CuO Nanoparticles Research Articles

Investigation on Critical Characteristics of Edible Vegetable Oil by using Cuo Nanoparticles

This work demonstrates how the composition of the nanoparticles affects the thermal, electrical, and physical characteristics of vegetable oil (RBO). Cuo nanoparticles with particle volume fractions varying from 0.1 percent to 0.4 percent were injected one at a time into vegetable oil (RBO) to produce nanofluids (NFs) that affect the basic characteristics of the oil. It was able to evaluate characteristics including room temperature viscosity, firepoint, breakdown voltage (BDV), and flash point using IEC and ASTM standards. The breakdown voltage rises when the vegetable oil (RBO) oil is heated in the presence of nanoparticles. The size of the nanoparticles has changed the viscosity, and the flash and fire points have gone from 10°C to 15°C..

An Investigation into the Larvicidal Activity of Biologically Synthesized Silver and Copper Oxide Nanoparticles Against Mosquito Larvae.

This study is primarily focused on the synthesis of silver and copper oxide nanoparticles utilizing the extract of Ipomoea staphylina plant and their larvicidal activity against specific larvae. Notably, Anopheles stephensi and Aedes aegypti are significant disease vectors responsible for transmitting diseases such as malaria, dengue fever, Zika virus, and chikungunya (Anopheles stephensi), and dengue and Zika (Aedes aegypti). These mosquitoes have a substantial impact on urban areas, influencing disease transmission dynamics. In an effort to control these larvae, we have pursued the synthesis of a herbal-based nanomedicine derived from I. staphylina, a valuable herb in traditional medicine. Our successful synthesis of silver and CuO nanoparticles followed environmentally sustainable green chemistry methodologies. The I. staphylina plant extract played a dual role as a reducing agent and dopant, aligning with principles of sustainability. We employed X-ray diffraction (XRD) analysis to validate the nanoparticle structure and size, while field-emission scanning electron microscopy (FE-SEM) revealed well-defined nanostructures. Elemental composition was determined through energy-dispersive X-ray (EDX) analysis, and UV-visible spectroscopy provided insights into the bandgap energy (3.15 eV for silver, 1.2 eV for CuO nanoparticles). These nanoparticles exhibited robust larvicidal activity, with CuO nanoparticles surpassing silver nanoparticles in terms of LC50 and LC90 values. Moreover, the developmental toxicity of CuO and Ag NPs was evaluated in zebrafish embryos as part of non-target eco-toxicological studies conducted in a standard laboratory environment. These findings underscore the potential utility of these nanoparticles as highly effective and environmentally friendly natural pesticides, offering cost-effectiveness and ecological benefits.

Enhancing antibacterial activity against multi-drug resistant wound bacteria: Incorporating multiple nanoparticles into chitosan-based nanofibrous dressings for effective wound regeneration

Wound infection continues to pose a significant challenge in the field of wound healing. Multi-drug resistant bacteria (MDR) make it even more complicated. Therefore, there is a pressing need to fabricate wound dressings with enhanced antimicrobial activity, particularly against MDR strains. In this study, we aimed to incorporate three antimicrobial nanoparticles into a chitosan-based nanofibrous mat (CS) and assess their antimicrobial activity against MDR bacteria. We fabricated CS mats incorporated with silver nanoparticles (CS-nAg), CuO nanoparticles (CS-nCuO), ZnO nanoparticles (CS-nZnO), a combination of Ag and CuO nanoparticles (CS-nAC), and a combination of Ag, CuO, and ZnO nanoparticles (CS-nACZ). The antimicrobial activity of these mats against MDR clinical isolates of four common wound bacteria including Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Acinetobacter baumannii were investigated. Each strain was tested using 10 isolates. According to in-vitro study, mats incorporated with a single type of nanoparticle demonstrated antimicrobial activity against certain isolates of P. aeruginosa, S. aureus, and E. coli. However, the antimicrobial activity was enhanced when multiple types of nanoparticles were combined (CS-nAC and CS-nACZ). Notably, CS-nACZ was the only mat that demonstrated antimicrobial activity against A. baumannii. In addition to its superior antimicrobial activity, CS-nACZ did not exhibit cytotoxicity towards fibroblasts. In an animal study using an infected wound rat model, the CS-nACZ mat demonstrated superior antimicrobial activity and excellent wound regeneration ability. These results suggest that the use of multiple nanoparticles in CS based wound dressing can lead to enhanced antimicrobial effects and effective wound regeneration.

Preparation and characterization of ZnO/CuO nanocomposites thin films for highly efficient visible-light photocatalysis of acriflavine dye

Chemical bath deposition (CBD) was used to grow ZnO nanorods on glass substrates. Grown ZnO nanorods are dipped in a copper nitrate trihydrate [Cu(NO3)2.3 H2O] solution at 90 °C for 30 min before being annealed at 400 °C for 1 h to convert Cu2+ ions to CuO nanoparticles, forming a ZnO/CuO thin films nanocomposite. Images obtained from a Field Emission Scanning Electron Microscope (FESEM) indicated that the ZnO structure consisted of nanorods coated in CuO nanoparticles. The optical absorption of both ZnO NRs and ZnO/CuO nanocomposites thin films was strongly edged, with an energy gap of 3.26 and 3.21 eV, respectively. The photodegradation rate of the manufactured ZnO NRs and ZnO/CuO nanocomposites thin films against Acriflavin dye was investigated at room temperature under varying pH conditions and period exposure to visible light. The rate of photodegradation of the dye was increased by increasing the time it was exposed to light and/or the pH of the solution. The photodegradation rates for AFN dye under visible light irradiation ranged from 36% to 100% as the pH value was increased from 4 to 10, and from 78% to 66% at a pH value of 12 and reduced to 78% at a pH value of 12 after 330 min of irradiation. Furthermore, the trapping experiments of reactive species for Acriflavin dye degradation by ZnO/CuO nanocomposites photocatalysts were also carried out

On the combination of ultraviolet photoelectron spectroscopy with optical absorption studies to investigate Cu2O||TiO2 direct Z-scheme junctions with different Cu2O loading

Among the electronic properties, the positions of the electronic band edges and the work function are essential parameters for determining the potential of a photocatalyst and its ability to function in a solar conversion system. A novel type of photocatalysts, called direct Z-schemes, possesses many advantages over conventional heterojunctions, which all benefit the catalytic performance under solar light. As oxidation and reduction reactions are greatly affected by the electrical characteristics of the material, ultraviolet photoelectron spectroscopy (UPS) is a powerful tool to determine and quantify important electronic parameters of previously fabricated TiO2‖Cu2O junctions. TiO2 nanotubes modified with Cu2O nanoparticles exhibit a reduction in the value of the work function (WF = 3.67 ± 0.01 eV) and ionization potential (IP = 6.01 ± 0.04 eV) with respect to the TiO2 substrate (WF = 4.29 ± 0.02 eV and IP = 7.65 ± 0.05 eV). By varying the electrodeposition time, an optimized amount of deposited Cu2O nanoparticles was proven to reduce the WF and IP to facilitate the excitation of electrons, which could be correlated to the improved absorbance in the visible wavelength range. This work proposes a valuable methodology for band diagram tracing from UPS spectra and provides new insights in the relationship between synthesis, electronic properties and visible light absorption of titania based Z-schemes for photocatalytic applications with a combination of surface sensitive techniques and optical absorption studies.

Fabrication of CuO nanoparticles embedded novel chitosan/hydroxypropyl cellulose bio-nanocomposites for active packaging of jamun fruit

The study herein was intended to develop CuO nanoparticles (CuO NPs) embedded in chitosan (CS) and hydroxypropyl cellulose (HPC) based bio-nanocomposites with improved functional properties to prolong the shelf life of fruits using eco-friendly solvent casting technique. ATR-FTIR spectroscopy revealed hydrogen bonding interactions between the CS, HPC and CuO NPs. The homogeneity of the CuO NPs distributed bio-nanocomposites was verified by SEM images with minimum aggregations. Bio-nanocomposites showed improved mechanical properties (tensile strength of 33 MPa) with excellent UV-light blocking ability (4% of %transmittance at 360 nm and 20% transparency at 600 nm), also, a significant decrease in moisture adsorption (5.27%), water vapour permeability (2.47%), oxygen permeability (1.39%), and biodegradability (12.58%) compared to control CS/HPC blend film. Furthermore, CuO NPs induced CS/HPC bio-nanocomposites exhibited strong antimicrobial properties against B. subtilis, S. aureus, P. aeruginosa, E. coli, and C. albicans as well as antioxidant properties. Moreover, 0.8% of CuO NPs embedded in CS/HPC bio-nanocomposite film extended the shelf life of packed jamun fruits confirming the potential of prepared bio-nanocomposites to serve as an active food packaging material.

Evaluation of the antibacterial activity of CuO and ZnO nanoparticles against uropathogenic Escherichia coli

E. coli responsible for urinary tract infections (UTI) became resistant to obtainable therapies. So, nanotechnology appears currently as promising innovation among various strategies under development. In the present study we evaluate the antimicrobial effects of CuO and ZnO nanoparticles against E. coli isolated from UTI. Biofilm production and expression of quorum sensing genes luxS and motA were performed on E. coli treated with the nanoparticles. luxS and motA genes were detected in the tested E. coli. All isolates produced strong, moderate and weak biofilm. All isolates had a weak biofilm formation and decreased gene expression for luxS and motA genes after treatment with CuO, ZnO and their mixture. Besides, CuO and ZnO had non-toxic effects on Human Dermal Fibroblasts and neonatal normal cells. In conclusion, the mixture of CuO and ZnO had a role in decreasing the gene expression of luxS and motA genes more than each alone.

Pro-angiogenic and antibacterial copper containing nanoparticles in PLGA/amorphous calcium phosphate bone nanocomposites

Large bone defects after trauma demand for adequate bone substitutes. Bone void fillers should be antibacterial and pro-angiogenic. One viable option is the use of composite materials like the combination of PLGA and amorphous calcium phosphate (aCaP).Copper stimulates angiogenesis and has antibacterial qualities. Either copper oxide (CuO) nanoparticles (NPs) were therefore added to PLGA/aCaP/CuO in different concentrations (1, 5 and 10 w/w %) or copper-doped tricalcium phosphate NPs (TCP with 2% of copper) were electrospun into PLGA/CuTCP nanocomposites.Bi-layered nanocomposites of PLGA/aCaP with different copper NPs (CuO or TCP) and a second layer of pristine PLGA were fabricated. Two clinical bacterial isolates (Staphylococcus aureus and Staphylococcus epidermidis) were used to assess antibacterial properties of the copper-containing materials. For angiogenesis, the chorioallantoic membrane (CAM) assay of the chicken embryo was performed.The higher the CuO content, the higher were the antibacterial properties, with 10 % CuO reducing bacterial adhesion most effectively. Vessel and cell densities were highest in the 5 % CuO containing scaffolds, while tissue integration was more pronounced at lower CuO content. The PLGA/aCaP/CuO (1 % CuO) behaved similar like PLGA/CuTCP in all angiogenic and antibacterial readouts, based on the same copper fraction.We conclude that CuO NPs or CuTCP NPs are useful components to increase angiogenic properties of nanocomposites and at the same time exhibiting antibacterial characteristics.

Biosynthesis of Fe2O3 and CuO Nanoparticles and Comparative Study for Dielectric Properties

Biosynthesis of Fe2O3 and CuO Nanoparticles and Comparative Study for Dielectric Properties

Vacancy induced enhanced photocatalytic activity of nitrogen doped CuO NPs synthesized by Co-precipitation method

The chemical co-precipitation method, an effective approach in the synthesis of nanomaterials, was used to synthesize CuO nanoparticles (NPs). Structural and morphological modification of undoped and nitrogen (N) doped CuO nanoparticles were studied thoroughly using X-ray diffraction (XRD), FT-IR and field emission scanning electron microscope (FE SEM). Doping effect on defects was investigated using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and photoluminescence (PL) spectroscopy. Thus, the effect of doping on crystallinity, crystallite size, strain induced in lattice, defects and electron-hole recombination rate were investigated. Optical band gap was calculated using Kubelka-Munk function from the diffuse reflectance spectra (DRS) obtained using ultraviolet visible (UV–Vis) spectroscopy. Finally, photocatalytic performance was studied from rhodamine B (Rh B) degradation and reaction kinetics were analyzed. Maximum degradation efficiency was obtained for 1.0 mol% N doped CuO NPs which also exhibited minimum band gap and lowest electron-hole recombination rate. For the optimum doping concentration, nitrogen was found to create oxygen vacancies while substituting oxygen in the lattice, and thus reduce electron-hole recombination rate and increase photocatalytic degradation rate effectively.

Photocatalytic degradation of xanthates under visible light using heterogeneous CuO/TiO2/montmorillonite composites

Due to the significant demand for xanthate treatment in mineral effluents, photocatalytic techniques have emerged as one of the most promising solutions. In this study, a high-performance TiO2/CuO/montmorillonite photocatalyst was prepared. In this configuration, TiO2 was the classic photocatalytic material and CuO and montmorillonite were utilized to broaden the adsorption range of solar light and acted as carriers to support the photocatalyst. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were employed for the comprehensive characterization of the microstructure of the ternary photocatalyst. The results revealed that fine-sized TiO2 and CuO nanoparticles were uniformly and tightly loaded on the montmorillonite layers. The photocatalytic properties of the photocatalyst were evaluated using sodium butyl xanthate as the target contaminant. For pristine TiO2, ultraviolet (UV) light was required to effectively degrade sodium butyl xanthate. Meanwhile, the degradation reaction could be processed efficiently under visible light using the TiO2/CuO/montmorillonite composite as the photocatalyst. Moreover, UV–visible diffuse reflectance spectroscopy, photoluminescence spectroscopy, and radical quench experiments were performed to elucidate the degradation process, and a possible degradation model and mechanism were proposed.

Screen-printed electrodes on paper using copper nano- and micro-particles

Screen-printed copper electrodes have the potential to replace silver and lithium electrodes in printed batteries and sensors owing to the abundance of copper, its competitive electrical properties, and the low cost of raw materials. Herein, copper microparticle-glycerol-based inks were screen-printed onto paper to develop highly conductive electrodes. The conductivity and particle connectivity enhancement of screen-printed electrodes are the main research topics. These parameters translate to usability including increased sensitivity for sensor applications and reduced resistivity for battery electrode applications. CuO nanoparticles of 50 nm were deposited onto the electrodes at a concentration of 1 μl/cm2, which led to a 4-fold decrease in sheet resistivity from 200 to 50 Ω/m2. The increased connectivity and formation of new channels due to the addition of nanoparticles were visualised via field emission scanning electron microscopy. The CuO nanoparticles were developed via a hybrid approach incorporating wet chemistry for high yield and laser ablation for colloidal conductivity and Zeta potential enhancement which reached up to −45 mV. An optimal screen-printing viscosity of 62 mPa s was achieved through a precise 1.95:1 mass ratio of Cu microparticles to glycerol. Heat treatment at 100 °C after screen-printing enhanced particle connectivity by reducing glycerol content in the ink.

The role of photo‐catalytically synthesized poly (N‐vinyl pyrrolidone‐methyl methacrylate)/CuO‐rGO nanocomposite as a filler for the reinforcement for epoxy system

AbstractThis study demonstrates the effective copolymerization of N‐Vinyl pyrrolidone and methyl methacrylate using reduced graphene oxide adorned with copper oxide nanoparticles (CuO‐rGO) acting as a catalyst when exposed to blue LED irradiation to generate random copolymer hybrid system of P(NVP‐co‐MMA/CuO‐rGO). We investigated the effects of this copolymer hybrid system of P(NVP‐co‐MMA/CuO‐rGO) on the mechanical, thermal and antibacterial properties of epoxy (DEGBA‐DETDA) composite. By employing two different concentrations of CuO nanoparticle, we assessed the reinforcement capability of the synthesized copolymer‐nanoparticle hybrid within an epoxy matrix. We observed that the composite sample comprising P(NVP‐co‐MMA/CuO‐rGO), having 0.5% of CuO‐rGO (Cu002) with respect to the epoxy concentration resulted in significant enhancements in fracture toughness. Further mechanical properties and thermal properties of the composite samples were studied using DMA, DSC and TGA. Microstructural properties and Mechanisms of toughening are elucidated through the examination of SEM images depicting the fracture surfaces. Moreover, the hybrid composites exhibited notable antibacterial activity against both E. coli and S. aureus compared to control. These findings highlight the copolymer hybrid P(NVP‐co‐MMA/CuO‐rGO) system's role as a multifunctional filler, enhancing epoxy composites' durability, functionality, and antibacterial performance. Our work advances the field of composites by showcasing the customized use of nanoparticle‐enhanced copolymers to improve material properties, providing valuable insights for the development of next‐generation composite materials.Highlights Achieved novel copolymerization of N‐Vinyl pyrrolidone and methyl methacrylate. CuO‐rGO successfully facilitates P(NVP‐co‐MMA/CuO‐rGO) nanocomposite formation. P(NVP‐co‐MMA/CuO‐rGO) nanocomposite proved as an effective filler for epoxy. P(NVP‐co‐MMA/CuO‐rGO) reinforced epoxy enhances toughness by 143% over neat epoxy Reinforced epoxy showed better efficacy against E. coli & S. aureus versus control.

Characterization and Evaluation of the Antimicrobial Activity of CuO Nanoparticles Prepared by Pulse Laser Ablation in Double-Distilled Water

Characterization and Evaluation of the Antimicrobial Activity of CuO Nanoparticles Prepared by Pulse Laser Ablation in Double-Distilled Water

A comparative analysis of the blood-based hybrid nanofluid flow containing Cu and CuO nanoparticles over an exponentially extending surface

This work investigates thermal enhancement for Casson magnetohydrodynamics (MHD) hybrid nanofluid flow on an exponentially elongating surface. The flow is influenced by thermal radiations, chemical reactivity, and heat source/sink. A magnetic field has been applied to the flow of fluid in a direction normal to the flow system. The thermal transportation has been controlled with the help of thermophoresis and Brownian motion effects. The leading equations have been converted to a set of dimensionless forms and have then been solved by using the bvp4c technique. It has been noticed in this work that, fluid velocities have declined with growth in porosity, magnetic, and Casson factors, and there is more reduction in velocity in the case of Cu + CuO/blood-based hybrid nanofluid as compared to blood flow or Cu/blood nanofluid profiles. Thermal distribution has augmented with an escalation in heat sink/source factor, Brownian motion, thermophoresis, magnetic and radiation factors as well as Eckert number. Concentration distribution has augmented with an upsurge in Brownian motion factor, Schmidt number, and chemical reactivity factor. Nusselt number has augmented with an escalation in magnetic, radiation, and heat sink/source factors as well as Eckert number. A comparative analysis has been carried out in this work with a fine agreement with previously established data. It has been established in this work that maximum heat is transformed in the case of Cu + CuO/blood hybrid nanofluid flow on an exponentially stretching sheet.

A Photochemically Active Cu2O Nanoparticle Endows Scaffolds with Good Antibacterial Performance by Efficiently Generating Reactive Oxygen Species.

Cuprous oxide (Cu2O) has great potential in photodynamic therapy for implant-associated infections due to its good biocompatibility and photoelectric properties. Nevertheless, the rapid recombination of electrons and holes weakens its photodynamic antibacterial effect. In this work, a new nanosystem (Cu2O@rGO) with excellent photodynamic performance was designed via the in situ growth of Cu2O on reduced graphene oxide (rGO). Specifically, rGO with lower Fermi levels served as an electron trap to capture photoexcited electrons from Cu2O, thereby promoting electron-hole separation. More importantly, the surface of rGO could quickly transfer electrons from Cu2O owing to its excellent conductivity, thus efficiently suppressing the recombination of electron-hole pairs. Subsequently, the Cu2O@rGO nanoparticle was introduced into poly-L-lactic acid (PLLA) powder to prepare PLLA/Cu2O@rGO porous scaffolds through selective laser sintering. Photochemical analysis showed that the photocurrent of Cu2O@rGO increased by about two times after the incorporation of GO nanosheets, thus enhancing the efficiency of photogenerated charge carriers and promoting electron-hole separation. Moreover, the ROS production of the PLLA/Cu2O@rGO scaffold was significantly increased by about two times as compared with that of the PLLA/Cu2O scaffold. The antibacterial results showed that PLLA/Cu2O@rGO possessed antibacterial rates of 83.7% and 81.3% against Escherichia coli and Staphylococcus aureus, respectively. In summary, this work provides an effective strategy for combating implant-related infections.

Nanoparticle Effects on Ice Plant Mineral Accumulation under Different Lighting Conditions and Assessment of Hazard Quotients for Human Health.

Nanotechnologies can improve plant growth, protect it from pathogens, and enrich it with bioactive and mineral substances. In order to fill the lack of knowledge about the combined environmental effects of lighting and nanoparticles (NPs) on plants, this study is designed to investigate how different HPS and LED lighting combined with CuO and ZnO NPs influence the elemental composition of ice plants (Mesembryanthemum crystallinum L.). Plants were grown in hydroponic systems with LED and HPS lighting at 250 ± 5 μmol m-2 s-1 intensity, sprayed with aqueous suspensions of CuO (40 nm, 30 ppm) and ZnO (35-45 nm, 800 ppm) NPs; their elemental composition was measured using an ICP-OES spectrometer and hazard quotients were calculated. LED lighting combined with the application of ZnO NPs significantly affected Zn accumulation in plant leaves. Cu accumulation was higher when plants were treated with CuO NPs and HPS illumination combined. The calculated hazard quotients showed that the limits are not exceeded when applying our selected concentrations and growth conditions on ice plants. In conclusion, ice plants had a more significant positive effect on the accumulation of macro- and microelements under LED lighting than HPS. NPs had the strongest effect on the increase in their respective microelements.

Multitasking needle-shaped copper oxide nanorods decorated cystine modified polymer/graphene oxide nanocomposite for 4-nitrophenol reduction, dye degradation, and textile effluent treatment

Nitroaromatic chemicals, including 4-nitrophenol (4-NP) and dyes, pose substantial risks to human health and the environment. Various catalysts that facilitate the reduction of 4-NP to 4-aminophenol (4-AP) have been documented to reduce its toxicity. Herein, we developed a novel nanocomposite consisting of needle-like copper oxide nanorods immobilized with L-cystine functionalized polyglycidyl methacrylate integrated graphene oxide (Cys-PGMA@GO-CuO) nanocomposite. The formation of this nanocomposite was comprehensively characterized using various analytical techniques. X-ray diffraction revealed a semi-crystalline nature for pure PGMA/GO with a prominent peak at 2θ = 19.25°. The introduction of inherently crystalline CuO nanoparticles in Cys-PGMA@GO-CuO rendered the entire composite completely crystalline. Further, the photocatalytic efficiency of the Cys-PGMA@GO-CuO nanocomposite was evaluated through advanced oxidation processes (AOP) for treating various toxic pollutants in wastewater remediation. The nanocomposite efficiently degraded dyes like methyl orange (99.8%) and methylene blue (99.9%) in just 50 mins and reduced toxic 4-NP to 4-AP within 40 mins. We further investigated the optimal degradation conditions based on [oxidant], [dye], and the presence of scavengers to understand the rate of degradation. Notably, the composite exhibited remarkable recyclability and stability. The performance of Cys-PGMA@GO-CuO was further evaluated using real wastewater samples, achieving a remarkable decolorization of 99.5% in textile dyeing wastewater and 97.1% in methylene blue-contaminated tap water. These results demonstrate the promising potential of this nanocomposite as an economically viable alternative approach for removing various organic pollutants from wastewater. Additionally, its successful application in real water sample analysis suggests its significant potential for practical implementation in water treatment processes.

Integrative chemical, physiological, and metabolomics analyses reveal nanospecific phytotoxicity of metal nanoparticles

The increasing application of metal nanoparticles (NPs) via agrochemicals and sewage sludge results in non-negligible phytotoxicological risks. Herein, the potential phytotoxicity of ZnO and CuO NPs on wheat was determined using integrative chemical, physiological, and metabolomics analyses, in comparison to Zn2+ and Cu2+. It was found that ZnO or CuO NPs had a stronger inhibitory effect on wheat growth than Zn2+ or Cu2+. After exposure to ZnO or CuO NPs, wheat seedlings accumulated significantly higher levels of Zn or Cu than the corresponding Zn2+ or Cu2+ treatments, indicating the active uptake of NPs via wheat root. TEM analysis further confirmed the intake of NPs. Moreover, ZnO or CuO NPs exposure altered micronutrients (Fe, Mn, Cu, and Zn) accumulation in the tissues and decreased the activities of antioxidant enzymes. The metabolomics analysis identified 312, 357, 145, and 188 significantly changed metabolites (SCMs) in wheat root exposed to ZnO NPs, CuO NPs, Zn2+, and Cu2+, respectively. Most SCMs were nano-specific to ZnO (80%) and CuO NPs (58%), suggesting greater metabolic reprogramming by NPs than metal ions. Overall, nanospecific toxicity dominated the phytotoxicity of ZnO and CuO NPs, and our results provide a molecular perspective on the phytotoxicity of metal oxide NPs.

Thermal performance enhancement of lauric acid using nanomaterials as composite phase change material.

In the present work, lauric acid was taken as a phase change material (PCM), and different nanoparticles (NPs) such as SiO2, TiO2, CuO, and ZnO were taken as the supporting materials. CuO NPs were prepared through the co-precipitation technique; SiO2, TiO2, and ZnO NPs were synthesized via the sol-gel technique. These NPs with different weight fractions were dispersed into molten lauric acid, individually. The variations in thermal properties (phase change temperature and latent heat for solid and liquid) of the prepared composite PCMs due to the dispersion of NPs were observed by DSC analyses. An increase in thermal conductivity of the composite PCMs was observed with the increasing weight fraction of NPs. In order to ascertain the long-term utility, a thermal reliability test was conducted on the composite PCMs with repeated heating and cooling cycles. Also, the specific heats of the pure PCM and the composite PCMs were determined as a function of temperature. Further, the experimental investigation was performed on the pure PCM and the prepared composite PCMs to assess their phase change behavior, and the test results clearly proved that the time required for the complete melting and freezing process of the composite PCMs was less when compared to pure PCM. By considering the above facts, the newly prepared composite PCMs can be recommended as a potential candidate for low-temperature solar heating applications.