Number Of Carbon Atoms Research Articles

The effects of side chain engineering on the morphology and charge transport of the A-DA1D-A type of non-fullerene acceptor: a multiscale study.

The appearance of the A-DA1D-A type of non-fullerene acceptor Y6 and its derivatives significantly improves the power conversion efficiency of organic solar cells. However, the effects of the modulation of the side chains of Y6 on its morphology and charge transport in organic thin films are still not well understood. In this work, we have systematically studied the effects of symmetric modifications of the length of alkyl side chains and the types, such as branched or straight alkyl chains, and the introduction of heteroatoms to side chains on these properties. A multiscale study, including density functional theory and classical molecular dynamics simulations, has been used to answer this open question. We find that face-on configurations are generally dominant for the AA, A1A1, and DD stacking of molecular pairs. With respect to prototype Y6, the introduction of oxygen atoms to outer alkyl side chains could enhance AA stacking but worsen the electrical network and enlarge the reorganization energy during electron transfer, and changing outer side straight alkyl chains to branched chains ruins π-π stacking of all units significantly. Finally, we discover that shortening outer alkyl side chains appropriately or changing inner branched chains to straight chains with the same number of carbon atoms is a good strategy to improve the molecular π-π stacking and electron mobility of Y6 while changing outer straight side chains to branched chains or introducing oxygen atoms to outer straight chains is the opposite. This study provides a new insight into the relationship between morphology and electron mobility and will be helpful for the design of future high-performance non-fullerene acceptors.

Comparative investigations on α relaxation and conductivity of probe ions in a series of small molecular liquids

The coupling between translational motion and rotational motion in liquids is one of the long-standing concerns in condensed matter physics. The relaxation times of α relaxation and probe ion conductivities in a series of small molecular liquids, 15 types of single and binary small molecular liquids with different molecular shapes and functional groups when the number of carbon atoms is in a range from 3 to 14, are simultaneously obtained by dielectric spectroscopy method in this work. The results indicate that the coupling between translation and rotation is not directly related to the functional group of liquid molecules, nor very sensitive to the shape nor the size of molecules or ion size. However, the microstructure of liquid is a key factor affecting the coupling between translation and rotation. In other words, when the microstructure of the liquid is unchanged, the dependence of relaxation time on temperature is consistent with the dependence of conductivity reciprocal on temperature, whether in single small molecular liquids or in binary small molecular liquids, which provides a method for measuring relaxation time. The research results also show that the temperature dependence of the conductivity of the impurity ions carried by the liquid itself is consistent with the one of quantitatively doped ions, providing the ideas for investigating the ion conductivity behavior in organic small molecular liquids with low electrolyte solubilities. The experimental results of monohydroxy alcohol are consistent with the viewpoint that α relaxation rather than Debye relaxation corresponds to the system structure relaxation.

Discrimination of Diptera order insects based on their saturated cuticular hydrocarbon content using a new microextraction procedure and chromatographic analysis.

The nature and proportions of hydrocarbons in the cuticle of insects are characteristic of the species and age. Chemical analysis of cuticular hydrocarbons allows species discrimination, which is of great interest in the forensic field, where insects play a crucial role in estimating the minimum post-mortem interval. The objective of this work was the differentiation of Diptera order insects through their saturated cuticular hydrocarbon compositions (SCHCs). For this, specimens fixed in 70 : 30 ethanol : water, as recommended by the European Association for Forensic Entomology, were submitted to solid-liquid extraction followed by dispersive liquid-liquid microextraction, providing preconcentration factors up to 76 for the SCHCs. The final organic extract was analysed by gas chromatography coupled with flame ionization detection (GC-FID), and GC coupled with mass spectrometry was applied to confirm the identity of the SCHCs. The analysed samples contained linear alkanes with the number of carbon atoms in the C9-C15 and C18-C36 ranges with concentrations between 0.1 and 125 ng g-1. Chrysomya albiceps (in its larval stage) showed the highest number of analytes detected, with 21 compounds, while Lucilia sericata and Calliphora vicina the lowest, with only 3 alkanes. Non-supervised principal component analysis and supervised orthogonal partial least squares discriminant analysis were performed and an optimal model to differentiate specimens according to their species was obtained. In addition, statistically significant differences were observed in the concentrations of certain SCHCs within the same species depending on the stage of development or the growth pattern of the insect.

Impact of carbon number and atom number on cc-pVTZ Hartree-Fock Energy and program runtime of alkanes

Impact of carbon number and atom number on cc-pVTZ Hartree-Fock Energy and program runtime of alkanes

Understanding the impact of molecular structure on the formation of stable intermediates during the pyrolysis of monoalkylated cyclohexanes in a shock tube

Alkylcyclohexanes are common constituents of conventional jet fuels and are expected to be a vital molecular subclass in next-generation, sustainable aviation fuels (SAFs). In an effort to advance the current understanding of the combustion chemistry of these species at engine-relevant conditions, we measured the time-resolved evolution of key stable intermediates during the pyrolysis of cyclohexane (CH) and four monoalkylated cyclohexanes: methylcyclohexane (MCH), ethylcyclohexane (ECH), propylcyclohexane (PCH), and butylcyclohexane (BCH), using laser absorption spectroscopy (LAS) in a shock tube. These experiments were conducted using 2 % Fuel/Argon test mixtures at a nominal pressure of 2 atm over the temperature range 1150–1530 K. Simultaneous tracking of the mole fraction time histories of methane, ethylene, and larger alkenes (>C2) provided new, valuable insight into the high-temperature reactivity of the five fuels studied. Studying all five fuels under similar test conditions enabled us to observe clear trends in the yields of different pyrolysis products with varying molecular structure, specifically increasing the number of carbon atoms in the alkyl chain. The fuel structure effects investigated in this work are instrumental in characterizing the pyrolysis product distribution, and thereby the overall combustion behavior of cyclohexane derivatives with longer (>C4) alkyl chains. We believe the multi-wavelength speciation data presented in this work can significantly contribute towards the development of robust, simplified, and fuel-specific kinetic models for monoalkylated cyclohexanes.

Effect of 2-alkenals on the Maillard reaction of cysteine-glucose: Initial stage intermediate formation and flavor compound generation pathways

To explore the effect of (E)-2-hexenal, (E)-2-heptenal, and (E)-2-octenal on the initial Maillard reaction pathways and formation of volatile compounds, cystine-Amadori and thiazolidine derivatives were synthesized, identified by UPLC‒TOF/MS and NMR, and quantified by UPLC‒MS/MS. Depending on the concentration of the intermediates, the reactivity of the 2-alkenals in the reaction became weaker with the extension of the carbon chain. According to the content of 87 volatile compounds detected by GC‒MS‒O, the Maillard reaction was inhibited by decreasing the number of carbon atoms of 2-alkenal. The carbohydrate module labeling method demonstrated that the 2-ethylthiophene, 2-propylthiophene, and 2-butylthiophene carbon backbones were derived from 2-alkenal. Particularly, it was found for the first time that 2,3-dihydro-1 H-indole could be generated from both the intact skeleton of glucose and the degradation product of 2-alkenal. Notably, we proposed a route for the formation of 2-butanoylthiophene starting from (E)-2-octenal which was further converted to 2,4-octdienal. This study can be used as guidance in improving the flavor of meat and savory flavorings.

Performance of predictive approaches for the viscosity of binary liquid mixtures of 1-alcohols

The objective of this study is to evaluate the predictive performance of three semi-theoretical approaches for modeling viscosity of binary liquid mixtures composed of 1-alcohols. For the mixtures that contain 1-alcohols with a similar number of carbon atoms, three schemes including the Rough Hard-Sphere model, the McAllister model, and UNIFAC-VISCO were demonstrated to be able to reproduce the mixture viscosity with an average deviation of 5%. For highly asymmetrical mixtures without the presence of small molecules, only McAllister-type model successfully reproduced the experimental values. The prediction done by the Rough Hard-Sphere model on the basis of using simple mixing rules for characteristic parameters indicated that this model should be further modified to improve its predictive capability.

Synthesis of nanocarbon by high-voltage breakdown of hydrocarbons

The object of research is the mechanisms of synthesis of nanocarbon structures in the process of electric high-voltage breakdown of hydrocarbons. The problem to be solved is the purposeful synthesis of various types of nanocarbon with small losses of raw materials. Mechanisms of nanocarbon formation in the process of high-voltage electric breakdown of hydrocarbons have been established. It is shown that a high-voltage breakdown leads to a cascade of chemical transformations. As a result of transformations, lower gaseous hydrocarbons are formed due to the destruction of molecules and higher ones – as a result of polymerization, and as a result of dehydrocyclization and polymerization with the participation of metal catalysts – various carbon nanostructures. The possibility of targeted synthesis of fullerene-like structures, nanotubes with diameters from 10 to 50 nm, nanofibers, and films is demonstrated. Experimental studies have confirmed that the qualitative and quantitative composition of nanocarbon can be varied in a wide range. With an increase in the number of carbon atoms or the number of C–C bonds in the raw material molecules, other things being equal, the practical yield of solid nanocarbon increases. It was determined that the synthesis of structured nanocarbon from a mixture of hydrocarbon gases, formed as a result of high-voltage breakdown of liquid hydrocarbons, actively occurs on the nickel-chromium catalytic surface. An increase in the area of the catalytic deposition surface leads to an increase in the yield of nanocarbon. The study of the ability of the obtained nanocarbon samples to absorb electromagnetic radiation confirmed the potential of the method of high-voltage breakdown of hydrocarbons for the synthesis of materials that weaken electromagnetic radiation at a frequency of 25 to 38 GHz. The greatest weakening is observed for samples consisting mainly of carbon nanotubes and nickel nanoparticles

Highly Durable Membrane–Electrode-Assemblies Using High M w and Ether-Free Polyfluorene-Based Electrolytes for Anion Exchange Membrane Water Electrolyzer

Water electrolysis technology, which produces hydrogen through electrolysis of water using electricity derived from renewable energy, is attracting attention as a way to realize a carbon-neutral society. Among water electrolysis systems, anion exchange membrane water electrolysis (AEMWE) can achieve high energy conversion efficiency and quick response to fluctuating power supplies by using thin polymer electrolyte membranes, and operates in an alkaline environment, allowing the use of inexpensive non-precious metals for bipolar plates and electrodes. However, conventional AEMs and ionomers exhibit low durability in high-temperature and alkaline environments, which is a critical issue in realizing high-performance and highly durable membrane–electrode assemblies (MEAs) for AEMWE.Our group developed high-molecular-weight (M w) and ether-free, polyfluorene-based anion conducting polyelectrolyte (PFT-Cx-TMA, Cx represent the number of carbon atoms in the alkyl side chain) as shown in Fig. 1a.1 These polyelectrolytes show high OH− conductivity over 100 mS cm− 1, high chemical durability (stable in 8 M NaOH at 80 °C for 168 h), and high tensile strength (25–42 MPa, comparable to a Nafion membrane). This study applied PFT-Cx-TMA to AEMs and ionomers in MEAs to evaluate the durability against various AEMWE operations (constant current operation and start-stop operation in different voltage ranges), demonstrating MEAs with both high performance and high durability.Fig. 1b shows the constant current durability of the MEA with PFT-C8-TMA as AEM and ionomer.2 This test was performed at the constant current density of 0.2 A cm− 2 and 80 °C using a 1 M KOH aqueous solution fed to the anode. Here, to investigate the effects of AEMs and ionomers on MEA durability, conventional precious metal catalysts (anode: IrO2, cathode: Pt/C or PtRu/C) were used in the MEA. The MEA with PFT-C8-TMA exhibited a current density of 1.0 A cm− 2 at 1.79 V and there was almost no voltage change even after the constant current operation for over 100 h. It is noteworthy that the MEAs using PFT-C8-TMA and PFT-C10-TMA demonstrated high performance and high durability not only in the alkaline-fed operation but also in the pure-water-fed operation.Next, this study investigated the start-stop durability of MEAs using voltage cycles simulating the start-stop operation of water electrolyzer. Here, square-wave voltage cycling of holding at 1.8 V and 0.1 V for 1 min each was used for the start-stop test at 80 °C with a 1 M KOH solution fed to the anode. As a comparison, the MEA was prepared using a commercial AEM (Sustainion X37-50, 50 μm in thickness) and ionomer (Sustaionion XB-7). As shown in Fig. 1c, the MEA using a PFT-C10-TMA AEM (56 μm in thickness) and ionomer was highly durable in the start-stop test compared to the MEA using commercial Sustaionion. During the test, the elution of black solid particles from the catalyst layer and the increase in charge transfer resistance (Rct) were observed in the MEA with Sustaionion, whereas no elution of catalyst materials and no change in Rct were confirmed in the MEA with PFT-C10-TMA. These results suggest that nonlinear mechanical stress via rapid bubble formation and shutdown during start-stop cycles caused the leaching of catalysts, resulting in the performance loss of the MEA with Sustainion. The commercial ionomer (Sustainion XB-7) exhibits a large dimensional change (156%) compared to the PFT-C10-TMA membrane (34%) at 80 °C in a 1 M KOH aqueous solution. Catalyst particles covered with a highly swollen ionomer are easily detached from a catalyst layer by the nonlinear mechanical stress. On the other hand, the PFT-C10-TMA ionomer has a high molecular weight (M w = 240000 g mol−1), low swelling degree, and well-entangled polymer chains, hence preventing leaching of the catalyst particles.In summary, this study demonstrates that MEAs using high M w and ether-free polyfluorene-based electrolytes with both high chemical and mechanical durability have excellent durability for AEMWE operations including constant and dynamic (start-stop voltage cycling) operations. Acknowledgement This presentation is based on results obtained from a project, JPNP14021, commissioned by the New Energy and Industrial Technology Development Organization (NEDO). References (1) S. Miyanishi and T. Yamaguchi, Polym. Chem., 2020, 11, 3812–3820.(2) R. Soni, S. Miyanishi, H. Kuroki, and T. Yamaguchi, ACS Appl. Energy Mater., 2021, 4, 1053–1058. Figure 1

PH dependent physicochemical signatures of amino acids in aqueous buffers: Thermodynamic analysis

The physicochemical signatures such as apparent molar volume (V2,Φ), isoentropic compressibilities (KS,2,φ), and dilution enthalpies of a series of amino acids (AAs) glycine (Gly), L-alanine (Ala), DL-α-amino-n-butyric acid (ABA), L-valine (Val) and L-leucine (Leu) have been measured at various pH values (pH = 2, 5 7 and 9) at a buffer molality of 0.1 mol kg−1 of water at 298.15 K. The data obtained from high sensitivity densimeter and sound analyser along with ultrasensitive isothermal titration calorimetry has been analyzed to evaluate the values of standard partial molar quantities such as for volume at infinite dilution (V2,m0), compressibility KS, 2,m0 and dilution enthalpy (ΔdilH0) of the AAs together with standard partial molar quantities of transfer of these solutes from water to aqueous buffer systems at these pH values. The linear correlation of V2,m0 for this series of AAs against number of carbon atoms in their alkyl chain has been used to evaluate the contribution of zwitterionic end groups (NH3+, COO–), the CH2 group, and other parts of alkyl chains of the AAs to the overall value of V2,m0. The results of standard partial molar transfer properties on volumes, compressibilities and enthalpies of dilution from water to aqueous buffer systems at various pH values have been connected and explained in terms of ion-polar, ion-hydrophilic, hydrophobic-hydrophobic and ion-hydrophobic interactions of the participating groups. These thermodynamic signatures when compared at different pH values suggest that at electrostriction of water dominates at pH 2. Such physicochemical properties of constituents of proteins such as amino acids have not been reported earlier. Thus, the results demonstrate that the interaction of individual amino acid residues with the buffer components does not lead to significant change in their physicochemical properties thereby permitting their use in obtaining mechanistic insights into systems of biological interest consisting of these constituents.

Fast and reliable determination of phthalic acid esters in soil and lettuce samples based on QuEChERS GC–MS/MS

Phthalates are commonly used as plasticizers, and solvents in industry and households. We propose an application of the QuEChERS method for the determination of six PAEs in the soil and lettuce (roots and leaves) by GC–MS/MS. The QuEChERS method validation procedure was performed and good linearity (>0.997), recovery (97.2–99.1 %), very low detection limits (0.09–0.43 ng/g), and satisfactory inter- and intraday precision (∼4%) were obtained confirming that QuEChERS GC–MS/MS applied for PAEs determination in the environmental samples is a cheap and environmentally friendly method. In general, the higher the number of carbon atoms in PAEs, the higher the percentage noted in the lettuce roots. At higher PAEs concentration (60 ng/g) the main bis(2-ethylhexyl) phthalate (DEHP) sink were roots whereas at lower concentrations (30 ng/g) most of DEHP was noted in lettuce leaves implying that the fate of PAEs was governed not by the chemical structure of PAEs but rather partitioning (logKow).

The synthesis of higher-carbon sugar alcohols via indium-mediated acyloxyallylation as potential phase change materials

AbstractIn recent years, sugar alcohols have gained significant attention as organic phase change materials (PCMs) for thermal energy storage due to their comparably high thermal storage densities up to 350 J/g. In a computational study, outstandingly high values of up to ~ 450500 J/g have been postulated for specific higher-carbon sugar alcohols. These optimized structures feature an even number of carbon atoms in the backbone and a stereochemical configuration in which all hydroxyl groups are in an 1,3-anti-relationship, as found in the natural hexitol d-mannitol. However, these manno-configured higher-carbon sugar alcohols have not been experimentally investigated as PCMs yet and described synthetic routes are elaborate multiple steps syntheses. Therefore, we aimed to synthesize sugar alcohols of the manno-series with a concise synthetic protocol based on the indium-mediated acyloxyallylation (IMA) of aldoses. En route the C2-epimers were easily accessible, namely gluco-configured sugar alcohols, bearing one set of hydroxyl groups in a suboptimal 1,3-syn-realtionship. The synthesized compounds were found to possess thermal properties consistent with the predicted values, and the “perfect” higher-carbon sugar alcohol with eight carbon atoms was found to have indeed an outstanding high latent heat of fusion of ~ 380 J/g with a melting point of 260 °C. Graphical abstract

General Equation to Estimate the Physicochemical Properties of Aliphatic Amines.

Changes in various physicochemical properties (P(n)) of aliphatic amines (including primary, secondary, and tertiary amines) can be roughly divided into nonlinear (P(n)) and linear (PLC(n)) changes. In our previous paper, nonlinear and linear change properties of noncyclic alkanes all were correlated with four parameters, n, SCNE, ΔAOEI, and ΔAIMPI, indicating number of carbon atoms, sum of carbon number effects, average odd-even index difference, and average inner molecular polarizability index difference, respectively. To date, there has been no general equation to express changes in the properties of substituted alkanes. This work, based on the molecular structure characteristics of aliphatic amine molecules, proposes a general equation to express nonlinear changes in their physicochemical properties, named as the "NPAA equation" (eq 12), ln(P(n)) = a + b(n) + c(SCNE) + d(ΔAOEI) + e(PEI) + f(APEI) + g(GN), and proposes a general equation to express linear changes in the physicochemical properties of them, named as the "LPAA equation" (eq 13), PLC(n) = a + b(n) + c(SCNE) + d(ΔAOEI) + e(PEI) + f(APEI) + g(GN). In NPAA and LPAA equations, a, b, c, d, e, f, and g are coefficients, and PEI, APEI, and GN represent the polarizability effect index, average polarizability effect index, and N atomic influence factor, respectively. The results show that nonlinear and linear change properties of aliphatic amines all can be correlated with six parameters, n, SCNE, ΔAOEI, PEI, APEI, and GN. NPAA and LPAA equations have the advantages of uniform expression, high estimation accuracy, and usage of fewer parameters. Further, by employing the above six parameters, a quantitative correlation equation can be established between any two properties of aliphatic amines. Using the obtained equations as model equations, the property data of aliphatic amines were predicted, involving 107 normal boiling points, 10 refractive indexes, 11 liquid densities, 54 critical temperatures, 54 critical pressures, 62 liquid thermal conductivities, 59 surface tensions, 56 heat capacities, 55 critical volumes, 54 gas enthalpies of formation, and 57 gas Gibbs energies of formation, a total of 579 values, which have not been experimentally determined yet. This work not only provides a simple and convenient method for estimating or predicting the properties of aliphatic amines but can also provide new perspectives for quantitative structure-property relationships of substituted alkanes.

Density and speed of sound of (iodobenzene + n-alkane) liquid mixtures at T = (288.15 to 308.15) K. Application of the Prigogine-Flory-Patterson model

(Iodobenzene + n-alkane) liquid mixtures have been studied experimentally, in terms of densities (ρ) and speeds of sound (c), and theoretically, by the application of the Prigogine-Flory-Patterson (PFP) model. The n-alkanes considered are n-heptane, n-decane, n-dodecane, and n-tetradecane. ρ and c measurements have been performed at a pressure p = 0.1 MPa and in the temperature range T = (288.15 to 308.15) K. Excess molar volumes (VmE) and excess isentropic compressibilities (κSE) have been calculated and correlated by Redlich-Kister polynomials. (∂VmE/∂T)p curves at the same (p,T) conditions have been obtained from correlated VmE values. The mixtures are characterized by the following features: (i) VmE increases with the number of carbon atoms of the n-alkane (n), being negative for n = 7, small and S-shaped with positive and negative values for n = 10, and positive for n = 12 and n = 14; (ii) κSE and (∂VmE/∂T)p are negative, increase with n and are very close to zero for n = 14. From these experimental results and the knowledge of the excess molar enthalpies of mixtures containing fluorobenzene, chlorobenzene or bromobenzene with n-alkanes, we have inferred the presence of structural effects, especially important for n = 7 and less relevant for volumetric properties as n increases. The VmE obtained are compared with those of other (halogenated benzene + n-alkane) liquid mixtures existing in the literature, namely systems with fluorobenzene, chlorobenzene, and bromobenzene. From this comparison and the analysis of the isobaric thermal expansion coefficients of the pure compounds, it is inferred that the interactional effects on VmE do not vary appreciably with the length of the n-alkane, so the observed VmE variation is fundamentally determined by the corresponding variation of the contribution from structural effects. Moreover, the application of the PFP model supports this interpretation, providing free volume contributions to VmE that vary parallelly to VmE with the length of the n-alkane, and interactional contributions that rest approximately constant independently of the n-alkane size.

Fe-coating-mediated carburization: A new strategy for fabricating a tungsten carbide coating on tungsten

A tungsten carbide (WC) ceramic coating is fabricated by a new method of Fe-coating-mediated carburization, in which the tungsten substrate is carburized using a pre-electroplated Fe coating. In this carburization process, the electroplated Fe coating is transformed into a carbon steel coating, and a significant number of interstitial carbon atoms in the carbon steel coating diffuse into the tungsten substrate, forming a WC ceramic coating on it. The so-formed WC ceramic coating is nonporous, uniform in thickness, and has a microstructure with grain size gradient. The thickness of the electroplating Fe coating had no effect on the microstructure and growth rate of WC coating when the thickness of the electroplating iron coating was in the range of 5–20 μm. The hardness of the coating reached 2800 HV0.05, and the adhesion strength between the substrate and coating was greater than 100 N. Compared with conventional solid carburization, Fe-coating-mediated carburization can generate nonporous ceramic coatings over wider ranges of temperature and carbon potential at a higher growth rate. Accordingly, the microstructure and properties of the coating could be optimized further.

Inhibition effect of three types of biochar on volatile organic compounds from asphalt: Revealing chemical adsorption as the primary mechanism

For advancing sustainable and eco-friendly road materials, addressing the emissions of volatile organic compounds (VOCs) from asphalt binders is paramount. As an environment-friendly adsorbent, biochar is highly promising for mitigating such VOCs emissions. Herein, the feasibility and mechanism of using biochar to control VOCs emissions from asphalt were investigated. Biochar was derived from rice husk, straw and coffee grounds. The VOCs composition was analysed using thermal desorption–gas chromatography–mass spectrometry. Differential scanning calorimetry was employed to simulate asphalt VOCs release, while temperature-programmed desorption spectroscopy was employed to investigate biochar inhibition. Rice husk–derived biochar exhibited the highest inhibition effect on asphalt VOCs. The inhibitory effects of the three biochar samples were weakened with increasing number of carbon atoms in organic compounds, with less ideal inhibition efficiency for aromatic compounds. Chemical adsorption was the primary mechanism for the inhibition of VOCs emissions by biochar at high temperatures.

Using Activated Biochar from Caryocar brasiliense Pequi Almonds for Removing Methylene Blue Dye in an Aqueous Solution

Water pollution remains a global problem that urges researchers to develop new technologies aimed at environmental restoration. Here, this study aimed at obtaining an activated biochar from pequi almonds for dye removal. Before and after adsorption, the materials underwent characterization using techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Raman spectroscopy, and thermogravimetric analysis (TG). The biochar from the pequi almond was called BA, and the activated biochar from the pequi almond was called ABA. The influence of the pH, contact time, and adsorbate concentration on adsorption was investigated using the dye methylene blue. The morphological assessment revealed higher cracks and pores in the ABA than in the BA. The TG showed that the BA lost approximately 19% more mass than the ABA, indicating that activation occurred. The activation contributed to the decrease in the degree of disorder in the BA because of the increased number of graphitic carbon atoms (ordered) in the ABA, as observed via Raman. The adsorption kinetics followed a pseudo-second-order model, while the adsorption isotherms followed the Langmuir model. The BA adsorption capacity was 500.00 mg g−1, constituting a robust solution for dye removal from aqueous environments. Therefore, this implies the success of the process.

Retention characteristics, saturated vapor pressure and vaporization enthalpy of mesityl oxide ethers of linear alcohols C1–C5

Ethers of mesityl oxide and linear alcohols C1-C5 have been synthesized.Retention characteristics were determined using the method of gas–liquid chromatography with a column with a non-polar phase in the temperature range of 373.2–463.2 K. Based on these characteristics, the values of the sorption enthalpies of ethers, saturated vapor pressures and enthalpies of vaporization were calculated. Dependences of retention indices on temperature, retention indices and sorption enthalpies on the number of carbon atoms in the molecule of the alcohol radical of ethers have a linear form. The values of excess enthalpies of mixing are estimated and the enthalpies of vaporization obtained in the work and calculated by the QSPR-method are compared.

Silicon oxide film formation by spraying tetraethyl orthosilicate onto substrate with simultaneous low-energy SiO+ ion-beam irradiation

We attempted to deposit silicon oxide films by spraying tetraethyl orthosilicate (TEOS) onto a substrate while the substrate was also irradiated with a low-energy SiO+ ion beam. The energy of the SiO+ ions was 55 eV, and the substrate temperature was 300 °C. Following this process, we were able to deposit a film on the substrate. X-ray photoelectron spectroscopy (XPS) measurements of the film showed that it was composed of silicon oxide. XPS analysis also showed that the oxygen-to-silicon atomic concentration ratio (O/Si ratio) for the film was 1.57. For comparison, an SiO+ ion beam was used to irradiate a substrate at room temperature with simultaneous spraying of TEOS. XPS analysis of the deposited film showed that it was silicon oxide with an O/Si ratio of 1.45. In this case, however, a relatively large number of carbon atoms (7 at. %) were incorporated into the film. In both the 300 °C and room-temperature cases, we confirmed that the film deposition rate was substantially improved by supplying TEOS during SiO+ ion-beam irradiation.

Assessment of organic pollutants in petroleum refinery wastewater by LC-MS analyzer

The release of toxic and hazardous effluents from petroleum refining companies seriously threatens the poisoning of water bodies. Thus, it is necessary to determine an accurate treatment process by understanding the nature of wastewater. This work uses Liquid Chromatography-Mass Spectroscopy (LCMS), including LC-Tandem MS (LCMS/MS), ion trap (IT), and quadrupole-time-of-flight (Q-TOF) to comprehend the composition of petroleum refinery effluent. Many polar metabolites available, even as a trace fraction, can be found using advanced LCMS with defined molecular structure, which may or may not be itemized in CAS. Based on the number of carbon atoms (C1-C48), chemical reactivity (saturated, unsaturated, and aromatics), and functional group (hydrocarbons containing oxygen only and other minerals along with oxygen), substances are identified. Using LCMS/MS, 170 organic components, 77.10% negative and 22.90% positive metabolites, are quantified. A range of carbon between C8 and C48 is identified as having 6.50% C8-C12, 30% C13-C17, and 63.50% C18-C48. Higher molecular mass hydrocarbons from C22-C48 are less soluble in water and are more positively polarized, while C8-C21 hydrocarbons are more soluble under negative polarity. The principal ingredient is documented as consisting primarily of aromatic chemicals (72.30%), the majority of which are found as harmful metabolites. Further, 83% of the hydrocarbons are acknowledged to contain solely oxygen compared to other minerals in petroleum effluents. Overall, it was concluded that the direct discharge of petroleum refinery effluents without treatment may cause various health and environmental issues.