Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
Add more filters










Publication year range
1.
Heliyon ; 10(7): e28622, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38689963

ABSTRACT

To eliminate the hazardous pesticide 2,4-dichlorophenylacetic acid (2,4-D) through aqueous solutions, stacked nanorods known as hetero bimetallic organic frameworks (MOFs) of 2-methyl imidazole based on lanthanum and zinc are created. The research's convincing discoveries displayed that La/Zn-MOF is an actual adsorbent for the removal of 2,4-D through aqueous solutions. The La/Zn-MOF was investigated using a variability of techniques, with scanning electron microscope (SEM), powered X-ray diffraction (PXRD), and Brunauer-Emmett-Teller (BET) investigation. La/Zn-MOF has a significant pore capacity of 1.04 cm³/g and a comparatively large surface area of 897.69 m2/g. Our findings, which are quite intriguing, demonstrate that adsorption behavior is pointedly wedged by variations in pH. A pH 6 dose of 0.02 g was shown to be the optimal setting for the greatest capacity for adsorption. Because adsorption is an endothermic process, temperature variations affect its capability. The adsorption method was fit both isothermally and kinetically using the Langmuir isotherm classical. It was created that the entire process made use of a chemisorption mechanism. Solution pH, temperature, adsorbent dosage, and time were all improved using the Box-Behnken design (BBD) and Response Surface Methodology (RSM). We were able to accurately calculate the values of ΔHo, ΔSo, and ΔGo for 2,4-D by following the guidelines. These results demonstrated the spontaneous and endothermic character of the adsorption procedure employing La/Zn-MOF as an adsorbent. Adsorption-desorption cycles can be carried out up to five times. With the synthesized La/Zn-MOF adsorbent due to its exceptional reusability. Many processes, such π-π interaction, pore filling, H-bonding, or electrostatic contact, were postulated to explain the connection between La/Zn-MOF and 2,4-D after extra research to appreciate well the link was conducted. This is the first study to demonstrate the effectiveness of utilizing La/Zn-MOF as an adsorbent to eliminate 2,4-D from wastewater models. The results display that a pH of 6 is required to achieve the maximal 2,4-D adsorption capability on La/Zn-MOF, which is 307.5 mg/g.

2.
ACS Omega ; 9(11): 13458-13468, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38524465

ABSTRACT

The present study introduced a novel disposable screen-printed carbon electrodes (SPCEs) modified with copper oxide/zeolite nanostructures for eco-friendly selective differential pulse voltammetric quantification of tetrahydrozoline (THZ) in eyedrop samples and biological fluids. Modification of the electrode matrix with copper oxide nanoparticles/zeolite nanostructures (CuONPs/ZY) with their effective and synergistic electrocatalytic activity enhanced the electrode performance against electrooxidation of THZ at 0.960 V in BR at pH 9.0 with a diffusion-controlled reaction mechanism. The tentative oxidation mechanism based on molecular orbital calculations postulates the oxidation of THZ molecules through oxidation of a nitrogen atom five-membered ring and the participation of two electrons/protons in the electrode reaction. Linear calibration curves were illustrated within a wide THZ concentration range from 0.24 to 57.2 µg mL-1 recording a limit of detection (LOD) value of 0.0799 µg mL-1. The CuONPs/ZY/SPEs exhibited improved performance compared with the sole reported THZ sensor-based gold film-plated carbon paste electrodes, in addition to their high reproducibility of fabrication and measurement and prolonged shelf lifetime. Tetrahydrozoline was successfully assayed in the presence of excipients, degradation products, and chloramphenicol. The presented voltammetric sensor can be considered as an eco-friendly and reliable analytical approach for monitoring THZ residues in eye drop samples and biological fluids with high recovery compared with the official pharmacopeial analytical protocol. The presented sensors were assessed according to an EcoScale tool and also compared with the reported THZ sensor.

3.
ACS Omega ; 9(1): 1562-1572, 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38222558

ABSTRACT

Thermochromic inks have proven to be a promising security encoding approach for making commercially available products less susceptible to forgery. However, thermochromic inks have been plagued with poor durability. Thus, self-healable hydrogels can be used as self-repair inks with better durability. Herein, we combined hybrid cellulose nanofibers (CNFs) and sodium alginate (SA) with anthocyanidin(Cy)-based Brassica oleracea L. var. capitata extract in the existence of mordant (ferrous sulfate) to create a self-healing ink for authentication. CNFs were used as a reinforcement agent to enhance the mechanical strength of the sodium alginate hydrogel. Both durability and thermal stability were ensured using self-healing inks. Red cabbage was used to extract Cy-based chromophore as an environmentally friendly spectroscopic probe for immobilization into SA. Using varying concentrations of anthocyanidin, self-healable composite hydrogels (Cy@SA) with thermochromic properties were provided. Using the CIE Lab color coordinate system, homogeneous purple (569 nm) films were printed onto a sheet surface. Upon heating from 25 to 70 °C, the purple color changed to red (433 nm). Transmission electron microscopy was applied to study anthocyanidin/mordant (Cy/M) nanoparticles (NPs). The properties of the applied prints were analyzed using several methods. Both the hydrogel and stamped sheets were tested for their mechanical and rheological characteristics, respectively. Research on the nanocomposite ink (Cy@SA) antibacterial properties and cytotoxicity was also conducted.

4.
Environ Technol ; : 1-23, 2023 Nov 12.
Article in English | MEDLINE | ID: mdl-37953534

ABSTRACT

ABSTRACTResearch efforts are focusing on investigating cost-effective and ecologically friendly ways to create nanoparticles as a result of promising developments in green technology (NPs). This experiment focused on the effectiveness of using biochar (TWB) made from coffee waste to extract levofloxacin (LEV) from water. The conclusive results of the trials showed that TWB is an effective adsorbent for removing LEV from liquid solutions. The TWB produced through biological processes underwent comprehensive analysis using techniques such as X-ray diffractometry (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller surface area measurement (BET), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy. The bioengineered TWB's exceptional crystalline properties, which closely resemble the monoclinic structure of bulk TWB, were confirmed by the XRD analysis. Based on the scanning electron microscopy (SEM) data, the synthesis of TWB Nanoparticles resulted in the formation of spherical particles with an approximate diameter of 40 nm, accompanied by a substantial surface area of 285.55 m²/g. The Pseudo-Second-Order model, which best captured Levofloxacin's adsorption characteristics, was evaluated on the TWB, and the results showed that external mass transfer was the main determinant of response rate. It was also found that the adsorption process was endothermic and spontaneous. The system was optimized using the Box-Behnken design (BBD) methodology. The achieved removal capacity of 1119.19 mg/g utilizing the tested adsorbent was determined to be reasonable when compared to the performance of other previously used adsorbents when evaluating the effectiveness of eliminating LEV. The process of LEV adsorption onto TWB involves a number of different mechanisms, such as ion exchange, π-π interactions, electrostatic pore filling, and hydrogen bonding. Following extensive testing in connection with a real-world sample, the adsorbent demonstrated remarkable efficacy, and it maintained good performance even after undergoing three further regeneration cycles. By adjusting the annealing temperature, we controlled the synthesis of TWB nanoparticles across a range of sizes in order to maximize their antibacterial capabilities. This research utilized a pair of Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and a pair of Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) to evaluate the antibacterial efficacy of TWB.


Green synthesis of biochar via using tea waste.Adsorption studies of harmful pesticides Levofloxacin (LEV).The adsorbents exhibited good reusability for four adsorption/desorption cycles.Adsorption fit with pseudo second order kinetics and Langmuir isotherm model.The adsorption fitted to pseudo-second-order kinetically.This system will provide helpful guidance for coloured effluent treatment.Optimized the results by using Box-Behnken design.

5.
ACS Omega ; 8(33): 30374-30388, 2023 Aug 22.
Article in English | MEDLINE | ID: mdl-37636940

ABSTRACT

This study looked at the doxorubicin hydrochloride (DOX) anticancer drug's adsorption characteristics on a silver-based metal-organic framework (Ag-MOF). X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used for the characterization of Ag-MOF. The pore volume and surface area of Ag-MOF were determined through Brunauer-Emmett-Teller (BET) testing at 77 K to be 0.509 cm3/g and 676.059 m2/g, respectively. Adsorption at pH 6 was established to be the best for DOX compared to alkaline solution. Ag-MOF has a good capacity for eliminating DOX (1.85 mmol/g), according to adsorption experiments. From the adsorption results, we can find that Langmuir is the most fitted adsorption isotherm model and the pseudo-second order model best fitted the adsorption kinetics. The energy of activation for adsorption, which was determined to be 15.23 kJ/mol, also supported a chemisorption process. The mechanism of adsorption was evaluated, and details of all possible interactions between DOX and Ag-MOF were illustrated. On the other hand, while examining the impact of temperature, we identified the thermodynamic constraints as ΔG°, ΔH°, and ΔS° and confirmed that the reaction was an endothermic one and spontaneous. Even after numerous reuse cycles, the efficiency remained constant. The synthetic adsorbent was remarkably recyclable at a rate of more than 91.6%. By using the MTT assay, the cytotoxicity of the tested Ag-MOF and DOX@Ag-MOF against human breast cancer cells (MCF-7) was evaluated in vitro. The in vitro antimicrobial activity of Ag-MOF and DOX@Ag-MOF was also tested.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 302: 122986, 2023 Dec 05.
Article in English | MEDLINE | ID: mdl-37336189

ABSTRACT

Electrospun glass nanofibers (GNFs) were used to strengthen polycarbonate (PC) to create long-persistent photoluminescent and fluorescent smart materials such as afterglow concrete and smart window. Physical integration of lanthanide-activated aluminate (LA) nanoparticles (NPs) yielded transparent GNFs@PC smart sheets. Spectral investigations utilizing photoluminescence and CIE Lab parameters were performed to confirm that the translucent appearance of GNFs@PC changed to green when exposed to UV light. This fluorescence activity was quickly reversible for the GNFs@PC hybrids with low concentrations of LANPs, which indicate fluorescence emission. Higher phosphor concentrations in GNFs@PC led to longer-lasting afterglow photoluminescence and slower reversibility. The GNFs@PC hybrids showed an emission band detected at 518 nm upon excitation at 368 nm. The morphological characteristics of LANPs and GNFs were analyzed by transmission electron microscopy (TEM), which revealed sizes of 11-26 nm and 250-300 nm, respectively. GNFs were prepared using electrospinning technology and then used as a roughening agent into PC sheets. Morphological characteristics of GNFs and GNFs@PC smart sheets were examined using energy-dispersive X-ray spectroscopy (EDXA), X-ray fluorescence (XRF) and scanning electron microscopy (SEM). The GNFs@PC smart sheets were shown to have enhanced scratch resistance in comparison to LANPs-free PC control sample. Increases in LANPs concentration enhanced both hydrophobicity and UV protection.

7.
Luminescence ; 38(5): 613-624, 2023 May.
Article in English | MEDLINE | ID: mdl-36929638

ABSTRACT

Novel thermochromic and vapochromic paper substrates were prepared via screen printing with anthocyanin extract in the presence of ferrous sulfate mordant, resulting in multi-stimuli responsive colorimetric paper sheets. Environmentally friendly anthocyanin extract was obtained from red-cabbage (Brassica oleracea var. capitata L.) to function as spectroscopic probe in coordination with ferrous sulfate mordant. Pink anthocyanin/resin nanocomposite films immobilized onto paper surface were developed by well-dispersion of anthocyanin extract as a colorimetric probe in a binding agent without agglomeration. As demonstrated by CIE colorimetric studies, the pink (λmax = 418 nm) film deposited onto paper surface turns greenish-yellow (λmax = 552 nm) upon heating from 25 to 75°C, demonstrating new thermochromic film for anti-counterfeiting applications. The thermochromic effects were investigated at different concentrations of the anthocyanin extract. Upon exposure to ammonia gas, the color of the anthocyanin-printed sheets changes rapidly from pink to greenish-yellow, and then immediately returns to pink after taking the gaseous ammonia stimulus away, demonstrating vapochromic effect. The current sensor strip showed a detection limit for ammonia gas in the range 50-300 ppm. Both thermochromism and vapochromism showed high reversibility without fatigue. In addition to studying the rheological properties of the prepared composites, the morphological and mechanical properties of the printed cellulose substrates were also studied.


Subject(s)
Ammonia , Anthocyanins , Anthocyanins/chemistry , Cellulose , Plant Extracts
8.
Environ Technol ; : 1-17, 2023 Feb 20.
Article in English | MEDLINE | ID: mdl-36749794

ABSTRACT

The indirect emission had a negative influence on the ecosystem of enormous amounts of harmful dyes into water. Fe3O4@Ag-MOF was successfully fabricated to capture Gentine violet (GV)) as a model example of cationic dye from their aqueous solutions was evaluated in this search as a method to eliminate dyes from water contaminants. FTIR, XPS, BET, TGA, SEM, TEM, and XRD have all been used to study this adsorbent in order to determine its structural and chemical characteristics as well as to interpret its binding mechanisms. According to the results of the characterization, the synthesized composite had a size about 45 nm, a surface area of 856.06 m2/g, and considerable magnetic characteristics (66.2 emug-1). Consequently, we created mesoporous surfaces that had a strong ability to interface and absorb GV dye. It is possible to use the pseudo-second order rate equation to characterize the kinetic profile., while the Langmuir equation fits isotherm models. At pH 9, maximum sorption capacities can reach 1.68 mmol.g-1. Additionally, the investigations of temperature profiles indicated the endothermic process and Thermodynamic parameters were discovered as, ΔG°, ΔH° and ΔS° The synthesized adsorbent had an interestingly high reusability of > 92 percent up to the sixth cycle. These findings revealed that a mixture of electrostatic interactions, π-π stacking, hydrogen bonds, and pore filling were involved in the GV adsorption mechanism. Fe3O4@Ag-MOF was successful in demonstrating its effectiveness as a point-of-use colour collection candidate from actual dyeing effluents.

9.
Luminescence ; 37(9): 1482-1491, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35859299

ABSTRACT

Nacre structure has aragonite polygonal tablets, tessellated to generate separate layers, and exhibits adjacent layers and tablets within a layer bonded by a biopolymer. Here, we report the development of a nacre-like organic/inorganic hybrid nanocomposite coating consisting of epoxy tablets as well as rare-earth-activated aluminate and graphene oxide tablet/tablet interfaces. The lanthanide-activated aluminate was prepared using a high temperature solid-state approach followed by top-down technology to provide the phosphor nanoparticles (PNPs). Graphene oxide nanosheets were prepared from graphite. The prepared epoxy/graphene/phosphor nanocomposites were applied onto mild steel. Covalent bonds were formed between epoxy polymer chains resin and the graphene oxide nanosheets. These interface interactions resulted in a tough surface, high tensile strength, and excellent durability. The use of phosphor in the nanoparticle form guaranteed that no agglomerations were produced throughout the hardening procedure by allowing better distribution of PNPs in the nacre-like matrix. The generated nacre-like substrates displayed reversible fluorescence. The excitation of the white coloured nacre-like coats at 367 nm resulted in a green emission band at 518 nm as designated by the Commission Internationale de l'éclairage (CIE) Laboratory and photoluminescence spectra. Various analysis methods were utilized to inspect the surface structure and elemental composition of the nacre-like coats. An improved hydrophobicity and mechanical characteristics were detected when increasing the phosphor concentration. Due to the astonishing characteristics of the prepared nacre-like composite paint, both ceramics and metals can benefit from the current simple strategy.


Subject(s)
Graphite , Lanthanoid Series Elements , Nacre , Nanocomposites , Nanoparticles , Epoxy Resins , Graphite/chemistry , Nacre/chemistry , Nanocomposites/chemistry
10.
ACS Omega ; 7(23): 19454-19464, 2022 Jun 14.
Article in English | MEDLINE | ID: mdl-35721986

ABSTRACT

Linen has been a significant material for textile packaging. Thus, the application of the simple spray-coating method to coat linen fibers with a flame-retardant, antimicrobial, hydrophobic, and anticounterfeiting luminescent nanocomposite is an innovative technique. In this new approach, the ecologically benign room-temperature vulcanizing (RTV) silicone rubber was employed to immobilize the environmentally friendly Exolit AP 422 (Ex) and lanthanide-doped strontium aluminum oxide (RESAO) nanoscale particles onto the linen fibrous surface. Both morphological properties and elemental compositions of RESAO and treated fabrics were examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), wavelength-dispersive X-ray fluorescence (WD-XRF), Fourier transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). In the fire resistance test, the treated linen fabrics produced a char layer, giving them the property of self-extinguishing. Furthermore, the coated linen samples' fire-retardant efficacy remained intact after 35 washing cycles. As the concentration of RESAO increased, so did the treated linen superhydrophobicity. Upon excitation at 366 nm, an emission band of 519 nm was generated from a colorless luminescent film deposited onto the linen surface. The coated linen displayed a luminescent activity by changing color from off-white beneath daylight to green beneath UV source, which was proved by CIE Lab parameters and photoluminescence spectral analysis. The photoluminescence effect was identified in the treated linen as reported by emission, excitation, and decay time spectral analysis. The comfort properties of coated linen fabrics were measured to assess their mechanical and comfort features. The treated linen exhibited excellent UV shielding and improved antimicrobial performance. The current simple strategy could be useful for large-scale production of multifunctional smart textiles such as packaging textiles.

11.
Microsc Res Tech ; 85(7): 2607-2617, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35373877

ABSTRACT

Anticounterfeiting of commercial products has been improved using photochromism as an intriguing approach. In order to develop a mechanically reliable nanocomposite, the engineering procedure of the anticounterfeiting nanocomposite must be improved. Rare-earth doped aluminate/polypropylene (REA/PP) hybrid nanofibers were successfully made by electrospinning, and they were shown to be mechanically stable and highly photoluminescent, making them ideal for anticounterfeiting applications. UV-induced photochromic anticounterfeiting properties were monitored in the synthesized nanocomposite films. In order to ensure that the REA-PP film is completely transparent, REA must be embedded into the polypropylene nanofibers in nano-sized particle shape to facilitate a better dispersion without agglomeration of REA particles in polypropylene matrix. The morphology and structure of REA were studied by transmission electron microscopy and X-ray diffraction. The morphologies and chemical contents of the polypropylene nanofibrous films were studied by scanning electron microscopy, X-ray fluorescence, and energy-dispersive X-ray spectroscopy. The REA-PP nanofibrous film showed absorbance and emission maxima at 365 and 517 nm, respectively. When exposed to UV light, the photochromic activity of the transparent nanofibrous substrates to greenish-yellow was rapid and reversible without fatigue. Hydrophobicity of REA-PP films increased without affecting their original look or mechanical properties, while increasing the REA content. It was possible to produce ultraviolet-induced photochromic nanofibrous films that were transparent, flexible, and cost-effective. As a result of this method, numerous anticounterfeiting materials could be developed toward a better marketplace with both economy and community values. HIGHLIGHTS: Rare-earth aluminate/polypropylene (REA/PP) electrospun nanofibers were prepared. The photochromic transparent nanofibers displayed green emission under UV light. The nanofibrous films were flexible, mechanically stable and highly luminescent. Films showed absorbance and emission maxima at 365 and 517 nm, respectively. Hydrophobicity was improved without affecting the films original properties.

12.
Luminescence ; 37(3): 479-489, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35043557

ABSTRACT

Long-persistent phosphorescent smart paints have the ability to continue glowing in the dark for a prolonged time period to function as energy-saving products. Herein, new epoxy/silica nanocomposite paints were prepared with different concentrations of lanthanide-doped aluminate nanoparticles (LAN; SrAl2 O4 :Eu2+ ,Dy3+ ). The LAN pigment was firstly coated with silicon dioxide (SiO2 ) utilizing the heterogeneous precipitation technique to provide LAN-encapsulated between SiO2 nanoparticles (LAN@SiO2 ). The epoxy/silica/lanthanide-doped aluminate nanoparticles (ESLAN) nanocomposite paints were coated on steel. The prepared ESLAN paints were studied by transmission electron microscopy (TEM), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray fluorescence (XRF) analysis, and energy-dispersive X-ray spectroscopy (EDS). The transparency and coloration properties of the nanocomposite coated films were explored by CIE Lab parameters and photoluminescence spectra. The ultraviolet-induced luminescence properties of the transparent coated films demonstrated greenish phosphorescence at 518 nm upon excitation at 368 nm. Both hardness and hydrophobic activities were investigated. The anticorrosion activity of the nanocomposite films coated onto mild steel substrates immersed in aqueous sodium chloride (NaCl(aq) ) (3.5%) was studied by electrochemical impedance spectroscopy (EIS). The silica-containing coatings were monitored to exhibit anticorrosion properties. Additionally, the nanocomposite films with LAN@SiO2 (25%) exhibited the optimized long-lasting luminescence properties in the dark for 90 min. The nanocomposite films showed highly reversible and durable long-lived phosphorescence.


Subject(s)
Caustics , Strontium , Hydrophobic and Hydrophilic Interactions , Luminescence , Silicon Dioxide
13.
ACS Omega ; 6(41): 27315-27324, 2021 Oct 19.
Article in English | MEDLINE | ID: mdl-34693152

ABSTRACT

Photochromic materials have attracted broad interest to enhance the anti-counterfeiting of commercial products. In order to develop anti-counterfeiting mechanically reliable composite materials, it is urgent to improve the engineering process of both the material and matrix. Herein, we report on the development of anti-counterfeiting mechanically reliable nanocomposites composed of rare-earth doped aluminate strontium oxide phosphor (RESA) nanoparticles (NPs) immobilized into the thermoplastic polyurethane-based nanofibrous film successfully fabricated via the simple solution blowing spinning technology. The generated photochromic film exhibits an ultraviolet-stimulated anti-counterfeiting property. Different films of different emissive properties were generated using different total contents of RESA. Transmission electron microscopy was utilized to investigate the morphological properties of RESA NPs to display a particle diameter of 3-17 nm. The morphologies, compositions, optical transmittance, and mechanical performance of the produced photochromic nanofibrous films were investigated. Several analytical methods were employed, including energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared spectrometry. The fibrous diameter of RESA-TPU was in the range of 200-250 nm. In order to ensure the development of transparent RESA-TPU film, RESA must be prepared in the nanosized form to allow better dispersion without agglomeration in the TPU matrix. The luminescent RESA-TPU film displayed an absorbance intensity at 367 nm and two emission intensities at 431 and 517 nm. The generated RESA-TPU films showed an enhanced hydrophobicity without negatively influencing their original appearance and mechanical properties. Upon irradiation with ultraviolet light, the transparent nanofibrous films displayed rapid and reversible photochromism to greenish-yellow without fatigue. The produced anti-counterfeiting films demonstrated stretchable, flexible, and translucent properties. As a simple sort of anti-counterfeiting substrates, the current novel photochromic film provides excellent anti-counterfeiting strength at low-cost as an efficient method to develop versatile materials with high mechanical strength to create an excellent market as well as adding economic and social values.

SELECTION OF CITATIONS
SEARCH DETAIL
...