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Abstract: In the present study, we synthesized fluorocarbon-coated cobalt ferrite (CoFe2O4) magnetic nanoparticles using alkoxysilanes such as trimethoxy(3,3,3-trifluoropropyl)silane (TFPTMS), trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane (NFHTMS), and triethoxy(1H,1H,2H,2H-perfluorodecyl)silane (PFDTES). The synthesized nanoparticles were characterized by various techniques, including X-ray diffractometry (XRD), transmission electron microscopy (TEM/HRTEM/EDXS), Fourier transform infrared spectroscopy (FTIR), specific surface area measurements (BET), and magnetometry (VSM). To understand their surface characteristics, contact angle (CA) measurements were carried out, providing valuable insights into their hydrophobic properties. Among the samples of CoFe2O4 coated with fluoroalkoxysilanes, those with PFDTES surface coating had the highest water contact angle of 159.2°, indicating their superhydrophobic character. The potential of the prepared fluoroalkoxysilane-coated CoFe2O4 nanoparticles for the removal of waste low-SAPS synthetic engine oil from a model aqueous solution was evaluated based on three key parameters: adsorption efficiency (%), adsorption capacity (mg/g), and desorption efficiency (%). All synthesized CoFe2O4 samples coated with fluoroalkoxysilane showed high oil adsorption efficiency, ranging from 87% to 98%. The average oil adsorption capacity for the samples was as follows: F3-SiO2@CoFe2O4 (3.1 g of oil/g of adsorbent) > F9-SiO2@CoFe2O4 (2.7 g of oil/g of adsorbent) > F17-SiO2@CoFe2O4 (1.5 g of oil/g of adsorbent) as a result of increasing oleophobicity with increasing fluorocarbon chain length. The desorption results, which showed 77–97% oil recovery, highlighted the possibility of reusing the adsorbents in multiple adsorption/desorption cycles.
Keywords: cobalt ferrite, spinel, fluorocarbons, oil spill, adsorption, hydrophobicity, oleophobicity, water remediation
Published in DKUM: 06.08.2025; Views: 0; Downloads: 10
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Abstract: : There has been growing interest and increasing attention in the field of functional clothing textiles, particularly in product and process development, as well as innovations in heat-generating, retaining, and releasing fibers to maintain a healthy body temperature without relying on unsustainable energy sources. This study, for the first time, reports the various physio-mechanical properties of surface-functionalized regenerated cellulose fibers (RCFs) coated with ceramic particles. The coating imparts photothermal conversion-based heat generation and retention properties with the aid of polyelectrolyte binders. In this design, ZrC enables the conversion of light energy into thermal energy, providing heat for the human body. A feasible coating process was employed, utilizing industrially feasible exhaustion methods to deposit the ZrC particles onto the RCF surface in conjunction with two distinctive polymeric binders, specifically polyethyleneimine (PEI) and polydiallyldimethylammonium chloride (polyDADMAC). The morphological characteristics and tensile properties of the coated RCFs were analyzed via scanning electron microscopy (SEM) and single-fiber tensile testing. Heat retention and release behaviors of a bundle of fiber samples were assessed using infrared (IR) imaging and an IR emission lamp setup. The SEM results confirmed the successful coating of the ZrC particles on the surface of the RCF samples, influencing negligible on their physical–mechanical properties. The heat retention of the coated RCFs with ZrC and both binders was higher than that of reference regenerated cellulose fibers (RCFs), demonstrating their effective heat generation, retention, and heat release properties. Based on the highlighted prominent results for the coated RCFs, these findings highlight the suitability of the developed functional clothing textiles for targeted applications in non-extreme thermal conditions, ensuring thermo-physiological comfort by maintaining body temperature within a tolerable thermal range (36.5–37.5 ◦C), in contrast to studies reporting significantly higher temperatures (50–78 ◦C) for extreme thermal conditions.
Keywords: regenerated cellulose fibers, RCFs, ceramic particles, zirconium carbide, ZrC, surface functionalization, heat generation and retention
Published in DKUM: 01.04.2025; Views: 0; Downloads: 136
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Abstract: Nanomaterials and sensors play an important role in modern technologies, including medical diagnostics and biochemical research. This work presents the possibility of using o-Phthaldialdehyde (OPA) in combination with 3-mercaptopropyltriethoxysilane (MPTES) to develop a dopamine-responsive sensor. During the experiment, these materials were used at different pH and ratios to determine the optimal parameters for obtaining high fluorescence intensity of the reaction product. The data obtained demonstrate a linear relationship between the fluorescence response (λex/λem = 340/460 nm) of OPA/MPTES and dopamine concentration in the range of 0.1–3.0 µM at a pH of 8, and the detection limit was 8.7 nM. The obtained results confirm the potential of OPA/MPTES as a sensing component for the detection of dopamine
Keywords: fluorometric method, dopamine, o-phthalaldehyde
Published in DKUM: 13.03.2025; Views: 0; Downloads: 5
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Abstract: The research aim was to remove as many microfibres, microplastics and harmful bacteria as possible from the polluted water to produce suitable water for reuse. The test water was the effluent from the municipal wastewater treatment plant in Shalek Valley. A pilot plant with a ceramic SiC filter for membrane filtration and ozonation of filtered water was set up to remove suspended solids, micro-fibres, microplastics, and harmful microorganisms. The Microfibers Detection System was developed to identify microfibers on-site. The results showed that the microfiltration system combined with ozone treatment effectively removed total suspended solids, microfibres, microplastics and microorganisms. A detection system method for identifying microfibres and microplastic particles was used to determine how many microfibres and microorganisms were identified by membrane filtration and ozonation. The study showed that membrane filtration successfully removed all microfibres, 88% of total coliforms and 93% of E. coli. After additional ozonation, we achieved a 100% removal rate of total coliforms and a 100% removal rate of E. coli. The treated water (effluent from the municipal wastewater treatment plant) can be used for specific purposes, such as agricultural irrigation or enhancing bathing waters near the plant’s water effluent.
Keywords: microfibres removal, microplastics, microfiltration, ozonation, water reuse
Published in DKUM: 26.09.2024; Views: 0; Downloads: 304
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Abstract: Dopamine is an important hormone and neurotransmitter, and its levels in human fluids can indicate stress, depression, and various mental disorders. Food products, as well as medications, affect its level in the human body greatly. Therefore, dopamine monitoring is crucial, and necessary for improving the quality of life. The priority is to search for simple and environmentally friendly sensor systems for the in vitro detection of dopamine, enabling mass utilization. In this study, we explored the use of o-phthalaldehyde (OPA) as an indicator for the detection of dopamine, with fluorescence in the visible range (λex/λem = 390/455 nm), while direct dopamine fluorescence measurement was in the UV range (λex/λem = 280/320 nm). The longer excitation/emission wavelengths of dopamine-OPA complex, as well as lower detection limits, are useful for developing a simple detection method using LEDs. Three types of poloxamers were tested as additives to improve the fluorescence signal from the reaction between dopamine and OPA. Pluronic F127 led to a 16-fold increase in the fluorescence. Utilizing 4% Pluronic F127 with OPA at pH 7 resulted in a linear response within concentration ranges of dopamine (0.5–3 µM), achieving a limit of detection of 0.015 µM. In contrast, a direct detection of dopamine within the same range exhibited a detection limit of 0.13 µM.
Keywords: fluorometric method, dopamine, O-phthalaldehyde, Pluronic F127
Published in DKUM: 28.05.2024; Views: 317; Downloads: 38
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