Volume Ratio Of Ethylene Glycol Research Articles

Thermodynamic performance of air-cooled seasonal cold energy storage for space cooling: A case study

With the improvement in people's living standards, there is a growing demand for cooling, making it urgent to develop a low-carbon and energy-efficient refrigeration system. Therefore, this paper proposes an air-cooled seasonal energy storage (ACSES) system. The heat transfer model of the system is constructed. The impact of relevant parameters on the system's cold storage performance was analyzed. The results show that larger glycol flow rates, windward velocity, number of tube passes and tube rows, and the volume ratio of ethylene glycol to water (VR) are beneficial for improving cold storage performance. However, excessively large parameters do not significantly enhance cold storage performance. The influence of ambient temperature on cold storage performance is greater than that of ice thickness. When VR is 0.02, the cold storage performance is relatively superior. To demonstrate the energy-saving performance of the system, the energy consumption saving rate (ECSR) indicator was proposed. The ECSR of the ACSES system is 72.75 %. The system can significantly conserve resources and reduce energy consumption.

Controlled Synthesis and Visible-Light-Driven Photocatalytic Activity of BiOBr Particles for Ultrafast Degradation of Pollutants.

For the purpose of regulating the visible-light-driven photocatalytic properties of photocatalysts, we selected BiOBr as the research target and various routes were used. Herein, via the use of a hydrothermal method with various solvents, BiOBr particles with controllable morphology and photocatalytic activities are obtained. In particular, through changing the volume ratio of ethylene glycol (EG) to ethanol (EtOH), BiOBr compounds possess microspheres, in which samples synthesized by using EG:EtOH = 1:2 have the highest photocatalytic activity, and can completely decompose RhB under visible light irradiation within 14 min. Furthermore, we also used different volume ratios of EG and H2O reaction solvents to prepare BiOBr particles so as to further improve its pollutant removal ability. When the volume ratio of EG to H2O is 1:1, the synthesized BiOBr particles have the best photocatalytic activity, and RhB can be degraded in only 10 min upon visible light irradiation. Aside from the reaction solvent, the impact of sintering temperature on the photocatalytic properties of BiOBr particles is also explored, where its pollutant removal capacities are restrained due to the reduced specific surface area. Additionally, the visible-light-triggered photocatalytic mechanism of BiOBr particles is determined by h+, ·OH and ·O2- active species.

Heat Effectiveness Analysis of Knock Down Smoke LCS (Liquid Collection System) Design with a Mixture of Ethylene Glycol and Water as Cooling Media

One of the methods commonly used to treat biomass waste, including rice husks, is pyrolysis and gasification, both of which produce smoke that can disturb the surrounding environment. This study aims to optimize the conversion process of smoke released in the pyrolysis process of rice husks into two products at once, namely liquid smoke and producer gas. This study designed a Liquid Collection System (LCS) with a shell and tube type knock-down condenser mechanism where the hot smoke is cooled so that the components of the condensed smoke (become liquid smoke) are separated from the non-condensable components (become producer gas). The composition of the LCS coolant, a mixture of Ethylene Glycol and Water, is simulated with the help of Computational Fluid Dynamics (CFD) software to optimize the heat transfer effectiveness value obtained. The simulation results show that the heat transfer efficiency of the volume variation of Ethylene Glycol in the mixture with the volume ratio of Ethylene Glycol and Water is 0:100, 10:90, 20:80, and 30:70 is 9.43%, 13.21%, 15.32%, and 15.43%, respectively. The highest efficiency value was obtained at the highest Ethylene Glycol content, which was a ratio of 30:70.

Engineering bandgap structure of BiOCl nanoplates with oxygen vacancies for accelerated photocatalytic degradation of Rhodamine B

2D BiOCl nanoplates with exposed (001) crystal surface were synthesized via a simple solvothermal method and the photodegradation property can be improved via adjusting volume ratios of ethylene glycol (EG)/absolute ethyl alcohol (EA). The photocatalytic results suggest that the BiOCl prepared by using the ratios (1:2) of EG/EA (BOC-EG:2EA) with exposed (001) plane displays excellent photocatalytic performance and the removal efficiency of RhB reaches 99% for only 10 min under visible light. The enormous improvement of removal efficiency originates from existence of the oxygen vacancies, the narrow band gap, and limited recombination rate of photoexcited electron-hole pairs. Additionally, the superoxide radical anions (·O2-) and photogenerated holes (h+) are confirmed to be the primary active species to accelerate the photoactivity. This work provides a new perspective to fabricate high-efficient photocatalysts used in relative wastewater treatment system.

Hierarchical Nanoporous BiVO4 Photoanodes with High Charge Separation and Transport Efficiency for Water Oxidation.

To fabricate high efficiency photoanodes for water oxidation, it is highly required to engineer their nanoporous architecture and interface to improve the charge separation and transport efficiency. By focusing on this aspect, we developed hierarchical nanoporous BiVO4 (BV) from solution processed two-dimensional BiOI (BI) crystals. The orientation of the BI crystals was controlled by changing the solvent volume ratios of ethylene glycol (EG) to ethanol (ET), which resulted in different hierarchical and planar BV morphologies through a chemical treatment followed by thermal heating. The morphology with optimal particle dimension, connectivity, and porosity can offer a highly enhanced electrochemically active surface area (ECSA). The hierarchical BV owning a maximum ECSA showed the best photoelectrochemical (PEC) performance in terms of the highest photocurrent density and charge separation efficiency. However, to further improve the performance of the electrode, conformal and ultrathin SnO2 underlayers were deposited by a powerful atomic layer deposition technique at the interface to effectively block the defect density, which significantly improved the photocurrents as high as 3.25 mA/cm2 for sulfite oxidation and 2.55 mA/cm2 for water oxidation at 0.6 V versus the reversible hydrogen electrode (RHE). The electrode possessed record charge separation efficiency of 97.1% and charge transfer efficiency of 90.1% at 1.23 VRHE among to-date reported BiVO4-based photoanodes for water oxidation. Furthermore, a maximum applied bias photon-to-current efficiency (ABPE) of 1.61% was found at a potential as low as 0.6 VRHE, which is highly promising to make a tandem cell. These results indicate that the construction of the hierarchical nanoporous photoanode with an enhanced ECSA and its proper interface engineering can significantly improve the PEC performance.

Natural Convection Enhancement in the Annuli Between Two Homocentric Cylinders by Using Ethylene Glycol / Water Based Titania Nanofluid

The natural convection heat tranfer in annulate region confined between two homocentric cylinders were numerically studied in the present work. The annulus was filled by ethylene glycol / water based Titania nanofluid. Both internal and external cylinders are presereved at an isothermal hot and cold temperatures respectively, whereas, the upper and lower walls are adiabatic. The numerical solution is obtained by applying the finite volume method along with the SIMPLER, and TDMA algorithms. In the current study, the solid volumetric fraction is varied as (0 % ? ? ? 3 %), the volume ratios of EG to water are varied as (0:100 %, 40 : 60 %, 100:0 %), while both the Rayleigh number and radii ratio are considered fixed at (Ra = 104 and ? = 2). The obtained results indicated that, the average Nusselt number increases as the solid volumetric fraction and the volume ratio of ethylene glycol in the base fluid increase. Moreover, the velocity profiles reach their maximum value in the half region adjacent the internal hot wall when TiO2 – water nanofluid is used. Also, the temperature profiles decrease along the radial distance for all considered values of volume ratios of EG to water.

Solvothermal Synthesis of Lanthanide‐doped NaYF4 Upconversion Crystals with Size and Shape Control: Particle Properties and Growth Mechanism

AbstractLanthanide‐doped NaYF4 upconversion nano‐ and microcrystals were synthesized via a facile solvothermal approach. Thereby, the influence of volume ratios of ethylene glycol (EG)/H2O, molar ratios of NH4F/RE3+ (RE3+ represents the total amount of Y3+ and rare‐earth dopant ions), Gd3+ ion contents, types of activator dopant ions, and different organic co‐solvents on the crystal phase, size, and morphology of the resulting particles were studied systematically. A possible formation mechanism for the growth of crystals of different morphology is discussed. Our results show that the transition from the α‐ to the β‐phase mainly depends on the volume ratio of EG/H2O and the molar ratio of NH4F/RE3+, while the morphology and size could be controlled by the type of organic co‐solvent and Gd3+ dopant ions. Furthermore, the reaction time has to be long enough to convert α‐NaYF4 into β‐NaYF4 during the growth process to optimize the upconversion luminescence. The formation of larger β‐NaYF4 crystals, which possess a higher upconversion luminescence than smaller particles, proceeds via intermediates of smaller crystals of cubic structure. In summary, our synthetic approach presents a facile route to tailor the size, crystal phase, morphology, and luminescence features of upconversion materials.

Highly efficient solid-phase microextraction of polycyclic aromatic hydrocarbons in water based on worm-like nickel-titanium oxide nanocomposites coating grown on a nickel-titanium alloy wire by low-voltage anodization.

A novel worm-like nickel-titanium oxide nanocomposite coating was directly grown on a nickel-titanium alloy wire by low-voltage electrochemical anodization in alkaline ethylene glycol and water solution. The in situ growth of nickel-titanium oxide nanocomposites greatly depended on the volume ratio of ethylene glycol to water and temperature. Coupled to high-performance liquid chromatography with UV detection by static desorption in the mobile phase, the adsorption performance of the as-prepared fiber was evaluated for solid-phase microextraction of representative environmental analytes in water. The results indicate that the as-prepared fiber exhibits higher extraction capability for polycyclic aromatic hydrocarbons than commercial polydimethylsiloxane and polyacrylate fibers. After optimizing the extraction parameters, the calibration graphs of the developed method was linear in the range of 0.05-200 μg/L with correlation coefficients above 0.998. Limit of detection ranged from 0.013 to 0.145 μg/L for seven target analytes. Relative standard deviations of intraday and interday analyses varied from 4.0 to 5.3% and from 4.7 to 6.3% with the single fiber, respectively. The relative recoveries of 84.4-109% were achieved for highly efficient enrichment and determination of target analytes in spiked river and snow water. Moreover, the as-prepared fiber can be used more than 200 times.

DİK KONSANTRİK SİLİNDİRLER ARASINDAKİ AL2O3-ETİLEN GLİKOL VE SU KARIŞIM BAZLI NANOAKIŞKANLARIN DOĞAL KONVEKSİYONU

Natural convection of ethylene glycol (EG) and water mixture based Al2O3 nanofluids between vertical concentric circular cylinders heated from the inner wall and cooled from the outer wall was investigated numerically in this study. The computations were carried for the Rayleigh numbers of 104, 105, 106, and 107, nanoparticle volume fractions of 0%, 4% and 8%, ethylene glycol (EG) to water volume ratios of 0:100 %, 50:50%, and 100:0%, the radius ratios of 2, 3 and 4, and aspect ratios of 0.5, 1, and 2. The Brinkman model was used to predict the viscosity and the Yu and Choi model for the thermal conductivity of nanofluid. The results show that the average Nusselt number shows a considerable increase with an increase in the Rayleigh number and radius ratio. The results also show that the average Nusselt number shows a medium increase with increasing nanoparticle volume fraction and a slight increase with increasing volume ratios of EG to water. Furthermore, the results show that the average Nusselt number experiences first an increase then a decrease with an increase in the aspect ratio except for the low Ra numbers. Finally, the average Nusselt number experiences a slight increase with the aspect ratio for the low Rayleigh numbers.

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

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

Porous CoTiO3 with highly surface defects as effective sensing materials for ethanol detection

A series of nano/micro-structured CoTiO3 powders were synthesized using a facile mixed-solvothermal method, by adjusting the volume ratio of ethylene glycol (EG) to anhydrous ethanol in the mixed solvent. Nitrogen adsorption–desorption and electron microscopic analyses revealed that the as-prepared CoTiO3 products possess a bimodal porous structure with interconnected pore channels, which have great advantages for the diffusion of target gas and the effective utilization of active sites. The porous CoTiO3 obtained at the volume ratio of EG to anhydrous ethanol of 1:2 in the mixed solvent demonstrated the highest sensitivity (20.3) and rapid response time (7 s) to low concentration ethanol (20 ppm) at working temperature 300 °C. Moreover, excellent reproducibility and stability can be achieved within six cycles. Photoluminescence (PL) results illustrated that the porous CoTiO3 with the best sensing performance has more abundant surface defects than other samples. These defects can act as reactive sites to facilitate more O2 adsorption, leading to the enhanced accumulation of positive holes on the surface and an increase in the gas sensitivity. In view of the excellent sensing characteristics to low concentration ethanol and the facile preparation method, the obtained porous CoTiO3 products are promising candidates for fabricating effective ethanol sensors.

The Phase Morphology of Citrogypsum Waste Controlled by a Hydrothermal Process in Ethylene Glycol/Water Solutions

The acid purification of calcium citrate from citric acid production using sulfuric acid as a reagent resulted in citrogypsum waste. The identification of citrogypsum by XRD technique indicates that the main component consists of CaSO4∙2H2O (DH). Furthermore, the comparison of the colours between citrogypsum and natural gypsum are also different. Hence, this research mainly focused on the phase transformation of DH to α-CaSO4 ∙0.5H2O (α-HH) due to high strength and heat resistant. The preparation of α-HH carry out in different volume ratios of ethylene glycol (EG): water solutions at 95oC for 7 hrs under atmospheric pressure. The FT-IR spectra of DH and α-HH results reveal that the absorption frequencies at 1700 and 1800 cm-1 of –OH group are 0.5 and 1.5 water molecule in CaSO4 respectively. TGA thermograms show the theoretical crystal water content of DH approximately 20.1 wt% and the converted α-HH about 4-5 wt%. DSC thermograms of the citrogypsums show two endothermic peaks regarding to two steps of water molecule loss at 151.2oC and 168.5oC respectively. In addition, the α-HH shows exothermic peak at 238.7oC. The morphology of citrogypsum and α-HH are observed by SEM, showing the plate-like shape of citrogypsum and hexagonal shape of α-HH. Moreover, the products could be applied to several other industries for increasing the value and reducing the environmental concerns.

Fabricating visible-light photoactive 3D flower-like BiOCl nanostructures via a one-step solution chemistry method at room temperature

Three dimensional (3D) flower-like BiOCl nanostructures were synthesized by a facile and mild solution chemistry method at room temperature without any post-treatment. It is found that the volume ratios of ethylene glycol to water (EG-W) play an important role in the nucleation and growth of BiOCl, which consequently determine the self-assembly and thus the morphology of BiOCl nanostructures. In the solution of high EG-W ratio, the thin nanosheets self-assemble into 3D flower-like nanostructures, resulting in large surface area and abundant oxygen vacancies. The oxygen vacancies facilitate the trapping and transfer of photogenerated electrons to adsorbed oxygen molecules, producing active O2·− species. As a result, the BiOCl nanoflowers exhibit much higher photocatalytic activity for RhB degradation under visible light irradiation than their nanosheets counterparts synthesized in the solution of low EG-W ratios.

Solvent-mediated crystalline phases of NixSy anchored on rGO sheets as electrocatalysts for hydrogen evolution application

A facile, one-pot solvent-mediated hydrothermal process was adopted to prepare nickel sulfide nanoparticles decorated on reduced graphene oxide (NixSy/rGO) as electrocatalysts for hydrogen evolution reaction (HER). The designed solvent (ethylene glycol and deionized water) played a decisive role in controlling both crystalline phase and morphology of NixSy/rGO composites, leading to pure [Formula: see text]-NiS nanoparticles uniformly distributed on rGO sheets under suitable volume ratio of ethylene glycol and deionized water (2:1). The optimized [Formula: see text]-NiS/rGO showed prominent HER catalytic performance with a rather small Tafel slope of 93[Formula: see text]mV/decade and prominent current density of 10[Formula: see text]mA/cm2 at the overpotential of 177[Formula: see text]mV in alkaline environments when compared to pristine [Formula: see text]-NiS and NiS2/rGO catalysts. The excellent catalytic performance and long-term durability even after 8000 cycles confirmed the potential of [Formula: see text]-NiS/rGO composites as efficient electrocatalysts for HER in the alkaline media.

A comparative study of one-dimensional and two-dimensional porous CoO nanomaterials for asymmetric supercapacitor

In this study, porous one-dimensional (1D) CoO nanobelts and two-dimensional (2D) CoO nanoplates were successfully fabricated by calcining single crystalline cobalt carbonate hydroxide hydrate - Co(CO3)0.5(OH)·0.11H2O nanobelts and nanoplates obtained using a solvothermal method. Solvents applied in the reaction significantly affected the shape and size of Co(CO3)0.5(OH)·0.11H2O. Belt-like Co(CO3)0.5(OH)·0.11H2O crystals can be easy to turn into to plate-like by adjusting the volume ratio of ethylene glycol (EG) to water. The as-prepared porous CoO nanobelts, when used as the supercapacitor electrode materials, exhibit a higher specific capacitance of 1178 F g−1 at 1 A g−1 than porous CoO nanoplates. Asymmetric supercapacitor (ASC) based on CoO nanobelts and aqueous electrolyte also show more excellent electrochemical performance, e.g., higher energy density (68.5 Wh kg−1 at 850.0 W kg−1) and long-term cycling ability.

Fast, green microwave-assisted synthesis of single crystalline Sb2Se3 nanowires towards promising lithium storage

Abstract In this work, a fast (0.5 h), green microwave-assisted synthesis of single crystalline Sb2Se3 nanowires was developed. For the first time we demonstrated a facile solvent-mediated process, whereby intriguing nanostructures including antimony selenide (Sb2Se3) nanowires and selenium (Se) microrods can be achieved by merely varying the volume ratio of ethylene glycol (EG) and H2O free from expensive chemical and additional surfactant. The achieved uniform Sb2Se3 nanowire is single crystalline along [001] growth direction with a diameter of 100 nm and a length up to tens of micrometers. When evaluated as an anode of lithium-ion battery, Sb2Se3 nanowire can deliver a high reversible capacity of 650.2 mAh g−1 at 100 mA g−1 and a capacity retention of 63.8% after long-term 1000 cycles at 1000 mA g−1, as well as superior rate capability (389.5 mAh g−1 at 2000 mA g−1). This easy solvent-mediated microwave synthesis approach exhibits its great universe and importance towards the fabrication of high-performance metal chalcogenide electrode materials for future low-cost, large-scale energy storage systems.

Template-free synthesis of mesoporous ZnCo2O4 nanosheets and quasi-cubes via a simple solvothermal route

Porous ZnCo2O4 nanosheets (NSs) were synthesized via a solvothermal method in ethylene glycol (EG) and water combined solvent, and followed by calcination in air at 400 °C for 2 h. No surfactant or template was employed during the entire synthetic process. The ZnCo2O4 NSs have a thickness of about 100–150 nm, and possess a BET surface area and pore size of 54.4 m2 g−1 and 7.8 nm, respectively. Such porous NSs would gradually stack into quasi-cube-like microstructures with reaction time prolonging. Quasi-cubes with edge length ranging from 10 to 30 μm were produced, and NSs almost disappeared after 15 h of solvothermal treatment. It was found that the volume ratio of EG to water played important role for the final shapes of ZnCo2O4. Some irregular and broken NSs were formed if less amount of EG was used, while quasi-microcubes stacked by NSs were dominant in the product as the ratio of EG to water increased to 4:1. The current approach is simple and low cost, and can be extended for preparation of other transition metal oxides in nanoscaled size and porous structure.

Fluoride adsorption on manganese carbonate: Ion-exchange based on the surface carbonate-like groups and hydroxyl groups

Manganese carbonate (MnCO3) nanowires and microcubes were controlled synthesized by a simple ethylene glycol (EG) mediated solution method. The volume ratios of EG and water has a decisive impact on the morphology of MnCO3 products. With a decreased water volume, MnCO3 products were transformed from microcubes to nanowires. The obtained MnCO3 nanowires were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption isotherm. The adsorption properties of the MnCO3 products towards fluoride were investigated. The adsorption capacities of the nanowires were higher than that of the microtubes. According to the Langmuir model, the maximum adsorption capacity was 46.80mgg−1 at pH 7.0. The adsorption capacity was 11.58mgg−1 when the equilibrium fluoride concentration was just below the WHO guideline of 1.5mgL−1. The kinetic data were well fitted to pseudo-second-order model. The fluoride removal was attributed to the ion-exchange based on the surface hydroxyl groups and carbonate-like groups, which was revealed by Fourier transform infrared absorption spectroscopy and X-ray photoelectron spectroscopy.

Li1.2Ni0.13Co0.13Mn0.54O2 with Controllable Morphology and Size for High Performance Lithium-Ion Batteries.

The controllable morphology and size Li-rich Mn-based layered oxide Li1.2Ni0.13Co0.13Mn0.54O2 with micro/nano structure is successfully prepared through a simple coprecipitation route followed by subsequent annealing treatment process. By rationally regulating and controlling the volume ratio of ethylene glycol (EG) in hydroalcoholic solution, the morphology and size of the final products can be reasonably designed and tailored from rod-like to olive-like, and further evolved into shuttle-like with the assistance of surfactant. Further, the structures and electrochemical properties of the Li-rich layered oxide with various morphology and size are systematically investigated. The galvanostatic testing demonstrates that the electrochemical performances of lithium ion batteries (LIBs) are highly dependent on the morphology and size of Li1.2Ni0.13Co0.13Mn0.54O2 cathode materials. In particular, the olive-like morphology cathode material with suitable size exhibits much better electrochemical performances compared with the other two cathode materials in terms of initial reversible capacity (297.0 mAh g-1) and cycle performance (95.4% capacity retention after 100 cycles at 0.5 C), as well as rate capacity (142.8 mAh g-1 at 10 C). The excellent electrochemical performances of the as-prepared materials could be related to the synergistic effect of well-regulated morphology and appropriate size as well as their micro/nano structure.

Coordination and reduction in polyol-mediated solvothermal synthesis of nickel-based materials with controllable morphology and magnetic and electrochemical properties

The coordination and reduction effects in polyol-mediated solvothermal synthesis were studied using nickel acetate as model precursor and ethylene glycol (EG)–ethanol (Et) mixture as polyol medium. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed that the morphology and phases of the nickel-based products depended on the volume ratio of EG to Et, because of their differing coordination and reduction capacities. When the Et content in the polyol mixture was low, EG dominated and the system exhibited superior coordination as well as the ability to self-assemble to produce sphere-like α-Ni(OH)2. When Et was dominant, the strong reducing effect of Et and decarboxylating effect of nickel on ethanol led to formation of α-Ni(OH)2 nanosheets. However, at EG:Et ratio of 1:1, polyhedral metallic nickel was produced due to the synergistic effect of coordination and reduction by EG and Et. For other EG:Et ratios, mixed products of α-Ni(OH)2 and metallic nickel of different shapes were obtained, providing evidence of the coordinating and reducing abilities of the polyol mixture. The prepared α-Ni(OH)2 material has potential for application in supercapacitors, while the metallic nickel displayed magnetic properties. This study demonstrates a new route for solvothermal synthesis of different nanomaterials using polyols as solvents.