Article
Chemistry, Physical
Sahin Demirci, S. Duygu Sutekin, Olgun Guven, Nurettin Sahiner
Summary: Poly(2-aminoethyl methacrylate) (p(AEM)) microgels were synthesized and used for metal nanoparticle preparation. These microgels were then incorporated into p(AEM) based poly ionic liquid (PIL) microgels, which served as catalysts for hydrogen production from sodium borohydride (NaBH4) reactions. The catalytic activity and regeneration ability of the microgels were analyzed, showing promising results.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Sahin Demirci, Selin S. Suner, Mustafa Yildiz, Nurettin Sahiner
Summary: In this study, polymeric ionic liquid (PIL) forms of polyethyleneimine (PEI) microgels were prepared and used as metal-free catalysts for hydrogen production from sodium borohydride (NaBH4) solution in methanol. The PEI-based PIL microgels exhibited excellent catalytic performances and regenerability, enabling hydrogen production at various temperatures and easy recovery of catalytic activities through regeneration treatments.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Lijing Yang, Congmin Fan, Jiapeng Zhang, Fengming Zhang, Ran Li, Shuang Yi, Yue Sun, Hua Dong
Summary: A SiO2@PAA catalyst composed of silica nanoparticles modified with poly(acrylic acid) was developed for NaBH4 methanolysis, showing excellent catalytic performance. The catalyst exhibited significantly higher hydrogen generation rate and lower activation energy compared to unmodified silica. Furthermore, the catalytic activity of the SiO2@PAA catalyst could be restored after regeneration with diluted hydrochloric acid solution.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Cafer Saka
Summary: In this study, activated carbons prepared from microalgae with KOH activation were used for the first time as sulphur (S) and phosphorus (P) doped metal-free carbon catalysts in NaBH4 methanolysis reaction, showing a high hydrogen generation rate and low activation energy. After five cycles, the catalyst retained 59% of its initial catalytic activity, demonstrating the potential for environmentally friendly efficient catalytic reactions.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Medhen W. Abebe, Anteneh F. Baye, Hern Kim
Summary: In this study, an interpenetrating polymer network (IPN) strategy was utilized to prepare a recyclable polymeric catalyst for catalytic methanolysis of NaBH4 to produce hydrogen gas. The catalyst exhibited excellent cyclic performance and prolonged catalyst life.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Cafer Saka
Summary: Metal-free carbon catalysts doped with sulfur and phosphorus were prepared from activated carbon obtained from microalgae, showing high hydrogen generation rate and low activation energy in NaBH4 methanolysis. The catalytic activity was attributed to the synergistic effects of porous structure and P- and S-containing active sites, providing a new strategy for environmentally friendly efficient catalytic reactions.
Article
Engineering, Chemical
Dandan Lei, Xiao-Li Sun, Shasha Hu, Huibin Cheng, Qinghua Chen, Qingrong Qian, Qiao Xiao, Changlin Cao, Lireng Xiao, Baoquan Huang
Summary: Recycling waste PET fibers and recovering monomers is crucial for environmental and resource protection. By using a stepwise feeding process and adding the fibers to a glycolysis agent at an elevated temperature, the conversion rate of PET fibers and the yield of water-soluble products were significantly increased. However, the conversion rate and yield of fibers were lower than those of bottle flakes and particles.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Chemistry, Physical
Geeta Durga, Pooja Kalra, Vinay Kumar Verma, Kanjur Wangdi, Anuradha Mishra
Summary: Ionic liquids have established themselves as a preferred solvent in synthetic chemistry, particularly in polymer chemistry. They are versatile solvents used for polymeric reactions and can also be polymerized to enhance their inherent properties, finding applications in various fields such as electrochemical devices, nanocomposites, optoelectronics, and more. This comprehensive review covers both aspects of ILs as a solvent in polymeric reactions and their polymeric form, poly(ionic liquids), presenting their diverse potential applications.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Chemistry, Physical
Duygu Elma Karakas
Summary: In this study, orange peel was used as a metal-free catalyst for hydrogen production from sodium boron hydride. The catalyst was prepared by treating the orange peel with phosphoric acid and burning it at a specific temperature and time. The catalytic activity of the catalyst was characterized and the hydrogen generation rates and activation energy were determined.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
O. V. Netskina, E. S. Tayban, V. A. Rogov, A. M. Ozerova, S. A. Mukha, V. I. Simagina, O. V. Komova
Summary: In the study, it was found that cobalt catalysts are more active than nickel catalysts in the hydrolysis of sodium borohydride. One reason for the lower activity of nickel catalysts is the presence of hydrogen on its surface, which interferes with reactant adsorption. The addition of cobalt to nickel catalysts can enhance hydrogen generation rate.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Babloo Sharma, Susanne Striegler
Summary: The systematic study revealed the correlation between the nature, polarity, and critical micelle concentration of nonionic surfactant blends, the size of resulting polyacrylate gels, and their catalytic performance. An optimized, translucent gel showed catalytic efficiency of up to 0.35 min(-1) M-1 and catalytic proficiency of up to 1,300,000 in HEPES buffer at pH 7. The catalytic efficiency was found to be inversely proportional to the hydrodynamic diameters of the polyacrylates.
Article
Chemistry, Physical
Valentina G. Minkina, Stanislav I. Shabunya, Vladimir I. Kalinin, Vladimir V. Martynenko
Summary: This study investigated the catalytic hydrolysis of aqueous NaBH4 solutions and found that the catalyst used showed stable catalytic activity. It was also observed that conducting the hydrolysis under near adiabatic conditions significantly reduced the hydrolysis time.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Jinlin Song, Ran Li, Hua Dong
Summary: The addition of cheap and environment-friendly acetic acid (CH3COOH) into NaBH4 solutions stabilized with NaOH can significantly accelerate the hydrolysis reaction and control the start/stop of the reaction by adding acid or base into the solution, enabling on-site hydrogen production. This finding is of great significance for efficient and convenient hydrogen production.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Chemical
Fang Li, Jia Li, Luyao Chen, Yanmei Dong, Pinhong Xie, Qiming Li
Summary: A stable and efficient supported CoB catalyst with excellent catalytic performance and cycling stability has been successfully developed for hydrogen production from NaBH4 hydrolysis. The as-prepared CoB/PANI composite catalyst exhibits high hydrogen production rate and low activation energy, showing great potential in practical applications.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2021)
Article
Chemistry, Physical
Cafer Saka, Asim Balbay
Summary: Metal-free catalysts were produced from apricot kernel shells for efficient H-2 generation from NaBH4 methanolysis. The catalysts were activated through a two-step process and characterized for their structure and properties. The results showed that the metal-free catalyst exhibited a high hydrogen production rate and low activation energy.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Duygu Alpaslan, Tuba Ersen Dudu, Nahit Aktas
Summary: In this study, organo-hydrogels containing different cross-linkers and different amounts of onion oil were prepared to investigate their swelling behavior and drug-release properties. The results showed that onion oil affected the structure of the hydrogels and influenced the drug release. The type of cross-linker and the amount of onion oil also affected the release rate of drugs. The drug release of the organo-hydrogels followed the Higguci and Korsmeyer-Peppas models.
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Environmental
Tuba Ersen Dudu, Duygu Alpaslan, Nahit Aktas
Summary: This study aimed to investigate the synthesis, characterization, and drug release behaviors of organo-hydrogels containing pH-sensitive Agar, Glycerol, and Sweet Almond oil. The synthesized organo-hydrogels were examined for swelling, bond structures, blood compatibility, and antioxidant properties. In addition, the release kinetics of Ceftriaxone and Oxaliplatin loaded organo-hydrogels were studied under various pH conditions. Release results were analyzed using different equations, showing consistency with the diffusion of drugs from the gels.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2022)
Article
Engineering, Environmental
Duygu Alpaslan, Tulu Olak, Abdullah Turan, Tuba Ersen Dudu, Nahit Aktas
Summary: This study synthesized six different organo-hydrogels containing Agar-Glycerol-based Coconut Oil with different crosslinkers for controlled release of D-3 Vitamin and 5-Flu. The organo-hydrogels showed blood compatibility and antioxidant properties, with the most release occurring at pH 2 with glutaraldehyde crosslinker. Release kinetics models indicated that the p(AG-co-CnO) organo-hydrogel is a suitable carrier for controlled release of D-3 Vitamin and 5-Flu.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2022)
Article
Oncology
Ertug Avci, Hulya Yilmaz, Nurettin Sahiner, Bilge Guvenc Tuna, Munevver Burcu Cicekdal, Mehmet Eser, Kayhan Basak, Fatih Altintoprak, Ismail Zengin, Soner Dogan, Mustafa Culha
Summary: This study investigates the reliability of surface-enhanced Raman scattering (SERS) for cancer diagnosis by varying several parameters. The results demonstrate the potential of this technique to accurately differentiate blood samples from cancer patients, healthy individuals, and patients with chronic diseases.
Article
Engineering, Environmental
Duygu Alpaslan, Tuba Ersen Dudu, Nahit Aktas
Summary: The fast generation of hydrogen through the methanolysis of NaBH4 was achieved using metal-free catalysts synthesized from natural and environmentally friendly materials. The polymeric GO particles with suitable hydrodynamic diameters and zeta potential demonstrated efficient catalytic performance under various conditions. The study revealed the kinetic properties of the methanolysis reaction and successfully transformed GO into a product with high energy value.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2023)
Article
Materials Science, Multidisciplinary
Omer Faruk Er, Duygu Alpaslan, Tuba Ersen Dudu, Nahit Aktas, Sebahattin Celik, Hilal Kivrak
Summary: Ovarian cancer is a gynecological disease with high mortality rates worldwide. Carbohydrate antigen 125 (CA-125) is a recognized tumor marker for ovarian cancer. The use of organo-hydrogels as sensing materials has allowed for sensitive detection of CA-125 in serum samples. The electrochemical sensor based on organo-hydrogel sweet almond oil (OHSAO) shows promise for CA-125 detection.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Pharmacology & Pharmacy
Mehtap Sahiner, Aynur S. S. Yilmaz, Ramesh S. S. Ayyala, Nurettin Sahiner
Summary: Poly(glycerol) (p(Gly)) particles were successfully synthesized using the micro-emulsion method, with an average size of 14.5+/-5.6 μm. The particles showed good biocompatibility and non-toxicity, making them promising vehicles for drug delivery systems. Loading the flavonoid quercetin into the p(Gly) particles demonstrated their improved bioavailability and sustained release profiles.
Review
Engineering, Biomedical
Mehtap Sahiner, Aynur Sanem Yilmaz, Buket Gungor, Nurettin Sahiner
Summary: Neurodegenerative diseases are characterized by the progressive loss and death of nerve cells, and efforts are being made to understand their pathogenesis. This review focuses on Alzheimer's disease, which has a high prevalence and lacks radical treatment, and explores the potential neurological effects of phytochemicals as therapeutic agents. The survey highlights the inhibitory effects of herbal compounds on acetylcholinesterase, an enzyme with significant value in AD treatment. It has been shown that phytopharmaceuticals can have long-term effects in protecting nervous system health, reducing inflammation, improving cognitive damage, and alleviating dementia sequelae. Herbal-based therapeutics offer advantages as new generation or complementary agents with high compliance, fewer adverse effects, and lower cost compared to traditional pharmaceutical agents in the fight against AD.
JOURNAL OF FUNCTIONAL BIOMATERIALS
(2023)
Article
Polymer Science
Adem Zengin, M. Utku Badak, Mustafa Bilici, Nahit Aktas
Summary: In this study, streptomycin-imprinted cotton fibers were prepared for the quantification of streptomycin in honey samples. The imprinted cotton fibers showed high adsorption capacity, satisfactory regeneration ability, and good linearity. The proposed method was as sensitive and selective as the ELISA method, indicating the potential of imprinted cotton fibers as an alternative for antibiotic quantification.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Polymer Science
Cihan Aktas, Osman Polat, Mohamadreza Beitollahpoor, Melika Farzam, Noshir S. Pesika, Nurettin Sahiner
Summary: In this study, the effect of plasma treatment on the wetting properties of LDPE films was investigated. The contact angle and surface energy values of LDPE films changed after plasma treatment. Kinetic friction force measurements proved to be more sensitive than contact angle measurements in differentiating the wetting properties of different LDPE films.
Article
Chemistry, Multidisciplinary
Aykut Caglar, Hilal Kivrak, Nahit Aktas
Summary: The sequential sodium borohydride (SBH, NaBH4) reduction method was used to prepare different catalysts. XRD, SEM-EDS, TEM, and XPS analyses were performed to characterize the catalysts. Electrochemical measurements were conducted to evaluate the catalytic activity of the catalysts for glucose electrooxidation. The 0.1% (CdSe-CNT)/CdTe catalyst exhibited the highest catalytic activity, stability, and resistance with a specific activity of 2.4 mA cm(-2).
Article
Chemistry, Medicinal
Selin S. Suner, Mehtap Sahiner, Evrim Umut, Ramesh S. Ayyala, Nurettin Sahiner
Summary: Chondroitin sulfate (CS) was physically crosslinked with Fe(III), Gd(III), Zn(II), and Cu(II) ions to obtain CS-metal ion-containing particles. These particles have the potential for use as injectable materials for intravenous administration, with excellent blood compatibility and low cytotoxicity. Additionally, CS-Zn(II) and CS-Cu(II) particles show strong antibacterial activity, and the CS-metal ion particles can enhance contrast in magnetic resonance imaging (MRI), making them versatile biomaterials.
Article
Polymer Science
Mehtap Sahiner, Aynur S. Yilmaz, Ramesh S. Ayyala, Nurettin Sahiner
Summary: In this study, water-soluble microgels of glycol chitosan (GC) were synthesized and their blood and cell compatibility were tested. The results showed that the microgels exhibited good blood compatibility and cell viability. Furthermore, the microgels were used for drug delivery of tannic acid (TA), and they exhibited strong antioxidant activity.
Article
Chemistry, Physical
Selin S. Suner, Venkat R. Bhethanabotla, Ramesh S. Ayyala, Nurettin Sahiner
Summary: Photo-activated antipathogenic carbon dots were prepared by modifying arginine carbon dots with fluorescent dyes, leading to enhanced antimicrobial potency. These modified carbon dots showed excellent fluorescence properties and broad-spectrum antimicrobial activity, with the photosensitive arginine-riboflavin carbon dots exhibiting the strongest antibacterial effect.
Article
Polymer Science
Mehtap Sahiner, Aynur S. Yilmaz, Ramesh S. Ayyala, Nurettin Sahiner
Summary: Carboxymethyl chitosan microgels show excellent biocompatibility and drug-loading ability, making them important in antibacterial applications. These microgels, synthesized in a microemulsion environment, have tailored size and zeta potential values, and possess a spherical structure.
