Nitrate Trihydrate Research Articles

Hydrothermal Synthesis of Copper (II) Oxide Microparticle

CuO microparticle was syntheszied by hydrothermal method. The starting precursors were used as copper (II) nitrate trihydrate (Cu (NO3)2·3H2O), nitric acid (HNO3) and sodium hydroxide (NaOH). The final pH value of the mixed solution was used 2M NaOH to adjust the pH was 8 and treated at 100-200 oC for 4-6 h in a hydrothermal vessel. The black fine powder was obtained after dried at 100 oC for 5 h. The phase and structure of CuO microparticle were characterized by X-ray diffraction (XRD). A single phase monoclinic structure synthezied by hydrothermal method at 200 oC for 4 and 6 h was obtained without calcination steps. The morphology CuO microparticle was investigated by scanning electron microscopy (SEM). It was likely grain in shape and the particle size in range of 2.94-4.06 μm. The element composition of CuO microparticle was indicated by energy dispersive X-ray spectrometry (EDX). The chemical compositions showed the characteristic X-ray energy of copper (Kα = 0.98 keV) and oxygen (Kα = 0.53 keV), respectively. The functional group of CuO microparticle was indentified by Fourier transform spectrophotometry (FTIR). The wavenumber at 690, 514 and 437 cm-1 was corresponded to vibration of Cu-O stretching.

Synthesis, Characterization, and Anticancer Activity of Novel Macrocyclic Indenedione Based on the Tröger’s Base and N,N′-Disubstituted Phenhomazine Candidates

1,3-Indenedione has been reacted with p-aminobenzaldehyde to give the corresponding p-aminobenzylidine-1,3-indenedione, treatment of which with paraformaldehyde and trifluroacetic acid has led to the Troger’s base analogue. Treatment of that compound with dimethyl sulfate, acetic anhydride, benzoyl chloride, or trifluroacetic anhydride can afford the correspondingN,N′-disubstituted phenhomazines. Complexation of the Troger’s base with ferric nitrate trihydrate or nickel chloride hexahydrate has resulted in the corresponding complexes. The structures of all compounds have been confirmed by their elemental analyses and spectral data. All the newly synthesized Troger’s base and the derived N,N′-disubstituted phenhomazines have been tested for anticancer activity.

Comparison of Model Predictions and Performance Test Data for a Prototype Thermal Energy Storage Module

Abstract Although model predictions of thermal energy storage (TES) performance have been explored in previous investigations, relevant test data that enable experimental validation of performance models have been limited. This is particularly true for high-performance TES designs that facilitate fast input and extraction of energy. In this paper, we present a summary of experimental tests of a high-performance TES unit using lithium nitrate trihydrate phase change material as a storage medium. Performance data are presented for complete dual-mode cycles consisting of extraction (melting) followed by charging (freezing). These tests simulate the cyclic operation of a TES unit for asynchronous cooling in a variety of applications. The model analysis is found to agree reasonably well, within 10%, with the experimental data except for conditions very near the initiation of freezing, a consequence of subcooling that is required to initiate solidification.

Cyclic stability of lithium nitrate trihydrate in plate fin heat exchangers

Latent heat thermal energy storage systems based on hydrated salts are effective solutions for thermal management of transient thermal systems. Hydrated salts have relatively large specific and volumetric latent heat compared to paraffin phase change material. However, hydrated salts are not ubiquitous in energy storage systems because they exhibit inconsistent sub-cooling temperatures and tend to phase segregate due to incongruent melting which leads to degradation in the energy storage capacity. Here we demonstrate high stability of a congruently melting salt hydrate - lithium nitrate trihydrate, in a vacuum sealed plate-fin heat exchanger with water as heat transfer medium cycling between 40 °C and 20 °C, over 500 heating and cooling cycles. The specific latent heat of lithium nitrate trihydrate remained stable at 294 ± 37 J·g−1 and the sub-cooling temperatures increased only by 0.27 °C, demonstrating its stability in operational thermal energy storage systems.

Electrical and microstructure characteristics of SU8–Cu composite thin film fabricated using femtosecond laser direct writing

Through photo-patterning by a femtosecond laser direct writing on a spin-castable composite, this study presents a novel approach for fabricating highly conductive composite microstructures. Composite material was developed using SU8 (glycidyl ether of bisphenol A) and copper precursors, particularly copper (II) nitrate trihydrate and copper (II) chloride dehydrate. Copper was employed as the filler due to its excellent electrical conductivity and cost-effectiveness. The synthesized composite solution was first spin-coated on a substrate, and the dried thin film was then subjected to femtosecond laser direct writing to form pattern microstructures. Femtosecond laser irradiation induced two-photon absorption that led to polymerization of SU8, reduction of copper ions and sintering of copper particles. The resulting surface morphology of microstructures was affected by scanning speed, as low speed subsequently led to heat accumulation and ablation, while the line width was mainly determined by laser power. Electrical resistance decreases with the increase in scanning speed until an optimum scanning speed was achieved. On the other hand, as laser power increased, line width increased, while resistance decreased. Electrical conductivity of 365.5 S/m was achieved, which is a leap of advancement as compared to pure SU8 with conductivity of 10–14 S/m.

Phosphate Coatings Enriched with Copper on Titanium Substrate Fabricated Via DC-PEO Process.

The present paper covers the possible ways to fabricate advanced porous coatings that are enriched in copper on a titanium substrate through Direct Current Plasma Electrolytic Oxidation (DC-PEO) with voltage control, in electrolytes made of concentrated orthophosphoric acid with the addition of copper(II) nitrate(V) trihydrate. In these studies, solutions containing from 0 to 650 g salt per 1 dm3 of acid and anodic voltages from 450 V up to 650 V were used. The obtained coatings featuring variable porosity could be best defined by the three-dimensional (3D) parameter Sz, which lies in the range 9.72 to 45.18 μm. The use of copper(II) nitrate(V) trihydrate in the electrolyte, resulted, for all cases, in the incorporation of the two oxidation forms, i.e., Cu+ and Cu2+ into the coatings. Detailed X-Ray Photoelectron Spectroscopy (XPS) studies layers allowed for stating that the percentage of copper in the surface layer of the obtained coatings was in the range of 0.24 at% to 2.59 at%. The X-Ray Diffraction (XRD) studies showed the presence of copper (α-Cu2P2O7, and Cu3(PO4)2) and titanium (TiO2-anatase, TiO3, TiP2O7, and Ti0.73O0.91) compounds in coatings. From Energy-Dispersive X-Ray Spectroscopy (EDS) and XPS studies, it was found that the Cu/P ratio increases with the increase of voltage and the amount of salt in the electrolyte. The depth profile analysis by Glow-Discharge Optical Emission Spectroscopy (GDOES) method showed that a three-layer model consisting of a top porous layer, a semi-porous layer, and a transient/barrier layer might describe the fabricated coatings.

Synthon Robustness and Structural Modularity of Copper(II) Two-Dimensional Coordination Polymers with Isomeric Amino Acids and 4,4′-Bipyridine

Reactions of copper(II) nitrate trihydrate with 4,4′-bipyridine (bipy) and isomeric amino acids (aa) l-leucine or l-isoleucine were investigated under different solution-based and mechanochemical s...

Porous Coatings Containing Copper and Phosphorus Obtained by Plasma Electrolytic Oxidation of Titanium

To fabricate porous copper coatings on titanium, we used the process of plasma electrolytic oxidation (PEO) with voltage control. For all experiments, the three-phase step-up transformer with six-diode Graetz bridge was used. The voltage and the amount of salt used in the electrolyte were determined so as to obtain porous coatings. Within the framework of this study, the PEO process was carried out at a voltage of 450 VRMS in four electrolytes containing the salt as copper(II) nitrate(V) trihydrate. Moreover, we showed that the content of salt in the electrolyte needed to obtain a porous PEO coating was in the range 300–600 g/dm3. After exceeding this amount of salts in the electrolyte, some inclusions on the sample surface were observed. It is worth noting that this limitation of the amount of salts in the electrolyte was not connected with the maximum solubility of copper(II) nitrate(V) trihydrate in the concentrated (85%) orthophosphoric acid. To characterize the obtained coatings, numerous techniques were used. In this work, we used scanning electron microscopy (SEM) coupled with electron-dispersive X-ray spectroscopy (EDS), conducted surface analysis using confocal laser scanning microscopy (CLSM), and studied the surface layer chemical composition of the obtained coatings by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), glow discharge of optical emission spectroscopy (GDOES), and biological tests. It was found that the higher the concentration of Cu(NO3)2∙3H2O in the electrolyte, the higher the roughness of the coatings, which may be described by 3D roughness parameters, such as Sa (1.17–1.90 μm) and Sp (7.62–13.91 μm). The thicknesses of PEO coatings obtained in the electrolyte with 300–600 g/dm3 Cu(NO3) 2∙3H2O were in the range 7.8 to 10 μm. The Cu/P ratio of the whole volume of coating measured by EDS was in the range 0.05–0.12, while the range for the top layer (measured using XPS) was 0.17–0.24. The atomic concentration of copper (0.54–0.72 at%) resulted in antibacterial and fungicidal properties in the fabricated coatings, which can be dedicated to biocompatible applications.

Photocatalytic Activity of Cu-based Nanoparticles Synthesized by Glycine-Nitrate Combustion Technique

The copper based nanoparticles was synthesized by glycine-nitrate process (GNP), using copper nitrate trihydrate [Cu(NO3)2 · 3H2O] as main starting materials and glycine [C2H5NO2] as complexant and incendiary agent. The as-prepared powders were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. Results of the photocatalytic degradation of Nonylphenol polyethoxylates (NP9EO) in a custom-made photoreactor indicated that the maximum degradation (more than 94% and 70% TOD removal) of NP9EO occurred with CuO+Cu2O composite catalyst (dosage of 0.3 g/L) when a combination of ultraviolet (UV) irradiation for 600 min, and a heterogeneous system was used.

Solvation and diffusion of poly(vinyl alcohol) chains in a hydrated inorganic ionic liquid.

While the behavior of polyelectrolyte chains in aqueous salt solutions has been extensively studied, little is known about polar polymer chains in solvents with extremely high concentrations of inorganic ions, such as those found in ionic liquids (ILs). Here, we report on expansion, solvation and diffusion of poly(vinyl alcohol), PVA, chains in dilute solutions of a hydrated inorganic IL phase change material (PCM), lithium nitrate trihydrate (LNH). This solvent has an extremely high concentration of inorganic ions (≈18 M) with a low concentration of water molecules largely forming solvation shells of Li+ and NO3- ions, as shown using ATR-FTIR spectroscopy. Diffusion and hydrodynamic size of PVA chains of different molecular weights in this unusual solvent were studied using fluorescence correlation spectroscopy (FCS). A higher scaling exponent obtained from the molecular weight dependences of the diffusion coefficients of PVA chains as well as a lower overlap concentration (c*) of PVA in LNH solutions as measured by FCS suggest an expansion of the polymer coils in this solvent. We argue that enhanced solubility of PVA in LNH solutions is likely a result of increased rigidification of polymer chains due to the binding of solvated Li+ ions, which is demonstrated using 7Li NMR spectroscopy. We believe that an understanding of solvation and ion-binding capability can offer crucial insight into designing polymer-based shape stabilization matrices for inorganic PCMs.

Characterization of Sol-gel Prepared Silica Supported NiO-CuO Composites

Silica (SiO2) supported nickel oxide-copper oxide (NiO-CuO) composites were synthesized through alkoxide route of sol-gel process using tetraethyl ortthosilicate (TEOS), nickel nitrate hexahydrate and copper nitrate trihydrate as precursors. A series of different compositions were prepared varying NiO:CuO molar ratios keeping all other process parameters constant. The gels thus obtained were calcined at a moderate temperature i.e. 500and#186;C for one hour. The crystal structure and thermal stability of metal oxide particles embedded in silica matrix were studied using X-ray diffraction technique (XRD) and differential scanning calorimetry (DSC-TGA) respectively. The purity of the composites was checked by Infrared spectroscopy (IR) whereas the composite formation was confirmed by scanning electron microscopy. The results revealed that crystals of NiO and CuO nanoparticles aggregated to form spheres of variable sizes were successfully embedded in the amorphous silica matrix composed of silica particles agglomerated to form clusters.

Characterization of Sol-gel Prepared Silica Supported NiO-CuO Composites

Silica (SiO2) supported nickel oxide-copper oxide (NiO-CuO) composites were synthesized through alkoxide route of sol-gel process using tetraethyl ortthosilicate (TEOS), nickel nitrate hexahydrate and copper nitrate trihydrate as precursors. A series of different compositions were prepared varying NiO:CuO molar ratios keeping all other process parameters constant. The gels thus obtained were calcined at a moderate temperature i.e. 500and#186;C for one hour. The crystal structure and thermal stability of metal oxide particles embedded in silica matrix were studied using X-ray diffraction technique (XRD) and differential scanning calorimetry (DSC-TGA) respectively. The purity of the composites was checked by Infrared spectroscopy (IR) whereas the composite formation was confirmed by scanning electron microscopy. The results revealed that crystals of NiO and CuO nanoparticles aggregated to form spheres of variable sizes were successfully embedded in the amorphous silica matrix composed of silica particles agglomerated to form clusters.

Fabrication of ultrafine W-Cu composite powders and its sintering behavior

Ultrafine W-Cu composite powders with various copper (Cu) contents (5, 20 and 40 wt.%) have been fabricated by a method consisting of a carbothermic pre-reduction step and a subsequent hydrogen reduction step. After roasting the mixture of ammonium tungstate ((NH4)10[H2W12O42]·xH2O) and copper nitrate trihydrate (Cu(NO3)2·3H2O), the mixture of CuWO4 and CuO (or WO3) was obtained. Subsequently, this mixture was pre-reduced by insufficient carbon black to generate the products containing W, Cu and a small amount of WO2 which was further reduced to W in the following hydrogen reduction process. Thus, the ultrafine W-Cu composite powders were successfully produced. After sintering the green compacts made of these powders at 1100 ℃, 1150 ℃, 1200 ℃ and 1250 ℃, respectively, the microstructure, relative densities, electric conductivity and thermal conductivity of the sintered alloys were measured. The experimental results indicated that the higher the sintering temperature is, the better the performance of alloys will be.

Photodegradation of Methylene Blue Dye Using Nanocomposites of Copper Sulfide Doped with Fe/Cd/Zr as Nanophotocatalyst

Objectives: To characterize and to know the nature of the synthesized products and identify the photocatalytic response of the hybrid nanocomposites was investigated by the decolourization of (MB) dye under natural Sunlight radiation. Methods/statistical analysis: We report fabrication of mesoporous nanocomposites (Fe–CuS, Cd–CuS, Zr–CuS) with uniform nanostructures via a hydrothermal method employing copper nitrate trihydrate (Cu (NO3).3H2O), Thiourea (Tu,Sc(NH2)2, Iron trinitrate (Fe(No3)3), (Cd(No3)3) and (Zr(No3)3) as starting materials with cationic surfactant cetyltrimethylammonium bromide (CTAB) as stabilizer/ size controller and ethylene glycol as solvent at 130˚C temperature. The products were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy TEM, and UV-Vis spectrum (UV) analysis. Findings: X-ray diffraction (XRD) spectra confirmed the Fe doped copper sulfide nanocomposites are crystalline in nature with the hexagonal CuS phase. XRD pattern showed Fe doped spherical structure of CuS with a grain size of 21 nm. An intense surface Plasmon resonance between 250–300 nm in the UV–Vis spectrum clearly reveals the formation of Fe doped copper sulfide nanocomposites. The XRD pattern of Cd incorporated CuS shows crystallite nature and crystallinity increases with the addition of cadmium on CuS. The observed results show that Zr is homogeneously dispersed on CuS and well separated from one another. The XRD results confirm the presence of well-dispersed cubic ZrS2 on the covellite CuS surface. Photo reactivity of copper sulfide nanoparticles as undoped and doped with ferrous, cadmium and Zirconium were studied in the decolorization of methylene blue under natural sunlight. The concentration of dopants and concentration of dye are variables that influence the photoreactivity of nanocatalysts. Application/improvements: The prepared nanoparticles CuS, Fe–CuS, Cd–CuS and Zr–CuS show the most degradation efficiency. The optimum dosage of the photocatalyst was 120 mg/L. In the optimized conditions, the degradation efficiency was 86–95% for methylene blue in irradiation time of 150 min.Keywords: Nanophotocatalyst, Copper Sulfide, Methylene Blue, Photodegradation.

Hydrothermally Grown Copper-Doped ZnO Nanorods on Flexible Substrate

In this study, we observe the effect of Cu doping on the ZnO nanorod (NR) structure grown on a polyethylene terephthalate flexible substrates by hydrothermal growth of sol–gel method proceeded at 150 °C. Copper (II) nitrate trihydrate (Cu-nitrate) and copper (II) acetate monohydrate (Cu-acetate) are employed as precursors for Cu dopants in aqueous growth solution to examine the evolutionary change of the growth morphology, optical characteristics, and chemical composition of as-grown ZnO NRs. A significant influence of dopant molarity on the morphology of wurtzite ZnO nanocrystals is observed by field-emission scanning electron microscopy. X-ray diffraction analysis also reveals more enhanced crystalline quality from Cu-doped NR crystals prepared by Cu-acetates than that grown with Cu-nitrate precursor. Near band-edge emission of 2 mM Cu-acetate doped NRs is greatly enhanced by 2.5 times compared to those grown with Cu-nitrate precursors. A great reduction in visible emissions is also realized, and this phenomenon is associated with overall improvement in NR crystalline quality by suppressing the oxygenated carbon groups or hydroxyl introduced by the aqueous solution-based growth. X-ray photoelectron spectroscopy also shows that a very high O/Zn atomic ratio of 0.73 can be achieved in the case of NR crystals prepared by 2 mM Cu-acetate. Cu doped ZnO nanostructures of improved optical and structural properties achieved in this study can be utilized in the wide emerging field of flexible device applications such as laser diodes, light-emitting diodes, piezoelectric transducers and generators, gas sensors, and ultraviolet detectors.

Study of structural features and antibacterial property of ZnO/CuO nanocomposites derived from solution combustion synthesis

ZnO/CuO nanocomposite was synthesized by solution combustion method using three organic fuels - EDTA, Citric Acid and Oxalic Acid with Zinc Nitrate Hexahydrate and Copper Nitrate Trihydrate as precursors. ZnO/CuO nanocomposite was characterised for PXRD, SEM and EDAX to analyse the Structural, Morphological properties and Elemental composition. Crystallite size of 13.82 nm was found for the ZnO/CuO nanocomposites prepared from Oxalic Acid (OA). Further, ZnO/CuO nanocomposites synthesised from three different metal nitrate weight ratios (25:75, 45:55 and 65:35) using OA as fuel and Antibacterial studies was carried out on E.coli by disc diffusion method. PXRD results confirm that the nanocomposites prepared were in nano domain with the average crystallite size was found to be in the range of 13–21 nm. SEM micrographs of ZnO/CuO nanocomposites showed hexagonal ZnO and spherical CuO particles and the particle size was found to be in the range of 30–60 nm. EDAX results confirmed the presence of four elements namely C, O, Cu and Zn. Antibacterial studies showed that the inhibition zone of the nanocomposite was maximum (24 mm for 20 μL) for the sample having high concentration of ZnO nanoparticles and it depends on the crystallite size of the ZnO/CuO nanocomposite.

Preparation and characterization of nanostructure CuS for biological activity

Nanostructure copper sulfide derived from copper nitrate trihydrate precursors have been prepared by hydrothermal route with three different time reactions. All prepared samples were inspected by X-ray diffraction (XRD), zeta potential, field emission scanning electron microscopy (FE-SEM), Fourier transforms infrared (FTIR) spectroscopy and UV-Vis spectrophotometer. XRD patterns show that all samples have confirmed the formation of the hexagonal phase. Absorbance spectra were measured using UV-Vis spectrophotometer. The optical band gap energy of CuS nanostructure also decreased as the reaction time increased. In particular, their optical band gap energies were 3.25, 3.2 and 3.1 eV for 5, 15 and 25 h, respectively. Antibacterial activity of CuS nanostructure against S. aureus, P. aeruginosa and E. coli was evaluated by a zone of inhibition. The test revealed the minimum concentration of CuS nanostructure has very strong antibacterial activity against gram-positive than for gram-negative. Anticancer treatment was applied based on employing CuS nanostructure by exploiting their unique morphological and optical properties as therapeutic agents against Murine fibroblast (L20B) and Rhabdomyosarcoma (RD) cancer cell lines without using laser. Cytotoxicity effect was evaluated by MTT assay; results demonstrated that CuS nanostructure for 15 h exhibits more toxicity effect than for 5 h and 25 h for all particles concentration, where as cytotoxicity reaches 100% at 0.5 mg/ml, the most influential concentration, at which it could be a promising agent for cancer treatment.

Activation Energy for Dissociation of Hydrogen‐Bonding Crosslinkers in Phase‐Change Salogels: Dynamic Light Scattering versus Rheological Studies

AbstractDissociation energy of dynamic bonds in thermoresponsive phase‐change salogels is explored using rheology and dynamic light scattering (DLS). The salogels are formed by polyvinyl alcohol (PVA) reversibly crosslinked by hydrogen‐bonding amine‐terminated molecules in an inorganic phase‐change material—lithium nitrate trihydrate (LNH) salt—as a solvent. The crosslinker geometry (linear vs branched) has a strong effect on both the gelation temperature (Tgel) and the crosslinker to polymer ratio at which the gelation occurs. Due to their higher functionality, dendritic crosslinkers are more efficient gelators as compared to their linear counterparts, inducing PVA gelation at a lower concentration of a crosslinker and resulting in salogels with higher Tgel. Both stress relaxation and DLS data can be fitted by the exponential functions with temperature‐independent exponents of ≈0.5 and 2, respectively. For the first time, it is reported that the crosslinker dissociation activation energy determined from the rheological stress relaxation time and DLS slow mode decay time are in very good agreement, comprising ≈130–140 kJ mol−1 for salogels with both linear and dendritic crosslinkers.

Preparation of Ultrafine W-10 Wt Pct Cu Composite Powders and Their Corresponding Sintered Compacts

We propose a process to produce ultrafine W-10 wt pct Cu composite powders by reducing the mixtures of copper tungstate (CuWO4) and tungsten trioxide (WO3) (from the calcination of a mixture of ammonium paratungstate and copper nitrate trihydrate) with carbon black and hydrogen. First, ultrafine pre-reduced tungsten-copper (W-Cu) powders containing a small amount of WO2 were produced by reducing mixtures of CuWO4 and WO3 with insufficient carbon black; then the obtained products were further reduced by hydrogen to remove the residual oxygen. This method provides a simple and low-cost route to prepare ultrafine W-10 wt pct Cu composite powders. The composite powders were sintered at different temperatures [1323 K (1050 °C), 1373 K (1100 °C), 1423 K (1150 °C), 1473 K (1200 °C), and 1523 K (1250 °C)] for 3 hours. A maximum densification of the obtained compact was achieved at a sintering temperature of 1523 K (1250 °C), with a relative density, Vickers hardness and thermal conductivity of the W-10 wt pct Cu composites of 97.8 pct, 365 HV and 165 W/m K, respectively.

The effects of thioacetamide/copper molar ratio and reaction time on the phase evolution, morphology, optical, and photocatalytic properties of the nanosheets‐based flower‐like copper sulfide

AbstractIn this paper, various morphologies including spherical and flower‐like nanosheets‐based CuS were synthesized by the green hydrothermal synthesis method. Copper (II) nitrate trihydrate and thioacetamide (TAM) were selected as a Cu2+ and sulfur source, respectively. The effects of TAM/Cu molar ratio and reaction time on the phase and morphological evolution of the samples were studied. For this purpose, the samples were distinguished by FT‐IR, FE‐SEM, XRD, and ultraviolet‐visible spectroscopy. The photocatalytic and optical properties of the products were evaluated. It was found that self‐organized nanoflower(SONF) structures exhibit very good photocatalyst efficiency to degrade organic dye due to a significant increase in their surface area because of decorated nanosheets on the sample. Therefore, the SONF structures exhibited a very suitable potential as the photocatalyst agents.