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Öğe A neutral state colorless phosphazene/carbazole hybride dendron and its electrochromic device application(Elsevier Science Sa, 2015) Sezgin, Meryem; Özay, Özgür; Koyuncu, Sermet; Ozay, Hava; Koyuncu, Fatma BaycanIn this work, a new phosphazene/carbazole hybride dendron (PC) was synthesized and then directly coated onto ITO glass surface to provide a dendritic polymer network, poly-(PC), by using potentiodynamic electrochemical process. Structure of dendron was identified by FT-IR, H-1 and P-31 NMR, and also TOF-MS analyses. The optical and electrochemical properties of PC and its electrochemical crosslinked product were investigated by using UV-vis absorption, fluorescence and CV techniques. A neutral, colorless electrochromic device was constructed in the sandwich configuration [indium tin oxide (ITO)coated glass/anodically coloring material (poly-(PC))//gel electrolyte//cathodically coloring material (PEDOT)/ITO-coated glass] and revealed a short response time (about 0.5 s), high coloration efficiency (981 cm(2) C-1) and high redox stability. (C) 2015 Elsevier B.V. All rights reserved.Öğe A New Approach to Synthesis of Highly Dispersed Gold Nanoparticles via Glucose Oxidase-Immobilized Hydrogel and Usage in The Reduction of 4-Nitrophenol(Wiley-V C H Verlag Gmbh, 2020) Ozay, Hava; Tarimeri, Nur; Gungor, Zeynep; Demirbakan, Burcak; Ozcan, Burcu; Sezgintürk, Mustafa Kemal; Özay, ÖzgürIn this study, for the first time in the literature, synthesis of Au(0) nanoparticles supported by a crosslinked gel structure was performed via enzyme-mediated reduction of Au(III) ions without using any chemical reductant. In our newly-developed method, glucose oxidase enzymes immobilized in the crosslinked gelatine structure ensured simultaneous reduction of the Au(III) ions diffused within the gel to Au(0). The Au@Gel obtained was structurally characterised with TEM (Transmission electron microscopy), EDX (Energy dispersive X-ray analysis) elemental mapping, XPS (X-Ray photoelectron spectroscopy) and XRD (X-Ray Diffraction) analyses. The catalytic activity of Au(0) particles with nearly 8 nm size in the Au@Gel was investigated for the reduction of 4-nitrophenol (4-NP) as a model compound in the presence of NaBH(4)as reducing agent. The activation parameters for the reduction reaction of 4-nitrophenol in the presence of Au@Gel catalyst were determined as E-a= 30.16 kJmol(-), Delta H= 27.52 kJmol(-)and Delta S= -197.45 Jmol(-)K(-). The Au@Gel catalyst system, with good catalytic activity, simultaneously has nearly perfect reusability.Öğe A new candidate for wound dressing materials: s-IPN hydrogel-based highly elastic and pH-sensitive drug delivery system containing pectin and vinyl phosphonic acid(Pergamon-Elsevier Science Ltd, 2024) Seref, Elif; Ilgin, Pinar; Özay, Özgür; Ozay, HavaIn this study, we developed pH-sensitive semi-interpenetrating network (s-IPN) hydrogels, composed of pectin, 2hydroxyethyl methacrylate (HEMA), and vinyl phosphonic acid (VPA) using N,N'-methylene bis(acrylamide) (MBA) as a cross-linker with the free-radical polymerization method. The formation of s-IPNs was confirmed by FTIR studies. SEM images showed the addition of VPA to the polymeric matrix of s-IPN hydrogels formed additional microporous structures within the hydrogel network. The s-IPN hydrogel had perfect mechanical features like stretchability, compressibility and elasticity. Additionally, the swelling behavior of s-IPN hydrogels in deionized water and solutions with diverse pH was assessed. To research use as a controlled drug delivery material, the hydrogel was loaded with cimetidine and trimethoprim. At pH 7.2, the in vitro drug release profile was observed and nearly 60 % of the drugs were released from s-IPN hydrogel within 10 h. Additionally, the most appropriate kinetic release model was Higuchi, followed by Korsmeyer-Peppas. Finally, silver sulfadiazine (SSD) was added to s-IPN hydrogel for use as a smart wound dressing material. Antimicrobial analysis of the SSDloaded s-IPN hydrogel found it had antimicrobial features, inducing 15, 17 and 23 mm inhibition zones against Staphylococcus aureus (gram-positive), Escherichia coli (gram -negative) and Candida albicans (fungus) microorganisms, respectively. In light of the obtained results, based on being easily shapable with appropriate mechanical and physical features, pectin/p(HEMA-co-VPA) and pectin/p(HEMA-co-VPA)@SSD s-IPN hydrogels are potential candidates for use as controlled drug delivery and wound dressing materials in the biomedical field.Öğe A new dual stimuli responsive hydrogel: Modeling approaches for the prediction of drug loading and release profile(Pergamon-Elsevier Science Ltd, 2019) Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürIn this study, N-tert-butylmaleimic acid was designed for the first time and synthesized by reaction of maleic anhydride with tert-butylamine and evaluated as a new functional monomer for preparation of new pH-responsive hydrogels. Its structure was verified with FTIR, H-1 and C-13 NMR. A new pH- and temperature-responsive hydrogel p(TBMAC-co-NIPAM), based on TBMAC and NIPAM, was successfully prepared via free-radical copolymerization technique in an aqueous solution. The chemical and structural properties of the hydrogels were identified by FTIR and SEM. The swelling properties of these hydrogels were systematically investigated according to various parameters such as time, temperature, pH and salt effects, and the results show that they are strongly influenced by the content of TBMAC and exhibit strong pH, temperature and salinity sensitivity. In addition, swelling kinetics and water diffusion mechanisms in hydrogels were discussed. In addition, in vitro drug release studies were performed in simulated gastric, isotonic serum and intestinal fluid at two different temperatures (23 and 37 degrees C) by taking R6G as a model drug. Drug loading results were investigated with various isotherm models such as Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. Various kinetic models such as zero-order, first-order, Higuchi model and Korsmeyer-Peppas models were applied to determine the drug release mechanism. The results indicated that drug release involves non-Fickian transport mechanism. These results suggest that this new pH - and thermo-responsive hydrogel may be used to improve sustained release of drugs.Öğe A novel hydrogel containing thioether group as selective support material for preparation of gold nanoparticles: Synthesis and catalytic applications(Elsevier Science Bv, 2019) Ilgin, Pinar; Özay, Özgür; Ozay, HavaIn this study, firstly N-metacrylamido thiomorpholine containing thioether group was synthesized as monomer. Then, p(AAm-co-MTM) hydrogels were prepared from the redox polymerization of acrylamide and N-metacrylamido thiomorpholine as a selective support material. p(AAm-co-MTM) hydrogel-gold nanoparticles were obtained as a result of the reduction of the selectively absorbed gold(III) ions by the hydrogel network using NaBH 4 as reducing agent. All materials were characterized using techniques such as SEM, EDX, TEM and XRD analysis. It was determined that p(AAm-co-MTM)-Au composite material has high catalytic activity for the reduction of 4-nitrophenol. The activation parameters of the reduction reaction of 4-nitrophenol using NaBH4 in the presence of p(AAm-co-MTM)-Au catalyst were calculated as E-a = 38.80 kJ/mol, Delta H-# = 36.16 kJ/mol and Delta S-# = - 161.37 J/mol K.Öğe A simple azoquinoline based highly selective colorimetric sensor for CN- anion in aqueous media(Canadian Science Publishing, Nrc Research Press, 2017) Koc, Omer Kaan; Ozay, HavaAzoquinoline based sensor AZQ was designed and synthesized as a new molecular ion sensor containing an azo group in its structure. The structural characterization of AZQ was carried out using FTIR, NMR, mass, and elemental analysis. Then, the interaction of AZQ with anions was observed visually and UV-vis measurements were made in EtOH/H2O (1:1, v/v) solvent mixture. As a result of this investigation, it was determined that AZQ is a fast and highly selective sensor for CN-ions. The solution colour of AZQ changed from light yellow to orange only in the presence of CN-ions. The limit of detection of AZQ was calculated as 2.6 mu mol/L from anion titration experiments. Also, to identify the interaction mechanism of AZQ with CN-ions, H-1 NMR spectra of AZQ in the presence of CN-anions were recorded and the structure was proposed for AZQ-CN- host-guest complex.Öğe A single-use electrochemical biosensor system for ultrasensitive detection of Aflatoxin B1 in rice, corn, milk, peanut, chili pepper samples(Academic Press Inc Elsevier Science, 2024) Demirbakan, Burcak; Koseer, Nur Tarimeri; Uzman, Ecem; Özay, Özgür; Ozay, Hava; Sezgintürk, Mustafa KemalAflatoxin B1, a common food contaminant in peanuts and corn and a genotoxic carcinogen in humans poses a significant risk for hepatocellular carcinoma, making its detection crucial; this study aims to develop a label-free electrochemical biosensor using a disposable indium tin oxide polyethylene terephthalate (ITO-PET) electrode modified with 3-Aminopropyltriethoxysilane for detecting Aflatoxin B1 in real food samples. Initially, optimization steps for the proposed biosensor were conducted using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. Characterization steps such as storage capacity, regeneration, and single frequency impedance (SFI) were completed for the proposed disposable biosensor after the optimization steps. The electrochemical biosensor, based on AFB1, exhibited excellent repeatability and reproducibility. It had a broad dynamic detection range from 0.1 fg/mL to 500 fg/mL, with low limits of detection (LOD) and quantitation (LOQ) at 0.19 fg/mL and 0.65 fg/mL, respectively. Finally, the proposed AFB1-based biosensor system was applied to real food samples (rice, chili pepper, milk, corn, and peanuts) for testing and validation.Öğe A soft hydrogel reactor for cobalt nanoparticle preparation and use in the reduction of nitrophenols(Elsevier Science Bv, 2010) Şahiner, Nurettin; Ozay, Hava; Özay, Özgür; Aktas, NahitBulk poly(2-acrylamido-2-methyl-1-propansulfonic acid) (p(AMPS)) hydrogels were prepared by irradiation of an aqueous solution of AMPS in the presence of crosslinker and photoinitiator. These p(AMPS) hydrogel networks were utilized for in situ cobalt nanoparticle synthesis by reduction of metal ions absorbed into the hydrogel network with a reducing agent, i.e., NaBH(4). TEM images confirmed that Co particles are about 100 nm in size. The hydrogel network with embedded Co nanoparticles was utilized as a catalyst in the reduction of 4-nitrophenol (4-NP) and 2-nitrophenol (2-NP) in aqueous media in the presence of an excess amount of NaBH4. The kinetics of the reduction reaction under different reaction conditions was investigated to determine the activation parameters. Activation energies are 27.8 kJ mol(-1) and 39.3 kJ mol(-1) for 4-NP and 2-NP, respectively. It was found that hydrogel-Co composites were 99% active after 5 days storage. (C) 2010 Elsevier B.V. All rights reserved.Öğe Adsorption of Malachite Green from Aqueous Solution Using Hydroxyethyl Starch Hydrogel Improved by Graphene Oxide(Springer, 2022) Onder, Alper; Kivanc, Mehmet Riza; Durmus, Secil; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürThis study is the first report of the preparation of hydroxyethyl starch (HES) hydrogels rapidly crosslinked with divinyl sulfone in a single step and single pot. To develop the physical and chemical features of hydrogels, Graphene oxide (GO) nanoparticles were combined with the crosslinked HES. In addition to swelling studies, structural characterization of the samples was conducted with a scanning electron microscope (SEM) and transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) analysis and thermogravimetric analysis (TGA). For the removal of malachite green model dye by GO-HES, the effects of GO content, solution concentration, temperature, contact duration, dosage and pH on varying adsorption features were researched. Additionally, adsorption isotherms, kinetic and thermodynamic systematics were analyzed. The maximum adsorption capacity of GO-HES composite hydrogel was found to be 89.3 mg/g for Langmuir isotherm. The possible adsorption mechanism of the composite hydrogels for malachite green dye involved electrostatic, hydrogen bonding, and pi-pi interactions. In addition to reasonable cost and simple synthesis method, the prepared composite materials have potential use in wastewater treatment as adsorbents for the removal of dye from aqueous solutions due to efficient adsorption capacity.Öğe Ag(0) nanocatalyst stabilized with networks of p(SPA-co-AMPS) for the hydrogen generation process from ethylenediamine bisborane hydrolysis(Pergamon-Elsevier Science Ltd, 2020) Durgut, Sinem; Ozay, HavaIn this study, the hydrogen generation from the catalytic hydrolysis of the ethylenediamine bisborane (EDAB) was performed. For this purpose, the p(sulfopropyl acrylate potassium salt-co-2-acrylamido-2-methylpropansulfonic acid sodium salt)@Ag(0) (p(SPA-co-AMPS)@Ag) catalyst was prepared. Later the p(SPA-co-AMPS)@Ag containing Ag(0) particles with nanodimensions was used as catalyst in EDAB hydrolysis. Our study is the first in the literature from this aspect, and investigated in detail the effect of catalyst amount, reactive concentration, temperature and dry or swollen nature of the catalyst on the EDAB hydrolysis. At the end of the reaction series, the hydrolysis reaction of EDAB with p(SPA-co-AMPS)@Ag catalyst was determined to have activation energy (E-a) of 43.24 kJmol(-1). Additionally, the turn over frequency (TOF) was 0.560 mol H-2(mol Ag(0).min)(-1) at 30 degrees C. The p(SPA-co-AMPS)@Ag catalyst had perfect reusability with 95% of initial activity after the 5th use for the hydrogen generation from EDAB. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Öğe An innovative approach to use zeolite as crosslinker for synthesis of p(HEMA-co-NIPAM) hydrogel(Springer Wien, 2022) Durmus, Secil; Yilmaz, Betul; Onder, Alper; Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürThis study introduced a modified method to synthesize organic-inorganic hybrid crosslinker based on zeolite. First, zeolite nanoparticles were modified with 3-(aminopropyl)trimethoxysilane. Then, the amine-functionalized zeolite has been reacted with the glycidyl methacrylate via an epoxide ring-opening mechanism. The vinyl-functionalized zeolite was applied as a crosslinking agent to form hydrogel network. A novel temperature-sensitive nanocomposite hydrogel was prepared by crosslinking N-isopropylacrylamide as a comonomer and 2-hydroxyethyl methacrylate as a monomer with free-radical polymerization. Results showed that p(2-hydroxyethyl methacrylate-co-N-isopropylacrylamide)/vinyl-functionalized zeolite nanocomposite hydrogel has a chemically crosslinked and porous network structure. The content of crosslinker and monomers had obvious effects on the swelling ratio of the nanocomposite hydrogel. The temperature and salt-sensitive behavior of the hydrogels are also discussed. We offer a multifunctional crosslinker for preparing sensitive materials that can serve biomedical or environmental applications.Öğe An unusual impedimetric biosensor design based on 3-MPDS for highly sensitive detection of AFB1 in food samples(Elsevier, 2024) Demirbakan, Burcak; Koseer, Nur Tarimeri; Özay, Özgür; Ozay, Hava; Sezgintürk, Mustafa KemalAflatoxin B1 (AFB1), a mycotoxin produced by fungi of the genus Aspergillus, particularly Aspergillus flavus, is recognized as the aflatoxin with the highest carcinogenic and mutagenic potential. This study presents a costeffective, disposable AFB1 biosensor system based on 3-mercaptopropyltrimethoxysilane (3-MPDS) and the highly sensitive impedance technique. The surfaces of the ITO-PET (indium tin oxide/polyethylene terephthalate) electrodes were modified with 3-MPDS, and N-hydroxysuccinimide (NHS) was used as a crosslinker. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques were employed for immobilization, optimization, and analytical studies. Additionally, the surface morphology of the biosensor was analyzed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The biosensor demonstrated a linear range from 0.01 fg/mL to 200 fg/mL, with a limit of detection (LOD) of 0.01 fg/mL and a limit of quantification (LOQ) of 0.04 fg/mL. Finally, the proposed biosensor was tested and validated with real food samples, including rice, peanuts, milk, chili pepper, and corn.Öğe Assessment of release and anticancer effect of innovative pH-responsive and antioxidant-biodegradable hydrogel by using Parthenocissus quinquefolia L. extract as a crosslinker(Elsevier, 2023) Onder, Ferah Comert; Kalin, Sevil; Onder, Alper; Ozay, Hava; Özay, ÖzgürThe level of toxicity in cancer treatment with chemotherapy can negatively affect the treatment process. Therefore, targeted drug delivery systems play an important role in reducing treatment-related toxicities. Hydrogels with three-dimensional networks are being investigated as drug delivery systems due to their unique properties such as swelling capacity, biocompatibility, and bioavailability. Poly(2-hydroxyethyl methacrylate-co- methacrylic acid)/PQ (p(HEMA-co-MAA)/PQ) hydrogel was prepared by redox polymerization method using Parthenocissus quinquefolia L. (PQ) plant extract, known for its anticancer, antioxidant, and antimicrobial properties, as a crosslinker. PQ hydrogels were prepared with various monomer and cross-linker ratios. The p(HEMAco-MAA)/PQ10 (1:1) with a highly porous structure exhibited high swelling behavior. The phenolic content of p (HEMA-co-MAA)/PQ10 (1:1) hydrogel which has been determined to have high in vitro biodegradability at pH 6.5, increased with the amount of PQ extract used as crosslinker. The pH-responsive, antioxidant, biodegradable, and highly porous p(HEMA-co-MAA)/PQ10 (1:1) hydrogel showed higher doxorubicin (Dox) release behavior at pH 6.5. The Dox-loaded p(HEMA-co-MAA)/PQ10 (1:1) hydrogel drug carrier showed its anticancer effect on inhibition of colonies and cell proliferation against breast cancer cell lines. Our findings show that the p(HEMAco-MAA)/PQ10 (1:1) hydrogel using the PQ plant extract as a crosslinker will be significant potential in combination and cancer therapy studies.Öğe COLL 246-Hyaluronic acid hydrogel particles with micron and nano dimensions and their applications in drug delivery(Amer Chemical Soc, 2009) Ilgin, Pinar; Ozay, Hava; Aktas, Nahit; John, Vijay T.; Blake, Diane A.; Ayyala, Ramesh S.; Şahiner, Nurettin[Anstract Not Available]Öğe Comparison Study of Low Cost Fly Ash Supported Cu, Co and Ni Metal Catalyst Systems for the Reduction of 4-Nitrophenol(Amer Scientific Publishers, 2013) Ozay, HavaLow cost fly ash-supported Cu, Co and Ni metal catalyst systems were prepared by the reduction of Cu2+, Co2+ and Ni2+ ion adsorbed raw fly ash particles by using sodium borohydride (NaBH4) as reducing agent in aqueous media and were used in catalytic studies. For this purpose firstly raw fly ash particles were characterized by scanning electron microscopy (SEM), particle size analysis, X-ray diffractometry (XRD), X-ray fluorescence spectrometry (XRF) and inductive coupled plasma-optic emission spectroscopy. Afterwards, the prepared fly ash-metal composite materials were used as catalyst for the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4 aqueous solution. The reduction studies were completed at four different temperatures (20-50 degrees C). The activation parameters were calculated from the obtained rate constants for the four different temperatures (20-50 degrees C). The activation energies for the reduction reaction of 4-NP utilizing fly ash-Cu, Co and Ni composites as catalysts were 26.81 kJ mol(-1), 32.89 kJ mol(-1) and 34.98 kJ mol(-1) respectively. The total turnover frequency (TOF) for fly ash-Cu, Co and Ni composite catalysts were 0.278 mol 4-NP (nnol Cu)(-1) (min)(-1), 0.033 mol 4-NP (mol Co)(-1) (min)(-1) and 0.024 mol 4-NP (mol Ni)(-1) (min)(-1), respectively.Öğe Complexation of some pendant arm tetraazamacrocyles of Cu(II) and Co(II): Structural, thermodynamic and kinetic studies(Amer Chemical Soc, 2009) Baran, Yakup; Ozay, Hava; Aktas, Nahit; Miyamae, Hiroshi; Şahiner, Nurettin[Anstract Not Available]Öğe Copper and cobalt complexes of octadentate azamacrocycles: Spectrophotometric titration, stopped-flow kinetics and crystallographic study(2011) Ozay, Hava; Baran, Yakup; Ishii, YouichiDetails of complex formation kinetics are reported for tetrakis(2- hydroxyethyl) substituted cyclen (L 1) and cyclam (L 2) with Cu(II) and Co(II). Stopped-flow kinetics and spectroscopic titration methods were employed for the activation parameters and stability constants, respectively. X-ray studies revealed that the pendant 2-hydroxyethyl groups are not equivalent: two are folded over the macrocycle and maintained by intramolecular hydrogen bonds while the others are extended and pointed away from the macrocyclic cavity. Complex formation kinetics and spectroscopic titration were performed in aqueous acidic buffer solutions. Thermodynamic and kinetic parameters revealed that the ring size of the macrocycles plays an extremely important role for each metal ion studied. Stopped-flow kinetic measurements explained the mechanism of the complex formation process of both Cu(II) and Co(II) which proceed in outer-sphere interactions with ligands. There are two steps in the complex formation of the system studied. The initial step is a second order reaction between the metal ion and macrocycle with a second order rate constant. © 2011 Elsevier B.V.Öğe Dual use of colorimetric sensor and selective copper removal from aqueous media with novel p(HEMA-co-TACYC) hydrogels: Cyclen derivative as both monomer and crosslinker(Elsevier, 2020) Ozay, Hava; Gungor, Zeynep; Yilmaz, Betul; Ilgin, Pinar; Özay, ÖzgürWithin the scope of this study, p(2-hydroxyethyl methacrylate-co-tetraacrylic cyclen) (p(HEMA-co-TACYC)) hydrogels were synthesized for the first time in the literature using a tetraacrylic cyclen (TACYC) as both functional monomer and crosslinker. The hydrogels designed especially for Cu2+ ions showed colorimetric sensor behavior selective for Cu2+ ions in all aqueous media (deionized, tap, river and sea water) and in metal ion mixtures. The p(HEMA-co-TACYC) hydrogels forming a stable complex with Cu2+ ions simultaneously showed properties of being a good adsorbent material. The hydrogels have reuse capacity as both sensor and adsorbent material. Changing the amount of TACYC in the hydrogel structure changes the maximum adsorption capacity for Cu2+ ions. The Langmuir and Freundlich adsorption constants for Cu2+ ion adsorption of the hydrogels, acting as selective adsorbent in all aqueous media and metal ion mixtures, were determined.Öğe Early detection of the ovarian cancer with a label-free and disposable ITO-PET based immunosensor platform(Elsevier, 2024) Ozcan, Burcu; Ozay, Hava; Özay, Özgür; Sezgintürk, Mustafa KemalAlpha fetoprotein (AFP), a popular biomarker for ovarian cancer, was the target of this study to create an immunosensor based on electrochemical impedance spectroscopy (EIS). For this purpose, a disposable Indium tin oxide coated PET (In2O3/SnO2, ITO-PET) electrode was used as a basic electrode for working of the triple electrode system and the electrodes were modified with 3-(Trimethoxy silyl) propyl methacrylate (3- TMSPM) silanization agent. Although there are studies on the determination of AFP, the determination of AFP with a cheap, flexible and sensitive electrode system such as ITO-PET in this study makes the study remarkable. With the designed biosensors, AFP protein determination at a wide concentration range (0.05 pg/mL-100 pg/mL) could be successfully performed. To prove that the designed immunosensor was constructed correctly, linear range, repeatability, reproducibility and regeneration capacity (characterization studies) were investigated. Obtaining successful results in the storage capacity studies of the biosensor, which has high reproducibility and repeatability, showed that it also has potential for commercial use. The high specificity of the biosensor also proves its reliability. Finally, the performance of the biosensor in commercial human serum samples was also evaluated.Öğe Eco-Friendly Preparation of Pectin-Stabilized Ruthenium Catalyst for Hydrogen Generation from Sodium Borohydride Hydrolysis(Wiley-V C H Verlag Gmbh, 2024) Ilgin, Pinar; Ozay, Hava; Özay, ÖzgürIn this study, we report that pectin-supported ruthenium nanoparticles (pectin@Ru0) can be easily prepared at room temperature by a simple and effective method and that they exhibit outstanding catalytic activity in the hydrolysis of sodium borohydride (NaBH4). The structure, oxidation state, morphology, and thermal studies were analyzed using XRD, XPS, SEM, TEM and TGA analysis. The kinetic performance of pectin@Ru0 biocatalyst was evaluated depending on ruthenium loading, NaBH4 concentration, NaOH concentration, temperature, reusability and storage. The pectin@Ru0 biocatalyst containing 2 wt.% Ru0 metal catalyzed the hydrolysis of 50 mM NaBH4+1 wt.% NaOH with 100 % yield. The activation energy (Ea) and the TOF values of the reaction was estimated as 54.7 kJ mol-1 and 53.1 mol H2 (mol Ru0 min) -1 at 30 degrees C and this is consistent with other previously reported catalysts, making it a remarkable result in comparison. Reusability and catalytic life studies reported that pectin@Ru0 biocatalyst is also highly active and relatively long-lived catalyst in the hydrolysis of NaBH4 in a slightly basic solution. Pectin@Ru0 biocatalyst was successfully synthesized and tested for H2 production in catalytic hydrolysis of NaBH4. HGR and TOF were calculated as 12848 mL/(min.g) and 53.1 mol H2/(mol Ru0 min) at 30 degrees C. Ea was calculated as 54.7 kJ/mol. The reusability of this new catalyst was tested 10 times with 81.5 % stability and 100 % conversion. Storage of biocatalyst can retain 87 % of initial HGR after 30 days. image
