School of Chemistry - Research Publications

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    Flow-through passive sampler for zinc in freshwaters free from flow pattern, water cationic composition and temperature effects
    Nitti, F ; Almeida, MIGS ; Morrison, R ; Cattrall, RW ; Pettigrove, VJ ; Coleman, RA ; Kolev, SD (ELSEVIER, 2022-06)
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    Cluster Analysis of the EU-27 Countries in Light of the Guiding Principles of the European Green Deal, with Particular Emphasis on Poland
    Rybak, A ; Rybak, A ; Joostberens, J ; Kolev, SD (MDPI, 2022-07)
    The article presents a cluster analysis of the EU-27 countries. The clusters were built to identify groups of countries similar to each other in relation to the set of Eurostat indicators from the Climate Change Drivers and Environment and Energy sections. During the research, tools of spatial information systems were used, such as cluster analysis, diagram maps, rasterization and the TSA method. ARIMA prediction models were also used. The research aims to verify our hypotheses. Particular attention was paid to Poland; therefore, it was verified whether the composition of the country’s energy mix translated into excessive emissions of pollutants in relation to other EU countries. Furthermore, the level of integration of energy markets in the European Union and its changes over time were examined. The authors also proposed a methodology to create detailed energy and climate strategies for designated clusters. The results of the presented research are particularly important in light of recent events in Ukraine.
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    Recent Development of Atmospheric Water Harvesting Materials: A Review
    Feng, A ; Akther, N ; Duan, X ; Peng, S ; Onggowarsito, C ; Mao, S ; Fu, Q ; Kolev, SD (AMER CHEMICAL SOC, 2022-09-14)
    The lack of freshwater has been threatening many people who are living in Africa, the Middle East, and Oceania, while the discovery of freshwater harvesting technology is considered a promising solution. Recent advances in structured surface materials, metal-organic frameworks, hygroscopic inorganic compounds (and derivative materials), and functional hydrogels have demonstrated their potential as platform technologies for atmospheric water (i.e., supersaturated fog and unsaturated water) harvesting due to their cheap price, zero second energy requirement, high water capture capacity, and easy installation and operation compared with traditional water harvesting methods, such as long-distance water transportation, seawater desalination, and electrical dew collection devices in rural areas or individual-scale emergent usage. In this contribution, we highlight recent developments in functional materials for "passive" atmospheric water harvesting application, focusing on the structure-property relationship (SPR) to illustrate the transport mechanism of water capture and release. We also discuss technical challenges in the practical applications of the water harvesting materials, including low adaptability in a harsh environment, low capacity under low humidity, self-desorption, and insufficient solar-thermal conversion. Finally, we provide insightful perspectives on the design and fabrication of atmospheric water harvesting materials.
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    Speciation of inorganic arsenic in aqueous samples using a novel hydride generation microfluidic paper-based analytical device (μPAD)
    Bonacci, ME ; Almeida, MIGS ; Zhang, Y ; Kolev, SD (SPRINGER WIEN, 2022-07)
    The development of the first microfluidic paper-based analytical device (µPAD) for the speciation of inorganic arsenic in environmental aqueous samples as arsenite (As(III)) and arsenate (As(V)) which implements hydride generation on a paper platform is described. The newly developed µPAD has a 3D configuration and uses Au(III) chloride as the detection reagent. Sodium borohydride is used to generate arsine in the device's sample zone by reducing As(III) in the presence of hydrochloric acid or both As(III) and As(V) (total inorganic As) in the presence of sulfuric acid. Arsine then diffuses across a hydrophobic porous polytetrafluoroethylene membrane into the device's detection zone where it reduces Au(III) to Au nanoparticles. This results in a color change which can be related to the concentration of As(III) or total inorganic As (i.e., As(III) and As(V)) concentration. Under optimal conditions, the µPAD is characterized by a limit of detection of 0.43 mg L-1 for total inorganic As (As(III) + As(V)) and 0.41 mg L-1 for As(III) and a linear calibration range in both cases of 1.2-8.0 mg As L-1. The newly developed µPAD-based method was validated by applying it to groundwater and freshwater samples and comparing the results with those obtained by conventional atomic spectrometric techniques.
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    Analysis of the EU-27 Countries Energy Markets Integration in Terms of the Sustainable Development SDG7 Implementation
    Rybak, A ; Rybak, A ; Kolev, SD (MDPI, 2021-11)
    The article presents the results of research related to the SDG7 sustainable development implementation analysis. The goal is to provide affordable and clean energy. Its implementation will allow for development that will simultaneously provide the possibility of economic growth and the achievement of an optimal level of citizens’ health and life. The research was conducted for the countries of the European Union EU-27. During the analysis, the indicators proposed by Eurostat were used. The research aimed to examine the progress in EU member states’ energy markets integration. In order to carry out the indispensable research, it was necessary to use a spatial information system. Cluster analysis, as well as TSA analysis, were applied. The conducted research made it possible to verify the posed hypotheses and showed that the energy transformation process of the EU-27 countries is so complicated and heterogeneous that it has given rise to new independent and unique clusters. The authors also verified the adopted set of SDG7 achievement indicators using multiple regression. Additional indicators were also proposed that could complement the set and clarify its analyses.
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    Hybrid organic-inorganic membranes based on sulfonated poly (ether ether ketone) matrix and iron-encapsulated carbon nanotubes and their application in CO2 separation
    Rybak, A ; Rybak, A ; Boncel, S ; Kolanowska, A ; Kaszuwara, W ; Kolev, SD (ROYAL SOC CHEMISTRY, 2022-04-28)
    The need to reduce greenhouse gas emissions dictates the search for new methods and materials. Here, a novel type of inorganic-organic hybrid materials Fe@MWCNT-OH/SPEEK (with a new type of CNT characterized by increased iron content, 5.80 wt%) for CO2 separation is presented. The introduction of nanofillers into a polymer matrix has significantly improved hybrid membrane gas transport (D, P, S, and α CO2/N2 ), and magnetic, thermal, and mechanical parameters. It was found that magnetic casting has improved the alignment and dispersion of Fe@MWCNT-OH carbon nanotubes. At the same time, CNT and polymer chemical modification enhanced interphase compatibility and membrane CO2 separation efficiency. The thermooxidative stability, and mechanical and magnetic parameters of composites were improved by increasing new CNT loading. Cherazi's model turned out to be suitable for describing the CO2 transport through analyzed hybrid membranes. The comparison of the transport and separation properties of the tested membranes with the literature data indicates their potential application in the future and the direction of further research.
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    Characteristics of Inorganic-Organic Hybrid Membranes Containing Carbon Nanotubes with Increased Iron-Encapsulated Content for CO2 Separation
    Rybak, A ; Rybak, A ; Kaszuwara, W ; Boncel, S ; Kolanowska, A ; Kolev, SD (MDPI, 2022-02)
    Novel inorganic-organic hybrid membranes Fe@MWCNT/PPO or Fe@MWCNT-OH/SPPO (with a new type of CNTs characterized by increased iron content 5.80 wt%) were synthesized for CO2 separation. The introduction of nanofillers into the polymer matrix has significantly improved the hybrid membrane's gas transport (D, P, S, and αCO2/N2), magnetic, thermal, and mechanical parameters. It was found that magnetic casting has improved the alignment and dispersion of Fe@MWCNTs. At the same time, CNTs and polymer chemical modification enhanced interphase compatibility and the membrane's CO2 separation efficiency. The thermo-oxidative stability and mechanical and magnetic parameters of composites were improved by increasing new CNTs loading. Cherazi's model turned out to be suitable for describing the CO2 transport through analyzed hybrid membranes.
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    On the Potential of a Poly(vinylidenefluoride-co-hexafluoropropylene) Polymer Inclusion Membrane Containing Aliquat(R) 336 and Dibutyl Phthalate for V(V) Extraction from Sulfate Solutions
    Bahrami, S ; Dolatyari, L ; Shayani-Jam, H ; Yaftian, MR ; Kolev, SD (MDPI, 2022-01)
    A polymer inclusion membrane (PIM) composed of 50 wt% base polymer poly(vinylidenefluoride-co-hexafluoropropylene), 40 wt% extractant Aliquat® 336, and 10 wt% dibutyl phthalate as plasticizer/modifier provided the efficient extraction of vanadium(V) (initial concentration 50 mg L-1) from 0.1 M sulfate solutions (pH 2.5). The average mass and thickness of the PIMs (diameter 3.5 cm) were 0.057 g and 46 μm, respectively. It was suggested that V(V) was extracted as VO2SO4- via an anion exchange mechanism. The maximum PIM capacity was estimated to be ~56 mg of V(V)/g for the PIM. Quantitative back-extraction was achieved with a 50 mL solution of 6 M H2SO4/1 v/v% of H2O2. It was assumed that the back-extraction process involved the oxidation of VO2+ to VO(O2)+ by H2O2. The newly developed PIM, with the optimized composition mentioned above, exhibited an excellent selectivity for V(V) in the presence of metallic species present in digests of spent alumina hydrodesulfurization catalysts. Co-extraction of Mo(VI) with V(V) was eliminated by its selective extraction at pH 1.1. Characterization of the optimized PIM was performed by contact angle measurements, atomic-force microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis/derivatives thermogravimetric analysis and stress-strain measurements. Replacement of dibutyl phthalate with 2-nitrophenyloctyl ether improved the stability of the studied PIMs.
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    Differential toxicological effects of natural and synthetic sources and enantiomeric forms of limonene on mosquito larvae
    Ross, PA ; Nematollahi, N ; Steinemann, A ; Kolev, SD ; Hoffmann, AA (SPRINGER, 2022-01)
    Abstract Common fragranced consumer products, such as cleaning supplies and personal care products, emit chiral compounds such as limonene that have been associated with adverse effects on human health. However, those same compounds abound in nature, and at similar concentrations as in products, but without the same apparent adverse human health effects. We investigated whether different types of limonene may elicit different biological effects. In this study, we investigated the mortality rate of mosquito larvae in response to changes in their environment. Specifically, we tested different sources of naturally occurring R-limonene and chemically synthetized limonene, containing one of its enantiomeric forms (R-, S-) in mortality bioassays with Aedes aegypti mosquito larvae. We found that a natural source of limonene extracted from oranges induced lower mortality of mosquito larvae compared to synthetic sources at the same concentration. However, enantiomeric forms did not differ in their effects on mortality. Our results provide novel evidence that natural sources of a chemical can cause lower rates of mortality than synthetic sources.
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    Limonene Emissions: Do Different Types Have Different Biological Effects?
    Nematollahi, N ; Ross, PA ; Hoffmann, AA ; Kolev, SD ; Steinemann, A (MDPI, 2021-10)
    Limonene is one of the most abundant pollutants indoors, and it contributes to the formation of additional pollutants, such as formaldehyde and photochemical smog. Limonene is commonly used in fragranced consumer products, such as cleaning supplies and air fresheners, which have also been associated with health problems. Limonene can exist in different enantiomeric forms (R-limonene and S-limonene) and be derived from different sources. However, little is known about whether different forms and sources of limonene may have different effects. This research explored whether different types of limonene, at the same concentrations, could elicit different biological effects. To investigate this question, the study employed Aedes aegypti mosquitoes, which have sophisticated olfactory abilities, in olfactometer tests of repellency/attraction. The results indicate that a synthetic source of R-limonene is more repellent than a natural source of R-limonene. In addition, synthetic sources of both R-limonene and S-limonene are not significantly different in repellency. These findings can contribute to our understanding and further exploration of the effects of a common fragrance compound on air quality and health.