Acetone Molecules Research Articles

Synthesis, crystal structure and hydrogen bonding of a Cp*Rh(III) complex bearing pyridyl azine ligands: a combined experimental and DFT approach

We report the synthesis of a Cp*Rh complex bearing a pyridyl azine ligand with a free amine (NH2) group. The reaction of [Cp*RhCl2]2 with ligand (L) formed a cationic complex with the formula [RhIII(η5-C5Me5)(L)к2 (N,N’)Cl]SbF6 (1) that was characterized by IR, UV-Vis, 1H, 13C{1H} NMR, etc. The SC-XRD analysis of the complex revealed the condensation of an acetone molecule with the azine NH2 group, thus forming an imine –C=N– bond in the ligand, giving [RhIII(η5-C5Me5)(L’)к2 (N,N’)Cl]SbF6 (2). The coordination geometry around rhodium in 2 is pseudo-tetrahedral with coordination sites occupied by a Cp* moiety in an η5 manner, a terminal chloride, and a pyridyl azine ligand in a bidentate N,N’ fashion through N(pyridine) and N(azine) nitrogen atoms occupying the four vertices of the tetrahedron. The crystal packing is mainly directed by moderate and weak hydrogen bonds including C–H⋯F, C–H⋯Cl, N–H⋯Cl and C–H⋯N interactions. The overall crystal packing and the significant role of hydrogen bonding in the supramolecular assembly has been discussed by performing Atoms-In-Molecules (AIM) and Natural Bond Orbital (NBO) analyses.

Effect of solvation shell structure on thermopower of liquid redox pairs

AbstractDeveloping redox electrolytes with high thermopower is the key to making efficient thermogalvanic batteries for harvesting low‐grade heat. This work applies molecular dynamics simulations to predict the thermopower (i.e. thermogalvanic temperature coefficient) of the redox pairs Fe(CN)63−/Fe(CN)64− and Fe3+/Fe2+, showing excellent agreement with experimental values. We showed that of the Fe3+/Fe2+ redox pair can be increased from 1.70.4 mV/K to 3.80.5 mV/K with the increased acetone to water fraction. We discovered a significant change in the variance of solvent dipole orientation between Fe3+ and Fe2+, which can serve as a microscopic indicator for large . In mixed acetone‐water solvent, of Fe3+/Fe2+ showed a rapid increase at high acetone fractions, due to the intercalation of acetone molecules into the first solvation shell of the Fe2+ at high acetone fractions. Our discovery provides insights into how solvation shell order can be engineered to develop electrolytes with high .image

Pt-modified BiVO4 nanosheets for enhanced acetone sensing

Two-dimensional (2D) BiVO4 nanosheets (NSs), featuring distinctive chemical properties and dangling-bond-rich surfaces, are promising for developing high-performance gas sensors. However, the previously reported 2D BiVO4 NSs-based devices suffer from a low responsivity and poor selectivity. Here, catalytic metal (Pt) nanoparticles (NPs) are functionalized on the surface of BiVO4 NSs to improve the sensing ability. Comparative investigations verify the significant enhancement in acetone sensing after Pt modification. The Pt NPs-loaded BiVO4 exhibits a response of 12.5–100 ppm acetone, which is 3.2 times higher than that of pure BiVO4 sensor. Besides, the Pt-BiVO4 sensor possesses better selectivity and lower detection limit. From both the experimental results and density functional theory (DFT) calculation, the effects of Pt modification are elucidated as a synergy of chemical and electronic sensitization. The loading of Pt benefits the thickening of electron depletion layer, and accumulating and activating the acetone molecules, which accelerate the reaction between acetone and chemisorbed oxygen species, resulting in enhanced sensing performance. This work gives deep insights into the effects of noble metal modification on metal oxide-based sensing material and could serve as a guideline for further designing novel high-performance sensing materials.

Two 3D Ln(III)-MOFs Based on Phosphineoxide Ligand: Synthesis, Structure Luminescent and Photocatalytic Properties.

Two new 3D metal-organic frameworks (MOFs) ZZUT1 and ZZUT2 were prepared through the reaction of tris-(4-carboxylphenyl) phosphineoxide (H3TPO) ligand with nitrate of neodymium and praseodymium by solvothermal method. The structure, fluorescence and photocatalytic properties of ZZUT1 and ZZUT2 were studied. The crystalline structure of two 3D Ln(III)-MOFs both exhibit triclinic system and P-1 space group. The results of fluorescence analysis showed that two 3D Ln(III)-MOFs could selectively recognize acetone molecule through the fluorescence quenching mechanism. Meanwhile, ZZUT1 and ZZUT2 showed good adsorption and degradation ability on organic dye methylene blue (MB) in photocatalytic condition, and the degradation efficiency can reach to more than 90%.

Improvement of electron mobility of mesoporous PCN-600 single crystal microwires aligned via the steric hindrance effect

One of mesoporous iron-based porphyrin metal-organic framework (MOF) materials, namely, PCN-600 exhibits one-dimensional channels, and features high stability in acid-base solutions and very high pore volume. It would be potentially applied in catalysis, lithium storage, solar cells, etc. However, when this material is prepared as a thin film, the thin film is usually un-oriented and its electron mobility is not strong enough. In this work, needle-like mesoporous PCN-600 single crystal microwires are first prepared via the solvothermal method with optimized synthesis procedure. Then, the acetone molecules adsorbed on the surface of adjacent PCN-600 microwires undergo the aldol condensation reaction under the catalysis of hydrochloric acid, and 4-hydroxy-4-methyl-pentanone-2 molecules are synthesized between adjacent PCN-600 microwires. Via the steric hindrance effect induced by 4-hydroxy-4-methylpentanone-2, the PCN-600 microwires are aligned to construct an array. Finally, the PCN-600 microwire array is transferred to an ITO substrate by a dipping method to form an oriented PCN-600 thin film. To demonstrate the feasibility of this oriented PCN-600 thin film applied in solar cells, its electron mobility is measured to be 117 ​cm2/Vs, which is twice that of poorly oriented film.

Separation of azeotrope acetone-methanol mixture at high-concentration conditions: Experimental and theoretical perspective of the molecular packing effects in mesopores

The recycling and concentration of acetone-methanol mixture organic solvents are very important to the chemical industry and biologically related processes. Hence, the separation properties of microporous and mesoporous activated carbons (MIC and MEC) for the acetone-methanol mixture were investigated for the first time by combining experiments and theoretical calculations. The results showed that the calculated dynamic acetone (methanol) adsorption capacities of MIC and MEC are 1.60 (10.66) and 5.15 (6.01) mmol/g at high pressures, respectively. MEC exhibited a greater methanol/acetone selectivity (6.66) than MIC (1.17). Subsequent theoretical calculations studied the adsorption behaviors of acetone and methanol molecules from the perspective of the adsorbate-framework as well as adsorbate–adsorbate interactions and found the different molecular structure of acetone and methanol was the main factor in their different separation preferences. Notably, the molecular packing effects associated with three molecular packing steps in the separation were further clarified by the radical distribution functions and self-created slit model. The 2.0–3.0 nm mesopore had more unfilled pore spaces after adsorbing a layer of acetone molecules, and thus had a significant selectivity towards methanol molecules.

Interaction of Vinyl-Type Carbocations, C3H5+ and C4H7+ with Molecules of Water, Alcohols, and Acetone.

X-ray diffraction analysis and IR spectroscopy were used to study the products of the interaction of vinyl cations C3H5+ and C4H7+ (Cat+) (as salts of carborane anion CHB11Cl11-) with basic molecules of water, alcohols, and acetone that can crystallize from solutions in dichloromethane and C6HF5. Interaction with water, as content increased, proceeded via three-stages. (1) adduct Cat+·OH2 forms in which H2O binds (through the O atom) to the C=C+ bond of the cation with the same strength as seen in the binding to Na in Na(H2O)6+. (2) H+ is transferred from cation Cat+·OH2 to a water molecule forming H3O+ and alcohol molecules (L) having the CH=CHOH entity. The O- atom of alcohols is attached to the H atom of the C=C+-H moiety of Cat+ thereby forming a very strong asymmetric H-bond, (C=)C+-H⋅⋅⋅O. (3) Finally all vinyl cations are converted into alcohol molecule L and H3O+ cations, yielding proton disolvates L-H+-L with a symmetric very strong H-bond. When an acetone molecule (Ac) interacts with Cat+, H+ is transferred to Ac giving rise to a reactive carbene and proton disolvate Ac-H+-Ac. Thus, the alleged high reactivity of vinyl cations seems to be an exaggeration.

Bisphenol-A-Carbon Nanotube Nanocomposite: Interfacial DFT Prediction and Experimental Strength Testing.

Epoxies, their derivatives, and composites, due to superior specific strength, are preferred for many potential applications in the field of automobiles, aircraft, bonding of structures, protective coatings, water filtration, etc. As structural members in automobiles and aircraft, the epoxy-based components are exposed to various static/dynamic mechanical loading conditions during their service life. The interfacial interactions, between the matrix and reinforcement, greatly affect the final properties of the composites. The present study demonstrates that the solvent used for the preparation of the composite can also contribute toward interfacial interactions. Present research systematically finds out a suitable solvent (acetone) and reinforcement type [multi-walled carbon nanotube (CNT)] for epoxy [bisphenol-A (BPA)] nanocomposites. Dynamic and static strengths of the as-prepared epoxy-CNT nanocomposites were carefully investigated. Well dispersed CNTs in acetone were mixed with an ester of BPA under constant magnetic stirring conditions. Samples of tablet shape were prepared for testing static and dynamic performance of the composite using a nano-indentation technique. Considerable enhancement by 55 and 22% in the static elastic modulus and hardness of BPA-CNT composites, respectively, was observed (compared with that of pristine BPA). The storage modulus and tan-delta of the nanocomposites were also improved by 14 and 46%, respectively. Improved static and dynamic performance, reported in this work, significantly enhances the scope of utilization of BPA-CNT-based nanocomposites under severe static and dynamic loading conditions simultaneously. Static and dynamical analysis of CNT-reinforced epoxy provides more realistic understanding of the mechanical performance of the nanocomposite. Density functional theory (using QuantumATK software) simulations were performed to investigate and identify the alterations in the atomic morphology of CNTs during interfacial interaction with the acetone molecule and epoxy matrix. The calculations predicted that CNTs with mild defects as compared to pristine CNTs were better suited for synthesis of the nanocomposite and also assisted in a homogeneous distribution of CNTs in BPA without aggregation (with acetone as the solvent). Furthermore, structural changes in CNTs after treatment with BPA and the curing agent and the role of defects are studied in detail.

Studies of the interaction of modified nitro group boronitride nanotubes with gas-phase carbon-containing molecules to create sensor devices

Recently, the environmental situation in the world has been deteriorating everywhere and there is a need to find new effective means of detecting harmful substances in the air. Every year, the content of carbon dioxide in the air is growing, which in the end can lead to a deterioration in the health of people. Various types of sensor devices are currently used to timely fix the increase in the gas level. As the active material of such a sensor, modern unique materials can be used – nanotubes, which, due to their sorption properties, are able to detect the presence of harmful impurities in the air space of the premises. It is also possible to use such sensors as detectors of some human diseases by analyzing exhaled air, which makes their use in medicine possible. The results of a theoretical study of the sorption interaction of modified boronitride nanotubes with molecules of carbon dioxide and acetone, obtained using the quantum-chemical DFT method, are presented, which prove the possibility of using this type of nanotubes as a sensor material for sensor devices.

Sea urchin-like SnO2/α-Fe2O3 heterostructural microspheres for enhanced acetone gas sensing: Materials preparation, performance evaluation, and mechanism investigation

Herein, sea urchin-like SnO2/α-Fe2O3 (SU-SnO2/α-Fe2O3) heterostructural microspheres was prepared successfully by two-steps hydrothermal treatment, and used as semiconductor for acetone gas sensing. SEM and TEM characterizations showed that as-prepared composites exhibited sea urchin-like morphology with microstructures of inner SnO2 microspheres and outer vertically grown α-Fe2O3 nanorods. SnO2/α-Fe2O3 microspheres presented higher and faster response / recovery for acetone in comparison to pure SnO2. At the optimum temperature of 300 °C, response value of SU-SnO2/α-Fe2O3 sensor reached 18.7 towards acetone vapor with concentration of 100 ppm. The response time was 8 s, and recovery time was 2 s. Moreover, the proposed method displayed an excellent linearity for measuring acetone vapor with concentration range of 1–200 ppm. The improvement of gas sensing properties for SnO2/α-Fe2O3 microspheres was ascribed to the unique microstructures, formation of heterojunction, and abundant adsorbed oxygen. To further demonstrate the promoted mechanism, adsorption behavior of as-prepared composites for acetone molecule was investigated by density-functional theory (DFT), with results that Fe sites on the hetero-interface possessed strong interaction with acetone molecule, which enhanced the gas sensing properties towards acetone. This study confirmed the gas sensor performance of SnO2/α-Fe2O3 microspheres towards acetone, and supplemented the promotion mechanism by DFT calculations.

Nitrogen-phosphorus codoped carbon nanotube sponges for detecting volatile organic compounds: experimental and DFT calculations.

The sensing of harmful gases and vapors is of fundamental interest to control the industrial emissions and environmental contamination. Nitrogen/phosphorus codoped carbon nanotube sponges (NP-CNTSs) were used to detect ethanol, acetone, cyclohexane, isopropanol, and methanol. The NP-CNTSs were produced through the aerosol-assisted chemical vapor deposition (AACVD) method using acetonitrile and triphenylphosphine as precursors at 1020 °C. The sensors based on NP-CNTSs were tested with varying operating temperatures (25-100 °C) and gas vapor concentrations (5-50 ppm). For instance, for a gas vapor concentration of 30 ppm and an operating temperature of 65 °C, the sensors showed changes in the electrical resistance of 1.12%, 1.21%, 1.09%, 2.4%, and 1.34% for ethanol, acetone, cyclohexane, isopropanol, and methanol, respectively. We found that the response and recovery times for isopropanol gas vapor are up to 43.7 s and 95 s, respectively. The current sensor outperformed the sensors reported in the literature by at least two times in the response measurement. Additionally, we performed van der Waals density functional theory calculations to elucidate the role of nitrogen and phosphorous codoped single-walled carbon nanotubes (SWCNTs) and their interaction with the considered gas molecule. We analyzed the molecular adsorption energy, optimized structures, and the density of states and calculated the electrostatic potential surface for N-doped, P-doped, NP-codoped, and OH-functionalized NP-codoped metallic SWCNTs-(6,6) and semiconducting SWCNTs-(10,0). Adsorption energy calculations revealed that in most cases the molecules are adsorbed to carbon nanotubes via physisorption. The codoping in SWCNTs-(6,6) promoted structural changes in the surface nanotube and marked chemisorption for acetone molecules.

Синтез и строение комплексов сурьмы [n-C5H11PPh3]2[Sb2I8(acetone)2] и [Ph4P]3[Sb2I9]∙EtO(CH2)2OH

The interaction of antimony iodide with n-pentyltriphenylphosphonium iodide (1:1 mol.) in acetone and tetraphenylphosphonium iodide (3:2 mol.) in ethylene glycol monoethyl ether (ethyl cellosolve) has been used to synthesize ionic complexes [n-C5H11PPh3]2[Sb2I8(acetone)2] and [Ph4P]3[Sb2I9]∙EtO(CH2)2OH. According to the X-ray analysis data obtained on an automatic diffractometer D8 Quest Bruker (MoKa-radiation, λ = 0.71073 Å, graphite monochromator) at 293 K, of crystals 1 [C26H32OPI4Sb, M 1020.84, the triclinic syngony, the symmetry group Р-1; cell parameters: a = 10.573(4) Å, b = 13.303(5) Å, c = 13.569(5) Å, α = 117.749(16) degrees, β = 95.534(17) degrees, γ = 100.715(14) degrees; V = 1622.4(10) Å3; the crystal size is 0.32 × 0.22 × 0.13 mm; intervals of reflection indexes are -16 ≤ h ≤ 16, -20 ≤ k ≤ 20, -21 ≤ l ≤ 21; total reflections 98254; independent reflections 13003; Rint 0.0285; GOOF 1.037; R1 = 0.0438, wR2 = 0.0745; residual electron density 1.25/-2.06 e/Å3] and 2 [C76H70I9O2P3Sb2, M 2493.83, the triclinic syngony, the symmetry group Р–1; cell parameters: a = 10.881(7) Å, b = 16.549(7) Å, c = 25.287(12) Å, α = 109.03(2) degrees, β = 94.67(2) degrees, γ = 98.52(3) degrees; V = 4216(4) Å3; the crystal size is 0.37×0.11×0.07 mm; intervals of reflection indexes are -14 ≤ h ≤ 14, -22 ≤ k ≤ 22, -33 ≤ l ≤ 33; total reflections 146846; independent reflections 21003; Rint 0.0708; GOOF 1.014; R1 = 0.0763, wR2 = 0.0967; residual electron density 1.23/-1.06 e/Å3], the phosphorus atoms in cations have a slightly distorted tetrahedral coordination with the CPC bond angles 107.48(11)-111.52(11) and 106.5(3)-113.3(3) degrees and similar P–C bond lengths 1.795(3)–1.802(2) Å and 1.787(5)–1.809(6) Å in 1 and 2, respectively. In the centrosymmetric [Sb2I8(acetone)2]2– anion, the antimony atoms have a distorted octahedral coordination (trans-angles 171.476(9)–176.33(3) degrees, the acetone molecule occupies an axial position being coordinated by the oxygen atom (Sb∙∙∙O 2.820(10) Å). The Sb–Ib. bonds (3.0997(12) Å) are longer than Sb–Iterm: 2.7780(8)–2.9553(10) Å. In the [Sb2I9]3– anion trans-ISbI angles vary in the range 169.612(17)–173.426(19) degrees, Sb–Iterm. bonds 2.8613(13)–2.9609(12) Å are shorter than Sb–Ib: 3.0986(12)–3.2760(13) Å. Solvate ethyl cellosolve mole-cules form dimers via hydrogen bonds O(1)∙∙∙H(2A) 2.11 Å. Complete tables of coordinates of atoms, bond lengths and valence angles for structures 1 and 2 are deposited at the Cambridge Structural Data Bank (no. 1984511 (1), 2157456 (2); deposit@ccdc.cam.ac.uk; http: //www.ccdc.cam.ac.uk).

Estimation of electrostatic and covalent contributions to the enthalpy of H-bond formation in H-complexes of 1,2,3-benzotriazole with proton-acceptor molecules by IR spectroscopy and DFT calculations

Using the methods of IR-spectroscopy and quantum chemical calculations, we determined the formation of an H-bond between the 1,2,3-benzotriazole molecule and the molecules of acetone, dioxane, DMF, and DMSO. Quantum chemistry methods have been used to calculate the sums of charge changes in the atoms of the 1,2,3-benzotriazole molecule and of proton acceptor molecules (acetone, dioxane, DMF, and DMSO) due to the formation of their complexes with an H-bond (H-complexes NH…O). The sum of charge changes was taken as a contribution of a covalent component to H-bond formation. It has been established that as the sum of charge changes in N, H, and O or H and O, forming the H-complex, increases, the enthalpy of H-complex formation (EF) decreases. On the contrary, the EO of H-complexes increases when the product of the initial charges on the H and O atoms increases. In the absence of H-complexes, the product of charges was considered the electrostatic component of H-bond formation. The criterion of the value of H-bond EF was the value of a low-frequency shift of the initial position of the maximum IR absorption band of the NH vibration of the 1,2,3-benzotriazole molecule relative to its position in a neutral CCl4 solvent. The results of QTAIM, NCI, and RDG analyses showed that the values of energy densities in BCPs have a positive value in the complexes formed by 1,2,3-benzotriazole with acetone, dioxane, and DMFA, and such hydrogen bonds are electrostatic in nature. In the complex formed by 1,2,3-benzotriazole and DMSO, it has a negative value and a covalent character. The data obtained have allowed for two main conclusions: (i) In the formation of the H-complexes of the 1,2,3-benzotriazole molecule with proton-acceptor molecules containing oxygen atoms, the main contribution to H-bond formation is made by the electrostatic component. (ii) The contribution of the covalent component increases with increasing enthalpy of H-bond formation.

Mild Oxidation of Toluene to Benzaldehyde by Air

We report here the green oxidation of toluene to benzaldehyde by air under mild conditions in >99% selectivity at 35% conversion at 180 °C. This is an important reaction in both theoretical and practical research studies, but little progress has been made in the past five decades. Either the selectivity or the conversion is very low, and the sum of selectivity and conversion is hardly more than one hundred. In previous investigation, we have constructed a highly efficient system of catalysis, i.e., Pickering-like emulsion of toluene in water stabilized by amphiphilic catalysts HDPA-FeOx/Al2O3, hexadecyl phosphonic acid-modulated iron oxides, which work in an enzyme-like mechanism for oxidation of toluene to benzaldehyde. However, the oxygen pressures more than 3 MPa needed for high conversion impede their practical uses. In this work, we modify the catalytic system for the green oxidation of toluene to benzaldehyde using 1 MPa of air as an oxidant. First, the catalytic center of HDPA-FeOx/Al2O3 is optimized as PPA-CuFeOx/Al2O3 with promoted activity of crystal oxygen toward toluene oxidation. Readily available phenylphosphonic acid (PPA), in place of HDPA, shows good performance in the new catalytic system. Second, 5 vol % acetone/water is used as a mixed solvent of the reaction, which markedly modifies the oxygen dissolving and transferring, the access of the toluene molecule to the catalyst, and the recovery rate of catalytic center. The acetone molecule itself, however, is proved not converted and can be recycled in the catalytic process. Comprehensively, the catalytic system including multifactor synergism and good intrinsic safety developed in the current work has realistic feasibility for benzaldehyde production from toluene green oxidation in high-performance and atomic economy.

Hydrothermal synthesis of cubic-rhombohedral-In2O3 microspheres with superior acetone sensing performance

Efficient and reliable acetone gas sensors are of great significance to human health and safety. The acetone sensing properties of In2O3 materials can be further improved by morphology control and heterostructure engineering. Herein, rough microspheres of pure cubic-In2O3 nanoparticles, bumpy microspheres of cubic-rhombohedral-In2O3 nanoparticles, and porous aggregates of cubic-rhombohedral-In2O3 nanocubes and nanoparticles were prepared by setting the hydrothermal temperatures as 120℃, 160℃, and 200℃, respectively. At the lowest optimal working temperature of 190℃, the sensor based on the cubic-rhombohedral-In2O3 microspheres exhibited the highest gas response value of 16.9 to 100 ppm acetone, a shorter response/recovery time of 4.7/6.0 s, and the highest selectivity against N,N-dimethylformamide (DMF), ethanol, ethylene glycol (EG), and methanol. The superior acetone sensing performance of the cubic-rhombohedral-In2O3 microspheres is attributed to its maximum BET specific surface area (45.5 m2/g), largest relative contents of surface In+ (62.39 %) and OV (28.19 %), and efficient heterojunction between cubic-In2O3 and rhombohedral-In2O3 nanocrystals, which in combination enhance the regulation of acetone molecules on the carrier concentration and conduction within the microspheres.

Dewetting Behavior of Random Copolymer Films Induced by Solvent Vapor Annealing.

In recent years, the dewetting behavior of block copolymer films has been studied a lot, but that of random copolymer films was rarely studied. In this study, effects of film thickness and solvent vapor annealing duration (0 s-24 h) on the dewetting behavior of the spin-coated poly(styrene-co-acrylonitrile) (SAN) random copolymer films were mainly investigated by atomic force microscopy and contact angle method for the first time. The film thicknesses of the SAN films prepared at different concentrations were characterized by X-ray reflectometry to be 6-34 nm. With the annealing of acetone vapor, the SAN films first appear holes and then rupture into droplets which fuse and break periodically. The periodic evolutions of the droplets are due to the preferred affinity of acetone molecules with the AN segments and the change of surface energy. This phenomenon is different from the single evolutions in the spin-coated polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) block copolymer films. This illustrates the interactions between AN segments and the substrate are stronger than those between PMMA segments and the substrate in the spin-coated films.

Recent advances in ZnO nanostructure as a gas-sensing element for an acetone sensor: a short review.

Air pollution is a severe concern globally as it disturbs the health conditions of living beings and the environment because of the discharge of acetone molecules. Metal oxide semiconductor (MOS) nanomaterials are crucial for developing efficient sensors because of their outstanding chemical and physical properties, empowering the inclusive developments in gas sensor productivity. This review presents the ZnO nanostructure state of the art and notable growth, and their structural, morphological, electronic, optical, and acetone-sensing properties. The key parameters, such as response, gas detection limit, sensitivity, reproducibility, response and recovery time, selectivity, and stability of the acetone sensor, have been discussed. Furthermore, gas-sensing mechanism models based on MOS for acetone sensing are reported and discussed. Finally, future possibilities and challenges for MOS (ZnO)-based gas sensors for acetone detection have also been explored.

Molecular Dynamics Simulation for Separation Performance of PDMS/Fluorosilane Membrane with Different Mass Ratios in Acetone–Water Mixture

AbstractPolydimethylsiloxane (PDMS) membrane in suitable‐fluorinated level have excellent pervaporation performance as well as antibiological contamination performance. The pervaporation membranes with different PDMS/fluorosilane mass ratios, the adsorption and dissolution behaviors of acetone molecules on the membrane surface, as well as the diffusion and permeation behaviors in the membranes are studied by all‐atom molecular dynamics simulation (AAMDS). The results show that when the mass ratio of PDMS/fluorosilane is 100/20, the surface solubility of acetone is 11.711 (J cm−3)0.5, and the interfacial interaction is −16897.0415 kcal mol−1, both of which are the highest. The results of wide‐angle X‐ray diffraction (WAXD) showed that there are amorphous regions in the membranes suitable for acetone penetration. The maximum chain spacing of the PDMS/fluorosilane(100/20)_membranes is 10.8482 Å, and the free volume fraction (FFV) is 3.03%, both of which are the largest. The change rate of long‐term mean square displacement (MSD) in PDMS/fluorosilane(100/20)_Membrane with time is 0.45269. The Young's modulus E, shear modulus G, volume modulus K, and Poisson's ratio ν of PDMS/fluorosilane(100/20)_Membrane are 0.3249, 0.4061, 0.0492 GPa and ‐0.5999, respectively. The elasticity of the membrane enhances the diffusion behavior of acetone molecules, and the self‐diffusion coefficient of acetone in the membrane is 0.07545 Å2 ps−1.

Sensing properties of acetone gas on the two-dimensional orthorhombic diboron dinitride sheet: A DFT investigation

In recent years, the removal of various organic solvents from different mediums, particularly through nano-structured materials, has an important place in various industries, for example in producing novel versatile nano-adsorbents. Within this work, dispersion-corrected DFT is employed for investigating how the acetone (ACT) molecule is adsorbed on the o-B2N2 monolayer (o-B2N2ML) because computational methods have been considered as powerful tools to explore molecular systems at the atomic level and to explore the nature of interactions. Here, by investigating charge transports, density of states, electronic/energy properties, and orbitals, the experimental observations are inspected at the molecular level. A relationship is established between the sensor response (R) and its Eg (the energy gap between the HOMO and the LUMO). ACT interacts strongly with the o-B2N2ML with the energy of adsorption of −17.82 kcal/mol. The adsorption of ACT on o-B2N2ML is a strong physical adsorption. After ACT is adsorbed, there is an increase in the conductivity of these systems, which makes the application of o-B2N2ML as an electrical gas sensor possible. The sensor recovery time is 428 s, which is similar to the experimental value.

Facile Synthesis of Co3O4/CoMoO4 Heterostructure Nanosheets for Enhanced Acetone Detection.

Although p-type semiconductors exhibit highly selective and stable chemiresistive gas sensing performances compared to conventional n-type semiconductors, their low sensitivity had long impeded their practical development. In this work, we developed highly porous Co3O4/CoMoO4 heterostructure nanosheets (NSs) with enhanced sensitivity and superior stability toward acetone gas through a facile solution-based approach with Mo-impregnated Co-based metal-organic frameworks as the starting material. The spontaneous formation of a large number of p-p heterojunctions at the Co3O4-CoMoO4 interface would facilitate the adsorption of oxygen and acetone molecules, as verified by density functional theory calculations. Consequently, experimental results showed that the Co3O4/CoMoO4 NSs have a greatly enhanced response of 8.5 toward 5 ppm acetone, which is 7.1 times higher than that of pure Co3O4 NS, without involving any noble metal catalysts. Moreover, the limit of detection of the Co3O4/CoMoO4 NSs was as low as 10 ppb. Altogether, we propose that our synthetic approach for the engineering of p-p heterojunctions is an effective strategy for the future development of highly practical and sensitive gas sensors based on p-type semiconductors.