Glycol Medium Research Articles

Effect of Ground Vulcanizate Modification Methods on Properties of Oil-Petroleum-Resistant Rubber

In this paper, the influence of the modification method applied to ground vulcanizate (GV) on the properties of elastomeric compositions based on nitrile rubber is discussed. Modified GV has been mixed with the elastomeric composition, which is used for the manufacturing of oil-petroleum-resistant rubber products.The work takes into consideration two types of GV with different chemical nature. The first GV type is rubber crumb produced from end-of-life tires. The second GV type was obtained from rubber wastes based on nitrile rubber. Three methods of the modification are compared in the research: mechanical activation in a planetary ball mill, swelling in a Polyethylene glycol (PEG-400) medium, and the mechano-chemical transformation of GV with PEG-4000. It is shown that depending on the dosage addition of GV modified with PEG-4000 reduce the compression set up for (16.1±0.7%), the strength decreases only by 2.1–8.3%, and the elongation at break increases by 0.8–10.3% compared to rubber without additives.

Luminescence from ZrO2 Nanopowders Doped with Sm3+ Ions Processed by Polyol Method at Low Processing Temperature

ZrO2 and ZrO2:Sm3+ nanopowders are synthesized by means of polyol method, from [Zr(NO3)2.xH2O] and (SmCl3·6H2O) precursors dissolved in a diethylene glycol medium. X‐ray diffraction (XRD) results show polymorphic powders because monoclinic structure and tetragonal are exhibited. The crystal size is estimated by Scherrer formula; an averaged crystallite size of 9 nm is obtained. Surface morphology study, by means of SEM, evidences multiform particles, some with straight edges associated with monoclinic or tetragonal structure. The chemical composition microanalysis results indicate agreement with ideal stoichiometry for ZrO2 and ZrO2:Sm3+ powders. The photoluminescence emission spectra show that maximum intensity is reached at λ = 614 nm due to transition 4G5/2→6H7/2, exciting with λex = 240 nm, which corresponds to sample ZrO2:Sm3+ (0.75 at%); this sample is labeled as M3. Very similar results are obtained by cathodoluminescence studies. On the contrary, exciting with λex = 380 nm (monitoring emission band peaked at 614 nm), emission bands of host lattice and ZrO2:Sm3+ are favored simultaneously. The luminescent quenching phenomenon occurs when doping concentration (Sm3+ ions) is >=0.75 at%. The photoluminescent emission exhibits a reddish orange color, characteristic of Sm3+ ions, and yellowish‐orange for cathodoluminescence emission.

Absorption, fluorescence and sensing quality of Rose Bengal dye-encapsulated cinnamon nanoparticles

Some new types of Rose Bengal dye-encapsulated cinnamon nanoparticles (RB-CNPs) were prepared via the laser ablation in liquid (PLAL) method at various laser fluences (LFs) and characterized. The influence of different LF (1.7–14.2 Jcm−2) on the absorption, fluorescence and color chromaticity properties of these RB-CNPs was evaluated. Both fluorescence and absorption spectra of the RB-CNPs displayed two prominent peaks at approximately 439 nm and 571 nm, and 267 nm and 546 nm, respectively due to the presence of phenolic acids in CNPs and structural units in RB dye. The fluorescence lifetime and quantum yield were in the range of 6.12–6.911 ns and 0.341–0.61%. Furthermore, these RB-CNPs coated fiber-optic sensor showed very fast response when exposed to ethylene glycol medium. It is established that the proposed optically active and stable RB-CNPs can be advantageous designing low-cost fiber-optic sensors useful for environmental tracers and optical probes.

Improved fluorescence quantum yield of nanosecond pulse laser ablation wavelength controlled cinnamon nanostructures grown in ethylene glycol medium

Nanosecond pulse laser ablation in liquid (PLAL) method was used to prepare some crystalline cinnamon nanostructures (Cin-NSs) in ethylene glycol (EG) medium. Effect of various laser wavelengths (532, 1064, and 1139 nm) on the structures, morphologies, and optical characteristics of these Cin-NSs were determined. The average diameter and lattice spacing of these crystalline Cin-NSs was ranged from 4.9 ± 0.1 to 6.8 ± 0.1 nm and 0.112 to 0.149 nm, respectively. The fluorescence quantum yields of these NSs were increased from 0.024 to 0.043 due to the change of laser wavelengths. The presence of cinnamaldehyde and flavonoids compounds in the Cin-NSs was mainly responsible for the observed improvement of the optical and structural properties. The obtained Cin-NSs may be useful for the new drug formulation.

Synthesis of Tin Oxide Nanoparticles by Pulsed Laser Ablation Method Using Low-Energy Nd: YAG Laser as an Antibacterial Agent

Tin oxide nanoparticles (SnNPs) are very useful to be employed as an antibacterial agent for both gram-positive and gram-negative bacteria. In this present work, the synthesis of SnNPs was successfully carried out using the neodymium yttrium aluminum garnet (Nd:YAG) laser with a wavelength of 1064 nm, pulse duration of 7 ns, and a laser frequency of 10 Hz. Experimentally, a pulse Nd:YAG laser was directed and focused on a high-purity tin (Sn) metal, immersed in various liquid media including pure water and ethylene glycol. A brownish colloidal colour was produced both in pure water and ethylene glycol liquid media. Characterizations of tin oxide nanoparticles were made using UV-Vis, EDX, FTIR, and TEM. UV-Vis characterization produced absorbance values in pure water and ethylene glycol media of 1.314 a.u. and 1.119 a.u., respectively. TEM images show that the shape of tin oxide nanoparticles produced is spherical. Measurement of nanoparticle size distribution was made using image-J software and the average diameter of nano-size in the ethylene glycol medium is 12.55 nm, which is smaller than the size in the pure water of 19.98 nm. The EDX spectrum analysis results show that there are only Sn and O atoms in colloidal tin oxide nanoparticles (SnNPs). FTIR results show the formation of tin oxide (SnO2) spectrum at the wavenumber of 629.03 cm-1. The produced colloidal SnNPs were then applied as an antibacterial agent of E. coli using the disk diffusion method. Results certified that various concentrations of SnNPs of 10 ppm, 20 ppm, and 30 ppm gain the diameter of inhibition zone (DIZ) in sequence 6.50 mm, 6.75 mm, and 9.50 mm. Based on these experimental results, it shows that the higher the concentration of SnNPs given, the greater the ability to degrade and inhibit bacteria.

In Vivo Tissue Implantation Model of In Vivo Tissue Implantation Model of Lidocaine (LCH)-Encapsulated Dextran (DEX)/Glycol (GLY) Nanoparticles Delivery for Pain Management.

Lidocaine-loaded nanoparticles are versatile nanomaterials that may be used in pain treatment due to their wound healing properties. The current study describes a wound dressing formulation focused on lidocaine-loaded dextran/ethylene glycol nanoparticles (an anesthetic drug). The lidocaine-loaded dextran/ethylene glycol membranes were fabricated using lidocaine solutions inside the dextran/ethylene glycol medium. The influence of various experimental conditions on dextran/ethylene glycol nanoparticle formations were examined. The sizes of dextran/ethylene glycol and lidocaine-loaded dextran/glycol nanoparticles were examined through the HR-SEM. Moreover, the efficacy antibacterial activity of dextran/glycol and lidocaine-loaded dextran/ethylene glycol nanoparticles was evaluated against the microorganisms grampositive and negative. Furthermore, we observed the In Vivo wound healing of wounds in skin using a mice model over a 16 days period. In this difference to the wounds of untreated mouse, quick healing was observed in the lidocaine-loaded dextran/glycol nanoparticles-treated wounds with fewer injury. These results specify that lidocaine-loaded dextran/ethylene glycol nanoparticles-based dressing material could be a ground-breaking nanomaterial having wound repair and implantations potential required for wound injury in pain management, which was proven using an animal model.

Photocatalytic degradation of malachite green dye using zero valent iron doped polypyrrole

The zero valent iron doped polypyrrole (Ppy/Fe) was synthesized via chemical oxidative polymerization method in diethylene glycol medium for the first time in this study. The characterization of synthesized Ppy and Ppy/Fe composites was realized by using fourier transform infrared spectrometer (FTIR), UV-visible diffuse reflectance spectrometer (DRS), scanning electron microscope (SEM), elemental dispersion X-ray analysis (EDX), four point probe electrical conductivity X-Ray diffraction spectroscopy (XRD) and pH at point of zero charge (pHpzc) methods. These characterizations show that there is an interaction between zero valent iron (Fe0) and Ppy polymer. The photocatalytic activity of synthesized Ppy and Ppy/Fe composite were investigated by degradation of malachite green (MG) dye under UV light irradiation. Ppy/Fe composite was achieved complete degradation within 60 min, which is 5.92 times faster than pure Ppy. The effect of irradiation time, ratio of Ppy and Fe0 in the synthesized composites, photocatalyst amount to photocatalytic efficiency of Ppy/Fe is studied. Also, the photocatalytic stability of Ppy/Fe is investigated under UV light illumination for degradation MG dye.

Disclosure of the solvatochromism and the reversal switch in some tailor-made electron push-push anils

The impacts of a series of organic solvents, having diverse polarities on the electronic absorption spectra of some selected anils, N-benzylideneaniline, and its five derivatives with hydroxy and methoxy substituents were investigated. The absorption spectra of each of the anils displayed a cluster of absorption bands within 200–500 nm. The electronic transitions and the effect of substituents on the solvatochromism of these anils were successfully deciphered. The reversal in solvatochromism was observed in moving from the hydrogen bond acceptor to hydrogen bond donor solvents. This fact was attributed to the structural transition of the anils due to the interaction with solvents of differential polarity or due to the obscurity of anils within the solvent cage. The ET(30) values at which the reversal solvatochromic switch due to the anils appeared was controlled by the position and nature of the substituents. The early accomplishment of the reversal solvatochromism in o-OH substituted anils connoted the non-polar characteristics of these anils. By subjecting the electronic transition energies to multiple regression analysis with fourteen different solvent parameters, the multi-parametric regression models were optimized following the successive exclusion of variable technique. The linearity of the plot of the calculated electronic transition energy against corresponding observed values validated the regression models. The induced solvatochromism observed in the case of o/p-hydroxy-substituted anils in ethylene glycol medium was attributed to the formation of the corresponding conjugate acids of the anils. The solvent-solute interaction models were proposed to probe the localization site of anils in the solvents. The intramolecular H-bonding and the twisted structure of the anils due to the substituent effects were found to play the predominant role in deciding the localization sites of the anils.

Preparation of metallic bismuth by reduction of bismuth formates in ethylene glycol medium

Nano -and microcrystalline bismuth metal powders consisting of spherical particles with a size of 150-250 nm were obtained by reducing bismuth formates in an ethylene glycol medium. The phase composition and morphology of the obtained reaction products were studied by X-ray phase and thermal analysis, differential scanning calorimetry, scanning and transmission electron microscopy. Using Uv-vis, it was shown that a bismuth-ethylene glycol complex is formed with an absorption maximum at 249 nm and an extinction coefficient of 5.7×103 (L mol-1 cm-1) in a solution of chloric acid at 23°C. The concentration of bismuth enhances to 0.018 g L-1 in the ethylene glycol medium with a gradual increase in the temperature to 60°C of the reaction mixture. Thermolysis of bismuth glycolate with a composition of Bi2(OCH2CH2O)3 is accompanied by the formation of metallic bismuth at 190°C, which is oxidized to a monoclinic modification of bismuth oxide when the temperature increases in the air.

STUDY OF THE CONDITIONS FOR THE ACQUISITION OF Tl3AsS4 IN ETHYLENE GLYCOL

The article presents the results of obtaining thallium thioarsenate in ethylene glycol medium and physicochemical analysis methods (XRD, DTG, TG and SEM). It was found that when ethylene glycol is used as a solvent and TlNO3 and As2S5 as the initial component, thallium thioarsenate is obtained at 353 K temperature. Thallium thioarsenate is formed by the interaction of TlNO3 and As2S5 at a ratio of 4:15 mol. After the compound was obtained at a temperature of 353 K (pH = 7-8), thermally processed at a temperature of 523-543 K, the melting point of the thallium thioarsenate sample has been 683 K. According to the results of thermogravimetric analysis, at temperatures above 733 K thallium thioarsenate decomposes in nitrogen gas environment. The micromorphology of the Tl3AsS4 compound obtained in the ethylene glycol medium was studied and it was determined that nanoparticles of the Tl3AsS4 compound are formed at a temperature of 353 K.

Molecular Dynamics Simulations Suggest a Possible Role for NO in the Polyol Synthesis of Silver Nanostructures

Polyol synthesis allows the preparation of silver nanostructures with different well-controlled morphologies and opens a window to explore their potential in various emerging applications. Despite their success in controlling the size and shape of many noble-metal nanostructures, some fundamental aspects of this control during the synthesis remain unclear. In this paper, we used molecular dynamics (MD) simulations (three replications 1550 ns long) to represent a possible adsorption structure of poly(vinylpyrrolidone) (PVP) with an average molecular weight of 55,000 Da (PVP55) on an Ag(100) surface on ethylene glycol (EG) medium. The conditions employed in the simulations reproduce the PVP chain length and density reported experimentally. We found that the adsorbed PVP55 layer has a first polymer contact, with some degree of order, where interactions are mediated by carbonyl groups close to the Ag(100) face. In order to study the effects of the presence of AgNO3 and NO in the medium on PVP55, three sets of simulations were run comprising (i) one PVP55 molecule in pure EG and with (ii) 0.25 M AgNO3 or (iii) NO. These simulations showed that the PVP55 compacts in pure EG and in the presence of AgNO3 but expands in the presence of NO. This points at new insights into the roles of the PVP adsorption layer and PVP/AgNO3 ratio in polyol synthesis.

Role of the solvent medium in the wet-chemical synthesis of CuSbS2, Cu3SbS3, and bismuth substituted Cu3SbS3

Co-thermal decompositions of equimolar concentrations of thiourea complexes ([Cu(tu)3]Cl and [Sb(tu)2]Cl3) in ethylene glycol and ethanolamine were attempted. Based on the results from powder X-ray diffraction, Raman spectroscopy, and energy dispersive spectral analysis of the products, Cu3SbS3 in cubic symmetry emerged from ethylene glycol. In contrast, orthorhombic CuSbS2 resulted from the ethanolamine medium. The generation of copper-rich and copper-poor sulfides was found to be the major reason behind the formation of these stoichiometries of the Cu-Sb-S system as verified by reacting the preformed Cu-S and Sb-S species in ethanolamine and ethylene glycol. Attempts to include bismuth (up to 50 mol%) for antimony were successful only in ethylene glycol medium. The inclusion of bismuth stabilized the orthorhombic form of Cu3SbS3, possibly due to the non-bonded lone pairs present on Bi3+ and Sb3+-ions. The inclusion of bismuth confirmed from the successful refinement of powder X-ray diffraction pattern by the Rietveld method, Raman spectroscopy, and energy dispersive spectroscopy analysis. CuSbS2, Cu3SbS3 (cubic) and Cu3Sb0.50Bi0.50S3 showed broad absorption extending up to visible region in their UV-visible spectra. The bandgap values of 1.31, 1.40 and 0.94 eV were estimated by Tauc plots for Cu3SbS3, CuSbS2, and Cu3Sb0.50Bi0.50S3, respectively. CuSbS2, Cu3SbS3 (cubic) and Cu3Sb0.50Bi0.50S3 showed broad absorption extending up to visible region in their UV-visible spectra. The bandgap values of 1.31, 1.40 and 0.94 eV were estimated by Tauc plots for Cu3SbS3, CuSbS2, and Cu3Sb0.50Bi0.50S3, respectively.

СОЛВОТЕРМАЛЬНЫЙ СИНТЕЗ ТРОЙНЫХ НАНОСОЕДИНЕНИЙ BİSBSE3 В ЖИДКОЙ ФАЗЕ

Ternary compounds of bismuth antimony selenide have been synthesized under solvothermal conditions in ethylene glycol medium at the temperature of 453-463 K during 15 hours from bismuth (III) oxide, antimony (III) oxide, elemental selenium (amorph) and hydrazine monohydrate. At a temperature of 453-463 K, after a 15-hour synthesis, a flocculent precipitate is obtained. The thermographic, differential thermal (DTA), X-ray (XRD), chemical, and morphological analyses of the compound were performed and it was found that the crystals of the compound are presented in the form of nano and micro-shelves. The results showed that the composition of selenium compounds of antimony bismuth corresponds to the BiSbSe3 formulas

Fast improved polyol method for synthesis of Pd/C catalyst with high performance toward ethanol electrooxidation

Highly dispersed palladium nanoparticles that are successfully decorated on the charcoal activated carbon by a rapid and simple improved polyol method in Ethylene Glycol (EG) media in the presence of ethanolic sodium hydroxide, without any protection by capping agent, is proposed for the first time in this paper. Along this process, H2PdCl4 in ethylene glycol media can be reduced to metallic palladium at 40°C in the presence of alcoholic sodium hydroxide. Therefore, it can be claimed that ethanolic sodium hydroxide is behaving like a mild reducing agent in the EG media. Pd/C catalysts are also synthesized using improved and traditional methods for comparison. Catalysts synthesized in two different ways were characterized by Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results illustrated that Pd/C synthesized using the improved polyol method had better dispersity and its diameter was equal to 8–10 nm which was lower compared to the conventional polyol method. The electrocatalytic performance of both Pd/C catalysts synthesized by two methods was investigated by cyclic voltammetry and chronoamperometry in the solution of 1.0 M EtOH +1.0 M NaOH at room temperature. The results showed that the Pd/C catalyst synthesized by the improved method had a significantly enhanced the activity and durability for Ethanol Oxidation Reaction (EOR) that can be related to the good dispersity of Palladium nanoparticles over support due to the improved polyol method.

Aggregation and adsorption properties of benzyldimethylhexadecylammonium tetrachloromanganate(II) metallosurfactant in water–ethylene glycol medium

The aggregation and adsorption properties of metallosurfactant, benzyldimethylhexadecylammonium tetrachloromanganate(II) (BDHA2[MnCl4], where BDHA represents benzyldimethylhexadecylammonium group) in binary aqueous mixtures of ethylene glycol (EG) were investigated by tensiometric, conductometric, dynamic light scattering (DLS) and transmission electron microscopy (TEM) methods at 298.15 K. The percentage of EG (by weight) was varied between 0 and 100%. The physicochemical properties determined and discussed include critical micelle concentration (cmc), counterion binding constant (β), Gibbs free energy of micellization (), surface excess at cmc (), minimum area per surfactant molecule (), surface pressure (πcmc), minimum free energies (G min) and size of aggregates. This study revealed that with increase in percentage of EG the cmc of BDHA2[MnCl4] metallosurfactant increases and the cmc of BDHA2[MnCl4] in EG is about 158 times higher than that in water. The counterion binding constant values increase with increase in percentage of EG from 10% to 70% and thereafter decrease. The adsorption of metallosurfactant at the air–solution interface decreases as the EG content in the bulk increases. The values were found to be negative and the negative value decreases with increase in percentage of EG. Gordon parameter and ratio of surface tension of medium to that of the metallosurfactant solution at cmc are used to represent solvophobicity of the medium. DLS measurements revealed that the hydrodynamic diameters (d H) of the micelles increase with increase in percentage of EG (in pure EG, d H = 28.3 nm). TEM measurements showed the presence of spherical micelles.

Versatile seed-mediated method of CoxFe3-xO4 nanoparticles synthesis in glycol media via thermal decomposition

Series of CoxFe3-xO4 with x = 0.0, 0.5 and 1.0 were synthesized by novel seed-mediated method in glycol media. Nanoparticles gradually change their structure from monocrystalline seeds of 6–7 nm size to polycrystalline nanoclusters of 26–33 nm size while crystallite size grows from 5 to 6 nm to 8–10 nm. All series of initial seeds as well as subsequent iron oxide nanoparticles show superparamagnetic behavior whereas other 1st and 2nd series with x = 0.5 and 1.0 show ferrimagnetic behaviour. Coercitive force of Co0.5Fe2.5O4 have comparable or even higher values than CoFe2O4 while saturation magnetization value close to iron oxide samples of same size. The proposed method may be perspective for synthesis of ferrites with controlled size, structure and Co to Fe ratio.

Improvement of the milling process performance by using cutting fluids prepared with nano-silver and boric acid

Today, it is aimed to produce high quality products and reduce energy consumption in metal cutting processes. For this purpose, it is necessary to use cutting fluids with high tribological performance in metal cutting processes. With the use of these fluids, the lubrication and cooling functions required in metal removal processes will be provided effectively. In addition, minimal and effective use of fluids will reduce processing costs and energy consumption. In this study, tribological performances of cutting fluids consisted of nano-silver and boric acid were investigated comprehensively in the milling process of AA7075-T6 material. First, colloidal suspensions were prepared in ethylene glycol medium using nano-silver as a cooling and surface film-forming agent and boric acid as a lubricating agent. Secondly, milling experiments were performed according to semi factorial design method. Surface roughness (Ra) and cutting forces were considered as performance criteria. Visual and elemental analyses of chips were performed via scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy. Tool wear and build-up-edge (BUE) formation was examined by optical microscope. According to the results, the cutting fluid prepared with nano-silver (nAg) and boric acid (BA) in a medium of ethylene glycol (EG) decreased surface roughness by 14.59% more than the nAg and EG mixture and by 5.27% more than the BA and EG mixture. In addition, cutting forces of EG + BA + nAg was observed 0.846% and 0.115% lower than the EG + nAg and EG + BA, respectively. In terms of tool wear and chip morphology, EG + BA + nAg cutting fluid showed better results than other cutting fluids.

Thiomalic acid/ferric chloride-based deep eutectic solvent for microextraction of chromium in natural water samples prior to FAAS analysis

ABSTRACT Deep eutectic solvents have become interested green materials for microextraction applications. In this study, a novel deep eutectic solvent have been formed by combination of thiomalic acid and ferric chloride in ethylene glycol medium, which then used for liquid–liquid microextraction of trace chromium from water samples. The microextraction process is donated the name of deep eutectic solvent-liquid liquid microextraction (DES-LLME). The microextraction procedure was optimised by evaluating the effect of pH, amount of deep eutectic solvent and sample volume. The optimum recoveries for chromium were achieved at pH 7.0, 200 µL of deep eutectic solvents, and sample volume up to 40 mL, with limits of detection and quantification of 1.18 µg·L−1 and 3.54 µg·L−1 respectively. By validating the DES-LLME with TMDA-53.3 fortified water reference materials, the chromium recovery was 99%.

Определение констант кислотности катиона пиридиния в этиленгликолевых и водно-этиленгликолевых средах методом предельных катодных токов

Определение констант кислотности катиона пиридиния в этиленгликолевых и водно-этиленгликолевых средах методом предельных катодных токов

TiO2NT as Platform for Drug Release: The Effect of Film Wettability

Modifications of Ti–based surface are increasingly studied to improve biological responses on the biomedical implants field. In this study, nanotubular arrays were grown from Ti cp (T) and its alloy, Ti 6 Al 4 V (A), by potentiostatic anodization at 25 V for 90 min in ethylene glycol media containing 0.75 % w/w of NH 4 F, H 2 O 9% v/v and 1% v/v of Simulated Body Fluid (SBF) maintained at 10 °C (T10 and A10) and 40 °C (T40 and A40) for drug release studies. Coatings were top filled with cefazolin (1 mg) and the releasing procedure was performed in 5 mL of PBS at 37 °C, taking 0.5 mL aliquots at 1, 4, 7, 10, 15 and 30 min. The as-formed coatings were characterized by Scanning Electron Microscopy (SEM), X-rays Diffraction (XRD) and contact angle measurements. Contact angle measurements indicate that T-based nanotubular coatings are highly wettable, being ≈ 0.00° and 6.74° ± 1.96 for T10 and T40 respectively. Coatings obtained from Ti-alloy exhibits low wettability than T-based samples for both temperatures. All samples release the drug on short time intervals (4 to 10 min). The drug release rate is inversely proportional to the contact angle, considering substrate groups. Thus, a higher wettability tendency presents a higher release rate. This result shows that wettability is an important parameter to be considered in the design of Ti-based biomaterials. DOI: http://dx.doi.org/10.17807/orbital.v11i6.1251