Zero-valent Copper Nanoparticles Research Articles

Silver and Copper Nanoparticles Hosted by Carboxymethyl Cellulose Reduce the Infective Effects of Enterotoxigenic Escherichia coli:F4 on Porcine Intestinal Enterocyte IPEC-J2.

Zero-valent copper and silver metals (Ms) nanoparticles (NPs) supported on carboxymethylcellulose (CMC) were synthesized for treating Enterotoxigenic Escherichia coli fimbriae 4 (ETEC:F4), a major cause of diarrhea in post-weaned pigs. The antibacterial properties of Cu0/CMC and Ag0/CMC were assessed on infected porcine intestinal enterocyte IPEC-J2, an in vitro model mimicking the small intestine. The lower average particle size (218 nm) and polydispersity index [PDI]: 0.25) for Ag0/CMC, when compared with those of Cu0/CMC (367 nm and PDI 0.96), were explained by stronger Ag0/CMC interactions. The minimal inhibitory concentration (MIC) and half inhibitory concentration (IC50) of Ag0/CMC were lower in both bacteria and IPEC-J2 cells than those of Cu0/CMC, confirming that silver nanoparticles are more bactericidal than copper counterparts. IPEC-J2, less sensitive in MNP/CMC treatment, was used to further investigate the infective process by ETEC:F4. The IC50 of MNP/CMC increased significantly when infected IPEC-J2 cells and ETEC were co-treated, showing an inhibition of the cytotoxicity effect of ETEC:F4 infection and protection of treated IPEC-J2. Thus, it appears that metal insertion in CMC induces an inhibiting effect on ETEC:F4 growth and that MNP/CMC dispersion governs the enhancement of this effect. These results open promising prospects for metal-loaded biopolymers for preventing and treating swine diarrhea.

Onion Seed Essential Oil-Grafted Zerovalent Copper Nanoparticles as Promising Material for Supercapacitor Electrodes in Energy Storage Device

Onion Seed Essential Oil-Grafted Zerovalent Copper Nanoparticles as Promising Material for Supercapacitor Electrodes in Energy Storage Device

BBD optimized antioxidants of Crotalaria candicans and its nanoconjugates, exert potent in vivo anti-biofilm effects against MRSA

Crotalaria genus is extensively dispersed in tropical and subtropical provinces, and it is found to harbor antioxidant flavonoids. Response surface methodology-based optimization was carried out for the purpose of efficient extraction involving a suitable solvent which can maximize the yield along with higher total phenolic content and total flavonoid content (TFC). Optimization conditions for extraction of C.candicans flavonoids (CCF) based on variables such as solvent, solid-solvent ratio and extraction temperature were evaluated. The optimized conditions were found as Solvent i.e., Aqueous-ethanol (53.42%), Solid-solvent ratio (1:15.83 w/v) and temperature (44.42 °C) and resulted to obtain the TFC as 176.23 mg QRET/g C. candicans extract with the yield 27.42 mg CCF/g (C. candicans dry weight). LC–MS analysis of CCF, revealed the presence of seven major flavonoids. The antioxidant flavonoids were further used to functionalize the zero-valent silver (ZVAgF) and copper (ZVCuF) nanoparticles. The ZVAgF and ZVCuF were investigated using UV–Vis spectrophotometry, FT-IR spectroscopy and X-ray diffractometry to confirm the presence of the zero valent metals and possible functional groups which capped the elemental metal. Further transmission electron microscopy, dynamic light scattering method and zeta-potential studies were done to understand their respective structural and morphological properties. The efficacy of the as-prepared ZVAgF/ZVCuF as antibiofilm agents on Methicillin-resistant Staphylococcus aureus (MRSA) with the mechanism studies have been explored. The MRSA-colony count from the infection zebrafish (in vivo) model, portrayed a reduction of > 1.9 fold for ZVCuF and > twofold for ZVAgF, with no alteration in liver morphology when treated with ZVAgF, implying that the nanoparticles were safe and biocompatible.

Synergistically adsorbing and reducing Uranium from water by a novel nano zero-valent copper/MXene 0D/2D nanocomposite

Proper disposal of uranium-containing waste is of utmost importance for safeguarding the environment and human health. In this study, we proposed a novel zero-dimensional (0D)/two-dimensional (2D) nanocomposite material, nZVC/Ti3C2, composed of nano zero-valent copper (nZVC) nanoparticles loaded onto Ti3C2 MXene nanoflakes, which was prepared using a simple in situ chemical reduction method. The uniform dispersion of 0D nZVC nanoparticles, with a size of approximately 5 nm, onto the 2D ultrathin Ti3C2 MXene effectively prevented agglomeration and corrosion of nZVC. This unique configuration provided numerous adsorption sites for UO22+and facilitated a fascinating charge channel for reducing adsorbed UO22+ into low-mobilized UO2 by nZVC. Under the synergistic effect of Ti3C2 MXene and nZVC, remarkable efficiency and selectivity of nZVC/Ti3C2 for U (VI) removal were demonstrated, which exhibited an exceptional adsorption capacity of up to 360 mg/g, coupled with a high removal efficiency of 97.5 % and rapid kinetics. Importantly, the presence of humic acid did not significantly affect the U (VI) removal efficiency of the composite because of the reduction effect of nZVC. The underlying mechanism of U (VI) removal was elucidated, revealing the involvement of reductive immobilization in the form of UO2 (as high as 73.6 %), inner-sphere surface complexation, and hydrolytic precipitation. This mechanism was dependent on the availability of active nZVC and the solution's pH. These findings highlight the potential of nZVC/Ti3C2 composites as efficient decontaminants for radioactive wastewater, thus contributing to advancements in environmental remediation endeavors.

Catalytic dechlorination of 1,2-DCA in nano Cu0-borohydride system: effects of Cu0/Cun+ ratio, surface poisoning, and regeneration of Cu0 sites

Aqueous-phase catalyzed reduction of organic contaminants via zerovalent copper nanoparticles (nCu0), coupled with borohydride (hydrogen donor), has shown promising results. So far, the research on nCu0 as a remedial treatment has focused mainly on contaminant removal efficiencies and degradation mechanisms. Our study has examined the effects of Cu0/Cun+ ratio, surface poisoning (presence of chloride, sulfides, humic acid (HA)), and regeneration of Cu0 sites on catalytic dechlorination of aqueous-phase 1,2-dichloroethane (1,2-DCA) via nCu0-borohydride. Scanning electron microscopy confirmed the nano size and quasi-spherical shape of nCu0 particles. X-ray diffraction confirmed the presence of Cu0 and Cu2O and x-ray photoelectron spectroscopy also provided the Cu0/Cun+ ratios. Reactivity experiments showed that nCu0 was incapable of utilizing H2 from borohydride left over during nCu0 synthesis and, hence, additional borohydride was essential for 1,2-DCA dechlorination. Washing the nCu0 particles improved their Cu0/Cun+ ratio (1.27) and 92% 1,2-DCA was removed in 7 h with kobs = 0.345 h−1 as compared to only 44% by unwashed nCu0 (0.158 h−1) with Cu0/Cun+ ratio of 0.59, in the presence of borohydride. The presence of chloride (1000–2000 mg L−1), sulfides (0.4–4 mg L−1), and HA (10–30 mg L−1) suppressed 1,2-DCA dechlorination; which was improved by additional borohydride probably via regeneration of Cu0 sites. Coating the particles decreased their catalytic dechlorination efficiency. 85–90% of the removed 1,2-DCA was recovered as chloride. Chloroethane and ethane were main dechlorination products indicating hydrogenolysis as the major pathway. Our results imply that synthesis parameters and groundwater solutes control nCu0 catalytic activity by altering its physico-chemical properties. Thus, these factors should be considered to develop an efficient remedial design for practical applications of nCu0-borohydride.

Green Synthesis of Nano-Zero-Valent Copper for the D-Blue 60 Textile Dye Removal from Aqueous Medium

Green synthesis of zero-valent copper nanoparticles successfully performed using Ficus benjamina leaves. The novel adsorbent Ficus nano-zero-valent copper (FB-nZVCu) characterized by utilizing scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FT-IR). The size of these nanoparticles typically ranges from 16 to 18 nm. This adsorbent investigated for removal of D-blue 60 from textile wastewater. The impact of different operating parameters, including pH, adsorbent dose, stirring rate, time, and initial dye concentration, had been tested, and optimum conditions were selected to gauge the optimum dye removal performance of the adsorbent. The maximum removal efficiency of D-blue 60 reached 87% under the following proper conditions: adsorbent dose 0.3 g L−1, time 30 min, and pH 8. The Langmuir isotherm was found to be the most appropriate system for the adsorption process (R2 = 0.9994) and (qmax = 30.03 mg g−1). The pseudo-second-order model defined the adsorption. From the data obtained and the fruitful discussion, it detected that the FB-nZVCu green adsorbent strongly recommended as a hopeful substance for removing D-blue 60 from both synthetic and actual waste samples.HighlightsGreen synthesis of eco-friendly FB-nZVCu nanoparticles utilizing low-cost material Ficus benjamina leaves.The FB-nZVCu nanoparticles are efficient nano-adsorptive agents for removing D-blue 60 from wastewater under optimum conditions.The Langmuir isotherm and PSO kinetics model provided a good fit to the adsorption data.

Synthesis and structural characterization of copper nanoparticles doped activated carbon derived from coconut coir for drinking water purification

Modifying and functionalizing activated carbon using metal nanoparticles have received great scientific attention in recent decades as a method to improve its inherent properties. The synergistic effects between the dopant and the activated carbon could lead to advanced properties in the hybrid material compared to individual counterparts. In this study, copper-doped activated carbon from coconut coir (Cu-ACC) is synthesized by an in-situ reduction method. The successful doping of zerovalent copper nanoparticles (Cu np) into the activated carbon matrix was confirmed using several characterization techniques. Peaks related to zerovalent Cu np in the X-ray diffractogram confirmed the successful formation of zerovalent Cu np. The dopant-matrix interactions were confirmed through peak shifts in the Fourier Transform Infrared Spectroscopy and D and G band changes in the Raman spectrum of Cu-ACC. The Cu 2p band in XPS of the Cu-ACC showed a sharp doublet at 932.7 eV, confirming the presence of metallic Cu. As indicated in the TEM/SEM images, Cu np demonstrated a spherical morphology with an average diameter of 5 nm. It was further observed that the Cu-ACC nanohybrid material could remove fluoride (63%) and hardness (69%) in synthetic water. Cu-ACC further demonstrates an enhanced antimicrobial activity against three commonly found water pathogens; E. coli, S. typhi, and S. flexneri. The material is expected to be used in next-generation domestic water filters formulated as single-use sachet bags.

Cytotoxic, apoptotic and necrotic effects of starch coated copper nanoparticles on Capan 1 pancreatic cancer cells

In the present study we utilized a green synthesis approach by reduction route with ascorbic acid in the presence of starch as the capping agent. Here we aimed to generate a stable starch coating copper nanoparticles (Cu-SNPs) and to investigate their apoptotic and necrotic effects on Capan 1 pancreatic cancer cell line. The water soluble monodisperse starch-protected zero-valent copper nanoparticles were characterized by transmission electron microscopy, XPS, FTIR analysis. TEM images showed that the presence of metallic copper nanoparticles with anisotrophic morphologies and the sizes of 90% copper nanoparticles were in 50 nm and 80 nm range. Cetyltrimethylammonium bromide (CTAB) coated copper nanoparticles was also synthesized to compare the stability of starch coating copper nanoparticles. It was also found that copper nanoparticles were significantly protected by starch coating. Cu-SNPs exhibited stronger antimicrobial effects on Staphylocossus and Enterococcus. In vitro cell culture studies demonstrated that Cu-SNPs were not cytotoxic on L929-fibroblasts and Capan 1 pancreatic cancer cell in all concentrations used here (6.25–100 ppm) in different extends. The cytotoxic, necrotic, and apoptotic effects of Cu-SNPs on the Capan 1 pancreatic cancer cell line have been exhibited. Furthermore, the micronucleus test and hemolytic activity test were also performed.

Tuning Polyol-Mediated Process towards Augmentation of Zero-Valent Copper Nanoparticles

Tuning Polyol-Mediated Process towards Augmentation of Zero-Valent Copper Nanoparticles

Fabrication and characterization of starch-copper nanoparticles/rutin nanofiber hybrid scaffold

Rutin has antiviral, anticancer, anti-inflammatory and heart disease protective activities but its poor solubility plays a critical role in limiting its activity. To relieve this problem, we prepared polyvinylpyrrolidone (PVP) electrospun nanofibers as carrier to release rutin for potential applications. Starch-coated copper nanoparticles were also added to the polymeric precursor solution before electrospinning to increase the activity of rutin. The water soluble monodisperse starch-protected zero-valent copper nanoparticles of about 36 nm diameter have been synthesized by chemical reduction route using starch as green capping agent. The resulting starch coated copper nanoparticles were characterized by transmission electron microscopy and energy dispersive X-ray analysis (EDX). It was found that copper nanoparticles were significantly protected by starch coating. PVP solutions incorporated with rutin and starch capped copper nanoparticles were electrospun at different weight percentages. The nanofibers were characterized by using scanning electron microscopy, energy dispersive spectroscopy, and Raman spectroscopy. We confirmed that copper nanoparticles were embedded in PVP nanofibers. The cytotoxic efficacy of the nanofiber involving starch capped copper nanoparticles and rutin against L929 mouse fibroblast cells was compared using a standard MTT assay. The in vitro release studies were performed using rutin-copper loaded nanofibers through dialysis membrane on the Franz diffusion cells. The nanofiber involving starch capped copper nanoparticles and rutin exhibited no cytotoxicity compared to PVP nanofibers.

Potential of nanocomposites of zero valent copper and magnetite with Eleocharis dulcis biochar for packed column and batch scale removal of Congo red dye

The current study is the first attempt to prepare nanocomposites of Eleocharis dulcis biochar (EDB) with nano zero-valent Copper (nZVCu/EDB) and magnetite nanoparticles (MNPs/EDB) for batch and column scale sequestration of Congo Red dye (CR) from synthetic and natural water. The adsorbents were characterized with advanced analytical techniques. The impact of EDB, MNPs/EDB and nZVCu/EDB dosage (1–4 g/L), pH (4–10), initial concentration of CR (20–500 mg/L), interaction time (180 min) and material type to remove CR from water was examined at ambient temperature. The CR removal followed sequence of nZVCu/EDB > MNPs/EDB > EDB (84.9–98% > 77–95% > 69.5–93%) at dosage 2 g/L when CR concentration was increased from 20 to 500 mg/L. The MNPs/EDB and nZVCu/EDB showed 10.9% and 20.1% higher CR removal than EDB. The adsorption capacity of nZVCu/EDB, MNPs/EDB and EDB was 212, 193 and 174 mg/g, respectively. Freundlich model proved more suitable for sorption experiments while pseudo 2nd order kinetic model well explained the adsorption kinetics. Fixed bed column scale results revealed excellent retention of CR (99%) even at 500 mg/L till 2 h when packed column was filled with 3.0 g nZVCu/EDB, MNPs/EDB and EDB. These results revealed that nanocomposites with biochar can be applied efficiently for the decontamination of CR contaminated water.

Effect of copper dispersion on SBA-15 and SBA-16 affinity towards carbon dioxide—an approach through thermal programmed desorption

A new approach for the synthesis of zero-valent copper nanoparticles (CuNPs) supported on ordered mesoporous silica SBA-15 and SBA-16 by using vegetal antioxidants, coffee Robusta and green tea was developed in the present work. Diverse characterization techniques such as X-ray diffraction, nitrogen adsorption–desorption, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy and thermal programmed desorption of CO2 and water allowed stating that the appreciable specific surface area and porosity favor CuNP formation. Copper-loaded SBA-15 and SBA-16 exhibited higher surface basicity and hydrophilic character according to the type of the source of reducing agents and silica framework, respectively. OH-compounds interactions with both CuNP and SBA surface and more particularly with available Si–O-Si groups were found to promote metal dispersion reducing the particle size. The results obtained herein open promising prospects for designing low cost and “green” silica-based materials with judiciously tailored basicity and hydrophilic character for catalysis, adsorption and other surface processes.

Simple borophosphate glasses for on-demand growth of self-supported copper nanoparticles in the reduction of 4-nitrophenol

Herein, we demonstrate a single-step synthesis of simple copper-doped borophosphate glasses and their unusual use for catalytic reduction of nitro groups from the aromatic nitro compounds. The copper-doped glasses were evaluated as an affordable heterogeneous catalytic glass-based material for the reduction of 4-nitrophenol by sodium borohydride. The glass matrix acts as a host and support material for in situ self-growth of zero-valent copper (Cu) nanoparticles (NPs) on the glass surface. Thus, zero-valent CuNPs are produced in situ on the glass surface that is accomplished by the interaction of copper ions with hydride ions. Using an intrinsic reaction kinetic constant, we find a catalytic activity of 0.144 L s−1 g−1 for a glass-based catalyst doped with a non-noble metal, which is an order of magnitude higher when compared to the values observed elsewhere. Furthermore, the reuse of glass catalyst after six successive cycles demonstrates an outstanding performance compared to that of the parent material. A mathematical model based on the Langmuir-Hinshelwood mechanism related to an empirical growth rate of the zero-valent CuNPs was proposed to describe the kinetic of the 4-nitrophenol catalytic hydrogenation.

Catalytic Removal of Selected Textile Dyes Using Zero-Valent Copper Nanoparticles Loaded on Filter Paper-Chitosan-Titanium Oxide Heterogeneous Support

A facile and highly porous heterogeneous matrix was designed as a support for zero-valent Cu nanoparticles. This heterogeneous support is composed of filter paper, chitosan, and titanium dioxide, and on this support matrix, a metallic Cu2+ nanoparticle was loaded. The metallic Cu2+ nanoparticle was then reduced to Cu0 in NaBH4 solution. The prepared catalyst (Cu/CHTiO2/FP) was characterized by X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), and energy-dispersive X-ray spectroscopy (XPS) and the results indicated that the synthesis of zero-valent Cu nanoparticles on the heterogenous support by this method was successful. The prepared Cu/CHTiO2/FP catalytic activity was investigated to remove four different textile dyes: Rhodamine B, Bromocresol Green, Methyl Orange, and Eriochrome Black T in the presence of NaBH4. The results show that the catalyst is efficient and can be adapted to remove the different classes of dyes studied. Aside from the catalyst's efficiency, it could be quickly recovered by simply pulling out from the reaction medium, washed, and reused. The reusability of the catalyst recorded over 90% removal after five cycles.

Supercritical Hydrothermal Synthesis of Polyacrylic Acid-Capped Copper Nanoparticles and Their Feasibility as Conductive Nanoinks

Polyacrylic acid (PAA) applied as surface modifier of zero-valent copper nanoparticles (CuNPs) for electronic printing inks has great potential to replace presently used polymers, because of its favorable technical, environmental and biodegradability characteristics. Continuous synthesis (400°C, 30 MPa) of nanoparticles in supercritical water with short reaction times (1.1 s) was used to form PAA-surface-modified zero-valent (34–46 nm) CuNPs. CuNP particle sizes decreased with an increase in PAA molecular mass (5000, 250,000) and were stable as dispersions in methanol and 1-propanol, respectively. The resistivity of conductive films prepared with CuNPs decreased with an increase in heating temperature. The minimum resistivity of the PAA-modified CuNPs was 1.4 × 10−5 Ω cm at 320°C (PAA25000) and 4.2 × 10−4 Ω cm at 350°C (PAA5000), demonstrating the feasibility of PAA as a dispersant and surface modifier for CuNPs. Polyacrylic acid is thus effective as a surface modifier for zero-valent metal nanoparticles and expands the possible applications in sustainable printed electronics.

Sonochemical synthesis of amphoteric Cu0-Nanoparticles using Hibiscus rosa-sinensis extract and their applications for degradation of 5-fluorouracil and lovastatin drugs

Recent studies reported the detection of numerous emerging and active pharmaceutical constituents in the ground and surface water. To address these issues, the present study reported the ultrasound-assisted synthesis of zero-valent copper (Cu0) nanoparticles using Hibiscus rosa-sinensis extract as reducing and stabilizing agent. The catalyst was characterized using XRD, SEM, EDX, PSA, BET, etc., and the results revealed that sonochemical synthesis technique influenced the crystallinity with controlled growth of Cu0. While the hard ligand hydroxyl group (−OH) reduces the Cu2+ to Cu0 and soft ligand carbonyl group (CO) present in the oxidized polyphenols helps in capping and stabilizing the Cu0-nanoparticles. During the ultrasound application, continuous release of Cu+ from Cu0 promoted the degradation by producing OH and O2•− radicals. Approx. 91.3 % and 93.2 % degradation efficiencies were achieved for 5-fluorouracil and lovastatin. The results showed that Cu0 nanoparticles were amphoteric in nature and the synergy calculation revealed that ultrasound has a direct influence on degradation of drugs which are difficult to degrade/mineralize using conventional techniques. Based on the results, a possible degradation mechanism of drug molecules in the presence of oxidants, zero-valent copper and ultrasound has been proposed.

Polyol-mediated synthesis of size-controlled copper nanoparticles under microwave irradiation

In this research, well-dispersed zero-valent copper nanoparticles (CuNPs) were successfully synthesized from a well-defined complex of [Cu(OH)(TMEDA)]2Cl2 in neat glycerol via a polyol method, under microwave irradiation (MW) assistance. The as-prepared CuNPs were thoroughly characterized by means of various techniques such as inductively coupled plasma mass spectrometry (ICP-MS), Ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses, evidencing the formation of the spherical nanoparticles with the range of 3.24.2 nm in mean diameter. In addition, the size control of obtained CuNPs was examined via reaction time, thereby showing that the formation of CuNPs conformed to the model of “mono-dispersion”.

Assessment of Antibacterial Activity and the Effect of Copper and Iron Zerovalent Nanoparticles on Gene Expression DnaK in Pseudomonas aeruginosa

The use of antibiotics in addition to drug resistance can cause harmful side effects. The presence of nanoparticles as novel antibacterial agents and carriers for drug delivery are important for the treatment of diseases. Pseudomonas aeruginosa is an opportunistic pathogen and resistance to antibiotics that infects damaged tissues and also people with a weak immune system. In this study, zerovalent copper (Cu0) and iron (Fe0) nanoparticles with the average size of 25 nm and less than 50 nm, respectively, were synthesized by chemical reduction method. Scanning electron microscopy (SEM) has been used to determine the particle size and morphology. The antibacterial effect of these nanoparticles against Pseudomonas aeruginosa was assessed. The minimum inhibitory concentrations (MIC), as well as minimum bactericidal concentration (MBC), were determined using colony count and measurement of optical density methods. The results of treatment Pseudomonas aeruginosa with zerovalent iron and copper nanoparticles showed that the rate of growth was reduced in a dose-dependent manner and these nanoparticles showed that bactericidal effect on Pseudomonas aeruginosa. The effect of zerovalent iron and copper nanoparticles on heat shock gene expression dnaK were studied using real-time RT-PCR. Gene expression levels indicated that dnaK expression was reduced 10- and 7-fold in treatment with Fe0 and Cu0, respectively. Since the nanoparticles inhibited the bacterial growth, the expression level has decreased compared with control.

Catalytic reduction of nitrophenols by a novel assembled nanocatalyst based on zerovalent copper-nanopolyaniline-nanozirconium silicate

A novel nanocatalyst (Cu0-NPANI-ZrSiO4) was fabricated via solvent free microwave synthesis for surface immobilization of zerovalent copper nanoparticles (Cu0-NPs) on modified nanopolyaniline (NPANI) with nanozirconium silicate. The assembled nanocatalyst was characterized by different techniques to confirm the structure, thermal stability, surface morophology and nanoscale size. Cu0-NPANI-ZrSiO4 nanocatalyst was then subjected to extensive investigation and evaluation of its potential capability for reduction of a series of nitrophenol (NPhs) derivatives. The Langmuir-Hinshelwood mechanism was applied on the catalytic reduction of 2-nitrophenol (2NP), 3-nitrophenol (3NP) as well as 4-nitrophenol (4NP) and the reaction rate constants (k) were calculated through the pseudo-first-order kinetics due to the presence of excessive NaBH4. The results revealed a pseudo-first-rate type of reaction with high constant (k). The reduction of NPhs by NaBH4 as a reducing agent over Cu0-NPANI-ZrSiO4 was explored in different pH values (2–10) of NPhs and the results confirmed the strong dependency of the reduction process on the pH. In low pH, high reduction efficiency was established and confirmed from the pseudo-first-rate constant k (min−1) for 4NP, 3NP and 2NP as 0.811, 0.249 and 0.584, respectively at pH 2 and these values were then finally decreased to 0.112, 0.1 and 0.116 at pH 10, respectively. Rate constant (k) was in a good correlation with concentration of [H3O+] ion. An extrathermodynamic study for reaction rate (k) through isokinetic relationship was mathematically expressed. The calculated thermodynamic parameters led to an extrathermodynamic analysis as a type of compensation effect to give a good linearity plot with the slope to represent the isokinetic temperature, β that was identified as 298.82 at 298 K.

Copper-Containing Nanosystems Based on Macromolecular Hydrophilic Stabilizers

An original method for the synthesis of copper-containing nanosystems for biomedical applications using hydrazine hydrate as a reducing agent was developed. The process involves intermediate formation of the [Cu(NH3)4]2+ complex ion, which ensures the formation of Cu0 nanoparticles without oxide impurity. The 2-deoxy-2-methacrylamido-D-glucose copolymer with 2-(dimethylamino)ethyl methacrylate or bovine serum albumin was used as a macromolecular hydrophilic stabilizer. The spectral and structure-morphological characteristics of the nanosystems were studied. This stabilization resulted in an almost unimodal distribution of zerovalent copper nanoparticles in aqueous solutions due to their rather good shielding by macromolecules.