Showing papers on "Acetone published in 2023"

Polypyrrole-Ag/AgCl Nanocomposite-Enabled Exhaled Breath-Acetone Monitoring Non-Invasive Biosensor for Diabetes Diagnostics

Abstract: The state-of-the-art diabetes diagnosis is concerned with developing non-invasive nano-enabled exhaled breath-acetone detection strategies. Here, we detail the potential of polypyrrole(PPy)– Silver/silver chloride (Ag/AgCl) ternary nanocomposites (NCs) for monitoring low-trace of acetone in human breath for diabetes diagnosis. The PPy–Ag/AgCl NCs were synthesized through in-situ chemical oxidative polymerization of aniline by silver nitrate in the presence of hydrochloric acid. The morphological analysis revealed the existence of spherical Ag/AgCl nanoparticles (~50 nm diameter) embedded in PPy matrix of nano fibrillar morphology (~20 nm diameter). The structural investigations confirm the co-existence of PPy, Ag and AgCl nanoparticles in the ternary nanocomposite. The NC exhibited manifold superior sensing performance towards low trace (as low as ~1 ppm) of breath-acetone with excellent sensitivity (~ 20%), prompt response (~20s), fast recovery (~100s), linear detecting range, and high repeatability at room temperature compared to pristine PPy. It is attributed to synergistic effects in ternary NC due to physicochemical merits of all precursors. Moreover, it showed high stability and selectivity towards acetone in the presence of prominent interfering VOCs and varying humidity. It opens a new window for non-invasive, economic, energy-efficient and point-of-care sensors for diagnosing diabetes in humans and, revolutionizing clinical diagnostics and personal healthcare.

Metallic Zinc Anode Working at 50 and 50 mAh cm−2 with High Depth of Discharge via Electrical Double Layer Reconstruction

Abstract: Achieving high‐rate and high‐areal‐capacity Zn anode with high depth of discharge (DOD) offers a bright future for large‐scale aqueous batteries. However, Zn deposition suffers from severe dendrite growth and side reactions, which compromises achievable lifetime. Herein, an electrical double layer (EDL) reconstruction strategy is proposed by employing acetone as electrolyte additive to fully address these issues. Experimental and theoretical simulation results reveal that the adsorption priority of acetone to water on Zn creates a water‐poor inner Helmholtz layer. Meanwhile, the intense hydrogen bonding effect between acetone and water confines the activity of free water and weakens the Zn2+ solvation in the outer Helmholtz layer and diffusion layer. Such ion/molecule rearrangement in EDL suppresses hydrogen evolution, facilitates the desolvation process, and promotes the Zn2+ diffusion kinetics, which guides homogeneous Zn nucleation and uniform growth, even in extreme situations. At both ultrahigh current density of 50 mA cm−2 and areal capacity of 50 mAh cm−2, the addition of 20 v/v% acetone in 2 m ZnSO4 extends the lifespan of Zn//Zn symmetric cells from 12 to 800 h, with a high DOD of 73.5%. The effectiveness of this strategy is further demonstrated in the Zn‐MnO2 full batteries at wide temperature range from −30 to 40 °C.

One-step fabrication of TiO2@polyoxometalates@α-Fe2O3 one-dimensional tandem heterojunctions for conductometric acetone sensors

Abstract: Herein, we provide a new strategy to construct TiO2 @[email protected] α-Fe2O3 one-dimensional tandem heterojunctions materials utilizing one-step coaxial electrospinning. Three series of TiO2 @[email protected] α-Fe2O3 core-middle-shell nanoribbons with different Keggin-type POMs are synthesized. The tandem heterogeneous interfaces between the three layers are continuously distributed in a one-dimensional line along the nanoribbons. Gas sensing performances of the nanoribbons are investigated. The gas sensors show significantly improved sensitivity and selectivity to acetone compared with both composite nanoribbons and POMs-free nanoribbons. The enhancement can be due to the addition of POMs electron acceptors, the construction of tandem heterojunctions and the one-dimensional nano-structure, which can together accelerate electrons transfer and reduce their recombination. Besides, the effects of different kinds and contents of POMs on gas sensing performance are studied. The results show that the response value of the optimal sensor to 100 ppm acetone can reach 14.81, which is 2.9 times of that of TiO2 @ α-Fe2O3 double-layered nanoribbons. This work provides a novel strategy for developing high performance gas sensors by constructing tandem heterojunctions as well as introducing POMs electron acceptor, and offers new insight into the development of POMs-based gas sensors.

V2CTX MXene-based hybrid sensor with high selectivity and ppb-level detection for acetone at room temperature

Abstract: High-performance, room temperature-based novel sensing materials are one of the frontier research topics in the gas sensing field, and MXenes, a family of emerging 2D layered materials, has gained widespread attention due to their distinctive properties. In this work, we propose a chemiresistive gas sensor made from V2CTx MXene-derived, urchin-like V2O5 hybrid materials (V2C/V2O5 MXene) for gas sensing applications at room temperature. The as-prepared sensor exhibited high performance when used as the sensing material for acetone detection at room temperature. Furthermore, the V2C/V2O5 MXene-based sensor exhibited a higher response (S% = 11.9%) toward 15 ppm acetone than pristine multilayer V2CTx MXenes (S% = 4.6%). Additionally, the composite sensor demonstrated a low detection level at ppb levels (250 ppb) at room temperature, as well as high selectivity among different interfering gases, fast response-recovery time, good repeatability with minimal amplitude fluctuation, and excellent long-term stability. These improved sensing properties can be attributed to the possible formation of H-bonds in multilayer V2C MXenes, the synergistic effect of the newly formed composite of urchin-like V2C/V2O5 MXene sensor, and high charge carrier transport at the interface of V2O5 and V2C MXene.

Effects of Addition of CuxO to Porous SnO2 Microspheres Prepared by Ultrasonic Spray Pyrolysis on Sensing Properties to Volatile Organic Compounds

Abstract: Porous (pr-)SnO2-based powders were synthesized by ultrasonic spray pyrolysis employing home-made polymethylmethacrylate (PMMA) microspheres (typical particle size: 70 nm in diameter), and effects of the CuxO addition to the pr-SnO2 powder on the acetone and toluene sensing properties were investigated. Well-developed spherical pores reflecting the morphology of the PMMA microsphere templates were formed in the SnO2-based powders, which were quite effective in enhancing the acetone and toluene responses. The 0.8 wt% Cu-added pr-SnO2 sensor showed the largest acetone response at 350 °C among all the sensors. Furthermore, we clarified that the addition of CuxO onto the pr-SnO2 decreased the concentration of carrier electrons and the acetone-oxidation activity, leading to the improvement of the acetone-sensing properties of the pr-SnO2 sensor.

Antioxidant activity and phytochemical analysis of fennel seeds and flaxseed

Abstract: Abstract Natural herbs are now receiving more attention due to the growing demand for their antioxidant properties. This study compared flaxseed and fennel seeds for their nutritional composition, bioactive moieties, and antioxidant activity—the study comprised two different phases. According to methods, phase I analyzed flaxseed and fennel seeds for proximate composition, mineral profile, dietary fiber, and amino acid content. In phase II, seeds were extracted using three different solvents, i.e., ethanol 80%, acetone 80%, and distilled water, to probe the total phenolic and flavonoid content. Antioxidant activity was measured using DPPH and a FRAP in the final phase. Current study revealed that flaxseed had higher protein (17.33 ± 0.02%), fat content (36.76 ± 0.02%), potassium (763.66 ± 4.04 mg/100 g), iron (5.13 ± 0.03 mg/100 g), phosphorus (581.46 ± 4.07 mg/100 g), magnesium (406.60 ± 5.12 mg/100 g), and zinc (3.30 ± 0.49 mg/100 g), respectively. In fennel seed, high dietary fiber (53.2 ± 0.01 g/100 mg), calcium, manganese, and sodium (588.93 ± 7.77, 20.30 ± 0.95, and 57.34 ± 0.33 mg/100 g, respectively) were found. Acetone showed better extraction efficiency than acetone, ethanol, and distilled water. Moreover, acetone flaxseed extract showed higher total phenolic content (84.13 ± 7.73 mgGAE/g), flavonoid content (5.11 ± 1.50 mgQE/g), and FRAP (5031 ± 15.92 μMFe2+/g) than fennel seed extract. This study showed that, among both herbs, flaxseed extract may have pharmacological potential in preventing illnesses and may be suggested for use in the food industry as a natural antioxidant.

Performance of 1D tin (Sn) decorated spherical shape ZnO nanostructures as an acetone gas sensor for room and high temperature

Abstract: Spherical ZnO nanostructures doped with Sn nanoparticles (2 %, 5%, 7 %, and 10 %) were created using the hydrothermal technique. Characterizations included XRD, FTIR, XPS, HR-TEM, FESEM, SAED, EDS, BET and UV–Visible. Maximum gas response was achieved by optimising doping concentration. When ZnO and Sn doped ZnO nanostructures were examined at various temperatures (room temperature, 100, 150, 200, and 250 °C), it was discovered that 150 °C provided the best gas response. Using several saturated solutions, the gas sensing study was conducted at various humidity rates (11, 32, 51, 63, and 84 %). In comparison to the undoped and doped sensors (2, 7 and 10 %), the 5 % Sn doped ZnO sensor has the highest response (75 %). Compared to other gases, acetone gas exhibits improved selectivity towards Sn doped ZnO sensors. Response and recovery times for 5 % Sn doped ZnO are 30.19 and 63.54 s, respectively, and repeatability was examined for roughly 60 days.

Black Phosphorus Nanosheets Decorated Multiscale Zinc Ferrite Spheres Toward Swift and Humidity-Tolerant Breath Acetone Sensing

Abstract: Unreasonable acetone emission from various cosmetic and industrial products readily imposes severe ecological harm and human health through airborne transmission and groundwater circulation, thus necessitating the pressing requirement of sensitive and swift acetone detection. To this end, chemoresistive MEMS acetone sensors featuring the sensing layer of a few black phosphorus (BP) nanosheets-modified multiscale zinc ferrite (ZnFe2O4) spheres were leveraged in this work. After the optimization of constituent combination and operation temperature, the 0.5 wt% BP/ZnFe2O4 sensors could recognize 0.1–2 ppm acetone at 188 °C. With respect to pure ZnFe2O4 analog, the 0.5 wt% BP/ZnFe2O4 sensors delivered approximately twofold response enhancement (5.34 versus 2.73 toward 0.5-ppm acetone) and stronger sensitivity (5/ppm versus 3/ppm). Also, excellent selectivity, repeatability, and long-term stability were exhibited. The response/recovery times of 6/63 s toward 0.5-ppm acetone manifested a swift balance of gas–solid interaction. Inspiringly, the sensor showed an excellent humidity-resistant response toward 100-ppb acetone. Moreover, the simulated detection revealed a high application potential in diabetic monitoring featuring sub-ppm acetone and a high moisture environment. The ameliorated sensor performance after incorporating few but modest BP could be attributed to the consequent larger specific surface area, richer oxygen vacancies, and numerous p-n heterojunctions.

MOF Structure engineering to synthesize core-shell heterostructures with controllable shell layer thickness: Regulating gas selectivity and sensitivity

Abstract: Metal-organic framework (MOF)-derived metal oxide semiconductors have received significant attention for gas sensing applications. Herein, we reported core-shell In2O3@ZnO n-n heterostructures by depositing ZIF-8 derivative onto wrinkled In2O3 sphere, realizing the control of ZnO shell thickness (12.6–72.4 nm) through controlling MOF growth time. Due to the formation of n-n heterojunction at the core-shell interface, the tuning of shell thickness can lead to the radial modulation of the electron-accumulation layer in ZnO, and realizing the control of free charge carrier concentration that participated in gas sensing reaction. What’s more, the MOF-derived ZnO shell with rich oxygen vacancies is beneficial for oxygen chemisorption. Accordingly, compared with the In2O3 based sensor, the In2O3@ZnO based sensor exhibits higher sensitivity to trace-level acetone (100 ppb), faster response time (2 s vs. 100 ppm), better selectivity, and stronger anti-humidity capacity at operating temperature 300 °C, while the thickness of ZnO shell is 55.3 nm. In addition, the increase of ZnO shell thickness can lead to the selectivity change from ethanol to acetone of In2O3@ZnO owing to the inherent catalytic oxidation activity. Thus, the remarkable performance of the In2O3@ZnO sensor mainly relies on ZnO shell layer.

Defect Engineering of Green Phosphorene Nanosheets for Detecting Volatile Organic Compounds: A Computational Approach

Abstract: The high performance of chemical gas detection has become an essential factor for monitoring biotoxin volatile organic compounds (VOCs). Here, using first-principles modeling, defect engineering of green phosphorene (GreenP) with heteroatom substitution and vacancy formation was proposed to obtain high sensing ability and reusability of gas sensing materials for VOC gases. Our computations suggest that pristine and S- and C-doped GreenP weakly adsorbs the VOC gases with small charge transfer, leading to almost no change in the electronic properties. Although mono- and di-vacancy GreenP substantially improves the adsorption strength, the electronic structure exhibits negligible changes upon adsorption, resulting in low sensitivity. Remarkably, Si doping improves the adsorption of carbonyl-containing compounds, including acetone, propanal, and formaldehyde, and yields major changes in the electronic properties and work function, which promote sensitivity and selectivity. In addition, their adsorption energies are moderately strong, which also allow for fast desorption at elevated temperature, resulting in high reusability. From the computational viewpoints, we proposed Si-doped GreenP as a promising candidate for gas sensing material for VOC detection.

Nicotiana tabacum Leaf Waste: Morphological Characterization and Chemical-Functional Analysis of Extracts Obtained from Powder Leaves by Using Green Solvents

Abstract: Tobacco cultivation and industrialization are characterized by the production of trillions of pre-harvest and post-harvest waste biomasses each year with the resulting negative effects on the environment. The leaves of blunt, pre-harvest waste, could be further used to obtain bioactive metabolites, i.e., polyphenols and alkaloids, for its potential cosmetic use. This study was conducted to obtain bio-compounds from pre-harvest tobacco leaf waste (var. Virginia) by applying conventional and green solvents (NaDES). Leaves and ground leaf waste were characterized based on their microscopic features. Conventional solvents, such as water, acetone, ethanol, and non-conventional solvents, such as Natural Deep Eutectic Solvents (NaDES), i.e., sucrose:lactic acid (LAS), frutose:glucose:sucrose (FGS), lactic acid:sucrose:water (SALA), choline chloride:urea (CU), and citric acid: propylene glycol (CAP) were used for bioactive extraction from tobacco waste powder. CU, FGS, and acetone/ethanol had similar behavior for the best extraction of alkaloids (6.37–11.23 mg ACE/g tobacco powder). LAS, FGS, SALA, and CU were more effective in phenolic compound extraction than conventional solvents (18.13–21.98 mg AGE/g tobacco powder). Because of this, LAS and SALA could be used to obtain phenolic-enriched extracts with lower alkaloid content rather than CU and FGS. Extracts of the powder obtained with conventional solvent or CU showed a high level of sugars (47 mg/g tobacco powder) The ABTS antioxidant capacity of tobacco leaf powder was higher in the extracts obtained with CU, FGS, and acetone (SC50 1.6–5 µg GAE/mL) while H2O2 scavenging activity was better in the extracts obtained with LAS, CAP and SALA (SC50 3.8–8.7 µg GAE/mL). Due to the biocompatibility of the NaDES with the components of tobacco leaf waste, the opportunity to apply these extracts directly in antioxidant formulations, such as cosmetics, phytotherapic, and other formulations of topic use seems promising. Furthermore, NaDES constituents, i.e., urea and organic acid can also have beneficial effects on the skin.

Enzymatic Synthesis of Ascorbyl Palmitate in a Rotating Bed Reactor

Abstract: Ascorbyl palmitate, an ascorbic acid ester, is an important amphipathic antioxidant that has several applications in foods, pharmaceuticals, and cosmetics. The enzymatic synthesis of ascorbyl palmitate is very attractive, but few efforts have been made to address its process scale-up and implementation. This study aimed at evaluating the enzymatic synthesis of ascorbyl palmitate in a rotating basket reactor operated in sequential batches. Different commercial immobilized lipases were tested, and the most suitable reaction conditions were established. Among those lipases studied were Amano Lipase PS, Lipozyme® TL IM, Lipozyme® Novo 40086, Lipozyme® RM IM and Lipozyme® 435. Initially, the enzymes were screened based on previously defined synthesis conditions, showing clear differences in behavior. Lipozyme® 435 proved to be the best catalyst, reaching the highest values of initial reaction rate and yield. Therefore, it was selected for the following studies. Among the solvents assayed, 2-methyl-2-butanol and acetone showed the highest yields, but the operational stability of the catalyst was better in 2-methyl-2-butanol. The tests in a basket reactor showed great potential for large-scale application. Yields remained over 80% after four sequential batches, and the basket allowed for easy catalyst recycling. The results obtained in basket reactor are certainly a contribution to the enzymatic synthesis of ascorbyl palmitate as a competitive alternative to chemical synthesis. This may inspire future cost-effectiveness studies of the process to assess its potential as a viable alternative to be implemented.

Enhanced Acetaldehyde Sensing Performance of Spherical Shaped Copper Doped ZnO Nanostructures

Abstract: Spherical shape copper (Cu) doped ZnO nanostructures of various amount (3, 6, 9 and 12 %) were synthesized. The XRD, FTIR, UV-Visible, HR-TEM, FESEM, EDS, SAED and XPS were done to understand the structural, optical, morphology and shape of Cu doped ZnO nanostructures. To achieve the best gas reaction, doping concentration was optimized. ZnO and Cu doped ZnO nanostructures were exposed to various oxygenated volatile organic compounds (OVOCs) and found to be more selective towards acetaldehyde sensing. For 50 ppm acetaldehyde gas, temperature study was done at various temperatures (RT, 50, 100, 150, 200 °C) which showed optimal at 100°C for maximal gas response. The response and recovery time was 16.53 and 18.36 seconds for 50 ppm of acetaldehyde gas. The gas sensing study was carried out at different humidity rates (11, 32, 51, 63 and 84 %) using different saturated solutions. 9 % Cu doped ZnO shows maximum response (61.53 %) as compared to pure ZnO and 3, 6 and 12 % Cu doped ZnO. The spherical shape Cu doped ZnO sensing response was increases with increase in concentration of gas from 10 to 300 ppm. Acetaldehyde gas shows enhanced selectivity towards spherical shape Cu doped ZnO sensors as compared to the other OVOCs like acetone, ethyl methyl ketone, methanol, ethanol, n-propanol, n-butanol, formaldehyde, acetaldehyde, propionaldehyde and acrolein. The reproducibility of Cu doped ZnO was studied for 50 days. Also, after acetaldehyde gas sensing change in morphology study of sensor was done.

Monohydric aliphatic alcohols as liquid fuels for using in internal combustion engines: A review

Abstract: The environmental and air pollution brought about by the increasing energy consumption has increased the interest in the use of renewable energy sources in the transportation sector, where internal combustion engines are used, which is responsible for a large part of the exhaust emissions. Alcohol fuels have been evaluated as renewable energy sources for utilising in internal combustion engines and they are reported to have lowering exhaust emissions and costs. This study analyses four monohydric aliphatic alcohol fuels (methanol, ethanol, propanol and butanol) by reviewing the available literature to represent their applicability as an alternative fuel in internal combustion engines. In the study, researches on the directly use of acetone–butanol–ethanol and isopropanol–butanol–ethanol as alcohol fuel were also examined because the production of butanol by acetone–butanol–ethanol and isopropanol–butanol–ethanol distillation is costly, and isopropanol–butanol–ethanol is more preferred due to the corrosive feature of acetone. The higher fuel consumption of alcohol fuels than fossil fuels was the most common result, with reductions in NOx and smoke emissions except for isopropanol–butanol–ethanol, which had higher NOx emissions. It has been reported that less carbon and high oxygen content, low cetane number and high latent heat of alcohol fuels are responsible for the above results. The increase in thermal efficiency with the use of acetone–butanol–ethanol and isopropanol–butanol–ethanol in contrast to other alcohol fuels was a notable result. A comparison among the alcohol fuels showed that methanol was more effective than ethanol in reducing CO, unburned HC and smoke emissions while isopropanol–butanol–ethanol demonstrated high NOx emissions. A simultaneous reduction of NOx and Smoke emissions, which was commonly reported for most of alcohol fuels, makes a significant contribution to the development of internal combustion engines. This study gains importance in terms of comparing the individual effects of the use of alcohol fuels on exhaust emissions and better understanding the current status of these fuels.

Bi-function of photocatalytic Cr(VI) removal and monitoring acetone gas by one-dimensional hierarchical TiO2@polyoxometalates@MoS2 Tandem Heterojunctions

Abstract: Disposal and monitoring pollutions in water and air are very important for human health and ecological environment. Therefore, developing photocatalysts and gas sensors with high-performance is more necessary and urgent. In this paper, a group of novel one-dimensional hierarchical TiO2 @polyoxometalate(PW12)@MoS2 tandem heterojunction nanofibers was firstly designed and constructed using electrospinning-hydrothermal method. The morphology, structure, and photocatalytic properties were explored. The optimized sample (TiO2 @1%PW12 @MoS2) exhibits a 79.02% degradation rate of Cr(VI), which is 27% enhancement than PW12-free TiO2 @MoS2 (62.22%). Moreover, gas sensing properties to VOC gases were also explored. It has good selectivity and sensitivity to acetone. The response to 100 ppm acetone is 10.17, which is 4.21 times that of TiO2 @MoS2. The improvement in photocatalytic and gas sensing properties can be attributed to the formation of one-dimensional TiO2/PW12/MoS2 tandem heterojunctions. PW12 can act as electron acceptors and promote carriers migration. The one-dimensional structure provides a pathway for electrons transfer. The incorporated MoS2 nanosheets can improve specific surface area. This design strategy provides a new idea for the application of polyoxometalate in environmental treatment including disposal and monitoring pollutions.

Ethylene glycol-sensing properties of hydrothermally grown feather-like ZnO nanopowder with abundant oxygen vacancies

Abstract: The hydrothermal method was used to prepare feather-like ZnO nanopowder for sensing application. The morphological and structural properties have been investigated through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The abundance of oxygen vacancy was directly confirmed through the XPS and PL data and was implicitly approved by the resistance variations as a function of the temperature. The gas-sensing features were examined toward methanol, isopropanol, dimethylformamide, acetone, ethanol, and ethylene glycol vapors. The results showed that this sample has a very good selectivity to ethylene glycol (about 4–7 times more than other vapors). The best operating temperature, dynamic response, sensitivity, response/recovery times, and the detection limit of the sample were studied. The effect of the humidity on the performance of the sensor was also investigated. Graphical abstract

Synergistic effect between UV light and PANI/Co3O4 content on TiO2 composite nanoparticles for room-temperature acetone sensing

Abstract: Ternary hybrid composites are less explored for gas sensing purposes due to their complexity of structures. However, their complexity brings about a greater potential for resistance changes. In this study, we have synthesized a new ternary hybrid composite composed of polyaniline (PANI)-loaded Co 3 O 4 -TiO 2 composite nanoparticles (NPs) for acetone sensing at 25 ℃. For this purpose, PANI and Co 3 O 4 were added into TiO 2 NPs using sol-gel method. The gas sensing characteristics of PANI-TiO 2 , Co 3 O 4 -TiO 2 composite NPs and PANI-loaded Co 3 O 4 -TiO 2 composite NPs sensors were systematically investigated with and without UV illumination (at 25 °C). Based on the sensing results, the ternary 0.01 wt.% PANI-loaded 0.85TiO 2 -0.15 Co 3 O 4 composite NPs revealed the highest response to acetone under UV illumination at 25 ℃. The enhanced performance of optimized gas sensor was due to formation of p-n heterojunctions, promising effects of PANI, and UV light effect. The results obtained herein, highlighted the possibility of making a highly reliable acetone sensor working at 25 ℃ using this compounds or related compounds. • Gas sensing properties of PANI-Co 3 O 4 loaded TiO 2 nanoparticles were examined. • Heterojunctions and adsorbed oxygen species contributed to the sensing enhancement. • Higher adsorption energy between acetone and TiO 2 improved the selectivity.