Glycol Research Articles

A comparative study of mono ethylene glycol economic production via different techniques

Mono-ethylene glycol (MEG) is a high-volume chemical intermediate used as a raw material for a variety of chemical products. It could also be used as a hydrate inhibitor in natural gas. Recently, the importance of MEG has been increased due to its usage as a supporting emulsifier in diesel engines to reduce NOx and soot emissions, in addition to its usage as an additive to dual fuel diesel engines. The increase consumption of MEG in wide range of applications leads to the search for the most efficient, environmental friendly and cost effective technique to produce more quantities of it. MEG is most commonly manufactured via the hydration of ethylene oxide (EO). In this work, two different technologies of EO hydration to produce MEG are compared; the direct hydration of EO with water and the indirect hydration through the usage of ethylene carbonate (EC) as an intermediate. Comparative economic and environmental impact assessments were performed based on plant-scale simulations (per 600,000 tons per year of MEG produced) of the two hydration technologies using Aspen HYSYS version 11 simulation software. Economic analysis showed that the utilities’ energy consumption for direct hydration process is significantly higher than for indirect hydration by 279 megawatts. On the other hand, the environmental impact assessments showed that GHG emissions from natural gas power generation from utilities from direct hydration are three times greater than GHG emissions from indirect hydration. This leads to indirect hydration of ethylene oxide through ethylene carbonate formation being considered economically and environmentally preferable compared to the direct hydration process of ethylene oxide.

Thermodynamic evaluation of intermolecular interaction selectivity in separation of binary mixtures based on the activity coefficients at infinite dilution

Thermodynamic evaluation of deep eutectic solvents in separation of binary mixtures is increasing, and this is due to an easy preparation of deep eutectic solvents and their properties can be altered by different combinations of hydrogen bond acceptor to hydrogen bond donor. This study presents the intermolecular interactions between the prepared deep eutectic solvent with volatile organic solvents at different temperatures, T = (313.15 – 353.15) K and at atmospheric pressure. The investigated solvents were prepared by the combination of tetrabutylammonium acetate as hydrogen bond acceptor and ethylene glycol or diethylene glycol as hydrogen bond donor at a molar ratio of 1:3, respectively. The influence of hydrogen bond donor in separation of binary mixtures was evaluated and discussed. The intermolecular interactions of the prepared deep eutectic solvents with volatile organic solvents were evaluated based on the activity coefficients at infinite dilution values measured by the use of gas liquid chromatography. Excess thermodynamic properties at infinite dilution including excess enthalpies, Gibbs free energies and entropies were computed to further elucidate the interactions between the systems. Selectivity and capacity values were calculated to determine the feasibility of the solvents in separating industrial binary mixtures. The solvents were found promising for the separation of close boiling point mixtures comprising alcohols.

Comprehensive analysis and validation of TP73 as a biomarker for calcium oxalate nephrolithiasis using machine learning and in vivo and in vitro experiments.

Calcium oxalate (CaOx) nephrolithiasis constitutes approximately 75% of nephrolithiasis cases, resulting from the supersaturation and deposition of CaOx crystals in renal tissues. Despite their prevalence, precise biomarkers for CaOx nephrolithiasis are lacking. With advances in high-throughput sequencing, we aimed to identify biomarkers of CaOx nephrolithiasis by combining twoCaOx nephrolithiasis datasets (GSE73680 and GSE117518). Utilizing weighted gene co-expression network analysis (WGCNA) and four machine learning, we identified six hub genes (DLK2, BHLHA15, C12orf5, ICMT, LOXHD1, and TP73) as potential biomarkers. Additionally, CIBERSORT immune infiltration analysis suggested that these core genes may influence immune cell recruitment and infiltration in CaOx nephrolithiasis. Then, TP73 emerged as a significant hub gene in CaOx nephrolithiasis via receiver operating characteristic (ROC) analysis (AUC = 0.885). Furthermore, the role of TP73 was validated in CaOx nephrolithiasis rat models induced by 1% ethylene glycol, as well as clinical samples and renal tubular epithelial cell models treated with 1mM oxalate. Immunohistochemistry, RNA-Sequencing, and RT-qPCR experiments demonstrated an increased expression of TP73 in CaOx nephrolithiasis rat models and clinical samples. After transfection with TP73 lentivirus, CCK-8 assays suggested that TP73 could inhibit the proliferation of HK-2 and NRK-52E cells. In oxalate-induced cell models, dihydroethidium staining and flow cytometry apoptosis assays indicated that TP73 could enhance ROS levels and cell apoptosis. In summary, our study preliminarily identified TP73 as a diagnostic biomarker and elucidated the promoting role of TP73 in CaOx nephrolithiasis, providing a deeper understanding of the clinical diagnosis and pathogenesis.

Controlling Temporally and Spatially Homogeneous Temperature Distribution of Paper Substrates by Biogenic Phase Change Hybrid Material Coatings

AbstractHere the performance of phase change material (PCM)‐coated paper made from unbleached kraft pulp is introduced. The applied PCM consists of a mixture of ethylene glycol distearate (EGDS), a well‐known PCM wax material, and a fully substituted cellulose stearoyl ester (CSE). Transfer of the PCM material onto/into paper is achieved by spray as well as blade coating of EGDS + CSE mixture. It is shown that the kind of coating method used does not interfere with observed PCM properties. The significantly higher melt viscosity of the EGDS + CSE blends ensures that the EGDS wax is not bleeding out of the paper, which avoids the use of further encapsulation processes. The PCM behavior, as observed by thermal load measurements, and the thermal buffering of the coated paper is a function of the applied mass of the PCM material applied. The thermal retention exhibited a quasi‐isothermal behavior at ≈65 °C with EGDS + CSE coatings. These effects can offset fluctuations in temperature, and the PCM papers can be employed to achieve a more uniform temperature setting. PCM‐modified papers are therefore interesting candidates for paper‐based packaging or for use in paper‐based sensors, where overheating can strongly affect reliability of results.

Analysis of Poly(ethylene glycol) from the conservation of 17th century shipwreck Vasa and associated wooden objects

Vasa, a Swedish warship that sunk in 1628 and was excavated in 1961, and associated wooden objects underwent a preservation process using various low molecular weights (600, 1500, and 4000 Mn) of poly(ethylene glycol) (PEG) to gradually displace the water within the wooden structure, preventing the collapse of the waterlogged wood upon drying. However, after six decades of aging after application, to what extent are these polymers degraded? To investigate this, a Soxhlet apparatus was used to extract PEG from wooden samples of Vasa, and lyophilization was used to dry aqueous PEG solutions, these samples being the runoff accumulated during the application of different molecular weights of PEG to Vasa and other associated wooden objects. These samples underwent analysis via matrix-assisted laser desorption/ionization – time-of-flight mass spectrometry (MALDI-TOF MS), gel permeation chromatography (GPC), and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy.The primary discovery was that the PEG within Vasa exhibited minimal degradation, with the dominant identified species, as determined by MALDI-TOF MS and NMR spectroscopy, being HO-PEG-OH. However, small quantities of HO-PEG-OH had undergone degradation, resulting in the formation of PEG chains with distinct end groups, notably a range of carbonyl-based compounds, including aldehydes, carboxylic acids, and esters, as observed through MALDI-TOF MS, 1H, and 13C NMR spectroscopy. These mass spectrometry product peaks could be confirmed by the expected mass difference through various end-group functionalizations, such as oxidations, esterifications, or ether formations. In addition to the carbonyl-based degradation products, some PEG chains had completely cleaved into two separate lower molecular weight HO-PEG-OH polymers, each approximately half of their original molecular weight, as revealed by GPC analysis.

Nanofiber connected metal organic frameworks adsorption membrane to enhance Li+ conduction and alleviate interfacial side reaction for solid electrolyte

Polymer solid electrolytes have good flexibility and processibility, but the ionic conductivity is low and compositing with succinonitrile (SN) is one of the most effective strategies. However, severe side reaction between high reactive SN and lithium (Li) metal results in inferior interfacial stability. Herein, MOFs adsorption membrane poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)@ZIF-67 is prepared by facile electrospinning and in-situ coordinated growth to guarantee homogenous distributed MOFs connected by nanofibers, which is composited with in-situ polymerized (ethylene glycol) diacrylate (PEGDA)/SN/LiTFSI to construct composite solid electrolyte. MOFs adsorb SN and anions through porous structure and Lewis acid-base action to liberate more free Li+, leading to enhanced ionic conductivity (1.29 mS cm−1 at 30°C) and Li+ transference number (0.63). The adsorbed SN is limited to react with Li metal and MOFs can distribute Li+ evenly, leading to uniform plating/stripping and improved interfacial stability. The Li||Li cell shows stable Li plating/stripping for 920 h at 0.1 mA cm−2. The LFP||Li cell demonstrates excellent rate and cycling performances with capacity retention of 90 % after 500 cycles at 0.5C. The NCM622||Li shows good rate and cycling performances. This strategy opens up a new avenue to design adsorption membrane based solid electrolytes for Li metal batteries.

Theoretical and experimental insights of two surfactants’ effects on SnIn electrodeposited coatings from ethaline

This work uses computational methodologies to investigate the behavior of Sn2+ and In3+ ions in deep eutectic solvent (DES) based on choline chloride and ethylene glycol (1ChCl:2EG, ethaline), under different conditions, such as different temperatures, ion ratios, and in the presence and absence of hexadecyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants. Furthermore, SnIn alloys were electrodeposited on Cu surfaces to analyze the effect of the investigated different conditions on the surface morphology and chemical composition of the electrodeposited coatings. Morphology and composition were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDS). For computational approach, twelve Molecular Dynamics (MD) simulations were conducted using the GROMACS software. After MD simulations, Quantum Theory of Atoms in Molecules (QTAIM) properties were obtained. The results presented that In3+ showed a stronger affinity for Cl− than Sn2+ but it presents weaker and less stable interactions with OA (OA = oxygen of ethylene glycol-EG), particularly at higher temperatures. Electron Density and Electron Localization Function analysis indicated that In-Cl interactions are stronger and more polarized than other interactions. The Laplacian of Electron Density suggested an intermolecular nature for all interactions. The surfactant addition altered these interactions slightly, with CTAB reducing the density of Cl− around In3+ and SDS positively interacting with In3+ at 297 K and in a Sn2+:In3+ 1:1. As SDS interacted more with In3+ ions, the electrodeposition times varied between 4965 s and 75,541 s. SEM images revealed temperature- and potential-dependent changes in film morphology, changing from globular to smooth. CTAB and SDS additions led to uniform coating in Sn2+: In3+ solutions. For the 1:1 ratio at −1.4 V, there were no significant changes (between 75 and 77 %) in the percentage of Sn deposited with the use of surfactants at 297 K. At 343 K, the surfactant-free coating exhibited 69 % Sn, CTAB facilitated the Sn deposition, increasing the percentage to 92 %. At the same time, the presence of the SDS resulted in 79 % Sn. Similar behavior was obtained for −1.0 V. For 1:4 at −1.0 V at 297 K, 35 % of Sn was observed without surfactant, 29 % with CTAB, and 33 % with SDS. At 343 K, there was an increase in Sn content for 42 %, 49 % and 60 %, indicating the positive influence of the temperature, respectively. At −1.4 V, however, there was no observed influence on the Sn percentages without surfactant. With CTAB (between 29 and 34 %) at 297 and 343 K. At these temperatures, the addition of SDS promoted a higher content of Sn, increasing to 56 % and 43 %, respectively.

Block copolymer nanoparticles doping polyacrylonitrile membranes for efficient adsorption of water-soluble dyes from water

Polyacrylonitrile (PAN) membranes doped with cross-linked fluorinated block copolymer nanoparticles of poly[(poly(ethylene glycol) methacrylate)-b-poly(2,2,2-trifluoroethyl acrylate)-b-polystyrene] [P(PEGMA)-b-PTFEMA-b-PS] with high flux and high adsorption of water-soluble dyes were prepared by phase transition method. The preparation of the PAN membranes includes (1) preparation of P(PEGMA)-b-PTFEMA-b-PS nanoparticles containing the –OH terminal by polymerization induced self-assembly (PISA); (2) preparation of hydrolyzed PAN containing the –COOH moieties with about 1% hydrolysis degree to increase the adsorption of water-soluble dyes; (3) grafting hydrolyzed PAN onto the P(PEGMA)-b-PTFEMA-b-PS nanoparticles through esterification between the –OH terminal and –COOH; (4) formation of modified PAN membranes through phase transition method in the presence of the HPAN-grafting block copolymer nanoparticles. The flux and equilibrium absorption of the modified PAN membranes are 8 times higher and 143% higher than those of the unmodified PAN membranes, respectively. It suggests that modifying PAN membranes by doping with cross-linked fluorinated block copolymer nanoparticles may be a promising method to prepare high performance membranes.

A New (Trifluoromethane)Sulfonylimide Single-Ion Conductor with PEG Spacer for All-Solid-State Lithium-Based Batteries.

The choice of ionic-liquid-like monomers (ILM) for single-ion conducting polyelectrolytes (SICPs) is crucial for the performance of all-solid-state lithium batteries. In the current study, we propose a novel approach for development of SICPs via design and synthesis of a new ILM with long poly(ethylene oxide) spacer between methacrylic group and (trifluoromethane)sulfonylimide anion. Its homopolymer shows an ionic conductivity that is ∼5 orders of magnitude higher (9.2 × 10-8 S cm-1 at 25 °C), in comparison with previously reported analogues, while the conductivity of its random copolymer with poly(ethylene glycol)methyl ethermethacrylate reaches the levels of 10-6 and 10-5 S cm-1 at 25 and 70 °C, respectively. The copolymer provides excellent thermal (T onset ≈ 200 °C) and electrochemical (4.5 V vs Li+/Li) stabilities, good compatibility with Li metal, and effective suppression of dendrite growth. Li/SICP/LiFePO4 cells are capable of reversibly operating at different C rates, demonstrating excellent Coulombic efficiency and retaining specific capacity upon prolonged charge/discharge cycling at a relatively high current rate (C/5) at 70 °C.

Comparative efficacy of Knema retusa extract delivery via PEG-b-PCL, niosome, and their combination against Acanthamoeba triangularis genotype T4: characterization, inhibition, anti-adhesion, and cytotoxic activity.

Acanthamoeba spp. is a waterborne, opportunistic protozoan that can cause amebic keratitis and granulomatous amebic encephalitis. Knema retusa is a native tree in Malaysia, and its extracts possess a broad range of biological activities. Niosomes are non-ionic surfactant-based vesicle formations and suggest a future targeted drug delivery system. Copolymer micelle (poly(ethylene glycol)-block-poly(ɛ-caprolactone); PEG-b-PCL) is also a key constituent of niosome and supports high stability and drug efficacy. To establish Knema retusa extract (KRe) loading in diverse nanocarriers via niosome, PEG-b-PCL micelle, and their combination and to study the effect of all types of nanoparticles (NPs) on Acanthamoeba viability, adherent ability, elimination of adherence, and cytotoxicity. In this study, we characterized niosomes, PEG-b-PCL, and their combination loaded with KRe and tested the effect of these NPs on Acanthamoeba triangularis stages. KRe-loaded PEG-b-PCL, KRe-loaded niosome, and KRe-loaded PEG-b-PCL plus niosome were synthesized and characterized regarding particle size and charge, yield, encapsulation efficiency (EE), and drug loading content (DLC). The effect of these KRe-loaded NPs on trophozoite and cystic forms of A.triangularis was assessed through assays of minimal inhibitory concentration (MIC), using trypan blue exclusion to determine the viability. The effect of KRe-loaded NPs was also determined on A.triangularis trophozoite for 24-72 h. Additionally, the anti-adhesion activity of the KRe-loaded niosome on trophozoites was also performed on a 96-well plate. Cytotoxicity activity of KRe-loaded NPs was assessed on VERO and HaCaT cells using MTT assay. KRe-loaded niosome demonstrated a higher yielded (87.93 ±6.03%) at 286nm UV-Vis detection and exhibited a larger size (199.3 ±29.98 nm) and DLC (19.63±1.84%) compared to KRe-loaded PEG-b-PCL (45.2 ±10.07 nm and 2.15±0.25%). The EE (%) of KRe-loaded niosome was 63.67 ±4.04, which was significantly lower than that of the combination of PEG-b-PCL and niosome (79.67±2.08). However, the particle charge of these NPs was similar (-28.2 ±3.68 mV and -28.5 ±4.88, respectively). Additionally, KRe-loaded niosome and KRe-loaded PEG-b-PCL plus niosome exhibited a lower MIC at 24 h (0.25 mg/mL), inhibiting 90-100% of Acanthamoeba trophozoites which lasted 72 h. KRe-loaded niosome affected adherence by around 40-60% at 0.125-0.25 mg/mL and removed Acanthamoeba adhesion on the surface by about 90% at 0.5 mg/mL. Cell viability of VERO and HaCaT cells treated with 0.125 mg/mL of KRe-loaded niosome and KRe-loaded PEG-b-PCL plus niosome exceeded 80%. Indeed, niosome and niosome plus PEG-b-PCL were suitable nanocarrier-loaded KRe, and they had a greater nanoparticle property to test with high activities against A. triangularis on the reduction of adherence ability and demonstration of its low toxicity to VERO and HaCaT cells.

Effect of Deep Eutectic Solvent (DES) on physicochemical and electrochemical properties of triethylmethylammonium tetrafluoroborate in propylene carbonate and aqueous propylene carbonate solvent systems for energy storage applications: A comparative analysis

The use of non-toxic and biodegradable Deep Eutectic Solvents (DES) in energy storage has attracted a lot of attention as the toxic, costly and flammable organic electrolytes do not seem to be sustainable for the environment. So, to analyse the potential of DESs in this area their physicochemical properties and molecular interaction study can be quite helpful. The measurements were made of the density, sound speed, and electrical conductivity of Triethylmethylammonium Tetrafluoroborate (TEMABF4) at four different temperatures in two different solvent systems: propylene carbonate (PC) with ethaline DES (a mixture of ethylene glycol and chlorine in a 1:2 ratio) added as an additive, and binary aqueous PC with ethaline DES again, added as an additive. Density and speed of sound measurements were used to determine the physicochemical characteristics such as apparent molar volume and partial molar volume), apparent molar isentropic compressibility and partial molar isentropic compressibility and limiting molar expansibilities. The effects of DES on the intermolecular interactions in the PC and aqueous PC solvent environment were demonstrated using these parameters. The findings demonstrated that the solute–solvent interactions in both systems were enhanced by the addition of DES. Hepler’s constant additionally showed that TEMABF4 behaved as a structure maker in the DES in aq. PC system and a structure breaker in the DES in PC system. In order to investigate the electrochemical applications, the electrochemical stability and electrical conductivity of the systems being studied are also reported in this paper.

Preparation and characterization of poly(ethylene glycol)-b-poly(tert-butyl methacrylate) micelles as potential nanocarriers for donepezil

Polymeric micelles were prepared for the delivery of donepezil, a leading Alzheimer’s disease drug, to enhance its transport across the blood–brain barrier (BBB). Poly(ethylene glycol)-b-poly(tert-butyl methacrylate) amphiphilic block copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were characterized by gel permeation chromatography and nuclear magnetic resonance spectroscopy. Empty and donepezil loaded polymer micelles were formed using the dialysis method and characterized by dynamic light scattering and transmission electron microscopy. Drug loading efficiency and release behavior were monitored using UV/Vis spectroscopy, and cytotoxicity was evaluated via colorimetric tests and impedance measurements. Additionally, the permeability of the nanocarriers across an in vitro BBB culture model was assessed. Drug-loaded micelles demonstrated similar permeability to free donepezil but offered sustained release and improved stability. This micellar delivery system holds significant potential for improving therapeutic outcomes in Alzheimer’s treatment by enhancing donepezil’s delivery across the BBB. Improved BBB permeability and sustained drug release could lead to more effective concentration of the drug in the brain, potentially reducing peripheral cholinergic side effects, such as nausea and vomiting, often observed with traditional donepezil administration. This could result in better patient compliance and improved cognitive outcomes, making this nanocarrier system a promising alternative for Alzheimer’s therapy.

Enhancing the Mechanical Strength of a Photocurable 3D Printing Material Using Potassium Titanate Additives for Craniofacial Applications.

Photopolymerization-based three-dimensional (3D) printing techniques such as stereolithography (SLA) attract considerable attention owing to their superior resolution, low cost, and relatively high printing speed. However, the lack of studies on improving the mechanical properties of 3D materials highlights the importance of delving deeper into additive manufacturing research. These materials possess considerable potential in the medical field, particularly for applications such as anatomical models, medical devices, and implants. In this study, we investigated the enhancement of mechanical strength in 3D-printed photopolymers through the incorporation of potassium titanate powder (K2Ti8O17), with a particular focus on potential applications in medical devices. The mechanical strength of the photopolymer containing potassium titanate was analyzed by measuring its flexural strength, hardness, and tensile strength. Additionally, poly(ethylene glycol) (PEG) was used as a stabilizer to optimize the dispersion of potassium titanate in the photopolymer. The flexural strengths of the printed specimens were in the range of 15-39 MPa (Megapascals), while the measured surface hardness and tensile strength were in the range of 41-80 HDD (Hardness shore D) and 2.3-15 MPa, respectively. Furthermore, the output resolution was investigated by testing it with a line-patterned structure. The 3D-printing photopolymer without PEG stabilizers produced line patterns with a thickness of 0.3 mm, whereas the 3D-printed resin containing a PEG stabilizer produced line patterns with a thickness of 0.2 mm. These findings demonstrate that the composite materials not only exhibit improved mechanical performance but also allow for high-resolution printing. Furthermore, this composite material was successfully utilized to print implants for pre-surgical inspection. This process ensures the precision and quality of medical device production, emphasizing the material's practical value in advanced medical applications.

Mitochondrial-Targeting Mesoporous Polydopamine Nanoparticles for Reducing Kidney Injury Caused by Depleted Uranium.

Depleted uranium (DU), when accidentally released from the nuclear industry, can enter the human body and cause kidney damage, as DU induces oxidative damage and apoptosis through mitochondrial pathways and inflammatory reactions. The existing nanoparticles used to treat DU injury have low bioavailability and poor targeting. In this study, mesoporous polydopamine (MPDA), poly-(ethylene glycol) (PEG), and triphenylphosphonium (TPP) are combined to develop a novel mitochondrion-targeting bifunctional nanoparticle, MPDA-PEG-TPP, and confirm that it can protect the kidneys from DU. This study demonstrates the high selectivity of MPDA-PEG-TPP for uranyl in uranyl chelate assays and its promising efficiency in uranyl sequestration from the kidneys, lungs, and femurs, following immediate or delayed administration of MPDA-PEG-TPP nanoparticles. In vitro assays confirm its efficiency in removing reactive oxygen species and targeting the mitochondria. In addition, in vitro and in vivo assays confirm that MPDA-PEG-TPP can reduce mitochondrial dysfunction and ameliorate kidney injury. These results suggest that MPDA-PEG-TPP is a valuable agent for ameliorating the DU-induced kidney injury.

An integrated off-lattice kinetic Monte Carlo (KMC)-molecular dynamics (MD) framework for modeling polyvinyl chloride dehydrochlorination

In this study, a three-dimensional off-lattice kinetic Monte Carlo-Molecular Dynamics (KMC-MD) simulation framework [Comp. Mat. Sci. 229, 112421 (2023)] is used to investigate the dehydrochlorination/conjugation transformation of polyvinyl chloride (PVC) in sodium hydroxide (NaOH) with atomistic resolutions at experimental timescales (103 – 106 s). Our framework enables an examination of the competing reaction pathways and molecular-scale changes influenced by various solvents (acetone, ethylene glycol, triethylene glycol, tetrahydrofuran, and bio-derived solvents), as well as the influence of varying molecular weight distributions, NaOH concentrations, and temperatures. The algorithm simulates bond cleavage and formation during the KMC stages, whereas the MD stage is dedicated to the relaxation and thermalization of the PVC-NaOH-solvent system. The framework allows us to capture important configurational aspects (mixing, correlations, clustering, etc.) that are not accessible with a traditional microkinetic model, and it potentially allows us to perform benchmarking at experimental timescales.

Evaluation of morphological, structural, thermal, electrical, and chemical composition properties of graphene oxide, and reduced graphene oxide obtained by sequential reduction methods

This study investigates the preparation and characterization of reduced graphene oxide (RGO) derived from graphene oxide (GO) using various reduction methods, including ethylene glycol (EG), hydrazine, ascorbic acid, thermal reduction, and their sequential combinations. Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray Photoelectron Spectroscopy (XPS) were employed to analyze the morphological, structural, and thermal properties, as well as the composition and the functional groups of graphene oxide and its reduced forms. The highest electrical conductivity value of about 2500 S/m was obtained after the combined ascorbic acid-ethylene glycol-hydrazine treatment, which is attributed to the increase in C/O ratio determined by XPS compositional analysis and the decrease in area defects, as confirmed by Raman analysis.

Ruthenium-Substituted Polyoxoanion Serves as Redox Shuttle and Intermediate Stabilizer in Selective Electrooxidation of Ethylene to Ethylene Glycol.

The high carbon intensity of present-day ethylene glycol (EG) production motivates interest in electrifying ethylene oxidation. Noting poor kinetics in prior reports of the organic electrooxidation of small hydrocarbons, we explored the design of mediators that activate and simultaneously stabilize light alkenes. A ruthenium-substituted polyoxometalate (Ru-POM, {Si[Ru(H2O)W11O39]}5-) achieves 82% faradaic efficiency in EG production at 100 mA/cm2 under ambient conditions. Via the union of in situ spectroscopic techniques, electrochemical studies, and density functional theory calculations, we find evidence of a two-step oxidation mechanism: Ru-POM first undergoes electrochemical oxidation to the high valent state, activating ethylene via partial oxidation and forming an intermediate complex; this intermediate complex then migrates to the anode where it undergoes further oxidation to produce EG. The Ru-POM-mediated electrocatalytic system reduces the projected energy consumption required in EG production, requiring 9 GJ per ton of EG (and accompanied by 0.04 ton H2 coproduction), compared to 20-30 GJ/ton in typical prior processes.

Insight into crystal-plane-dependent of cobalt catalysts for ethylene glycol amination

Co possesses outstanding dehydrogenation and hydrogenation activitiy and is a suitable catalyst for the amination of ethylene glycol. Nevertheless, the catalytic activity of Co's different crystal surfaces remains unclear, which hinders the further advancements in its catalytic efficiency. This research comprehensively examines the influence of Co's crystal plane effect on the amination of ethylene glycol employing both experimental and theoretical methodologies. Three single-crystal Co catalysts with mainly exposed (10−11), (0001) and (11−20) crystal planes were synthesized by a hydrothermal method and evaluated for ethylene glycol amination. The experimental results indicated that the c-Co-R catalyst with exposed Co (11–20) crystal facets exhibits optimal performance, with a 55.4 % ethylene glycol conversion and a 43.7 % primary amines (ethylenediamine and ethanolamine) selectivity. Combined with density-functional theory calculations and experimental characterization, the results showed that the Co (11−20) surface exhibited robust C-H bond dissociation and strong adsorption of ethylene glycol, which markedly improved the dehydrogenation efficiency of ethylene glycol and improved ethylene glycol conversion. Furthermore, the weak adsorption capacity of NH3 further promoted the selectivity of the target products.

Photoelectrochemical Ethylene Glycol Oxidization Coupled with Hydrogen Generation Using Metal Oxide Photoelectrodes.

Photoelectrochemical (PEC) water splitting represents a promising approach for harnessing solar energy and transforming it into storable hydrogen. However, the complicated 4-electron transfer process of water oxidation reaction imposes kinetic limitations on the overall efficiency. Herein, we proposed a strategy by substituting water oxidation with the oxidation of ethylene glycol (EG), which is a hydrolysis byproduct of polyethylene terephthalate (PET) plastic waste. To achieve this, we developed and synthesized BiVO4/NiCo-LDH photoanodes capable of achieving a high Faradaic efficiency (FE) exceeding 85 % for the oxidation of EG to formate in a strongly alkaline environment. The reaction mechanism was further elucidated using in situ FTIR spectroscopy. Additionally, we successfully constructed an unassisted PEC device for EG oxidation and hydrogen generation by pairing the translucent Mo : BiVO4/NiCo-LDH photoanode with a state-of-the-art Cu2O photocathode, resulting in an approximate photocurrent density of 2.3 mA/cm2. Our research not only offers a PEC pathway for converting PET plastics into valuable chemicals but also enables simultaneous hydrogen production.

Photoelectrochemical Ethylene Glycol Oxidization Coupled with Hydrogen Generation Using Metal Oxide Photoelectrodes

AbstractPhotoelectrochemical (PEC) water splitting represents a promising approach for harnessing solar energy and transforming it into storable hydrogen. However, the complicated 4‐electron transfer process of water oxidation reaction imposes kinetic limitations on the overall efficiency. Herein, we proposed a strategy by substituting water oxidation with the oxidation of ethylene glycol (EG), which is a hydrolysis byproduct of polyethylene terephthalate (PET) plastic waste. To achieve this, we developed and synthesized BiVO4/NiCo‐LDH photoanodes capable of achieving a high Faradaic efficiency (FE) exceeding 85 % for the oxidation of EG to formate in a strongly alkaline environment. The reaction mechanism was further elucidated using in situ FTIR spectroscopy. Additionally, we successfully constructed an unassisted PEC device for EG oxidation and hydrogen generation by pairing the translucent Mo : BiVO4/NiCo‐LDH photoanode with a state‐of‐the‐art Cu2O photocathode, resulting in an approximate photocurrent density of 2.3 mA/cm2. Our research not only offers a PEC pathway for converting PET plastics into valuable chemicals but also enables simultaneous hydrogen production.