Mixture Of Glycol Research Articles

Estimation of Scattering Properties Modifications Caused by InVivo Human Skin Optical Clearing Using Line-Field Confocal Optical Coherence Tomography.

The image contrast and probing depth of optical methods applied to invivo skin could be improved by reducing skin scattering using the optical clearing method. The aim of this study was to quantify, from line-field confocal optical coherence tomography (LC-OCT) 3D images, the modifications of skin scattering properties invivo during optical clearing. Nine mixtures of optical clearing agents were used in combination with physical and chemical permeation enhancers on the human skin of three healthy volunteers. Scattering coefficient and anisotropy factor of the epidermis and the upper dermis were estimated from the 3D LC-OCT images of skin using an exponential decay model of the in-depth intensity profile. We were able to demonstrate a decrease in epidermal scattering (down to 33%) related to optical clearing, with the best results obtained by a mixture of polyethylene glycol, oleic acid, and propylene glycol.

Rapid and sensitive whole cell E. coli detection using deep eutectic solvents/graphene oxide/gold nanoparticles field-effect transistor

Every year, millions of people suffer from gastrointestinal inflammation caused by E. coli. The increase of antibiotic-resistant strains and similar inflammatory and infectious syndromes symptoms have made rapid and sensitive diagnosis of this pathogen challenging. This study developed a Field-Effect Transistor based on deep eutectic solvents, graphene oxide, and gold nanoparticles (DES/GO/AuNPs-FET) to detect E. coli. Comparing the output current showed DES, which was a mixture of ethylene glycol and choline chloride, with ionic behavior, in addition to improving the electrical properties of GO, also led to the formation of AuNPs by self-assembly, which significantly increased the sensor's sensing performance. E. coli lipopolysaccharide aptamer immobilized on DES/GO/AuNPs-FET; capturing E. coli and changing the conformation caused changes in the charge carrier flow in the FET. This nanobiosensor detected E. coli in a completely selective manner in complex matrices like human blood serum. The excellent sensing performance of this nanobiosensor compared to other biosensors with a low detection limit (LOD = 3 CFU/ml), label-free, fast, and real-time detection showed that DES/GO/AuNPs-FET could be a reliable alternative to existing detection methods.

Thermal and rheological behavior of aluminium-doped zinc oxide nanofluids: Experimental study and application of artificial neural network model

In this study, the influence of Al-doping concentration on the thermal and rheological characteristics of pristine zinc oxide (ZnO) nanofluids was investigated across a range of temperatures and nanoparticle concentrations. A multilayer perceptron (MLP) artificial neural network (ANN) with an optimized topology was employed to model the thermal conductivity and viscosity of nanofluids. The addition of 0.13 M of Al-doped zinc oxide nanoparticles at 1 % rate led to a remarkable 64 % increase in the thermal conductivity of the base fluid (50:50 ratio water + ethylene glycol mixture). Furthermore, incorporating 1 % of these Al-doped nanoparticles outperformed pure zinc oxide, resulting in a 44 % boost in thermal conductivity. The enhanced heat transfer capabilities of Al-doped zinc oxide were evident across different doping and nanoparticle concentrations. The viscosity of nanofluids increases with an increase in nanoparticle concentration and decreases with an increase in temperature. ZnO and Al-doped ZnO nanoparticles have been prepared and studied their structural, morphological and elemental properties using XRD, SEM and EDS respectively. The predicted thermal and rheological behaviours are in close agreement with the experimental values.

Characterization of Simulated Cytoplasmic Fluids

AbstractMolecularly crowded solutions have been used to simulate cytoplasmic fluids, but little justification is provided in the literature. This work compared three key physical properties of solutions containing polyethylene glycol and sucrose against those in the cytoplasmic fluid from bacteria Escherichia coli: fluid viscosity, relaxation time (T1 and T2) of water, and the diffusion coefficient of water. It was concluded that appropriate mixtures of sucrose and polyethylene glycol 10,000, such as 10% sucrose and 15% PEG10,000 and 7.5% sucrose and 19% PEG10,000, closely mimic these properties of cytoplasmic fluid from E. coli containing around 100 mg/mL of proteins.

IMMISCIBLE POLYMER–FILLER SYSTEMS FOR TUNABLE MECHANICAL PROPERTIES

ABSTRACT A model system consisting of a 50/50 immiscible mixture of polyethylene glycol (PEG) and polytetrahydrofuran (PTHF), with covalently bound nano silica–reinforcing particles, was used to investigate how the distribution of particles affects viscoelastic properties. The rubbery polymers were generated by chain extending from their respective oligomers through hydroxyl end groups with 1,6-diisocyanato hexane. The viscosity of the resulting PEG and PTHF polymers was 32 and 1000 Pa-s, respectively. Setting the overall SiO2 concentration to 10 phr, we explored three different silica distributions: (1) all-in-PEG, 20 phr in PEG and neat PTHF; (2) uniform, 10 phr in both PEG and PTHF; and (3) all-in-PTHF, neat PEG and 20 phr in PTHF. When compared with the uniform system, the storage and loss shear moduli and the viscosity of the all-in-PTHF system showed a 20-fold increase of the stiffness at low strain, yet nearly the same viscosity at high strain. Similarly, the storage and loss moduli of all-in-PEG mixtures were roughly 1/10 that of the uniform system. The surprisingly high modulus and high viscosity of the all-in-PTHF system can be understood as the entire PTHF regions themselves becoming solid filler.

Heat transfer enhancement in cylindrical heat pipes with MgO-Al2O3 hybrid nanofluids in water-ethylene glycol mixture: An RSM approach

Heat pipes are passive devices crucial for thermal management in various applications. However, conventional water-based fluids can limit their heat transfer capacity, especially in cold environments where freeze protection is necessary. This study investigates the potential of MgO-Al2O3 hybrid nanofluids to enhance heat transfer performance in cylindrical mesh heat pipes while addressing these limitations. The research demonstrates significant improvements in thermal performance compared to a water-ethylene glycol mixture. The MgO-Al2O3 hybrid nanofluid reduces thermal resistance by enhancing surface wettability in the evaporator section. Additionally, the formation of a nanofluid coating on the evaporator surface leads to a higher heat transfer coefficient. Furthermore, RSM successfully models the relationship between nanoparticle concentration, power input, and key thermal responses (thermal resistance and heat transfer coefficient). These findings highlight the effectiveness of MgO-Al2O3 hybrid nanofluids for augmenting heat transfer in heat pipes and provide valuable RSM models for predicting thermal behavior within the investigated range.

Improving adhesion strength between steel and 2K polyurethane containing organic–inorganic hybrid nanoparticles and its performance optimization

This research has developed a novel adhesion promoter using organic-inorganic hybrid nanoparticles (ATS) to address existing limitations, such as the cumbersome separate coating and drying stages and insufficient adhesion. ATS was synthesized through hydrolysis-condensation reactions of an alkoxysilane-functionalized amphiphilic polymer (AFAP) precursor and 3-aminopropyltriethoxysilane (APTES). When directly mixed with resin part of polyurethane, ATS significantly enhanced the adhesion strength of 2 K PU to steel substrates without altering the mechanical properties or chemical structure of the polyurethane. An optimization process was conducted to determine the ideal mixing ratio of ATS with other components of 2 K PU, including different types of glycols (butylene glycol, propylene glycol, and ethylene glycol) and polyols to achieve the highest adhesive performance. The results showed that 2 K PU resin formed by using a mixture of polycaprolactone diol (PCD) and butylene glycol (BG) containing ATS (1−2) with nanoscale size (30.86 nm) exhibited superior adhesion performance over the other modified 2 K PUs and was 2.16 times higher than the common 2 K PU. These results were further validated via predictive model following response surface methodology to assess the precise impact of three parameters: the amount of AFAP (X1), amount of APTES (X2), and amount of BG (X3) on the adhesion strength of 2 K PU. The properties of different types of ATS and modified 2 K PU including particle size, degree of condensation, moisture content, molecular structure, molecular weight, hydrogen bonding intensity, microstructure morphology, and adhesion strength, were characterized.

Comprehensive parametric study and sensitivity analysis of automotive radiators using different water/ethylene glycol mixtures: Toward thermo‐hydraulic performance and heat transfer characteristics optimization

Comprehensive parametric study and sensitivity analysis of automotive radiators using different water/ethylene glycol mixtures: Toward thermo‐hydraulic performance and heat transfer characteristics optimization

Analysing the thermal and electrical properties of Cocos nucifera shell-based nanofluids as coolant feasibility proton exchange membrane fuel cell

For an enhancement of the thermal and electrical conductivity of the proton exchange membrane fuel cell (PEMFC), extensive research is actively conducted on various waste bio sources. PEMFC offers the cleanest form of energy, an electrochemical energy conversion device that possesses zero emissions with by-products such as heat and water. In PEMFC, conventional coolants such as water and water:ethylene glycol mixture does not attain the substantial results in terms of heat dissipation, which impacts performance gradually reduces the operating life of the cell. Usually, bio-sources are environmentally friendly and have merits over chemically prepared methods. Bio-based nanofluids have remarkable performance in terms of heat transfer, lower electrical conductivity, and low corrosiveness in the system compared to other metal-based fluids and base fluids, which have also gained a great deal of scrutiny over the past few decades. In this research, bio-sourced Cocos nucifera shell (CNS) is utilised at various concentrations, such as 0.1 vol.-%, 0.3 vol.-% and 0.5 vol.-%, dispersed with a base fluid such as water (W), and ethylene glycol (EG) (80:20) is analysed prior to actual full stack PEMFC. Consequently, heat transfer has been improved by 13% for CNS in 80:20 (W:EG) at 0.5% volume concentration compared with W:EG (80:20). On the basis of findings on thermal, hydraulic and electrical conductivity, various properties have also been determined. Despite the drawbacks of the experimental design, it was concluded that up to 0.5 vol.-% CNS in an 80:20 (W:EG) nanofluid could be used as a cooling medium for PEMFCs with no adverse effects on the electrical performance. It was also observed that the nanofluid improved the efficiency of the fuel cells by reducing the ohmic losses.

Experimental analysis of W/EG based Al2O3-MWCNT non-Newtonian hybrid nanofluid by employing helical tape inserts inside a corrugated tube

Experimental analyses have been undertaken on friction factors and convective heat transfer using a helically corrugated tube (HCT) equipped with inserts, under laminar flow conditions. Water-ethylene glycol mixture with Al2O3-MWCNT hybrid nanofluids has been employed. The investigation focused on examining the synergistic effects of hybrid nanofluids, triangularly helical tape (THT) inserts and helical corrugation within the tubes on the friction factor, Nusselt number, and thermal performance factor (TPF). The fluid displayed non-Newtonian behaviour at volume fractions greater than 0.1 %. The study indicated that augmenting the concentration of Al2O3-MWCNT in the hybrid nanofluid and decreasing the helix ratio of the THT inserts led to increased heat transfer rates and TPF. The peak TPF of 2.31 was recorded when using the W/EG based Al2O3-MWCNT hybrid nanofluid with a 1 % volume fraction in an HCT equipped with THT inserts with a helix ratio of 2 at a Reynolds number of 2000. Moreover, Al2O3-MWCNT exhibits an average Nusselt number of 42.5 %, 49.47 %, and 56.2 % higher than the base fluid at φ = 0.1 %, 0.5 %, and 1 %, respectively.

Fructose-mediated single-step synthesis of copper nanofluids with enhanced stability and thermal conductivity for advanced heat transfer applications

A precisely controlled solution-phase approach was employed to synthesize copper nanofluid through the reduction of copper sulfate by fructose in the presence of cetyltrimethylammonium bromide, utilizing a mixture of water and ethylene glycol in 1:1 ratio as the base fluid. We delved into the nanofluid’s thermal conductivity and rheological properties, with a keen interest on particle size and reaction rates that exhibited significant sensitivity to variations in reaction parameters. The homogeneous dispersion of nanoparticles in the base fluid resulted in an augmentation of thermal conductivity to 2.31 Wm−1K−1 for particle loading fraction of 0.19%, with a never before achieved stability of 9 months. This method has proven to be not only straightforward and dependable but also efficient for the rapid synthesis of highly stable Newtonian nanofluids, underscoring the nanofluid’s potential for highly powerful cooling applications.

Simulation of UV curing of photosensitive resins with phase change materials

Based on the mechanism of the resin polymerization reaction and free radical diffusion under UV irradiation, here, a mathematical model of the curing process was established for the mixture of photosensitive resin (PAA) and polyethylene glycol (PEG, as the phase change material), and the factor influencing the mechanical performance of the cured samples was analyzed. The yield stress (σs) of the pure resin sample can reach 50 MPa when the monolayer curing depth is 5 mm. σs decreases with the increase in the PEG content and monolayer curing depth. With increasing the monolayer exposure time, the yield stress increases and then decreases, and there is an optimum value. The material has the maximum stress at the monolayer exposure time of 13.5 s when the resin content is 50 %.

Impact of multiple slips and thermal radiation on heat and mass transfer in MHD Maxwell hybrid nanofluid flow over porous stretching sheet

This study investigates the two-dimensional magnetohydrodynamic (MHD) boundary-layer flow over a stretching sheet embedded in a porous medium, focusing on the innovative use of hybrid nanofluids. The research has practical applications in heat exchangers, nanofluid technology, porous media, and MHD systems. Key governing parameters, including internal heat sources/sinks, multiple slips, and thermal radiation, are analyzed for their impact on the flow. The nanofluid consists of hybridized nanoparticles (Alumina-Magnetite) dispersed in a water and ethylene glycol mixture (WEG-50:50). Assuming steady-state, incompressible, and laminar flow with small boundary layer thickness and constant nanofluid properties, the governing equations for continuity, momentum, energy, and species concentration are formulated. The fluid is modeled as a non-Newtonian (Maxwell) fluid. The resulting nonlinear ordinary differential equations system, with specified boundary conditions, is solved using the Runge-Kutta integration scheme implemented in MAPLE 23. Numerical results of heat transfer rates are validated against existing data, showing a 12 % increase in the Nusselt number for the WEG-Al2O3 nanofluid and a 20 % increase for the hybrid WEG- Al2O3–Fe3O4 nanofluid. It is demonstrated that skin friction decreases by up to 15 % with increased thermal Grashof number and that the Nusselt number can be reduced by up to 10 % due to magnetic effects. Overall, hybrid nanofluids generally demonstrate higher Nusselt and Sherwood numbers, enhancing heat transfer efficiency.

Volumetric and ultrasonic studies of molecular interactions in binary mixtures of N,N-dimethylacetamide with some polyethylene glycols at temperatures from 293.15 to 323.15 K

The intermolecular interactions in N,N-dimethylacetamide (DMA) + polyethylene glycol (PEG) mixtures have been examined from the measurements of the densities, ρ and speeds of sound, u of DMA + PEG 200 or PEG 300 or PEG 400 or PEG 600 mixtures over the entire mole fraction range at temperatures, T = (293.15–323.15) K and atmospheric pressure. Various excess parameters, viz., excess molar volume, excess isentropic compressibility, excess intermolecular free length, excess speed of sound, excess molar isentropic compressibility and excess acoustic impedance were evaluated using measured data. These excess properties were correlated with the Redlich–Kister equation. In addition, the partial molar volume and compressibility; excess partial molar volume and compressibility of the components over the entire composition range; and partial molar volume and compressibility and excess partial molar volume and compressibility of the components at infinite dilution have also been calculated. These evaluated parameters have been interpreted by means of prevailing intermolecular interactions in these mixtures. The presence of strong intermolecular interactions among DMA and PEG molecules have been revealed from the evaluated parameters of these mixtures. The speeds of sound were predicted theoretically using scaled particle theory and compared with experimental values. FT-IR spectra of pure DMA, PEG 200 and their equimolar mixtures were also recorded and analysed for better understanding of prevailing intermolecular interaction.

Isolation of Polyethylene Glycol with Larger Molecular Weights via Metal-Organic Frameworks.

Polymer products typically present as mixtures with a range of molecular weights, which notably influence the expression of their properties. In this study, a technique is proposed to separate polyethylene glycol (PEG) mixtures of varying molecular weights using metal-organic frameworks (MOFs), thereby narrowing down their molecular weight distribution. Due to the hydrogen bond interactions between PEG and -OH groups in the pores of NU-1000, NU-1000 can selectively adsorb PEG with larger molecular weights from PEG mixture. This separation method consistently yields with narrower molecular weight distribution across multiple cycles. This is the first application of MOFs in regulating the dispersity (Ð) of polymers in solution, providing a novel approach for separating and purifying mixed molecular weight polymers.

The thawing process in gentamicin and polyethylene glycol hydrogel: The impact of selected parameters on the calculation of activation energy using the methods of Belichmaer and Duswalt

AbstractThe subject of the research conducted by differential scanning calorimetry (DSC) was hydrated mixtures of polyethylene glycol and gentamicin (GEN) in a 1:1 (w/w) ratio. In this way, a system with a particularly high ability to form hydrogen bonds was created. It was postulated that studying the effective activation energy (EA) of the thawing process of diverse hydrated polymer mixtures will indirectly allow for an attempt to assess the distribution of water molecules in the examined material in future studies. This article presents a detailed analysis of the impact of selected parameters on the calculation of EA using the Belichmaer and Duswalt methods. The research focused on assessing how the interpolation method affects the accuracy of results obtained from these techniques. The interpolation method was analyzed in terms of its ability to accurately replicate experimental data. By evaluating the impact of the number of points from the DSC curve used in linear interpolation, a standard deviation from the average value of EA was obtained, respectively: 2.4% for the Belichmaer method and 1.9% for the Duswalt method. The article also shows that by using both methods simultaneously, it is possible to detect the moment when additional endothermic and exothermic reaction activity becomes present in the reaction curve. This allowed for the avoidance of the depletion error. Computer modeling and simulations were used to compare the effectiveness of both techniques in various scenarios. The results showed that the choice of interpolation method and taking into account the depletion error significantly affect the accuracy of calculating EA. The computed activation energy via Duswalt method was EA = 363.32 kJ mol−1 with a standard deviation of 7.07 kJ mol−1 and using the Belichmaer method the EA was 364.81 kJ mol−1, with a standard deviation of 9.10 kJ mol−1.

Long-Term Estimation of Depositions on Heating Surface During Boiling of Long-Life Coolant

Abstract Long-term boiling experiments with long-life coolant have been made with the aim to apply a boiling cooling technology to the next generation high exothermic electronic devices. The long-life coolant commonly used for cooling electronic devices is a mixture of ethylene glycol and water with multiple antirust inhibitors as additives, which may result in some depositions on the heat transfer surface during the boiling. In this study, the heat transfer surface made of copper was set vertically, and long-term experiments have been performed under the pool boiling. The deposition process was monitored for constant heating conditions. From experimental results, a distinct surface temperature change was observed under constant heat flux conditions. Just after keeping constant heat flux, the surface temperature increases with time, a certain time later decreases, and finally takes a stable value. During the temperature rise, the deposition adheres to the heat transfer surface in dots, which may cause an increase in thermal resistance between the wall surface and the working fluid. However, during the temperature drop, large growth of dot-like depositions on the heat transfer surface could alter wettability and surface roughness, enhancing boiling heat transfer. In addition, to investigate the characteristics of the depositions adhered to the heat transfer surface, a component analysis has been performed, which shows that the main substance was strontium hydroxyapatite, which might be formed by chemical reaction between components in the additives under the boiling.

DETERMINATION OF POLYPHENOLIC COMPOUNDS IN PHYTOEXTRACTS WITH ANTIBACTERIAL PROPERTIES AND STUDY POTENTIAL EFFECTS

Objectives. The research work is a comparative study of the polyphenolic compounds and flavonoid content of the phytoextracts obtained from the ultrasonic extraction process (Stegler DG-360) with 95% ethanol and ethanol-propyleneglycol mixture (in 95 : 5 ratio) from the Clove buds (Caryophyllos aromaticus L. Myrtaceae), hibiscus flowers (Hibiscus sabdariffa L. (Hs, roselle; Malvaceae)) and common yarrow (Achillea millefolium L. Asteraceae) plants, which are rich in biologically active substances with high therapeutic effect, as well as their devoted to the investigation of antioxydant activity and antimicrobial potential. Material and methods. The research work was carried out in the Central Research and Application Laboratory of Ağrı İbrahim Çeçen University (MERLAB), Republic of Turkey, using a Japanese Shimadzu brand Mistral-AB SCIEX 4000 QTRAP liquid chromatograph-mass spectrometer device. Results.It was found that in both extraction processes, the active substances penetrated sufficiently from the medicinal-plant raw materials into the extractant. 20 names of compounds containing polyphenol, flavonoid and anthocyanin derivatives have been determined. However, the amount of active substances in the phytoextract obtained with the presence of the penetrate (propylene glycol) was higher. In particular, rutin ( 75.74 ± 4.91mg/g), quercetin (110.12 ± 1.30 mg/g), gallic acid (4503.19 ± 46.83mg/g), quinic acid (4041.99 ± 187.3 mg/g), chlorogenic acid (582.30 ± 1.30mg/g), vanilin (155.6g/g1 ± 3.95mg/g) prevailed. Conclusion. The research work proves once again that the studied phytoextracts are rich in polyphenolic compounds and flavonoids. The amount of biologically active substances in the phytoextract obtained with the ethanol-propylene glycol mixture which is the penetrate substance (in the ratio of 95:5) is higher than that of the other sample (with 95% ethanol). The resulting amount of biologically active substances is a clear proof that the phytoextract has sufficient antioxidant and antimicrobial properties.

Exploring a nanostructured X-ray optical device for improved spatial resolution in laboratory X-ray diffraction imaging

Analytical methods with wide field range and high spatial resolution are required to observe the distribution of the crystal structure in micro-regions undergoing macroscopic chemical reactions. A recent X-ray diffraction (XRD) imaging method combines XRD with an X-ray optical device such as a glass polycapillary consisting of a bundle of numerous monocapillaries. The former provides the crystal structure, while the latter controls the shape of the incident or diffracted X-rays and retains the positional information of the sample. Although reducing the monocapillary pore size should improve the spatial resolution, manufacturing technology challenges must be overcome. Here, an anodic aluminium oxide (AAO) film, which forms self-ordered porous nanostructures by anodic oxidation in an electrolyte, is applied as an X-ray optical device. The AAO film (pore diameter: 110 nm; size of the disc: 11 mm; and thickness: 620 µm) was fabricated by anodization in a mixture of oxalic acid and ethylene glycol. The film was incorporated into a laboratory XRD instrument. Compared with using a glass polycapillary alone, using a combination of a glass polycapillary and the AAO film improved the spatial resolution of the XRD imaging method by 40%. This XRD imaging method should not only provide practical analysis in a laboratory environment but also support various observations of the crystal structure distribution.

Photo-responsive anticounterfeiting inks switching between colorless and cyan/magenta/yellow for flexible, full-color, and large-area printing

Inkjet printing of photo-responsive patterns capable of switching between colorless and full-color is regarded as an innovative anticounterfeiting technique with a higher security level. Therefore, colorless inks which can be changed to cyan (C), magenta (M), and yellow (Y) upon photochromism are highly required. Herein, three photochromic (PC) inks C, M, and Y switching between colorless and cyan/magenta/yellow, respectively, have been successfully prepared by dissolving viologen derivatives AV, AEV, and NOV in solvent mixtures of water, ethanol, and ethylene glycol, with sodium dodecyl sulfate (SDS) as surfactant. With a mass fraction of 0.5 wt% for SDS, an optimal rheological property with a viscosity of 3.48 mPa·s, a contact angle of 29.4° on poly (ethylene terephthalate) (PET) substrate, a surface tension of 23.16 mN m−1, and a Z value of 3.85, is realized for ink C. Under the same conditions, inks M and Y are prepared and display suitable rheological properties for inkjet printing. The films are invisible initially and become colorful upon UV irradiation with no significant decay after 20 repetitive PC switching. Subsequently, various colorful patterns with high resolutions were printed on conventional A4 paper and become visible only after irradiation by a UV lamp. Therefore, these photo-responsive tricolor inks can be used in anticounterfeiting field and two practical examples of a stamp and a personal check with cryptical texts and color information have been demonstrated. Overall, the developed photo-responsive C/M/Y inks can be utilized in flexible, full-color, and large-area printing, providing a novel approach towards innovative anticounterfeiting technology.