Employing Ethylene Glycol Research Articles

Ni/ZSM‐23 Catalysts: Effect of Impregnating Solvent on the Hydroisomerization of n‐Hexadecane

AbstractBifunctional catalysts are widely used in the hydroisomerization of long‐chain n‐alkanes, which are of great significance in the production of high value‐added chemicals. Herein, the Ni/ZSM‐23‐W and Ni/ZSM‐23‐EG catalysts were prepared using water and ethylene glycol, respectively. The catalysts were characterized using XRD, SEM, TEM, NH3‐TPD, Py–IR, H2‐TPR, H2‐TPD, ICP–OES, and XPS, and their catalytic performance was evaluated by conducting the hydroisomerization of n‐hexadecane as a model reaction. It was revealed that the polarity of the impregnating solvent has a significant impact on the dispersion of Ni nanoparticles. When employing ethylene glycol as a solvent, a strong interaction occurred between NiOx and ZSM‐23 in the Ni/ZSM‐23‐EG catalyst, which facilitated the formation of small‐sized and well‐dispersed Ni nanoparticles. Consequently, the Ni/ZSM‐23‐EG catalyst demonstrated a strong hydrogenation capacity, yielding an impressive 72.9% of iso‐hexadecanes yield.

Passively mode-locked fiber laser based on ethylene glycol

A passively mode-locked Er-doped fiber laser employing ethylene glycol as a saturable absorber (SA) has been proposed and experimentally validated. The ethylene glycol-SA is fabricated by filling the space between the end facets of two optical patch cords inserted into a cannula with ethylene glycol. Utilizing such an SA with a modulation depth of 9.6 %, stable mode-locking operation are manifested in the laser cavity, including the production of bright pulse and bright-dark pulse pair. The generated bright pulse has a center wavelength at 1562.28 nm, a 3 dB bandwidth of 0.21 nm, a repetition frequency of 20.24 MHz, and a signal-to-noise ratio (SNR) of 57 dB. Through precisely manipulating the polarization state and the pump power in the laser cavity, the bright-dark pulse pairs can be successfully attained at the same repetition frequency. This is the first demonstration of a passively mode-locked fiber laser utilizing ethylene glycol as the saturable absorber. Due to their superior optical absorption characteristics, low cost, simplicity in fabrication and non-volatile nature, ethylene glycol-SAs have enormous potential in the field of nonlinear optics and ultrafast photonics.

Design and control of a distillation sequence for the purification of bioethanol obtained from sotol bagasse (Dasylirium sp.)

Sotol bagasse (SB) is a byproduct generated during the fermentation of the sotol plant (Dasylirium sp.) for the production of a traditional alcoholic beverage in Mexico. In this study, a novel ethanol purification distillation sequence is proposed, utilizing ethanol produced from SB treatment as described by González-Chavez et al. (2022). Prior to purification, the ethanol-water mixtures exhibited ratios of 0.054 and 0.935. The proposed distillation sequence comprises three columns: i) depletion, ii) extraction (employing ethylene glycol as the solvent agent), and iii) solvent recovery. To assess energy consumption and controllability, three solvent:feed ratios (1.5:1, 2:1, 2.5:1) were examined, taking into account the feed to the second column. The lowest energy consumption was observed at 31 × 103 kW, corresponding to the 1.5:1 ratio. Optimal controllability was achieved at a solvent:feed ratio of 2.5:1, as evidenced by the lowest Integral Absolute Error (IAE) value of 3.3 × 10–3 and the highest proportional gain (Kc) value of 250. In summary, we leveraged previously reported experimental data to design a new distillation sequence with potential applications in the ethanol purification derived from SB fermentation. The outcomes of this investigation underscore the importance of promoting circular economy practices, particularly in the northern region of Mexico, where significant quantities of agrowastes are generated.

Study on vapor-liquid equilibrium and azeotropic distillation simulation of fluorene- dibenzofuran system

ABSTRACT This study is centered on the separation of the fluorene-dibenzofuran system through binary phase equilibrium experiments and azeotropic distillation simulations. An enhanced Othmer equilibrium still was employed to conduct phase equilibrium experiments, and the obtained data were correlated to determine the missing binary interaction parameters. The resulting experimental data demonstrated thermodynamic consistency and reliability. Subsequent correlation using the NRTL, UNIQUAC, and Wilson models highlighted the UNIQUAC model’s exceptional agreement with experimental values. This underscores the model’s capability to precisely characterize the fluorene-dibenzofuran system’s phase behavior. The phase equilibrium study provided pivotal parameters and predictions, forming the groundwork for subsequent separation process simulations and equipment development. Azeotropic simulations, employing ethylene glycol as a co-boiling solvent and simulated via Aspen software, yielded high-purity fluorene products with a minimum purity of ≥ 98%. These findings emphasize the potency of azeotropic distillation in achieving high-purity separation within the fluorene-dibenzofuran system, with promising implications for industrial applications.

Insight into the motion of ethylene glycol (fluid) conveying magnesium oxide and aluminium oxide nanoparticles with emphasis on “upper branch” and “lower branch” solutions

To address the limitations of nanofluids and combine the physical and chemical characteristics of nanoparticles in a meaningful way, researchers have been focusing on the usage of hybrid nanofluids. A rising number of studies have been conducted in the literature to explore the thermal performance of hybrid nanomaterials. In the current study, dual analysis is carried out to show the impact of theoretical correlations on the heat transfer capabilities of hybrid nanofluids. In this context, a mathematical model for a hybrid nanofluid is developed employing ethylene glycol as a base fluid, conveying magnesia and silver as nanoparticles on an inclined porous stretching/shrinking surface. The thermal transport aspects of a hybrid nanofluid are analyzed in terms of thermal radiation, Ohmic and viscous dissipation, and variable heat source/sink effects. The mathematical model is numerically solved using the bvp4c function in the MATLAB program. The outcomes of controlling factors on the fluid velocity, thermal distributions, as well as friction drag coefficient and heat transfer rate, are illustrated graphically. The findings show that due to remarkable thermal capabilities, the hybrid nanofluid is more effective at transferring heat than ordinary nanofluid. Additionally, the upshots show that the suction and magnetic parameter expands the shrinking range for which the dual solution lives.

Solvothermal synthesis of MnCo2O4 microspheres for high-performance electrochemical supercapacitors

MnCo2O4 microspheres were synthesized via the solvothermal method by employing ethylene glycol as a solvent and these synthesized materials were characterized by Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive Analysis of X-rays (EDAX), X-ray Diffraction spectroscopy (XRD), X-ray Photoelectron Spectroscopy (XPS). The morphology and structural conformation of MnCo2O4 microspheres were confirmed by FESEM and XRD. The electrochemical performance of MnCo2O4 @ 18 h electrode material was analyzed by cyclic voltammetry, Galvanostatic charge discharge, and electrochemical impedance spectroscopy techniques. Impressively, the MnCo2O4 @ 18 h microspheres achieved remarkable results in pseudocapacitive performance with a high specific capacitance of 439 Fg−1 at 1 Ag−1 and exhibits excellent cyclic stability of 80.6% capacitance retention after 10,000 cycles at 1 Ag−1.

Robotics‐assisted high‐throughput catalytic investigation of PVP nanoparticles in the oxidation of morin

AbstractBACKGROUNDConventional methods used to evaluate the activity of catalysts are time consuming and tedious, which only several catalysts can successfully be discovered. By employing robotics, this approach can be shorted tremendously. A robotics‐assisted high‐throughput system for the fast and effective catalytic evaluation of Pd‐ and Au‐polyvinylpyrrolidone (PVP) nanoparticles (NPs) was investigated.RESULTSPalladium and gold PVP NPs were synthesised by employing ethylene glycol in the polyol method. These NPs were evaluated for the oxidation of morin using a high‐throughput system, including a liquid handling robot, a 96‐well plate and a microplate reader. The catalyst concentration variation step for both catalysts (Pd‐ and Au‐PVP NPs) was performed in one experiment in a 96‐well plate. A concentration range, including 12 concentrations in four replicates, was investigated simultaneously. Therefore, with one experiment, the optimal concentration of both catalysts could be determined. A similar approach was followed for the concentration variation steps of morin and hydrogen peroxide at different temperatures. This was done to determine the effect of concentration on the observed rate (kobs).CONCLUSIONThe catalytic oxidative degradation of morin can be investigated in a fast and effective way by employing robotics and a high‐throughput system. This system can also be applied to screen catalysts (homogeneous and heterogeneous catalyst) and the parallel synthesis of nanoparticles – particularly dendrimer‐encapsulated nanoparticles. © 2021 Society of Chemical Industry (SCI).

Conductive Nanocomposite Cotton Thread Strands for Wire and Industrial Applications

This paper reports the synthesis of conducting cotton thread strands obtained by dip coating in sodium dodecyl-benzene sulfonate (SDBS) surfactant with dispersed single-walled carbon nanotubes (SWCNT), as a promising candidate for energy storage applications. The effect of the dispersion and SDBS in the dissolved SWCNT solution was detected using field emission scanning electron microscopy (FE-SEM) and x-ray diffraction (XRD). XRD confirms that there was good dispersion of SWCNTs on the cotton thread strands obtained by doping employing ethylene glycol (EG) which lowers the corrugation of the cotton thread. FE-SEM images obtained at different magnifications show micro-fibril structure. Energy dispersive x-ray (EDX) analysis confirms the presence of only C, Na and S, ruling out the presence of any elemental impurity. A strong decrease from 3.587Ω to 0.01257Ω in electrical resistance was observed when the concentration of SWCNTs was increased from 0.008049 wt.% to 1.07269 wt.%, indicating that the SWCNTs induced conductive properties in the cotton thread strands. The study shows that sodium dodecyl benzyl sulfonate (SDBS) has the best dispersion of single-walled carbon nanotubes in water when used along with ethylene glycol. The results show that the coated threads can have great industrial applications as conduction wire substitute.

Engineered zinc oxide nanoaggregates for photocatalytic removal of ciprofloxacin with structure dependence

A simple and environment-friendly approach to prepare zinc oxide nanoaggregates was achieved by employing ethylene glycol–H2O as the reaction medium. The composition and structure of the as-fabricated ZnO products were confirmed using X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption measurements. By tailoring the volume ratio of ethylene glycol to water, coral-like, flower-like, and nanoparticulate ZnO nanoaggregates were successfully synthesized. The impact of the structure of the as-obtained ZnO nanoaggregates on the photocatalytic degradation of ciprofloxacin was further studied. Under simulated solar light irradiation, the photocatalytic removal rate of coral-like, flower-like, and nanoparticulate ZnO nanoaggregates for ciprofloxacin was 45%, 80%, and 90%, respectively. The reactive species trapping experiment result indicated that the generated holes, OH−, and ·O2− active species mainly contributed to the degradation of ciprofloxacin. On the basis of photoluminescence spectra and photo/electrochemical measurement results, the prevention of electron-hole recombination and the rapid charge transfer upon the ZnO nanoparticle aggregates resulted in their efficient photocatalytic activity.

Preparation and Characterization of Magnetic Biochar Nanocomposites via a Modified Solvothermal Method and Their Use as Efficient Heterogeneous Fenton-like Catalysts

In this study, magnetic biochar nanocomposites (FeC–S) were prepared by employing ethylene glycol as a liquefaction agent of corn stalks and solvent for the solvothermal synthesis approach. The eff...

Multistep synthesis of AgBr quantum dots coupled porous BiOBr spheres for enhanced photocatalysis

A three-step route has been adopted for the synthesis of AgBr quantum dots coupled porous BiOBr spheres. Firstly, porous Bi spheres were obtained through a simple solvothermal method employing ethylene glycol as a reducing agent. Sequentially, a redox reaction of Bi spheres with NH4Fe(SO4)2 as an oxidiser was employed to prepare porous BiOBr spheres. Finally, AgBr quantum dots were loaded on BiOBr spheres through in situ precipitation. The obtained powders were characterised by employing powder X-ray diffraction for phase confirmation and transmission electron microscopy for microstructure evolution. BiOBr hierarchical spheres with a diameter of ca. 500 nm were made up by two-dimensional nanosheets. AgBr quantum dots were deposited on BiOBr petals and did not influence the microstructure and morphology of the BiOBr host. The BiOBr/AgBr composite exhibited higher photocatalytic activity than pure BiOBr porous spheres in degrading Rhodamine B dyes.

Polyol-mediated synthesis of ZnO nanoparticle-assembled hollow spheres/nanorods and their photoanode performances

ZnO nanoparticle-assembled hollow spheres (raspberry-like) and elliptical nanorods (rice-like) were synthesized via a facile polyol process. Employing ethylene glycol as a polyol led to a ZnO nanoparticle-assembled hollow sphere structure, while diethylene glycol resulted in an elliptical nanorod structure. The ZnO hollow spheres had a higher Brunauer-Emmett-Teller (BET) surface area, better dye adsorption, more incident light trapping, and lower defect density than the ZnO elliptical nanorods. The ZnO hollow sphere-based dye-sensitized solar cells (DSSCs) exhibited a three-times higher current density than the ZnO elliptical nanorod-based DSSCs.

Synthesis of glycine-functionalized graphene quantum dots as highly sensitive and selective fluorescent sensor of ascorbic acid in human serum

In this work, highly photoluminescent glycine (GLY) functionalized graphene quantum dots (GQDs) (GLY-GQDs) were synthesized by a simple and green pyrolysis method employing ethylene glycol as carbon source, GLY as functional molecule. The as-synthesized GLY-GQDs exhibited excellent water solubility with a fluorescence quantum yield of 21.7%. The fluorescence of GLY-GQDs was intensively quenched by Ce4+ via forming non luminescent complexes of GLY-GQDs-Ce4+. When ascorbic acid (AA) was in presence, Ce4+ was reduced to Ce3+ and the fluorescence of GLY-GQDs regained. In the light of this theory, a simple AA sensor was fabricated without complicated, costly and time-consuming operations. Under the optimal conditions, the fluorescence recovery ratio and the concentration of AA has a linear relationship in the range of 0.03–17.0μM and with a detection limit of 25nM which was one order higher sensitive than the reported methods Furthermore, this established sensor system also shows a high selectivity toward AA over a wide range of common biological molecules such as uric acid, dopamine and glutathione and so on. The proposed method was successfully applied for the AA detection in serum samples. All these suggested the potential of this GLY-GQDs based sensor in the clinical analysis.

Synthesis of TiO2 microspheres building on the etherification and its application for high efficiency solar cells

This paper describes a facile solvothermal method to synthesize TiO2 microspheres by employing ethylene glycol monomethyl ether and ethylene glycol as solvent. By analyzing the resulted supernatant after reaction, it was proved that the etherification reaction of glycol monomethyl ether and the ligand exchange between ethylene glycol and tetra-n-butyl titanate played a key role in synthesis of TiO2 microspheres. These as-obtained TiO2 microspheres exhibited high specific surface area up to 113.24 m2 g−1 and have a narrow pore size distribution (6.94 nm). When applied to the photoanode, the TiO2 microsphere-based dye-sensitized solar cells achieved a high power conversion efficiency up to 10.25%.

Synthesis of palladium nanoparticles over graphite oxide and carbon nanotubes by reduction in ethylene glycol and their catalytic performance on the chemoselective hydrogenation of para-chloronitrobenzene

Pd nanoparticles have been synthesized over carbon nanotubes (CNT) and graphite oxide (GO) by reduction with ethylene glycol and by conventional impregnation method. The catalysts were tested on the chemoselective hydrogenation of p-chloronitrobenzene and the effect of the synthesis method and surface chemistry on their catalytic performance was evaluated. The catalysts were characterized by N2 adsorption/desorption isotherms at 77K, TEM, powder X-ray diffraction, thermogravimetry, infrared and X-ray photoelectron spectroscopy and ICP-OES. It was observed that the synthesis of Pd nanoparticles employing ethylene glycol resulted in metallic palladium particles of smaller size compared to those prepared by the impregnation method and similar for both supports. The presence of oxygen groups on the support surface favored the activity and diminished the selectivity. It seems that ethylene glycol reacted with the surface groups of GO, this favoring the selectivity. The activity was higher over the CNT-based catalysts and both catalysts prepared by reduction in ethylene glycol were quite stable upon recycling.

Modified Solvothermal Strategy for Straightforward Synthesis of Cubic NaNbO3 Nanowires with Enhanced Photocatalytic H2 Evolution

To further improve the photocatalytic H2 evolution activity, NaNbO3 photocatalyts simultaneously possessing cubic crystal structure and 1D morphology have been successfully synthesized via a modified solvothermal strategy. During the process of synthesis employing ethylene glycol as solvent, a temperature fluctuation during the autoclaving period is proposed to regulate the grain growth without any other additives or calcinations. It is demonstrated that the structure-directing effect of the solvent is enhanced in the condition of the temperature fluctuation, contributing to the formation of 1D nanostructure. Otherwise, the irregular NaNbO3 nanoparticles with severe aggregation resulted. Photocatalytic H2 evolution activities of samples under ultraviolet light irradiation with 0.5 wt % of Pt cocatalyst indicate that NaNbO3 nanowires expectedly exhibit an enhanced activity of 699 μmol h–1 g–1, approaching twice that of NaNbO3 nanoparticles. The higher photocatalytic activity of NaNbO3 nanowires is attributed to their large specific surface area, high chemical purity, and powerful reduction ability, which have been confirmed by the further characterizations and analysis based on crystal structure, valence state, elemental composition, and energy band structure. The modified solvothermal strategy provides an alternative pathway to regulate the crystal growth, which can effectively integrate the unique morphology with desired crystalline structure toward increasing photocatalytic activity.

Structural and magnetic studies of Co–Ti-substituted magnetoplumbite-type (M-type) strontium ferrites by sol–gel method

Magnetoplumbite-type (M-type) strontium ferrites doped with varying molar ratio of cobalt and titanium (SrFe12−2x Co x Ti x O19; x = 0.2, 0.4, 0.6, 0.8 and 1.0) were prepared via sol–gel technique employing ethylene glycol as a gel precursor. The prepared samples were characterized using X-ray diffractometry (XRD), field emission scanning electron microscopy, superconducting quantum interference devices and high-resolution transmission electron microscopy (HRTEM). The XRD patterns confirmed the formation of a highly homogeneous M-type strontium ferrite at molar substitution of 0.2 in the SrFe12−2x Co x Ti x O19 system (SF02) with calculated crystallite size of 48.5 nm. Sample SF02 showed the desired magnetic properties of a reduced coercivity at 4946 (192) Oe while having enhanced remnant and saturation magnetizations of 30.33 (0.81) and 61.45 (2.14) emu/g, respectively. HRTEM imaging of SF02 showed high regularity in the stacking sequence with corresponding lattice spacings matching that commonly found in the M-type ferrite structure.

Enhancement of luminescence in white emitting strontium fluoride core @ calcium fluoride shell nanoparticles.

Synthesis of lanthanide-doped fluoride SrF2:3Dy and SrF2:3Dy@CaF2 nanoparticles with different ratios of core to shell (1:0.5, 1:1 and 1:2) has been carried out by employing ethylene glycol route. X-ray diffraction (XRD) patterns reveal that the structure of the prepared nanoparticles was of cubical shape, which is also evident in TEM images. The size of the nanoparticles for core (SrF2:3Dy) is found to increase when core is covered by shell (CaF2). It is also evident from Fourier transform infrared spectroscopy (FTIR) that ethylene glycol successfully controls the growth and acts as a shape modifier by regulating growth rate. In the photoluminescence investigation, emission spectra of SrF2:3Dy is found to be highly enhanced when SrF2:3Dy is covered by CaF2 due to the decrease of cross relaxation amongst the Dy3+-Dy3+ ions. Such type of enhancement of luminescence in homonanostructure SrF2:3Dy@CaF2 (core@shell) has not been studied so far, to the best of the authors’ knowledge. This luminescent material exhibits prominently white light emitting properties as shown by the Commission Internationale d’Eclairage (CIE) chromaticity diagram. The calculated correlate colour temperature (CCT) values for SrF2:3Dy, SrF2:3Dy@CaF2 (1:0.05), SrF2:3Dy@CaF2 (1:1) and SrF2:3Dy@CaF2 (1:2) are 5475, 5476, 5384 and 5525 K, respectively, which lie in the cold white region.Graphical abstractWhite light emitting homonanostructure material SrF2:3Dy@CaF2(core@shell).

Effect of silver nitrate concentration of silver nanowires synthesized using a polyol method and their application as transparent conductive films

Silver nanowires were synthesized using a polyol process by employing ethylene glycol, poly(N-vinylpyrrolidone), and silver nitrate as precursors. The concentration of silver nitrate was varied to study the resulting changes in aspect ratios of silver nanowires. The experimental results indicated that the growth characteristics of silver nanowires were affected by the synthesis temperature, the concentration of silver nitrate, and the rate at which silver nitrate was added. Field-emission scanning electron microscopy, UV–visible spectrophotometry, and X-ray diffractometry were employed to characterize the silver nanowires. As the concentration of silver nitrate was reduced, the diameters of the silver nanowires decreased, increasing the aspect ratio. The optimal diameter and length of the silver nanowires were 100nm and 20μm, respectively. A thin film composed of silver nanowires exhibited average transmittance of 92.15% at visible wavelengths and a sheet resistance of 20Ω/sq; such a film could be used as a transparent conductive film in commercial applications.

Behavior of Hydrogel Microparticles Based on Acrylamide and 2-HEMA Obtained By Inverse Emulsion

ABSTRACTPoly(acrylamide-co-2-hydroxyethyl methacrylate), hydrogel microparticles were prepared by free radical copolymerization of acrylamide (AAm) and 2-hydroxyethyl methacrylate (2-HEMA) using an inverse emulsion polymerization technique, employing ethylene glycol dimethylacrylate (EGDMA) as crosslinker in the presence of w/o emulsifiers span-80 and span-85 (sorbitol mono-oleate) above the lower critical solution temperature. Water absorption capacity and characteristics of the hydrogel microparticles were analyzed by Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA). Thus, microparticles were submitted to a gravimetric study on their ability to absorb and to retain distilled water at 25°C. One gram of microparticles absorbed at least 15 g of water. By varying the relative ratio between the continuous phase (hexane and emulsifiers) and the dispersed phase (monomers, initiator and crosslinker), non-agglomerated dispersed particles with nearly spherical shape were obtained having a narrow size distribution in the range from 10 to 20 µm. At a constant value of the emulsifier, and as a result of increasing the stirring rate, a particle size reduction was observed from 13 to 7 µm. The PAAm and PHEMA structures of synthesized hydrogel were confirmed using FTIR analysis. Additionally, through thermal analysis the P(AAm-HEMA) hydrogel showed an increase of water retention and thermal stability due to PAAm addition.