conductivity of films were studied. The dielectric permittivity (έ), the dielectric loss (ε˝) and the electrical conductivity (σ) increased with increasing MMT content at frequencies between 100 Hz to 10 kHz. This nanocomposite with improved functional properties could be used in potential food packaging materials and electrical applications.
AtıfScopus21WoS19İncele - MakaleYalnız künye2022Scopus SJRQ2Synthesis, characterization, pH-sensitive swelling and antimicrobial activities of chitosan–graft-poly(hydroxyethyl methacrylate) hydrogel composites for biomedical applications
Torğut, Gülben; Yazdıç, Ferit Can; Gürler, Nedim
In this paper, 2-hydroxyethyl methacrylate (HEMA) was graft copolymerized onto chitosan (CHI) at different ratios using a radical initiator. The grafted hydrogel composites were then characterized by attenuated total reflection Fourier transform ınfrared spectroscopy (ATR-FTIR) and thermo-gravimetric analysis (TGA). Swelling behavior of the hydrogels was investigated at different pH and different times. The antimicrobial activity of the chitosan-graft-HEMA (CHI-HEMA) against gram-negative bacteria and gram-positive bacteria was studied by the standard agar well diffusion assay method. The CHI-HEMA 1:1 and CHI-HEMA 1:2 showed an obvious antimicrobial effect against six test strains. The CHI-HEMA 1:1 and CHI-HEMA 1:2 exhibited a highly significant increase (p < 0.01) in diameter of the inhibition zones compared with the standard antibiotics. Furthermore, CHI-HEMA 1:1 presented the highest antimicrobial activity against all test strains with a significant difference (p < 0.01) compared with CHI-HEMA 1:2. Meanwhile, the decreasing order of the average sensitivity to CHI-HEMA 1:1 and CHI-HEMA 1:2 was observed to be S. marcescens > E. coli > S. aureus subsp. aureus > S. enteritidis > E. faecalis > E. aerogenes. These results indicate potential application of CHI-HEMA 1:1 and CHI-HEMA 1:2 graft hydrogels as a novel and efficient antimicrobial agent in biomedical fields.
AtıfScopus40WoS36İncele - MakaleYalnız künye2022Scopus SJRQ2Dielectric Biodegradable Biopolymer-Based Graphene Nanocomposites for Use in the Packaging Industry and Capacitor Application
Gürler, Nedim; Torğut, Gülben
In this study, polyhydroxyalkanoate (PHA) and polylactic acid (PLA)-Graphene (G) nanocomposite films were synthesized by taking different concentrations of G via the solution casting process, and their structural, mechanical, opacity, thermal and dielectric properties were examined for the first time. Scanning electron microscopy (SEM) was used for investigating surface morphology. Films containing graphene were more opaque than films without graphene. The incorporation of graphene into the polymer matrix improved the mechanical property. The tensile strengths of the control PHA/PLA film and the graphene-reinforced 1 %G-PHA/PLA nanocomposite films were 18.98 and 24.34 MPa, respectively. Thermogravimetric analysis results showed that PHA/PLA−G nanocomposites had good thermal stability below 300 °C. Considering the dielectric measurements, it is seen that the dielectric constant (έ) and dielectric loss (ϵ”) decreased with increasing frequency and less changed at higher frequencies. The developer feature of graphene is remarkable in both parameters. The electrical conductivity of PHA/PLA−G nanocomposites was also examined as a function of frequency at room temperature. As the amount of G increased from 1 %wt to 5 %wt, the conductivity of the composites increased.
AtıfScopus9WoS8OpenAlex11İncele - MakaleAçık Erişim2021Grafen Katkılı Nişasta Filmlerinin Dielektrik Özelliklerinin Geniş Frekans Aralığında İncelenmesi
Torgut, Gulben; Gürler, Nedim
Bu çalışmada, gliserol ile plastikleştirilmiş patates nişastası (PN) filmlerine, farklı oranlarda (% 0.5, 1, 2) grafen (G) eklenerek döküm yöntemi ile hazırlanmış filmlerin dielektrik sabiti, dielektrik kayıp ve kayıp tanjantı gibi bazı dielektrik özelliklerinin frekansla değişimleri incelendi. PN’nın saf hali ve G ile hazırlanmış kompozitlerinin (PNG0.5, PNG1 ve PNG2) dielektrik sabiti (έ), dielektrik kayıp faktörü (ε՛՛) ve kayıp tanjantı (tanδ) değerleri oda sıcaklığında frekansın bir fonksiyonu olarak (100 Hz ile 10 kHz arasında) empedans analizör cihazı ile belirlendi. Nişastanın 1 kHz sabit frekans ve oda sıcaklığındaki dielektrik sabiti, dielektrik kayıp ve kayıp tanjantı değerleri sırasıyla 9.20, 4.45 ve 0.48 olarak bulundu. Ayrıca, farklı oranlarda G miktarının (ağırlıkça %0.5, %1 ve %2) filmlerin dielektrik özellikleri üzerindeki etkisi araştırıldı. G konsantrasyonu arttıkça dielektrik sabiti, dielektrik kayıp ve kayıp tanjantı değerlerinde, saf nişastaya göre önemli artış olduğu gözlendi.
AtıfOpenAlex2TR Dizin1
İncele - MakaleYalnız künye2021Scopus SJRQ2Graphene-reinforced potato starch composite films: Improvement of mechanical, barrier and electrical properties
Gürler, Nedim; Torğut, Gülben
In this study, PSG composite films were prepared by casting method by adding graphene (G) to glycerol plasticized potato starch (PS) films. The structure and properties of the composite films were investigated attenuated total reflectance Fourier transform infrared (ATR-FTIR), X-ray analysis (XRD), and swelling capacity, total soluble matter, transparency, tensile strength, and electrical conductivity. When the G content of PSG composite films increased from 0% to 1%, tensile strength increased from 1.035 MPa to 1.681 MPa, but decreased to 1.175 MPa in composite films containing 2% G. It also increased electrical conductivity when the G concentration increased. Also, the G layers are among the PS films and their swelling and solubility properties are reduced. With increased G concentration, the light transmittance decreased and the films were more opaque. These improvements can refer to the interface interaction between PS and G.
AtıfScopus43WoS35OpenAlex39İncele - MakaleYalnız künye2021Scopus SJRQ1Silane doped biodegradable starch-PLA bilayer films for food packaging applications: Mechanical, thermal, barrier and biodegradability properties
Gürler, Nedim; Paşa, Salih; Temel, Hamdi
In this work, pure potato starch (PPS) purified from waste potato starch, was recovered and used. PPS was modified by 3-APTMS (3-(aminopropyl) trimethoxy silane) to manufacture a crosslinked film. To obtain a bilayer PPS-3APTMS-PLA film, the polylactic acid (PLA) was employed with PPS-3APTMS by casting method. The resulting materials, PPS-3APTMS and PPS-3APTMS-PLA were characterized by attenuated total reflectance fourier transform ınfrared (ATR-FTIR), x-ray Diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The silane-doped bilayer films have more thermal stability compared to PPS. The mechanical, solubility, swelling, water vapor permeability, optical properties and biodegradability under controlled compost conditions were examined. When the tensile strength of the PPS, PPS-3APTMS and PPS-3APTMS-PLA films were evaluated, the tensile strength (TS) were to 1.017±0.35 MPa, 1.437 ± 0.19 MPa and 10.918 ± 1.30 MPa, respectively. The PPS and PPS-3APTMS films were not elongation at break, while it was found about 21.94 ± 9.48 for the bilayer PPS-3APTMS-PLA film. The solubility, swelling, water vapor permeability, and transparency decreased for bilayer films. The water vapor permeability of PPS, PPS-3APTMS and PPS-3APTMS-PLA films were obtained as 31.69±0.4 × 10−7 g s−1 m−1 Pa−1, 28.96±0.4 × 10−7 g s−1 m−1 Pa−1, and 14.26±0.3 × 10−7 g s−1 m−1 Pa−1, respectively. Then, the biodegradability of films was performed under controlled compost conditions for 46 days according to ISO-14,855 standard. The biodegradation of PPS, PPS-3APTMS and PPS-3APTMS-PLA was also calculated as 9.30%, 5.45% and 5.08%. Biodegradation of PPS-3APTMS film decreases compared to PPS. Furthermore, the biodegradation value of bilayer film, PPS-3APTMS-PLA, was also decreased due to the slower degradation tendency of PLA. The contribution to the reusability of waste starch and the modifying of starch for food packaging and coating applications are the novelty aspects of the current study.
AtıfScopus93WoS77OpenAlex90İncele - MakaleYalnız künye2021Scopus SJRQ2Nanofiller reinforced biodegradable PHA/PLA composites: physico-chemical, thermal and dielectric properties
Torğut, Gülben; Gürler, Nedim
In this study, the electrical, thermal, morphological and physical properties of polyhydroxyalkanoate (PHA) and polylactic acid (PLA) blends and its nanocomposites prepared in different content of montmorillonite (3%wt, 5%wt, 7%wt) were investigated. Biodegradable blends of PHA/PLA were prepared in different compositions ranging from 30–70%. Nanocomposite films were analyzed by Fourier Transform Infrared (FTIR), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and scanning electron microscopy for morphology (SEM). The effects of the amount of MMT used as a reinforcing filler on the morphology, color, opacity, thermal stability, and dielectric properties of PHA/PLA films were investigated. SEM analyses showed good interaction between MMT and PHA/PLA film. As the MMT concentration increases, the transparency of the films decreases. In addition, MMT has improved thermal stability. Also, the dielectric properties and electrical conductivity of nanocomposite films were studied. The measurements were performed at frequencies between 100 Hz to 10 kHz at room temperature. As the frequency increased, dielectric permittivity (έ), the dielectric loss (ε'') and the electrical conductivity (σ) decreased and remain constant at high frequencies. έ, ε'' and the σ increased with increasing MMT content.
AtıfScopus27WoS22OpenAlex28İncele - MakaleAçık Erişim2020Sitrik Asit ile Modifiye Edilmiş Mısır Nişastası/Mikrokristalin Selüloz Filmlerin Fiziksel ve Mekanik Özellikleri
Gürler, Nedim
Bu çalışmada gliserol ile plastikleştirilmiş modifiye mısır nişastası/mikrokristalin selüloz (NS) kompozit filmlerinfiziksel ve mekanik özellikleri üzerine sitrik asitin etkisi incelendi. Filmler dökme metoduyla hazırlandı. FTIRspektroskopisinde nişasta ile sitrik asitin çapraz bağlanması sonucu güçlü bir hidrojen bağı oluştuğu görüldü. NSfilmlerine farklı oranlarda (%1, %5, %10 ve %20) sitrik asit ilave edildi. %1 oranında sitrik asitin eklenmesiyle NS1filminin mekanik gerilimi sitrik asit içermeyen NS filmine göre daha iyi bir gerilme kuvveti sergiledi. Ayrıca NS1filminde en düşük su buharı geçirgenliği (SBG) ve çözünürlük meydana geldi. NS filminin SBG 5.56×10-7 g Pa-1s-1 m-1iken, %1 sitrik asit ilavesi ile 5.41×10-7 g Pa-1s-1 m-1 olup, SBG azalmaktadır. Filmlerin optik özellikleri de incelendi.NS filmleri, sitrik asit içeren filmlere göre daha opaktır, ayrıca çapraz bağlayıcı konsantrasyonu arttıkça opaklıkazalmaktadır.
AtıfOpenAlex5TR Dizin4İncele - MakaleYalnız künye2020Scopus SJRQ1The fabrication of bilayer polylactic acid films from cross-linked starch as eco-friendly biodegradable materials: Synthesis, characterization, mechanical and physical properties
Gürler, Nedim; Paşa, Salih; Hakkı Alma, M.; Temel, Hamdi
In this study, pure potato starch (PPS) was purified from waste potato residual to fabricate cross-linked bilayer materials with the casting method. Malonic acid (MA) was employed to get cross-linked material from PPS as PPS-MA. Then polylactic acid (PLA) was also implemented onto PPS and PPS-MA to produce bilayer materials as PPS-PLA and PPS-MA-PLA. The obtained these bilayer films were characterized by FTIR, XRD, and TGA. The mechanical and physical applications such as water vapor permeability, water uptake, moisture content, solubility, and opacity were investigated. The biodegradation calculations were also done by the process of composting. It has demonstrated that each application onto PPS increased the mechanical features. However, elongation wasn't seen during the breaking test of PPS and PPS-MA films, whereas the PPS-PLA and PPS-MA-PLA films demonstrated 9.34% and 10.14% elongation at break that substantiates the structural durability against rupture, fragmentation, and feeble. Furthermore, the water vapor permeability, water uptake, moisture content, and solubility decreased but the opacity has increased.
AtıfScopus70WoS64OpenAlex79İncele - MakaleYalnız künye2017Scopus SJRQ3Developments in transfer hydrogenations of aromatic ketones catalyzed by boron compounds
Pasa, Salih; Gürler, Nedim; Temel, Hamdi; Rafikova, Khadichakhan; Aydemir, Murat
Boron complexes BL1 and BL2 were prepared from O-donor ligands, 2,2′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(methane-1-yl-1-ylidene)diphenol (L1) and 2,2′-(propane-1,3-diylbis(azan-1-yl-1-ylidene))bis(methane-1-yl-1-ylidene)diphenol (L2). The complexes were fully characterized by 1H and 13C NMR, LC-MS/MS, TGA/DTA, UV-Vis, elemental analysis, SEM, and FTIR. The transfer hydrogenation of acetophenone derivatives was investigated by the boron complexes in the presence of isoPrOH, as the hydrogen source, under basic condition with NaOH. The results showed that the boron complexes were promising catalytic precursors for transfer hydrogenation of aromatic ketones in 0.1 M isoPrOH solution (up to 99%). Both steric and electronic factors of this class of molecules had a significant impact on the catalytic properties.
AtıfScopus4İncele