Ethylenediamine Concentration Research Articles

Fast fabrication, gas sense characteristics and kinetics of cubic Ti-BIPA-TC-MOF film composite optical waveguides

A cubic Ti-metal-organic framework (MOF) ([Ti2–(TpA)2–H2BIPA]), constructed from a titanium metal centre and a benzo-imidephenanthroline tetracarboxylic acid (H4BIPA–TC) ligand was photo-inductively grown on the surface of a titanium dioxide (TiO2) composite optical waveguide (COWG) substrate and the influence of photo-inductive growth period on the [Ti2–(TpA)2–H2BIPA] film surface morphology, optical properties and gas adsorption/sensing characteristics was investigated. The results showed that [Ti2–(TpA)2–H2BIPA] formed a cubic structure after grew for only 5 min. As an ideal gas adsorbent, it exhibits a specific response to ethylenediamine (EDA) among various benzene, amine and acid gases, due to the intrinsic electron deficiency, rich COOH active sites of the Ti–BIPA–TC–MOF–5 frame and the higher molar refractive indexes or dipoles of EDA than other gases. In the EDA concentration range from 10 ppt to 100 ppm, the Ti–BIPA–TC–MOF–5 film COWG exhibited a rapid, repeatable response. Moreover, the Ti–BIPA–TC–MOF–5 film COWG was relatively stable, within 17 d of EDA detection, the response intensity was almost constant and slightly decreased within 40 d. In a static gas adsorption stage at 283–313 K, the EDA gas adsorption behaviour of the Ti–BIPA–TC–MOF–5 film is consistent with the pseudo-second-order kinetic model.

Ni-B-PTFE Nanocomposite Co-Deposition on the Surface of 2A12 Aluminum Alloy.

The spinning cup, a crucial component of textile equipment, relies heavily on 2A12 aluminum alloy as its primary raw material. Commonly, electroplating and chemical nickel-phosphorus (Ni-P) plating are employed to improve the surface characteristics of the object. Nevertheless, due to the growing expectations for the performance of aluminum alloys, the hardness and wear resistance of Ni-P coatings are no longer sufficient to fulfill industry standards. This study primarily focuses on the synthesis of Ni-B-PTFE nanocomposite chemical plating and its effectiveness when applied to the surface of 2A12 aluminum alloy. We examine the impact of the composition of the plating solution, process parameters, and various other factors on the pace at which the coating is deposited, the hardness of the surface, and other indicators of the coating. The research findings indicate that the composite co-deposited coating achieves its optimal surface morphology when the following conditions are met: a nickel chloride concentration of 30 g/L, an ethylenediamine concentration of 70 mL, a sodium borohydride concentration of 0.6 g/L, a sodium hydroxide concentration of 90 g/L, a lead nitrate concentration of 30 mL, a pH value of 12, a temperature of 90 °C, and a PTFE concentration of 10 mL/L. The coating exhibits consistency, density, a smooth surface, and an absence of noticeable pores or fissures. The composite co-deposited coating exhibits a surface hardness of 1109 HV0.1, which significantly surpasses the substrate's hardness of 232.38 HV0.1. The Ni-B-PTFE composite coating exhibits an average friction coefficient of around 0.12. It has a scratch width of 855.18 μm and a wear mass of 0.05 mg. This coating demonstrates superior wear resistance when compared to Ni-B coatings. The Ni-B-PTFE composite coating specimen exhibits a self-corrosion potential of -6.195 V and a corrosion current density of 7.81 × 10-7 A/cm2, which is the lowest recorded. This enhances its corrosion resistance compared to Ni-B coatings.

Preparation technology comparison and performance evaluation of different protein A affinity chromatographic materials

Protein A affinity chromatographic materials are widely used in clinical medicine and biomedicine because of their specific interactions with immunoglobulin G (IgG). Both the characteristics of the matrix, such as its structure and morphology, and the surface modification method contribute to the affinity properties of the packing materials. The specific, orderly, and oriented immobilization of protein A can reduce its steric hindrance with the matrix and preserve its bioactive sites. In this study, four types of affinity chromatographic materials were obtained using agarose and polyglycidyl methacrylate (PGMA) spheres as substrates, and multifunctional epoxy and maleimide groups were used to fix protein A. The effects of the ethylenediamine concentration, reaction pH, buffer concentration, and other conditions on the coupling efficiency of protein A and adsorption performance of IgG were evaluated. Multifunctional epoxy materials were prepared by converting part of the epoxy groups of the agarose and PGMA matrices into amino groups using 0.2 and 1.6 mol/L ethylenediamine, respectively. Protein A was coupled to the multifunctional epoxy materials using 5 mmol/L borate buffer (pH 8) as the reaction solution. When protein A was immobilized on the substrates by maleimide groups, the agarose and PGMA substrates were activated with 25% (v/v) ethylenediamine for 16 h to convert all epoxy groups into amino groups. The maleimide materials were then converted into amino-modified materials by adding 3 mg/mL 3-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS) dissolved in dimethyl sulfoxide (DMSO) and then suspended in 5 mmol/L borate buffer (pH 8). The maleimide groups reacted specifically with the C-terminal of the sulfhydryl group of recombinant protein A to achieve highly selective fixation on both the agarose and PGMA substrates. The adsorption performance of the affinity materials for IgG was improved by optimizing the bonding conditions of protein A, such as the matrix type, matrix particle size, and protein A content, and the adsorption properties of each affinity material for IgG were determined. The column pressure of the protein A affinity materials prepared using agarose or PGMA as the matrix via the maleimide method was subsequently evaluated at different flow rates. The affinity materials prepared with PGMA as the matrix exhibited superior mechanical strength compared with the materials prepared with agarose. Moreover, an excellent linear relationship between the flow rate and column pressure of 80 mL/min was observed for this affinity material. Subsequently, the effect of the particle size of the PGMA matrix on the binding capacity of IgG was investigated. Under the same protein A content, the dynamic binding capacity of the affinity materials on the PGMA matrix was higher when the particle size was 44-88 μm than when other particle sizes were used. The properties of the affinity materials prepared using the multifunctional epoxy and maleimide-modified materials were compared by synthesizing affinity materials with different protein A coupling amounts of 1, 2, 4, 6, 8, and 10 mg/mL. The dynamic and static binding capacities of each material for bovine IgG were then determined. The prepared affinity material was packed into a chromatographic column to purify IgG from bovine colostrum. Although all materials showed specific adsorption selectivity for IgG, the affinity material prepared by immobilizing protein A on the PGMA matrix with maleimide showed significantly better performance and achieved a higher dynamic binding capacity at a lower protein grafting amount. When the protein grafting amount was 15.71 mg/mL, the dynamic binding capacity of bovine IgG was 32.23 mg/mL, and the dynamic binding capacity of human IgG reached 54.41 mg/mL. After 160 cycles of alkali treatment, the dynamic binding capacity of the material reached 94.6% of the initial value, indicating its good stability. The developed method is appropriate for the production of protein A affinity chromatographic materials and shows great potential in the fields of protein immobilization and immunoadsorption material synthesis.

Synthesis of Ethylenediamine Modified Chitosan Beads for Biodiesel Production Catalyst: A Preliminary Study

Biodiesel is an alternative fuel that can be easily produced through transesterification with the assistance of a catalyst. Palm oil is a widely utilized feedstock for biodiesel production due to its abundant availability. In this study, a catalyst was synthesized using chitosan (CS) modified with ethylenediamine (EDA) and cross-linked with epichlorohydrin (ECH) for a catalyst heterogeneous in transesterification reaction. The resulting product (CS/EDA/ECH) was characterized using Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Its performance was evaluated for biodiesel production. The CS/ECH/EDA catalyst achieved optimal reaction conditions with 5% EDA concentration at room temperature, an oil: methanol ratio of 1:1 (v/v), a total volume of 10 mL of oil and methanol, and a catalyst mass of 0.75 grams. The methyl esters formed corresponded to the fatty acid content in palm kernel, namely methyl palmitate, methyl 9,10-octadecadienoate, methyl oleate, methyl 12,13-tetradecadienoate, and methyl stearate with the highest methyl ester conversion is methyl oleate. The CS/ECH/EDA catalyst exhibited consistent performance after three use cycles.

A study on the photophysical properties of strong green-fluorescent N-doped carbon dots and application for pH sensing

Color tuneable effective pH sensor in both acidic and alkaline medium is important for environment and bioanalytical purpose. In this report, natural biomass derived N-doped fluorescent carbon dots are utilized as pH sensor. The fast microwave irradiation method was employed for synthesis using natural sweet lime juice extract. Ethylenediamine (EDA) was used for nitrogen doping with different amounts. The prepared N-doped carbon dots are comprehensively studied by various characterization methods to analyse the effect of dopant concentrations on photophysical and luminescence properties. Improved thermal stability from 900 °C to 1000 °C with EDA content is observed. The fluorescence spectra of prepared N-doped carbon dots exhibited stable green emission with high quantum yield 83 % under ultraviolet and 440 nm irradiation wavelengths for an optimal concentration of EDA. The color of emission confirmed by CIE plot and about 3.47 ns decay time is found by PL decay curve. The anti-photo bleaching ability and good photostability for 10 days are found. The prepared N-doped carbon dots exhibit high ionic stability and bio compatibility. Further, pH dependent color tuneable (green to yellow) emission spectra of prepared N-doped carbon dots displayed high fluorescence in acidic medium at pH -5. Although, emission was quenched and red shifted in alkaline medium. The effective pH-sensitivity, and good reversibility of fluorescent N-doped carbon dots samples were tested with real water samples having different pH values. The reasonable mechanism is discussed. It depicts the prepared N-doped carbon dots have potential to serve as pH sensor for physiochemical and bioanalytical measurements.

Enhanced adhesion of functional layers by controlled electrografting of ethylenediamine on ITO for electrochemical immunoassay in microfluidic channel.

Two-electrode (2E) system of the interdigitated electrode array (IDA), which operates neither reference nor counter electrodes, has great potential to miniaturize multiplex immunoassay in a microfluidic chip for point-of-care testing. However, it is necessary to firmly immobilize the mediator layer on IDA made of indium tin oxide (ITO) which is chemically inert. It is important because the mediator determines the electrochemical potential in the 2E system, but the layer is easy to be detached during the washing processes of immunoassay. Here, we controlled the concentration of ethylenediamine (EDA) to generate a permeable and robust film to adhere to mediators on the ITO IDA chip. Electrooxidation of EDA yielded thin oligomeric ethyleneimine (OEI) film and it provided amine groups for immobilizing the mediator, poly(toluidine blue) (pTB), via common conjugation reaction. Despite repeated flows in the microchannel, which are essential for sensitive immunoassay, the pTB/OEI layer was hardly washed and still remained on the ITO IDA. Myoglobin was measured down to∼pg/mL level. Therefore, the ITO IDA modified with the OEI film in the 2E system constituted a stable platform that withstands washing steps for sensitive electrochemical detection in the miniaturized immunoassay.

Impact of the Concentration Ethylenediamine on Optical Properties of Carbon Dots from Jengkol Peel (Archinendron pauciflorum)

Carbon dots (CDs) are a new member of fluorescent nano carbons that have attracted attention because of their potential applications derived from their optical, chemical, and electrical properties. CDs from jengkol peel via the solvothermal method at 200 oC for 7 h with the addition of ethylenediamine (EDA) as a heteroatom dopant have been successfully carried out. This study aims to determine the effect of concentration EDA on the optical properties of CDs for the possible reason. The results revealed that the CDs solution has fluorescence properties; that bluish-green glow can be observed under ultraviolet radiation (365 nm). The UV - Vis absorption peaks did not depend on the CDs concentration, but the absorbance intensity decreased with increasing EDA concentration. The best fluorescence properties were possessed by 10 % EDA in CDs which produced λex/λem of 370 nm / 518 nm, respectively, with a quantum yield of 42 %. The FTIR spectra of all samples showed that the CDs surface had functional groups such as carboxylic acids, hydroxyl, and amines. The obtained CDs have the potential to be used as heavy metal ion detectors, bioimaging, and antibacterial agents.

Silicon Wafer CMP Slurry Using a Hydrolysis Reaction Accelerator with an Amine Functional Group Remarkably Enhances Polishing Rate.

Recently, as an alternative solution for overcoming the scaling-down limitations of logic devices with design length of less than 3 nm and enhancing DRAM operation performance, 3D heterogeneous packaging technology has been intensively researched, essentially requiring Si wafer polishing at a very high Si polishing rate (500 nm/min) by accelerating the degree of the hydrolysis reaction (i.e., Si-O-H) on the polished Si wafer surface during CMP. Unlike conventional hydrolysis reaction accelerators (i.e., sodium hydroxide and potassium hydroxide), a novel hydrolysis reaction accelerator with amine functional groups (i.e., 552.8 nm/min for ethylenediamine) surprisingly presented an Si wafer polishing rate >3 times higher than that of conventional hydrolysis reaction accelerators (177.1 nm/min for sodium hydroxide). This remarkable enhancement of the Si wafer polishing rate for ethylenediamine was principally the result of (i) the increased hydrolysis reaction, (ii) the enhanced degree of adsorption of the CMP slurry on the polished Si wafer surface during CMP, and (iii) the decreased electrostatic repulsive force between colloidal silica abrasives and the Si wafer surface. A higher ethylenediamine concentration in the Si wafer CMP slurry led to a higher extent of hydrolysis reaction and degree of adsorption for the slurry and a lower electrostatic repulsive force; thus, a higher ethylenediamine concentration resulted in a higher Si wafer polishing rate. With the aim of achieving further improvements to the Si wafer polishing rates using Si wafer CMP slurry including ethylenediamine, the Si wafer polishing rate increased remarkably and root-squarely with the increasing ethylenediamine concentration.

Morphological variations of ZnO nanostructures and its influence on the photovoltaic performance when used as photoanodes in dye sensitized solar cells

Different hierarchical architectures of ZnO were synthesized via optimization of ethylenediamine (EDA) concentration in a simple low-temperature hydrothermal route and their various photoanode characteristics are effectively used in superior DSSC performance. In a sequence of morphological changes from the nanoparticles to nanorods and the nanoflowers structures, gradually and systematically, the zinc-interstitial and oxygen-vacancy related phases reduce, bandgap redshifts relative to its bulk structure, surface area increases and the dye-loading capacity improves. In photoanodes with ZnO nanoflower structures, the incident photon-to-current conversion efficiency gradually increases to ∼46.6% via significant photo-absorption by a larger number of dye-molecules adsorbed on its enhanced specific surface area and via its high dye-loading capacity that facilitate an amplified photogeneration of electrons upon light-exposure on the DSSC. Furthermore, the lowest charge transfer resistance and hence an improved charge transport pathway prevailing in the device consequences superior photovoltaic conversion efficiency (η) of the DSSCs, which gradually advances to ∼4.42%, via increasing the short-circuit current density (J SC ) to ∼10.75 mA cm −2 and the open-circuit voltage (V OC ) to 0.73 V. Morphological changes in the ZnO nanostructures are demonstrated to significantly influence the photovoltaic performance when used as an effective photoanode of the DSSCs, which has never been reported earlier. Highlights • Variety of ZnO nanostructures are synthesized, their striking features are ably used in photoanodes for superior DSSC activity. • Morphological changes from nanoparticle to nanorod to nanoflower sequentially reduce defects, bandgaps, increase surface area. • ZnO nanoflower photoanode with high dye-loading capacity gets good IPCE via better photocarrier generation by adsorbed dye-molecules. • Besides, the lowest charge transfer resistance facilitates superior photovoltaic conversion efficiency (η ∼4.42%). • ZnO in specific morphology significantly influences the PV performance when used as active photoanode in DSSCs.

Development of superhydrophobic and corrosion resistant coatings on carbon steel by hydrothermal treatment and fluoroalkyl silane self-assembly

Superhydrophobic polysiloxane coatings was prepared on the surface of carbon steel by combining the hydrothermal method and self-assembly. The results show that when the hydrothermal reaction time is 6 h, the temperature is 140 °C, and the ethylenediamine concentration is 3.00 mol L−1, the surface achieves super-hydrophobicity with a water contact angle of 152°. The rough regular octahedral and flower-like structures were formulated on the hydrothermal treat surface. The fluorosilane molecules are bonded to the surface of the carbon steel through Fe–O–Si bonds. The superhydrophobic coating with the thickness of 15–17 μm is dense and uniform. During the first 4 h of corrosion test in the simulated marine atmospheric environment, the superhydrophobic coating hindered the diffusion and migration of the corrosive medium on the metal interface, thus decreased the standard deviation of the current noise by 40%, increased the noise resistance by 5 times, showing a good corrosion resistance.

Kinetic and Thermodynamic Studies of Lysozyme Adsorption on Cibacron Blue F3GA Dye-Ligand Immobilized on Aminated Nanofiber Membrane.

The polyacrylonitrile (PAN) nanofiber membrane was prepared by the electrospinning technique. The nitrile group on the PAN nanofiber surface was oxidized to carboxyl group by alkaline hydrolysis. The carboxylic group on the membrane surface was then converted to dye affinity membrane through reaction with ethylenediamine (EDA) and Cibacron Blue F3GA, sequentially. The adsorption characteristics of lysozyme onto the dye ligand affinity nanofiber membrane (namely P-EDA-Dye) were investigated under various conditions (e.g., adsorption pH, EDA coupling concentration, lysozyme concentration, ionic strength, and temperature). Optimum experimental parameters were determined to be pH 7.5, a coupling concentration of EDA 40 μmol/mL, and an immobilization density of dye 267.19 mg/g membrane. To understand the mechanism of adsorption and possible rate controlling steps, a pseudo first-order, a pseudo second-order, and the Elovich models were first used to describe the experimental kinetic data. Equilibrium isotherms for the adsorption of lysozyme onto P-EDA-Dye nanofiber membrane were determined experimentally in this work. Our kinetic analysis on the adsorption of lysozyme onto P-EDA-Dye nanofiber membranes revealed that the pseudo second-order rate equation was favorable. The experimental data were satisfactorily fitted by the Langmuir isotherm model, and the thermodynamic parameters including the free energy change, enthalpy change, and entropy change of adsorption were also determined accordingly. Our results indicated that the free energy change had a negative value, suggesting that the adsorption process occurred spontaneously. Moreover, after five cycles of reuse, P-EDA-Dye nanofiber membranes still showed promising efficiency of lysozyme adsorption.

Hydrothermal synthesis of CeVO4 nanostructures with different morphologies for electrochemical hydrogen storage

In this paper, CeVO 4 nanostructures were produced with controlled hydrothermal method using hydrazine, cerium nitrate, and ammonium vanadate as reactants. Reaction control was performed utilizing hydrazine and ethylenediamine as new reactants. Other effective parameters such as solvent and surfactant were also carefully studied and optimized. The products were then identified through XRD, EDS, FTIR, FESEM, and BET analyses. FESEM results showed that by adjusting the concentration of ethylenediamine, hydrazine, and PVP surfactant, a rod-shaped morphology with suitable porosity could be created. Due to the high potential of CeVO 4 in electrochemical processes, it was first employed for electrochemical storage of hydrogen. The amount of hydrogen storage in nanostructures produced with rod-shaped morphology was about 2575 mAh/g, which is very significant compared to products obtained with sodium hydroxide with spherical morphology.

Kinetic and Thermodynamic Analysis of High-Pressure CO2 Capture Using Ethylenediamine: Experimental Study and Modeling

One of the alternatives to reduce CO2 emissions from industrial sources (mainly the oil and gas industry) is CO2 capture. Absorption with chemical solvents (alkanolamines in aqueous solutions) is the most widely used conventional technology for CO2 capture. Despite the competitive advantages of chemical solvents, the technological challenge in improving the absorption process is to apply alternative solvents, reducing energy demand and increasing the CO2 captured per unit of solvent mass. This work presents an experimental study related to the kinetic and thermodynamic analysis of high-pressure CO2 capture using ethylenediamine (EDA) as a chemical solvent. EDA has two amine groups that can increase the CO2 capture capacity per unit of solvent. A non-stirred experimental setup was installed and commissioned for CO2 capture testing. Tests of the solubility of CO2 in water were carried out to validate the experimental setup. CO2 capture testing was accomplished using EDA in aqueous solutions (0, 5, 10, and 20 wt.% in amine). Finally, a kinetic model involving two steps was proposed, including a rapid absorption step and a slow diffusion step. EDA accelerated the CO2 capture performance. Sudden temperature increases were observed during the initial minutes. The CO2 capture was triggered after the absorption of a minimal amount of CO2 (~10 mmol) into the liquid solutions, and could correspond to the “lean amine acid gas loading” in a typical sweetening process using alkanolamines. At equilibrium, there was a linear relationship between the CO2 loading and the EDA concentration. The CO2 capture behavior obtained adapts accurately (AAD < 1%) to the kinetic mechanism.

Hierarchically ordered macroporous TiO2 architecture via self-assembled strategy for environmental remediation

Hierarchical orderd macroporous TiO2 architecture (HOMTA) was prepared with aid of ethylenediamine (EDA) and investigated the impact of amine molecules on the properties of TiO2 architecture. The different variation of amine molecules (EDA) leads to tunning the morphology under hydrothermal approach which is confirmed by FESEM and TEM analysis. The XRD and Raman studies confirms the crystal structure of anatase and brookite phase of TiO2. The surface of the architecture strongly depended on the concentration of EDA which plays a vital role in surface area which is revealed by Brunauer Emmett-Teller (BET) analysis. The obtained HOMTA was employed as photocatalyst and active photoanode in the dye sensitized solar cells (DSSC). The DSSC device exhibits excellent efficiency (η) of 5.27% for the EDA capped TiO2 (S5) which had high surface area (167.11 m2/g) for better dye loading, whereas the lower concentration of EDA capped TiO2 (S1, S2, S3 and S4) resulted the efficiency of 2.14, 3.90, 3.25 and 4.37%, respectively. The efficiency of photocatlysis degradation of the prepared samples (S1, S2, S3, S4 and S5) was 94.8, 90.47, 91.41, 91.32 and 93.75% under light source. The excellent photocatalysis property was achieved by S5 within 6 min due to high surface area which inducing more active site.

Thin-film nanocomposite NF membrane with GO on macroporous hollow fiber ceramic substrate for efficient heavy metals removal

The ceramic membrane has been widely used in the wastewater treatment based on the chemical resistance and superior separation performance. A robust and defect-free thin-film nanocomposite (TFN) nanofiltration (NF) membrane on the macroporous hollow fiber ceramic (HFC) substrate was novelly developed for heavy metals removal. Before interfacial polymerization (IP), the aqueous solution of graphene oxide (GO) grafted with ethylenediamine (EDA) was deposited on the HFC substrate by vacuum filtration. Then, a thin polyamide (PA) film was fabricated by EDA and 1,3,5-trimesoyl chloride (TMC), followed by heat treatment. The effects of GO content and EDA concentration on the performance of the NF membrane have been systematically investigated. The results showed that when the GO content was 0.015 mg·mL−1 and the EDA concentration was 0.75 wt.%, the as-prepared eGO3/PA-HFC membrane had a rejection rate of 94.12% for MgCl2 and a pure water flux of 18.03 L·m−2·h−1. Additionally, the removal ability of eGO3/PA-HFC membranes for heavy metal ions was satisfactory (93.33%, 92.73%, 90.45% and 88.35% for Zn2+, Cu2+, Ni2+ and Pb2+, respectively). The study explored further that it was efficient and stable for heavy metal ions removal during 30 h in the simulated tap water and mining wastewater, which indicated that the eGO/PA-HFC membrane has great application potential in wastewater treatment.

Modeling and experimental studies on chemical absorption of sulphur dioxide with ethylenediamine-phosphoric acid solution in a θ-ring packed tower for purification of flue gas

In this paper, the main results of an experimental study on SO2 absorption in a bench-scale θ-ring packed tower using 0.3 mol·L−1 ethylenediamine-phosphoric acid solution was reported, and the effects of main technological parameters on the desulfurization efficiency were investigated. To uncover the mechanism behind the experimental observation, a one-dimensional model incorporated with equations of vapor-liquid equilibrium, heat, and mass transfer for simulating chemical absorption of SO2 with packed tower was also presented. Furthermore, the parameter distributions associated with heat and mass transfer characteristics along the absorber were also investigated. The results indicated that the relative errors of desulfurization efficiency between predicted and experimental values are less than 18.5% under different conditions and the model had depicted the tendency quite well. In addition, the desulfurization efficiency has positive correlation with increasing liquid-gas ratio, packing height, and ethylenediamine concentration, and declines with the increasing of inlet SO2 concentration, S(IV) concentration of lean amine, and operating temperature, respectively. Insights are given on the contribution of liquid chemistry reaction and interphase mass transfer on effective utilization of packing layer. Especially, enhancement factor and mass-transfer driving force along the absorber impact directly the SO2 absorption efficiency. Furthermore, the temperature rise has multiple effects on SO2 flux distribution, as mainly reflected in gradual accumulation of SO2(free) and decreasing of SO2 solubility in amine solution. This model can provide engineering guidance to design a packed tower as well as desulfurization process optimization.

Zn3V3O8 nanostructures: Facile hydrothermal/solvothermal synthesis, characterization, and electrochemical hydrogen storage

In this paper, a controlled hydrothermal method was employed to synthesize spherical-like Zn3V3O8 nanostructures. Reaction control was performed using hydrazine and ethylenediamine as new reactants. Other effective parameters such as solvent and surfactant were also carefully investigated and optimized, and the products were then identified by EDS, XRD, FTIR, and FESEM analyses. XRD results showed that Zn3V3O8 was formed using hydrazine while ZnO was the main product in the presence of NaOH, which is commonly utilized to produce metal oxides. SEM images showed that by adjusting the concentration of ethylenediamine and hydrazine, the morphology could be controlled by aggregating the nanoparticles to form uniform spherical structures with appropriate porosity. Owing to the high potential of Zn3V3O8 in electrochemical processes, it was used for electrochemical hydrogen storage for the first time, which exhibited a high power of 3325 m Ah/g after 20 cycles.

Inductively coupled plasma reactive ion etching of copper thin films using ethylenediamine/butanol/Ar plasma

The dry etching of copper thin films patterned with SiO2 hard masks was performed using an ethylenediamine (EDA)/butanol/Ar gas mixture. Ethylenediamine is an organic chelator that served as the main etching gas and butanol was used as an additive gas. As the concentrations of EDA and butanol in EDA/Ar and butanol/Ar increased, respectively, the etch rate of copper thin films decreased. The etch rate in EDA was less than that in butanol. However, a good etch profile of copper thin films was obtained with high EDA concentration in the EDA/Ar gas mixture, whereas high etch selectivity of copper was achieved from the butanol/Ar gas mixture. In the EDA/butanol/Ar gas mixture, the optimal ratio of EDA to butanol was investigated to increase the etch rate and improve the etch profile. The optical emission spectroscopy indicates that the main species in EDA were [CN] and [H], whereas in butanol, [H] was the main substance. The X-ray photoelectron spectroscopy reveals that copper reacted with [CN], [H], and [O] to form copper compounds that could be desorbed from the film surface by the sputtering of ions. The EDA/butanol/Ar gas mixture can be a good etch gas to dry-etch copper thin films.

Effective electron–hole separation over N‐doped TiO2 materials for improved photocatalytic reduction of 4‐nitrophenol using visible light

AbstractBACKGROUNDNitrogen‐doped titanium dioxide (TiO2) photocatalyst was synthesized successfully by a low temperature microwave‐assisted sol–gel method. Ethylenediamine was used as a source of nitrogen dopants to extend and improve the photoresponse of the materials to visible light. The photocatalysts were characterized by several techniques to determine the structural, textural and optical characteristics. The activity of the materials was tested in the photoreduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP) under visible light.RESULTSThe results indicate that nitrogen ions were substitutedly doped into oxygen sites of the TiO2 lattice, resulting in band gap narrowing, which significantly promotes the visible light absorption of TiEN catalysts. When initial ethylenediamine concentration was increased, the content of nitrogen dopant and optical absorption in the visible region increased. Moreover, it was found that TiEN photocatalyst significantly enhances the photoreduction of 4‐NP in comparison to the bare TiO2.CONCLUSIONThe increased photocatalytic activity of TiEN new materials are predominantly related to a lower energy gap, enhanced visible light absorption, higher reactive surface area and improved charge separation of photoinduced electron–hole pairs. © 2020 Society of Chemical Industry

Engineering the Synthesis of Luminescent Carbon Dots With Ultra High-Quantum Yield Using Experimental Design Approach in Order to Develop Sensing Applications

Carbon dots have been employed in a series of exciting fields such as bioimaging, drug delivery, fluorescent probing and analysis, photo-catalysis. Improving fluorescence performance of carbon dots could result in broadening their applications, especially, in sensing and bioimaging systems. The purpose of this study is to fabricate carbon dots by means of the hydrothermal method and designing an experiment in order to reach the highest quantum yield so as to develop their sensing and bioimaging applications. An experimental program was designed by taking into account factors effects on the quantum yield of carbon dots. The influencing variables to synthesize carbon dots in this project are citric acid concentration (F1), reaction temperature (F2), ethylenediamine concentration (F3) and reaction time (F4). By applying the experiment the quantum yield of carbon dots presents the maximum result of 85.69% at the optimal conditions of citric acid: 0.2 g, reaction temperature: 175°C, Ethylenediamine: $480~\mu \text{L}$ and reaction time: 4:43 h, which was the highest quantum yield from such carbon dots. These carbon dots have been applied as a fluorescence probe for Fe3+ ions determination with a perfect detection limit of 0.32 ppm. They were put to use for bioimaging of human ovarian carcinoma SKOV3 cells, which proved to be of outstanding biocompatibility.