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The increased energy demand and decreasing fossil resources have driven the research community to look into a sustainable, green process to meet the energy demands. India being one of the top producers of sugarcane derived sucrose, and conversion of surplus sucrose to value chemicals is always an advantage. 5%Ni-15%Ce/TiO2 catalyst is found to produce high yield of 1,2-PDO (~ 74%) under very mild reaction condition of 180 °C, 30 bar H2 for 3-h reaction time. The characterization of the catalyst by using various physicochemical methods indicates the synergy between Ni-Ce bimetal which enhances the selective production of glycol. The low temperature and pressure requirement and the advantage of being the one-pot process will always attract the future scope of commercialization. [ABSTRACT FROM AUTHOR]

This study explores the rheological and tribological behavior of water-based lubricants (WBLs) as potential alternatives for electric vehicle (EV) applications. As the transportation sector increasingly shifts towards EVs to reduce carbon emissions, the demand for efficient lubricants becomes critical. WBLs here are defined as fluids containing a minimum of 50 wt% water mixed with glycerol, ethylene glycol (MEG), polyethylene glycol (PEG), or one of two polyalkylene glycols (PAGs). Rheological properties were investigated and compared with traditional lubricating oils. Results demonstrate distinctive rheological characteristics in WBLs, with viscosity–temperature responses resembling traditional oils with lowered pressure–viscosity coefficients. Nevertheless, WBLs exhibit promising film-forming capabilities in highly loaded contacts. Additionally, in sliding contacts, WBLs generally display lower friction coefficients compared to traditional oils, with PEG exhibiting the lowest value near 0.1. These findings suggest that WBLs may offer advantages in reducing friction and energy loss in EV applications. Furthermore, sliding wear tests indicate low wear rates in WBLs such as PEG, PAG, and glycerol, supporting their potential as viable lubrication options. The study highlights the importance of high-pressure rheology and tribochemistry in wear mechanisms among the different lubricants. [ABSTRACT FROM AUTHOR]

The effect of glycol derivatives including ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) has been investigated on the characterization Al2O3 coating of anodized 7075-T6 aluminum in 20% w/w sulfuric acid, current density 4 A/dm2, and time 50 min. The thickness and hardness of Al2O3 layer measured and characterized by X-ray diffraction patterns, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Tafle plots of linear polarization method and electrochemical impedance spectroscopy technique used to investigate the resistance to corrosion Al2O3 layer. The results showed that the thickness, hardness, and resistance to corrosion of Al2O3 film are increased, respectively, 30, 42, and 40% in the presence of glycols (10% w/w). The ratio of dielectric constant (ε) to dynamic viscosity (η) of TEG, DEG, and EG, respectively, is 0.48, 0.89, and 2.28 that is due to improvement of anodized aluminum in the presence glycol derivatives as EG > DEG > TEG. [ABSTRACT FROM AUTHOR]

A computational investigation of the aerobic oxidative C–C bond cleavage reaction of glycol catalyzed by an Anderson-type heteropolyanion HPA [IMo6O24]5− in the presence of acetonitrile as solvent has been performed at the WB97XD/6-31G(d,p)/lanl2dz level. Two reaction pathways have been identified. The catalytic cycle of each pathway consists of three steps: oxidation cleavage of a glycol molecule by the HPA, oxidation of the HPA by one dioxygen molecule, and, finally, oxidation of a second glycol and regeneration of the catalyst. These reaction pathways have been thoroughly investigated in terms of energetic, natural bond orbital (NBO), natural charges, and geometrical parameters. It is found that (i) even though the top oxygen atoms of the Anderson heteropolyanion are not the most negatively charged ones, they are more likely to react with the diol hydroxyl groups, (ii) a direct relationship between the presence of the iodine ion I(VII) and the studied oxidation reaction could not be identified, and (iii) in terms of energy, the transfer of the two hydrogen atoms is the most energetic step. [ABSTRACT FROM AUTHOR]

A computational investigation of the aerobic oxidative C–C bond cleavage reaction of glycol catalyzed by an Anderson-type heteropolyanion HPA [IMo6O24]5− in the presence of acetonitrile as solvent has been performed at the WB97XD/6-31G(d,p)/lanl2dz level. Two reaction pathways have been identified. The catalytic cycle of each pathway consists of three steps: oxidation cleavage of a glycol molecule by the HPA, oxidation of the HPA by one dioxygen molecule, and, finally, oxidation of a second glycol and regeneration of the catalyst. These reaction pathways have been thoroughly investigated in terms of energetic, natural bond orbital (NBO), natural charges, and geometrical parameters. It is found that (i) even though the top oxygen atoms of the Anderson heteropolyanion are not the most negatively charged ones, they are more likely to react with the diol hydroxyl groups, (ii) a direct relationship between the presence of the iodine ion I(VII) and the studied oxidation reaction could not be identified, and (iii) in terms of energy, the transfer of the two hydrogen atoms is the most energetic step. [ABSTRACT FROM AUTHOR]

The review is devoted to noncyclic analogs of crown ethers (podands) containing an oxyethylene spacer and heterocyclic fragments at one or both of its ends. The paper considers publications on the methods of obtaining and properties of podands for the 2010–2021 period. [ABSTRACT FROM AUTHOR]

With the aim to prepare asymmetric acetylenic γ-glycols, the reactions of 1-(2-ethoxyethyl)piperidin-4-one with propargyl alcohol were studied and the reaction conditions were optimized to reach satisfactory yields of the target glycols. Some transformations of the γ-glycols were studied. It was found that the reaction of 1-(2-ethoxyethyl)-4-(3-hydroxyprop-1-yn-1-yl)piperidin-4-ol with ethyl bromide involves exclusively the OH group on the quaternary carbon atom to form a monoethyl ether, and the mercury-catalyzed hydration involves cyclization with the elimination of a water molecule from the keto glycol moiety, leading to a spiroketone. It was shown that the catalytic reduction of 1-(2-ethoxyethyl)-4-[2-(1-hydroxycyclohexyl)ethynyl]piperidin-4-ol at atmospheric pressure produces a mixture of a saturated and an unsaturated products in a 1 : 2 ratio. Quantum-chemical calculations of the stable conformers of the synthesized asymmetric acetylenic γ-glycols were performed by the RHF/STO-3G method with geometry optimization using Gaussian 09 software. [ABSTRACT FROM AUTHOR]

Growing demand for oil and gas has driven drilling activities to deep formations and complex well structures. Drilling fluid must be able to maintain wellbore integrity and thermal stability over extended drilling time. Besides, drilling fluid should produce high rate of penetration (ROP) and low damage to formation rock. Glycol mud satisfies these criteria thanks to its unique cloud point phenomenon. When temperature exceeds cloud point temperature, glycol starts precipitate from mud by forming micelles, coats the rock surface, and plugs the small fractures in rocks. As a result, the flow of mud into rocks is restricted and wellbore stability is improved. This paper surveys more than 40 wells that were drilled with glycol mud. Field cases reported good wellbore integrity, thermal stability, high ROP, and low formation damage. Glycol mud is an excellent choice for battling well instability and high temperatures. [ABSTRACT FROM AUTHOR]

Degumming bast fibers by organic solvents has been a promising method in recent years due to easy recovery and reuse of organic solvents. In this research, the possibility of ramie fiber degumming by glycol and a combination of acetic acid with glycol was studied, in which two steps were involved in the degumming process: distilled water boiling pretreatment and organosolv treatment by a combination of glycol/acetic acid (100/0, 90/10, 80/20, 70/30, 60/40, 50/50). Results displayed that the pretreatment could remove 6.99% of hemicellulose, 0.59% of lignin and 36.26% of other gums compared with raw ramie. While with organosolv treatment (130 °C, 6 h), fibers treated by glycol/acetic acid (50/50) had the best effect of removing gums. The hemicellulose and lignin content of fibers reduced by 44.81% and 54.12%, respectively (compared with raw ramie), while the residual gum content still failed to meet the requirements of spinning process. Besides, the tenacity of glycol/acetic acid treated fibers was lower than that of only glycol treated fibers (4.67 cN/dtex). Considering that the addition of acid could cause a decrease in fiber tenacity, the step of organosolv (only glycol) treatment was optimized by altering the degumming condition. The tenacity, linear density, non-cellulosic component ratio of fibers treated with the optimized condition (200 °C, 80 min) were 6.53 cN/dtex, 6.06 dtex, 5.78%, respectively, which met the needs of industrial production. Compared with the organosolv treated fibers, these properties of fibers with traditional alkaline treatment were better, but the yield (62.4%) was much lower than that of fibers treated with glycol in two degumming condition (77–82%). Considering impressive properties of the treated ramie, the method of organosolv degumming with high degumming efficiency and environmental protection would bring an innovative thought for natural fiber isolation. [ABSTRACT FROM AUTHOR]

A 3, 3′, 4, 4′-oxydiphthalic dianhydride-4, 4′-oxydianiline (ODPA-ODA)-type polyetherimide was modified by blending ethylene glycol (EG) for preparing precursor of freestanding pyrolyzed membranes. The thermal stability, surface elements, microstructure and solubility of modified membranes were investigated by the techniques of thermogravimetric analysis, infrared spectroscopy, X-ray photoelectric spectroscopy and X-ray diffraction, respectively. Results demonstrate that EG can effectively adjust the microstructure and property of the present polyetherimide membranes. As the usage amount of EG elevates, the microstructure of modified membranes tends to become more compact and amorphous. The gas permeability and selectivity of finally derived pyrolyzed membranes exceed 8000 Barrer for H2 and 17 for H2/CO2, respectively. [ABSTRACT FROM AUTHOR]

Airplane deicing is a safety measure to eliminate/prevent icing on airplanes that can lead to airflow disruption and emergency conditions. Aircraft deicing/anti-icing fluids (ADF) are high in glycol content. At Dallas Fort Worth International Airport (DFW), the major aircraft deicing activities are conducted at designated deicing pads called Source Isolation Deicing Sites, where ADF run-off can be captured and conveyed into the airport’s glycol collection system. A portion of ADF drips from the aircraft during taxiing and shears off the aircraft during take-off, entering nearby waterways without treatment. Glycol acts as a nutrient for bacteria in the airport’s receiving waterways, resulting in an increase in bacterial growth and a subsequent reduction in dissolved oxygen (DO), potentially endangering aquatic life. This paper proposes a prototype data-driven deicing activities management framework for DFW to address the complexity of airport deicing operations and its impacts. The proposed framework uses stochastic dynamic programming (SDP) to assign airplanes in each hour to deicing pad locations, so as to maximize DO in the receiving waters, subject to airport constraints. Some data were artificially generated using the available knowledge of airport operations. The state transition equations in SDP were estimated. The proposed framework was demonstrated using three cases during major deicing events. Improvements in DO compared with actual DO recorded in the data were mixed; however, the results motivated DFW to implement a new data collection process to replace the artificially-generated data, so that a more accurate optimization could be conducted in the future. [ABSTRACT FROM AUTHOR]

@Abstraction limits of flame propagation are determined for 13 glycols, as well as their enthalpy of formation and enthalpy of combustion. These characteristics depend on the number of carbon atoms in the glycol molecule. The combustion parameters are calculated for vapor-air mixtures of glycols and monoatomic alcohols, in the case where P = 1 atm and V = const. The adiabatic combustion temperature of mixtures of limiting and stoichiometric composition does not depend on the number of hydroxyl groups in the alcohol molecule. The explosive pressure of glycol is slightly higher than for monoatomic alcohols. [ABSTRACT FROM AUTHOR]

The synthesis of cerium dioxide (CeO) nanopowders via mechanical solid-state reaction combined with sol-gel method was studied. Cerium(III) nitrate hexahydrate, dihydrate oxalate, NHF, along with stearic acid or glycol, were mechanically milled. Calcination of the as-milled mixtures in air at 400 °C resulted in the formation of CeO nanoparticles. The dispersity and uniformity in particle size and morphology were greatly improved by both physical and chemical effects of the stearic acid or glycol brought in: on one hand, they had the space steric hindrance effect; on the other hand, they might act as complexing agents, letting the whole process being carried out in highly homogeneous dispersed circumstance. The CeO particles showed best dispersity and uniformity in particle size and morphology when the content of stearic acid was 20 g, along with 10 wt% NHF. As-obtained, near spherical CeO particles were controlled to the size of 30-60 nm. [ABSTRACT FROM AUTHOR]

Porous carbon foams were fabricated using phenol and formaldehyde (PF) as carbon precursors. The pore size and porosity of the foams were controlled using glycol-derivatives as porogen during condensation polymerization. The morphology of the resulting carbon foam with macroporous porosity and well dispersed pore structures were verified by mercury porosimetry and scanning electron microscopy. The compressive stress of the resulting carbon foam increased with increasing molecular weights of glycol-derivatives due to the decrease in porosity. Furthermore, the reaction mechanism was identified to involve glycol-derivatives in the condensation reaction of PF, which generated the porosity of the resulting carbon foam by releasing volatile compounds according to thermogravimetric analysis and Fourier transform infrared spectroscopy. As a result, the mechanical properites of the carbon foam could be affected by the morphological properties of macroporous structures using different types and concentrations of glycol-derivatives. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The tribological behavior of self-mated TiSiC in bath of alcohols are investigated at sliding velocity ranging from 0.005 to 0.3 m/s. The results show that the friction coefficient and wear rates of self-mated TiSiC are reduced greatly under lubrication of alcohols compared to that under dry condition. In alcohols, smooth worn surfaces of TiSiC can be obtained. The mechanical wear is inhibited and the oxidized Ti and Si species on the worn surface are TiO and silica gel. The friction coefficients decrease with carbon numbers and sliding velocity in the n-alcohols. The friction coefficient decrease with sliding velocity in glycol and glycerol as well. The decrease is determined by the increase of the viscosity of alcohols. In glycerol, at 0.1 m/s and 5 N, the friction coefficient of self-mated TiSiC is 0.08 which is the lowest in this paper. The lubrication regimes are calculated according to classical lubrication theory. At velocity from 0.005 to 0.3 m/s, in all of the alcohols except glycerol, the λ are below 1 which indicates that the lubrication regime is BL. While in glycerol, the lubrication regimes vary from BL to BL and EHL, then to EHL as the velocity increases. [ABSTRACT FROM AUTHOR]

Co/SiO catalysts with highly dispersed Co and reducible Co were prepared by impregnation using an aqueous solution of Co nitrate containing ethylene glycol or its homologs. Addition of glycols enhanced FTS activity by a factor of 4. Particle size of Co decreased from 30 to below 6 nm, while TOF of the catalysts was independent of the Co particle size. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In order to obtain thermoplastic starch plastics with improved properties, a novel method of starch modification was developed in this study. Starch derivatives were prepared using the following procedures: pea starch was first oxidized to make dialdehyde starch (DAS) by sodium periodate under mild conditions, and this was then acetalized with glycol to give Gly-ADS. The modified starch was characterized by FT-IR, 1H-NMR, TG, DSC, and XRD. The TG curves indicated that the thermal stability of Gly-ADS was better than that of DAS. The glass transition temperature of Gly-ADS with 95% carbonyl content (Gly-ADS95) was 97 °C by DSC. Although the intrinsic viscosity of DAS was less than that of pea starch, thermoplastic Gly-ADS (TPGly-ADS) exhibited good mechanical properties. The influence of moisture absorption on the mechanical properties of TPGly-ADS was also investigated. The results showed that TPGly-ADS possesses improved water resistance: the highest moisture absorption of TPGly-ADS95 was about 11%, and the tensile strength and the elongation at break were 18.1–14.6 MPa and 5.3–18%, respectively. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) coatings on pyrolytic carbon were produced via electrophoretic deposition (EPD) using glycol and ethanol as dispersion medium respectively. The effect of the solubility of HA in the dispersion medium on crack occurrence and adherence of the coating was investigated by means of scanning electronic microscope (SEM) and atomic absorption spectrometer (AAS). The results show that the solubility of HA in glycol is higher than that in ethanol. The usage of glycol as a dispersion medium can reduce the possibility of crack formation and enhance the adhesive strength between the coating and the carbon substrate. The green coatings can be sintered under vacuum at 1 000 °C whether the coatings are obtained using ethanol or glycol as dispersion medium. No HA decomposition was observed up to 1 000 °C by vacuum sintering by X-ray diffraction (XRD) analysis. [ABSTRACT FROM AUTHOR]

Polyol-based phase-change thermal interface materials that exhibit high thermal contact conductance and thermal stability have been developed for microelectronic cooling. By using a diol (polycaprolactone or polyester diol in the form of 2-oxepanone) of molecular weight 1,000-2,000 amu, along with 4 vol.%-hexagonal boron nitride particles, this work attained thermal contact conductance (at 70°C, across copper surfaces) that is higher than that attained by using paraffin wax, polyether glycol, polyethylene glycol, or tetradecanol (in place of the diol) and that attained by commercial phase-change thermal interface materials. The thermal stability of the diol is superior to the other phase change materials mentioned above, although the heat of fusion is lower. Boron nitride is more effective than carbon black (also 4 vol.%) for enhancing the conductance, but carbon black diminishes the heat of fusion less than does boron nitride. [ABSTRACT FROM AUTHOR]

The release of alkanolamines and glycols into the subsurface soils poses a potential hazard to the environment through impacted soil and groundwater. This study investigated aerobic and anaerobic biodegradability of monoethanolamine (MEA), ethylene glycol (MEG) and triethylene glycol (TEG). Significant levels of MEA (31 000 mg/kg), MEG (500 mg/kg) and TEG (2100 mg/kg) were successfully aerobically biodegraded in bioreactors. The aerobic slurry experiments suggested initial phosphate (P) limitation, as biodegradation rates increased by one order of magnitude after phosphate addition. Anaerobic decay of MEA, MEG and TEG was unaffected by P-addition. MEA, MEG and TEG degradation products such as acetate, ethanol and ammonium at about 75 000 mg/kg, 8100 mg/kg and 8800 mg/kg degraded completely and did not prevent aerobic biodegradation. This study confirms proposed biodegradation pathways of MEA, MEG, TEG and their breakdown products in natural soil and groundwater using indigenous microbes. Levels of contamination studied here are significantly higher than previously reported. [ABSTRACT FROM AUTHOR]

The optimum conditions for durable press treatment of cotton fabrics using glyoxal as a nonformaldehyde crosslinking agent were investigated. Crosslinking reaction was conducted in the presence of different catalysts such as aluminum sulfate, magnesium chloride, or magnesium chloride-citric acid mixture at various mole ratios of catalyst to glyoxal. Aluminum sulfate was proven the most effective one among those used. Glycol addition into a glyoxal padding bath increased the wrinkle recovery angle(WRA) and whiteness of treated fabrics. The optimum mole ratio of glycol to glyoxal was 1:1. Diethylene glycol addition produced better overall performance to the glyoxal-crosslinked fabric compared to ethylene glycol addition. [ABSTRACT FROM AUTHOR]

The interaction between unsaturated phosphatidylcholines and either exogenous or endogenous (produced by the enzyme system involving myeloperoxidase (MPO), H2 O2 ,and Cl–) hypochlorite was studied in multilayer liposomes containing oleic, linoleic, and arachidonic acid residues using MALDI TOF mass spectrometry. At pH 7.4, hypochlorite reacts with the double bond of the oleic acid residue in 1-stearoyl-2-oleoyl- sn-glycero-3-phosphocholine producing oleic acid chlorohydrin as the main product. Minor amounts of glycols and epoxides were also detected. The main products of the reaction of hypochlorite with 1-stearoyl-2-oleoyl- sn-glycero-3-phosphocholine were mono and di chlorohydrins of linoleic acid. The signals of monoglycol, epoxide, and glycol or epoxide containing monochlorohydrin derivatives were also present in the mass spectrum. The main products of the reaction of hypochlorite with 1-stearoyl-2-oleoyl- sn-glycero-3-phosphocholine were lysophosphatidylcholine (1-stearoyl-2-oleoyl- sn-glycero-3-phosphocholine) and mono-, di-, and trichlorohydrin. Monoglycol and its derivatives containing one or two chlorohydrin groups were also detected. Along with those, carbonyl compounds (aldehyde and acid) formed as a result of double bond breakage in fifth position of arachidonate were detected. Monochlorohydrin was also found when liposomes comprising 1-stearoyl-2-oleoyl- sn-glycero-3-phosphocholine were incubated in the presence of enzymatic mixture, MPO +H2 O2 +Cl–,at pH 6.0. In the absence of the enzyme or either of its substrates (H2 O2 or Cl–) or in the presence of the MPO inhibitor (sodium azide) or hypochlorite scavengers (taurine or methionine), monochlorohydrin formation was not observed. These data confirm the suggestion that just the hypochlorite generated in MPO catalysis provides for chlorohydrin formation. Thus, the use of MALDI TOF mass spectrometry has shown, along with chlorohydrins, glycols and epoxides as the products of hypochlorite interaction with unsaturated phosphatidylcholines at physiological pH. It was first determined that hypochlorite breaks double bonds in polyunsaturated phosphatidylcholine and also causes lysophosphatidylcholine formation. [ABSTRACT FROM AUTHOR]

The kinetics of anaerobic degradation of glycol-based Type I aircraft deicing fluids (ADFs) were characterized using suspended-growth fill-and-draw reactors. Both Type I ADFs tested showed near-complete anaerobic degradability. First-order degradation rate constants of 3.5 d-1 for the propylene glycol-based Type I ADF and 5.2 d-1 for the ethylene glycol-based Type I ADF were obtained through continuous-culture means under mesophilic conditions (35 °C). Fill-and-draw operation at lower temperatures affected anaerobic degradability only minimally down to 25 °C but substantially below 25 °C. High Type I ADF feed concentrations substantially affected degradability. Batch testing of fill-and-draw reactors resulted in first-order degradation rate constants of 1.9 d-1 for propylene glycol-based Type I ADF and 3.5 d-1 for ethylene glycol-based Type I ADF. [ABSTRACT FROM AUTHOR]