CuCl2 Concentration Research Articles

Biocompatible and hydrophilic copper-complexed polyvinyl alcohol coating for antifogging surfaces

Visibility is decreased when fog accumulates on the clear surface of optical devices. It is quite desirable to design the surface with antifogging properties. The current study used a dip coating process to prepare copper-incorporated polyvinyl alcohol (PVA) hydrophilic coating on the hydroxylated glass substrate. The formation of the PVA-Cu complex by the hydroxyl group was determined by FTIR and XPS methods. The surface morphology, adhesion test, wettability behavior, and cytotoxicity were investigated by SEM, cross-cut tape, contact angle measurement, and MTT experiment. By varying the CuCl2 concentration (0.0125–0.0625 M), the durability and adhesion of the coating were improved, as evidenced by its minimal mass loss and water uptake. The optimum coating condition showed a thickness of about 24.0 ± 0.7 μm and a good optical transmittance of over 90 %. Below 0.0375 M, the coating stability and water resistance could not be achieved due to the weak complexation of Cu with the PVA coating. In contrast, the PVA-Cu3 coating (0.0375 M, Cu2+ ions) was identified as an optimized condition for improved antifogging performance due to the effective complexation of Cu with the PVA matrix while maintaining the hydrophilicity and wettability behavior. Furthermore, no cytotoxicity was observed by L929 cell lines in response to the prepared coating. The current study results revealed that the adhesive, hydrophilic PVA-Cux coating with a contact angle of less than 62° might demonstrate strong antifogging properties and find its usage for endoscopic applications.

Functionalisation of the Aluminium Surface by CuCl2 Chemical Etching and Perfluoro Silane Grafting: Enhanced Corrosion Protection and Improved Anti-Icing Behaviour

This study aimed to prepare a facile hierarchical aluminium surface using a two-step process consisting of chemical etching in selected concentrations of CuCl2 solution and surface grafting through immersion in an ethanol solution containing 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane. The goal was to achieve superhydrophobic characteristics on the aluminium surface, including enhanced corrosion resistance, efficient self-cleaning ability, and improved anti-icing performance. The surface characterisation of the untreated aluminium and treated in CuCl2 solutions of different concentrations was performed using contact profilometry, optical tensiometry, and scanning electron microscopy coupled with energy dispersive spectroscopy to determine the surface topography, wettability, morphology, and surface composition. The corrosion properties were evaluated using potentiodynamic measurements in simulated acid rain solution and salt-spray test according to ASTM B117-22. In addition, self-cleaning and anti-icing tests were performed on superhydrophobic surfaces prepared under optimal conditions. The results showed that the nano-/micro-structured etched aluminium surface with an optimal 0.5 M concentration of CuCl2 grafted with a perfluoroalkyl silane film achieved superhydrophobic characteristics, with water droplets exhibiting efficient corrosion protection, self-cleaning ability, and improved anti-icing performance with decreased ice nucleation temperature and up to 545% increased freezing delay.

Influence of copper ion cross-linked CMC-PVA film on cell viability and cell proliferation study

In this study, films composed of carboxymethyl cellulose and polyvinyl alcohol were fabricated using the solution casting method. Citric acid (4 %) was employed as a cross-linking agent, while glycerol (3 %) as a plasticizer. Cupric chloride (CuCl2·2H2O) was used for cross-linking at concentrations 0.5 %, 1 %, and 3 % over different times. The cross-linking with copper ions led to a noticeable reduction in elasticity, with the breaking strain ranging from 17.9 %–52.9 %. The ion hydration phenomenon increased the contact angle and swelling ratio. Fourier-transform infrared (FTIR) spectroscopy confirmed esterification reactions and copper ion cross-linking with sodium carboxymethyl cellulose (Na-CMC). The films showed antibacterial activity against Staphylococcus aureus and Escherichia coli. The ion-released mechanism followed was the non-Fickian super case-II type. The concentration and duration of cross-linking significantly influenced cell viability and proliferation. FE-SEM analysis revealed that effective concentrations of CuCl2.2H2O were 0.5 % and 1 %, and cross-linking times were 5–15 min, facilitating cell attachment and proliferation. Films are non-adhesive with water vapor permeation 800–900 g/m2/day. These results indicate the potential use of the films in treating second-degree burn wounds with low to medium exudate levels. This study provides valuable insights into the development of copper-infused materials for advanced wound healing applications.

Effect of Copper Chloride on Phase Structure and Properties of Synthesized Materials from Flue Gas Desulfurization Gypsum

This research investigates the influence of crystal modifying agent, copper chloride (CuCl2) (0.3, 0.45, and 0.6 g), on the phase structure and characteristics of materials derived from flue gas desulfurization (FGD) gypsum. The raw material underwent hydrothermal transformation with 0.01 M H2SO4 at 90°C for 1 hour. XRD analysis revealed a notable shift in phase structure from hexagonal calcium sulfate dihydrate (DH) in FGD gypsum to monoclinic calcium sulfate hemihydrate (alpha-HH) up to 91%in the synthesized products, with an increasing CuCl2 content. SEM analysis revealed the elongated whisker-shaped particles (110.70 µm to 207.90 µm) of alpha-HH with higher CuCl2 concentrations. Specifically, when incorporating 0.6 g of CuCl2 in 0.01 M H2SO4 at 90°C, the longest alpha-HH crystals resulted in the cast plaster with the highest flexural strength of approximately 4.92 MPa, demonstrating suitability for applications requiring sufficient mechanical strength. Thermal analysis confirmed the complete conversion of the solid phase to alpha-HH at 1200°C. Additionally, the study revealed that higher CuCl2 content led to shorter setting time. These results suggest potential applications of the present synthesized materials from FGD gypsum in industries such as ceramics casting and dental materials, where precise control over material properties is critical.

Hexyltrimethylammonium ion enhances potential copper-chelating properties of ammonium thiomolybdate in an in vivo zebrafish model

Ammonium and hexyltrimethylammonium thiomolybdates (ATM and ATM-C6) and thiotungstates (ATT and ATT-C6) were synthesized. Their toxicity was evaluated using both in vitro and in vivo approaches via the zebrafish embryo acute toxicity assay (ZFET), while the copper-thiometallate interaction was studied using cyclic voltammetry, as well as in an in vivo assay. Cyclic voltammetry suggests that all thiometallates form complexes with copper in a 2:1 Cu:thiometallate ratio. Both in vitro and in vivo assays demonstrated low toxicity in BALB/3T3 cells and in zebrafish embryos, with high IC50 and LC50 values. Furthermore, the hexyltrimethylammonium ion played a crucial role in enhancing viability and reducing toxicity during prolonged treatments for ATM and ATT. In particular, the ZEFT assay uncovered the accumulation of ATM in zebrafish yolk, averted by the incorporation of the hexyltrimethylammonium ion. Notably, the copper-thiometallate interaction assay highlighted the improved viability of embryos when cultured in CuCl2 and ATM-C6, even at high CuCl2 concentrations. The hatching assay further confirmed that copper-ATM-C6 interaction mitigates inhibitory effects induced by thiomolybdates and CuCl2 when administered individually. These results suggest that the incorporation of the hexyltrimethylammonium ion in ATM increase its ability to interact with copper and its potential application as a copper chelator.

Molecular Dynamics Simulation of the Interaction within the Carboxymethyl Cellulose-Modified Montmorillonite Lamellae at Aggressive CuCl2 Concentrations.

To elucidate the degradation mechanism of the CMC-modified MMT composite at aggressive Cu2+ concentrations, large scale molecular dynamics simulation was conducted for CuCl2 concentrations ranging from 0 to 800 mM. Both CMC and MMT followed the Langmuir isotherm for Cu2+ adsorption, and the adsorption capacity of CMC (8.75 mmol/g) was much higher than that of MMT (0.83 mmol/g). Despite the CMC mass ratio being only 4.1%, it adsorbed up to 34.3% of the total adsorbed Cu2+. The Cu2+ attraction ability hierarchy of oxygen-containing functional groups in the CMC is as follows: carboxylic oxygens > alcoholic oxygens > carbinolic oxygens > bridging oxygens > glucose oxygens. Carboxyls were the most effective in chelating and complexing with Cu2+, and they could be intentionally added in artificially synthesized polymer-MMT composites for Cu2+ containment. Formation of the Cu2+ cation bridge between CMC and MMT at aggressive CuCl2 concentrations contributed to the transition of CMC density distribution from unimodality to bimodality and enhanced resistance of polymer elution. As the CuCl2 concentration increased, the stoichiometric ratio between the chelated Cu2+ and carboxylic oxygens increased from 1:2 to 1:1, suggesting the evolution of the Cu2+ chelation mechanism.

Embryo growth alteration and oxidative stress responses in germinating Cucurbita pepo seeds exposed to cadmium and copper toxicity

This study investigated the influence of cadmium (Cd) and copper (Cu) heavy metals on germination, metabolism, and growth of zucchini seedlings (Cucurbita pepo L.). Zucchini seeds were subjected to two concentrations (100 and 200 μM) of CdCl2 and CuCl2. Germination parameters, biochemical and phytochemical attributes of embryonic axes were assessed. Results revealed that germination rate remained unaffected by heavy metals (Cd, Cu). However, seed vigor index (SVI) notably decreased under Cd and Cu exposure. Embryonic axis length and dry weight exhibited significant reductions, with variations depending on the type of metal used. Malondialdehyde and H2O2 content, as well as catalase activity, did not show a significant increase at the tested Cd and Cu concentrations. Superoxide dismutase activity decreased in embryonic axis tissues. Glutathione S-transferase activity significantly rose with 200 μM CdCl2, while glutathione content declined with increasing Cd and Cu concentrations. Total phenol content and antioxidant activity increased at 200 μM CuCl2. In conclusion, Cd and Cu heavy metals impede zucchini seed germination efficiency and trigger metabolic shifts in embryonic tissue cells. Response to metal stress is metal-specific and concentration-dependent. These findings contribute to understanding the intricate interactions between heavy metals and plant physiology, aiding strategies for mitigating their detrimental effects on plants.

Determination of Lorenz number of composite films based on copper chloride(II) in polyvinyl alcohol matrix

The electrical and thermal conductivities as well as Lorenz number of polyvinyl alcohol (PVA) composites have been investigated at different concentrations of the copper chloride II (0, 1, 3, 5, 7 and 12 wt-%). The powder of copper chloride II (CuCl2) was casted with the PVA polymer1. The electrical conductivity was measured by using the impedance technique, and it was studied as functions of the CuCl2 concentrations, applied frequency range of 100–7000 kHz, and temperature range of 30–100 °C. The activation energy ( Ea) was also determined for all the studied samples at applied frequency of 1000 kHz. It was found that the Ea decreased with increasing the CuCl2 concentration. Moreover, the thermal conductivity of the samples was studied as functions of the CuCl2 concentration and temperature. It was found that the thermal conductivity increased with increasing the CuCl2 concentrations and temperature. Using the measured values of the thermal and electrical conductivities of the studied samples, the relationship between the Lorenz number ( L) of the PVA and CuCl2 concentrations with constant temperature was also studied based on the Wiedemann–Franz law. The results showed that the L number increased with CuCl2 concentrations increase at constant temperature.

Effect of heavy metals on phenylpropanoid biosynthesis in Euonymus alatus

The productivity of the phenylpropanoid biosynthesis pathway in plants varies depending on the type of stress. In this work, we looked into how different phenylpropanoid chemicals accumulated in Euonymus alatus following exposure to different concentrations of CuCl2 (0.1, 0.5, and 1 mM), HgCl2 (0.1, 0.5, and 1 mM), and NiSO4 (10, 50, and 100 mM). We analyzed some of the individual phenolic chemicals by high-performance liquid chromatography (HPLC). In nearly all cases, rutin showed the largest concentration among the phenylpropanoid chemicals, followed by epicatechin, sinapic acid, p-coumaric acid, trans-cinnamic acid, ferulic acid, and caffeic acid. However, due to the change in the concentration of the heavy metals, the amount of phenylpropanoid changed. The highest accumulation of phenylpropanoid was documented in 0.1 mM CuCl2, whereas it was reduced in 1 mM HgCl2 exposed plants. These findings unequivocally demonstrate that the phenylpropanoid metabolic pathway took part in the heavy metal tolerance process, which shielded E. alatus from the oxidative damage brought on by heavy metals. Thus, under a variety of environmental stress situations, this species with a high tolerance to heavy metals may survive.

Cu Tailoring Pt Enables Branched-Structured Electrocatalysts with High Concave Surface Curvature Toward Efficient Methanol Oxidation.

Surface engineering offers opportunities for the design and synthesis of Pt-based alloyed electrocatalysts with high mass activity and resistance to CO poisoning, which is of great significance for methanol electrooxidation. Surface curvature regulation may endow electrocatalysts with enhanced atomic utilization and abundance of unsaturated atoms; however, a reliable synthetic route for controlled construction of tailorable curved surface is still lacking. Here, a colloidal-chemical method to synthesize two types of PtCu branched-structured electrocatalysts, where the concave curvature can be customized is reported. These studies show that, among various synthesis parameters, the concentration of CuCl2·2H2O precursor is the key factor in manipulating the reaction kinetics and determining the concave surface curvature. Significantly, PtCu branched nanocrystals with long and sharp arms (PtCu BNCs-L), featuring a high concave surface curvature, exhibit remarkable activity and stability toward MOR, which is mainly attributed to advanced features of a highly concave surface and the synergistically bifunctional effect from introduced oxophilic Cu metal. In situ Raman spectroscopy and CO stripping test demonstrates weakened CO adsorption and accelerated CO removal on PtCu BNCs-L. This work highlights the importance of surface curvature, opening up an appealing route for the design and synthesis of advanced electrocatalysts with well-defined surface configurations.

Investigations on CuCl/HCl Electrolysis Using a Pt/C Electrocatalyst-based Membrane Electrode Assembly

The study reports the fabrication and performance evaluation of a Pt/C(Electrocatalyst) (20 wt% Pt)/Nafion MEA as cathode for CuCl/HCl electrolysis in a PEM-based electrolyser with an active area of ∼4 cm2. The electrolyser is indigenously developed consisting of graphite plates with serpentine fluid flow channels grooved. The anode half-cell reaction i.e. Cu+ oxidation is investigated by electrochemical (LSV, CV, EIS) methods, and I-V characteristics. An oxidation peak for Cu+ to Cu2+ is observed at a cell voltage of ∼0.55 V in the LSV curve recorded at 20 mVs−1 in the electrolyser with an anolyte of 0.2 M CuCl in ∼2 M HCl flowing at 2.2 ml min−1. The effect of the concentration of CuCl in the anolyte and its flow rate is also studied. A current density of ∼128 mAcm−2 is attained for CuCl/HCl electrolysis at a cell voltage of 1 V with an anolyte of 0.4 M CuCl in ∼4 M HCl flowing at 8.8 ml min−1. Further, a model showing the working of the above electrolyser is generated using COMSOL 6.0. Higher concentration of CuCl in the anolyte and higher anolyte flow rates favoring the electrolysis is evident from electrochemical characterizations.

Immunotoxic effects of exposure to the antifouling copper(I) biocide on target and nontarget bivalve species: a comparative in vitro study between Mytilus galloprovincialis and Ruditapes philippinarum.

Edible bivalves constitute an important bioresource from an economic point of view, and studies on their immune responses to environmental pollutants are crucial for both the preservation of biodiversity and economic reasons. The worldwide diffusion of copper(I)-based antifouling paints has increased copper leaching into coastal environments and its potential impact on both target and nontarget organisms. In this study, immunotoxicity assays were carried out with short-term (60min) cultures of hemocytes from the bivalves Mytilus galloprovincialis-a mussel dominant in the macrofouling community-and Ruditapes philippinarum-a clam dominant in the soft-sediment community-exposed to CuCl to compare the toxic effects on their immune responses. The LC50 values were similar, 40μM (3.94mgL-1) for the mussel and 44μM (4.33mgL-1) for the clam. In both species, apoptosis occurred after exposure to 1µM (98.9μgL-1) CuCl, the concentration able to significantly increase the intracellular Ca2+ content. Biomarkers of cell morphology and motility revealed microfilament disruption, a significant decrease in yeast phagocytosis and lysosome hydrolase (β-glucuronidase) inhibition beginning from 0.5µM (49.5μgL-1) CuCl in both the mussel and clam. The same concentration of CuCl affected biomarkers of oxidative stress, as a significant decrease in reduced glutathione content in the cytoplasm and inhibition of mitochondrial cytochrome-c oxidase (COX) were detected in both species. Comparison of the biomarkers showed that clam is more sensitive than the mussel regarding alterations to the lysosomal membrane and reactive oxygen species (ROS) production, which supports the potential harmful effects of antifouling biocides on the survival of nontarget pivotal species in the coastal community.

Cu2(OH)3Cl microspheres with self-assembled nanostructures through a dissolution regulation reaction and exhibits excellent antibacterial activity

Basic copper chloride (Cu2(OH)3Cl) microspheres with different surface nanostructure were synthesized via the dissolution regulation of calcite in CuCl2 solution. We studied the influence of CuCl2 concentration, reaction time and reaction temperature on the formation of Cu2(OH)3Cl, and the products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy and transmission electron microscopy. The concentration of CuCl2 has a great influence on the dissolution rate of calcite, dispersed microsphere particles assembled by nano-blocks formed in 20 mM CuCl2 solution. The surface of Cu2(OH)3Cl microsphere change from nano-block to nano-rod with increasing the reaction time from 20 min to 2 h Cu2(OH)3Cl microspheres with surface structure changed from nano-sheet, nano-plate to nano-block with the reaction temperature increase from 37 °C to 70 °C. The Cu2(OH)3Cl microsphere also displays superior antibacterial properties against S. aureus and E. coli. This work displays a new strategy to synthesize functional materials by the use of dissolution regulation methods.

Highly-efficient process for recovering gold from discarded mobile phones using pretreatment and mild extraction

Existing methods for recovering gold from electronic waste are based on mechanical and hydrometallurgy approaches. However, these methods usually use toxic chemicals and demonstrate low gold extraction efficiency (Ge) due to the negative influence of organic materials and other industrial metals also present in the waste. In this work, a more efficient and more environmentally friendly process is proposed that can achieve a high Ge from electronic waste by pre-treatment and pre-extraction before gold extraction. The powdered waste was first pre-treated by a supercritical water oxidation (SWO) process to remove organic materials and then pre-extracted using a mixture of FeCl3 and HCl to remove industrial metals. The solid powder thus produced was then re-extracted by a DMF-CuCl2-NaCl mild extraction system to complete the recovery of the gold content. Experimental results indicated that pre-treatment temperature, pre-treatment time, and the concentration of the FeCl3 and HCl solutions all significantly influenced the amount of gold extracted. The optimal parameters for achieving the highest Ge extraction (99.6%) using the DMF-CuCl2-NaCl extraction system were determined as follows: an extraction temperature of 65 °C, an extraction time of 70 min, a stirring speed of 420 rpm, a sample size of ≤ 850 µm, a solid/liquid (S/L) ratio of 1:12 g·mL−1, a CuCl2 concentration of 0.8 mol·L−1, and a NaCl concentration of 1.6 mol·L−1. After gold extraction, water was then used to precipitate the gold in the form of nanoparticles. Under optimal conditions (70%v/v water, 80 min), over 98.4% of the gold could be recovered in this way.

Promoter doping for tuning the redox behavior of CuCl2/γ-Al2O3-based catalysts in ethylene oxychlorination: Insights from kinetic studies

This study investigates the promoter effects of 14 metal chlorides (NaCl, KCl, RbCl, CsCl, MgCl2, CaCl2, SrCl2, CeCl3, PrCl3, NdCl3, ErCl3, FeCl3, YCl3, and SnCl3) on the CuCl2/γ-Al2O3-based catalysts used for ethylene oxychlorination. The study combines transient experiments of the two half-reactions in the redox cycle to understand the effects of different promoters on the reduction and oxidation rates of the catalysts. The results show that promoter doping can tune the redox behavior of the CuCl2/γ-Al2O3-based catalysts, affecting the reduction and oxidation steps, and the rate-determining step (RDS) changed between reduction and oxidation steps through the effects of different promoters. All the promoters have a positive effect on the reaction rate at steady-state, but the impact of promoter identity on steady-state CuCl2 concentration is variable and related to the electronegativity of the promoter metal. This work provides a better understanding of the reaction process and mechanism and highlights the potential of promoter doping for improving the efficiency and stability of CuCl2/γ-Al2O3-based catalysts in ethylene oxychlorination. The approach of both transient and steady-state kinetic modeling and simulation is a reliable and efficient method to study promoter effects on reduction–oxidation reactions.

Process design of a thermochemical cycle for hydrogen production compatible with nuclear fusion heat sources

We quantitatively design a hydrogen-producing copper–chlorine thermochemical cycle that is thermally combinable with nuclear fusion reactors. The mass and heat balances throughout the cycle, including the hydrolysis, pyrolysis, and electrolysis reaction processes, accompanied by multiple separation steps, are numerically investigated. Through the process design, the feasibility of the practical operation of the hydrogen production cycle is presented, and the thermal and electric power required for the operation is evaluated. As we first design a process with straightforward employment of the exact reaction condition from an earlier experimental study of the electrolysis process, the heat required for the condensation of CuCl2 solution is found enormous. By modifying the process condition with an increased electrolyte concentration, to reduce the amount of H2O to be evaporated in the CuCl2 condensation, the total heat for the cycle significantly decreases from 1270 GJ·h−1 (20.3 MJ·mol-H2−1) to 204 GJ·h−1 (3.26 MJ·mol-H2−1). This value is still larger than the heat required for hydrogen production by H2O electrolysis, 48.2 GJ·h−1 (0.772 MJ·mol-H2−1), but an extrapolation towards the saturated CuCl concentration achieves 46.0 GJ·h−1 (0.736 MJ·mol-H2−1). For energy-cost performance improvement of the thermochemical cycle, the development of the electrolytic cell operable with a high concentration of CuCl aqueous solution is thus found to be of primary effectiveness.

Five copper homeostasis gene clusters encode the Cu-efflux resistome of the highly copper-tolerant Methylorubrum extorquens AM1.

In the last decade, the use of copper has reemerged as a potential strategy to limit healthcare-associated infections and to control the spread of multidrug-resistant pathogens. Numerous environmental studies have proposed that most opportunistic pathogens have acquired antimicrobial resistance in their nonclinical primary habitat. Thus, it can be presumed that copper-resistant bacteria inhabiting a primary commensal niche might potentially colonize clinical environments and negatively affect the bactericidal efficacy of Cu-based treatments. The use of copper in agricultural fields is one of the most important sources of Cu pollution that may exert selection pressure for the increase of copper resistance in soil and plant-associated bacteria. To assess the emergence of copper-resistant bacteria in natural habitats, we surveyed a laboratory collection of bacterial strains belonging to the order Rhizobiales. This study proposes that Methylorubrum extorquens AM1 is an environmental isolate well adapted to thrive in copper-rich environments that could act as a reservoir of copper resistance genes. The minimal inhibitory concentrations (MICs) of CuCl2 were used to estimate the copper tolerance of eight plant-associated facultative diazotrophs (PAFD) and five pink-pigmented facultative methylotrophs (PPFM) belonging to the order Rhizobiales presumed to come from nonclinical and nonmetal-polluted natural habitats based on their reported source of isolation. Their sequenced genomes were used to infer the occurrence and diversity of Cu-ATPases and the copper efflux resistome of Mr. extorquens AM1. These bacteria exhibited minimal inhibitory concentrations (MICs) of CuCl2 ranging between 0.020 and 1.9 mM. The presence of multiple and quite divergent Cu-ATPases per genome was a prevalent characteristic. The highest copper tolerance exhibited by Mr. extorquens AM1 (highest MIC of 1.9 mM) was similar to that found in the multimetal-resistant model bacterium Cupriavidus metallidurans CH34 and in clinical isolates of Acinetobacter baumannii. The genome-predicted copper efflux resistome of Mr. extorquens AM1 consists of five large (6.7 to 25.7 kb) Cu homeostasis gene clusters, three clusters share genes encoding Cu-ATPases, CusAB transporters, numerous CopZ chaperones, and enzymes involved in DNA transfer and persistence. The high copper tolerance and the presence of a complex Cu efflux resistome suggest the presence of relatively high copper tolerance in environmental isolates of Mr. extorquens.

Extracellular β-d-fructofuranosidase from a novel Aspergillus sp. DHE1 with high potential for biotechnological applications: Purification and biochemical characterization

The current work focused on the purification and biochemical characterization of an extracellular β-d-fructofuranosidase from a novel fungus identified genetically using 18 S rRNA molecular sequencing, as Aspergillus sp. DHE1. The fungus was cultured under solid state fermentation using the Cotton (Gossypium herbaceum) seed waste as substrate. β-d-fructofuranosidase was purified through fractionation by ammonium sulphate salt, ion-exchange chromatography on DEAE-cellulose, and Sephadex G-100 gel filtration, yielding a 13.3-purification fold, 22.6% recovery and 192.9 U/mg protein specific activity. The apparent molecular mass of Aspergillus sp. DHE1 β-d-fructofuranosidase was 78 kDa as estimated on sodium dodecyl sulphate polyacrylamide gel electrophoresis. Optimal pH and temperature were observed at 6.0 and 50 °C, respectively, and the enzyme was quite thermostable at neutral/alkalophilic conditions, retaining 72% of its original activity after 1 h of incubation at 60 °C. The activity of the purified Aspergillus sp. DHE1 β-d-fructofuranosidase was stimulated by 1 mM of KCl (138.5%), NaCl (125.9%), CoCl2 (121.2%), and CaCl2 (112.3%), whereas the same concentration of AgCl, FeCl3, HgCl2, and CuCl2 inhibited the activity by 48.7%, 30.5%, 29.9%, and 26.2%, respectively. The kinetic studies using d-sucrose as the substrate were investigated using a Lineweaver-Burk plot, with Km and Vmax of 0.85 mM and 47.62 U/mL, respectively, indicating the high substrate affinity of β-d-fructofuranosidase. The ability of Aspergillus sp. DHE1 β-d-fructofuranosidase to tolerate ethanol suggests that it may have numerous uses in the food industry, including the production of alcoholic beverages.

Copper chloride and copper sulphate in combination with nitroxynil against gastrointestinal nematodes of ruminants: A possible hitchhiking synergic effect at low concentrations

Infections caused by Haemonchus spp. and Trichostrongylus spp. are major health problems for sheep and cattle. The objective of this study was to determine the efficacy of copper chloride (CuCl2), and copper sulphate (CuSO4) at 2.0, 7.0, 30.0, 125.0, 500.0, and 2000.0 µM formulations, and nitroxynil 34% (NTX) at 0.235 mM against gastrointestinal nematodes (GINs) of ruminants. Hence, the in vitro egg hatch test (EHT), the larval development test (LDT), and the larval migration inhibition test (LMIT) were used. Haemonchus spp. (52%) and Trichostrongylus spp. (38%) were the most frequently found parasites. The data fitted a concentration-dependent shape with the highest efficacies of CuCl2 and CuSO4 at 95.2 and 97.3% for parasites collected from sheep, and 95.8 and 93.4% from cattle, respectively. The combination of the 50% inhibitory concentration (IC50) of CuCl2 and CuSO4 and the IC10 of NTX showed up to a 52% increase in efficacy above the expected additive results, demonstrating a synergic/drug enhancer interaction. NTX may retain Cu-II ions by complexation, in a hitchhiking mechanism carrying the salts across the parasite cell wall, causing oxidative stress as a consequence of free radical production and cell damage. Synergy data between NTX and CuCl2, and CuSO4 represent a viable opportunity to develop new formulations for combating parasites of ruminants (i.e., Fasciola hepatica, Haemonchus spp., and Oesophagostomum spp.).

Impact of aluminum surface area on the rate of reaction with aqueous copper (II) chloride solutions

Throughout this experiment, we investigated the change in reaction temperature over the course of 120 seconds, with 30 second benchmarks, following the introduction of either aluminum strips or granular aluminum to variable concentrations of CuCl2(aq) in order to gain insight into the role that metal surface area plays within the rate of this single replacement reaction. We prepared solutions of CuCl2 (ranging from 0.33M to 1.00M) and mixed each solution with aluminum strips and granular aluminum; we then conducted three trials for each resulting reaction. We found that, for the aluminum strips, the experiments demonstrated an expected increase in temperature, with the 0.33M mixture increasing by 5.2 degrees, 0.66M mixture increasing by 14.8 degrees, and the 1.00M mixture increasing by 36.4 degrees. However, granular aluminum did not follow this same trend, as the temperature of the 0.33M mixture increased by 9.8 degrees, the temperature for the 0.66M mixture increased by 29.3 degrees, and the temperature for the 1.00M increased by 25.6 degrees. It was demonstrated that when CuCl2 solutions were mixed with aluminum strips, the change in temperature followed a linear relationship, however when CuCl2 was mixed with granular aluminum, the 0.33M mixture created a linear trend, but the 0.66M mixture and the 1.00M mixture did not show a trend, thereby concluding that by collision theory, the greater surface area inherent to granular aluminum allowed a faster reaction rate compared to the aluminum strips.