Efficient synthesis and detailed thermal studies of zinc phthalocyanine

A facile and efficient, one step synthesis of macrocyclic molecule zinc phthalocyanine (ZnPc), was proposed. Dark violet crystals of ZnPc dye were obtained in high boiling point solvent of dimethylformamide (DMF) in the presence of 2,2,6,6-tetramethylpiperidine (TMP) as a catalyst. Detailed thermogravimetric and kinetic analysis revealed high thermal stability of the investigated compound

Synthesis and physicochemical evaluation of new chitosan-based scaffolds for potential application in biomedicine

Chitosan is a natural polymer obtained by deacetylation of chitin. Due to its biocompatibility and biodegradability, chitosan-based materials have a wide range of biomedical applications in wound dressings, drug delivery systems, and tissue engineering. Also, studies in the fields of organic and medicinal chemistry show that compounds based on the pyridone core exhibit biological properties including antimicrobial, anticancer, and antioxidant activity, and moreover have the potential as new therapeutics for various diseases from cardiovascular to antitumor therapy. In this study, new biomaterials were synthesized using low and medium molecular weight chitosan polymers and pyridone-based hydrazone. In order to improve stability of the obtained scaffolds, scaffolds’ neutralization was carried out using ethanol and sodium hydroxide solutions. The interactions established between chitosan polymer chains and pyridone compound were analyzed by FT-IR spectroscopy. Swelling and degradation tests of the materials were studied in water and PBS, and the influence of different polymer molecular weights on the scaffolds’ properties was evaluated. The results indicated that synthetized scaffolds have a high potential for biomedical use

Production of liqueur from green walnuts using ionizing radiation

Liqueur from green walnuts is one of the many traditional medicines in folk medicine. It owes its healing properties to the main ingredient - unripe green walnuts. Green walnuts are a natural reservoir of vitamin C, vitamin B complex, vitamin E, calcium, potassium, magnesium, phosphorus, iron, zinc and iodine. Liqueur made from green walnuts is mostly used for problems with the thyroid gland, anemia, and various stomach infections. The liqueur is made by adding green walnuts to a container with sugar or honey and brandy, and leaving them to be exposed to the sun's rays for a period of 40 days. Photons accelerate the release of medicinal substances from green walnuts. This period of exposure is quite long, the quality of the liqueur is affected by the amount of solar energy delivered during that period, and contamination may occur during manual handling. All these problems can be solved by using photons from a radioactive gamma source instead of photons from the sun. The paper describes the process of obtaining liqueur from green walnuts using gamma radiation, as well as the comparison of the composition of liqueur obtained in the traditional way, with the effect of sunlight, and the application of an innovative method using gamma rays.RAD 2023 : 11th International Conference on Radiation Natural Sciences, Medicine, Engineering, Technology and Ecology (RAD 2023) 19–23.06.2023; Herceg Novi, Montenegr

2-OXO-1,2,3,4-tetrahydropyrimidine-azo-pyridone dye : a potential application as new green-emitting fluorescent probe

Molecular imaging is a relatively new research field, which has demonstrated great potential, especially in clinical oncology – from drug development to cancer early detection. The key of fluorescence imaging is the construction of fluorescent probe which is composed of two parts, the recognition groups to recognize cancer cells, and fluorophores to signal the recognition events. In this research, the structure of new fluorescent azo dye based on 2-oxo-1,2,3,4-tetrahydropyrimidin and 2-pyridone moieties has been reported. The absorption and emission properties of the investigated azo dye have been studied using UV-Vis and fluorescence spectroscopy. The obtained results suggest that studied dye meets the requirements for new green-emitting fluorescent probe, suitable for further application in biomedical researches

Thermal kinetic analysis of the spent mushroom substrate and hydrochar

A carbon-rich product, hydrochar, was synthesized by hydrothermal carbonization (HTC) of spent mushroom substrate (SMS), at temperature of 260 °C. The thermal kinetic analysis has shown that hydrothermally treatment improve the combustion behavior of hydrochar. The kinetic parameters were determined by Kissinger and Ozawa methods. The SMS-260 had a significantly lower activation energy compared to the SMS, which means that this hydrochar needs a smaller amount of energy to start combustion. Generally, the preliminary results show that HTC is an effective way to transform SMS into alternative solid biofuel

Optical and antioxidative properties of 5-(2,6-Dimethylphenyl)- 6-Hydroxy-4-Methyl-2-Oxo-1,2-Dihydropyridine-3-Carboxamide

A new heterocyclic azo dye 5-(2,6-dimethylphenyl)-6-hydroxy-4-methyl-2-oxo-1,2- dihydropyridine-3-carboxamide was synthesized and structurally characterized by elemental analysis, FTIR, 1H and 13C NMR spectroscopy techniques. These analysis have confirmed that synthesized dye exists in the tinctorial strongest tautomeric form, hydrazone form. The dye is characterized by reflection spectrum, while absorption and emisson spectra are recorded in nine different solvents. The antioxidant activity of the synthesized dye has been chemically tested and has been shown to have great potential as an antioxidant molecule

Adsorption of Pb2+ ions on gamma irradiated plum pomace biochar

Removal of heavy metals is important because of their toxic effects on living organisms and unwanted anthropogenic effects. Biochar is suitable as an adsorbent of heavy metals due to its advantages such as various sources of biomass, a large number of microporous channels and surface functional groups, as well as due to its economic viability. There is no data about the plum pomace biochar usage as adsorbent for lead removal. In this study, the plum pomace biochar modified with gamma irradiation (IrPP) is used for the removal of Pb2+ ions from the aqueous solution. The SEM micrographs revealed that surface morphology of plum pomace is suitable for metal adsorption. The results of adsorption kinetics demonstrated that the removal process of Pb2+ ions onto IrPP follows a pseudo-second kinetic model, which is confirmed by a better agreement between qe,cal=227 mg g–1 and qe,exp=224 mg g–1 . Therefore, based on preliminary research, it can be concluded that IrPP originating from biowaste is a promising, eco-friendly sorbent of heavy metal from wastewater

Removal of Cd2+ ions from aqueous solutions by gamma irradiation activated biochar of plum pomace

The use of waste biomass for the production of fuels, sorbent of different pollutants or natural fillers has significant economic and environmental benefits. Plum (Prunus domestica) is a lush fruit consisting of bones, flesh and skin. It can be consumed fresh, dried or used to make juices, jams and brandies known as plum brandy. Plum is also known as a laxative. During processing, plum pomace is formed as a by-product of plum brandy production. Plum pomace contains a large proportion of polyphenols, so it can be used to produce dietary supplements. Therefore, in this study, the gamma irradiation activated biochar of plum pomace was examined as a lowcost biosorbent of Cd2+ ions from aqueous solution. It was prepared using pyrolysis process at 500 °C for a reaction time of 1 h, then was activated by gamma irradiation. The characterization of plum pomace before and after pyrolysis was done by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Analysis of morphology and functional groups presented the formation of cracks on the biochar surface, which are mainly dominated by oxygen-rich functional groups. The adsorption capacity of activated biochar was higher than inactivated biochar because its improved surface functional properties after gamma activation. The Cd2+ ions contents in aqueous solution were analyzed using ICP-OES. The adsorption capacity was estimated using the Langmuir and Freundlich model. The findings of this study confirm that pyrolysis is a promising way to produce efficient environmentally friendly sorbents for wastewater treatment.X JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr

Radiation, thermal and optical properties of PVA films containing arylazo pyridone dyes

Films based on polyvinyl alcohol (PVA) containing different concentrations of some arylazo pyridone dyes have been introduced as plastic detectors for dosimetry. PVA was chosen due to its water solubility and the possibility to incorporate a variety of dyes. The significance of arylazo pyridone dyes resides in their simple synthesis and wide application areas. The following dyes were used in optical data storage, laser technology, dye-sensitized solar cells, non-linear optics and biological systems. The advantage of polymeric films based on arylazo pyridone dyes is a visual change of color after exposure to gamma radiation, making them easy to use. In addition, this form of dosimeters is cheap and easily portable. Films containing arylazo pyridone dyes change the color when irradiated with γ-radiation at least up to 20 kGy. The color changes were confirmed spectrophotometrically. All synthesized films were characterized by FTIR. Optical properties have been analyzed on the basis of reflection and excitation spectra. Thermal degradation processes of PVA films containing arylazo dyes were investigated with thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC).VII International Conference on Radiation in Various Fields of Research : RAD 2019 : book of abstracts; June 10-14, 2019; Herceg Novi, Montenegr

A comparative study of photocatalytically active nanocrystalline tetragonal T zyrcon- type and monoclinic scheelite-type bismuth vanadate

The authors from Vinča Institute of Nuclear Sciences acknowledge the financial support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (Project no: 172056 ). The work of K. Smits was supported by Latvian National Research Program IMIS2 (Grant no. 302/2012 ).Monoclinic scheelite-type BiVO4 is currently considered as one of the most promising non-titania photocatalysts, wheras tetragonal zircon-type BiVO4 is still poorly understood. Herein, a new and simple synthetic approach was applied and nanostructured single-phase zircon-type BiVO4 was successfully prepared by a controllable ethylene-glycol colloidal route. In addition, nanostructured monoclinic scheelite-type BiVO4 powders were also fabricated through annealing of the as-prepared samples. A comparative study of the two BiVO4 polymorphs was conducted and it turned out that the novel synthetic approach had a significant impact on porosity and photocatalytic performance of zircon-structured BiVO4. All the prepared materials, as-prepared and annealed, were mesoporous, while measured values of specific surface area of some zircon-structured samples (∼34 m2/g) were ∼7 times higher than those reported thus far for this phase. Interestingly, for the first time, zircon-type BiVO4, previously considered to be a poor photocatalyst, exhibited a better overall performance in degradation of methyl orange compared to monoclinic scheelite-type BiVO4. Hence, it could be expected that the here-presented synthesis and observations will both arouse interest in scarcely studied tetragonal zircon-type BiVO4 and facilitate as well as speed up further research of its properties.Ministry of Education, Science and Technological Development of the Republic of Serbia (Project no: 172056 ); Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART