Addition Of CuO Nanoparticles Research Articles

Polyvinyl pyrrolidone/ carboxymethyl cellulose (PVP/CMC) polymer composites containing CuO nanoparticles synthesized via laser ablation in liquids

Polyvinyl pyrrolidone/carboxymethyl cellulose (PVP/CMC) polymer composites containing CuO nanoparticles synthesized via laser ablation in liquids were prepared. Fourier transform infrared (FTIR) spectroscopy, UV/Vis spectroscopy, and scanning electron microscopy (SEM) were used to characterize the structural, optical, and morphological properties of the polymer composites. The addition of CuO nanoparticles resulted in changes in the FTIR spectra, indicating interaction between the polymer matrix and nanoparticles. UV/Vis spectroscopy showed a red shift in absorption and a decrease in optical bandgap with increasing CuO nanoparticle content. SEM micrographs revealed increases in surface roughness with higher CuO nanoparticle loading. Antibacterial activity of the composites against Gram-positive and Gram-negative bacteria increased with greater CuO nanoparticle concentration. The results suggest these biofilms have potential for use as coating materials in biomedical applications.

Structural, Optical and Dielectric Properties of Some Nanocomposites Derived from Copper Oxide Nanoparticles Embedded in Poly(vinylpyrrolidone) Matrix.

Polymer nanocomposite films based on poly(vinyl pyrrolidone) incorporated with different amounts of copper oxide (CuO) nanoparticles were prepared by the solution casting technique. The PVP/CuO nanocomposites were analyzed by X-ray diffractometry (XRD), scanning electron microscopy, UV-Visible absorption spectroscopy and dielectric spectroscopy. The XRD analysis showed that the monoclinic structure of cupric oxide was maintained in the PVP host matrix. The key optical parameters, such as optical energy gap Eg, Urbach energy EU, absorption coefficient and refractive index, were estimated based on the UV-Vis data. The optical characteristics of the nanocomposite films revealed that their transmittance and absorption were influenced by the addition of CuO nanoparticles in the PVP matrix. Incorporation of CuO nanoparticles into the PVP matrix led to a significant decrease in band gap energy and an increase in the refractive index. The dielectric and electrical behaviors of the PVP/CuO nanocomposites were analyzed over a frequency range between 10 Hz and 1 MHz. The effect of CuO loading on the dielectric parameters (dielectric constant and dielectric loss) of the metal oxide nanocomposites was also discussed.

Evaluation of the efficacy of NanoPak Mask®: A polyacrylonitrile/copper oxide nanofiber respiratory mask

The global spread and pandemics of various infectious and viral diseases, in recent years has doubled the significance of protection masks, especially respiratory masks with better breathability and antibacterial and antiviral properties. On the other hand, the COVID-19 pandemics has motivated researchers to study effective respiratory masks. Moreover, different factors such as air pollution have long led to various respiratory diseases and even death. In the meantime, the production of an antibacterial mask capable of trapping nanoscale particles is indispensable due to the conditions for the growth of bacteria on the mask. This study is thus aimed at investigating the performance of the first electrospun polyacrylonitrile (PAN)/Copper oxide (CuO) nanofiber respiratory mask, also called NanoPak Mask®. Copper oxide nanoparticles were selected as an antibacterial agent due to their favorable antimicrobial properties and abundance, as well as cost-effectiveness. FESEM, EDX, and FTIR analyses were used to assess the morphological properties, CuO content, and presence the substrate components, respectively. Surface hydrophilicity was evaluated based on the water contact angle. The biocompatibility and antibacterial properties were examined by MTT assay and viable cell count test. The addition of CuO nanoparticles did not alter the diameter of nanofibers and cell toxicity, on the contrary, it enhanced the surface hydrophilicity of nanofibers and its antibacterial properties. The results of the present study showed that the respirator NanoPak Mask® is a nanosized intermediate layer and biocompatible breath mask with antibacterial properties duo to containing PAN/CuO nanofiber. Therefore, the NanoPak Mask® demonstrates the promising potential for scaling up to an industrial level and entering the market.

Tailoring the rheological properties of biosynthesized Copper oxide nanoparticles decorated Carboxymethyl cellulose hydrogels for biomedical applications

Nanoparticle-decorated hydrogels have seized substantial momentum in recent years, exclusively in biomedical research. In this investigation, Copper oxide nanoparticles decorated carboxymethyl cellulose hydrogels were prepared in an eco-friendly approach without using toxic cross-linkers. Initially, Copper oxide nanoparticles were prepared by biosynthesis approach to diminish the harmful effects of chemicals and to improve the biological activities using the leaf extract of Justicia adhatoda. The prepared nanoparticles were incorporated into the Carboxymethyl solution and carbopol to form a hydrogel by non-covalent interactions. X-ray diffraction analysis of CuO nanoparticles revealed a monoclinic crystalline structure without impurity. Rheological investigation of the pure hydrogel and CuO-decorated hydrogels revealed that CuO contributed to the enhancement of the hydrogel's mechanical performance. All the hydrogels demonstrated shear thinning behavior and better flow behavior index with the addition of CuO nanoparticles. The yield stress of the hydrogels was improved and found to be in the range of 61–79 Pa, which matches the ideal yield stress values in transdermal drug delivery. Storage moduli of hydrogels as a function of frequency was doubled (14–47.5 Pa), endorsing the involvement of CuO nanoparticles in crosslinking the polymeric matrix. Temperature and time sweep measurements revealed that the stability of the hydrogels also improved with the addition of CuO nanoparticles. The antibacterial activity of the hydrogels was evaluated using biofilm inhibition and showed better inhibition of 70 ± 0.5%, 75 ± 0.9%, 86 ± 0.8%, and 83 ± 0.8% against Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, and Enterococcus faecalis, respectively with increased concentration of CuO nanoparticles. The cell viability of the CuO-decorated hydrogels against MCF-7 and A431 was found to be 39% and 42%, respectively. Therefore, the eco-friendly biosynthesized CuO nanoparticles decorated hydrogels with improved mechanical properties can be employed in injectable and transdermal drug delivery systems.

Nanoscale insight into the thermal properties of lauric acid and CuO based phase change material used for thermal energy storage

Lauric acid (LA) based phase change material (PCM) has been broadly used for thermal energy storage, whereas its poor thermal performance limits its practical application. In this paper, the microscale structure of LA as the PCM and CuO nanoparticles based composite PCM was established, the thermal properties including density, thermal diffusion, thermal conductivity, melting enthalpy were predicted by means of molecular dynamics (MD) simulations. The microscopic structure evolution and phase transition characteristic of the CPCM system were observed and investigated by structure snapshots and thermal diffusion behaviors. The addition of CuO nanoparticle makes the self-diffusion coefficient of LA based PCM decreased by 15.13 %, and addition of CuO nanoparticle is an effective way to enhance the thermal conductivity of LA based PCM significantly, and it can lead to a 33.765 % increase on average in thermal conductivity with an addition fraction of 6.86 wt%, the melting enthalpy was decreased by 17.57 %, and possible mechanism was revealed at nanoscale. This study is expected to be helpful for the preparation, performance enhancement and practical application of LA based PCM.

Effect of Copper Oxide Nanoparticles on the Performance of Polyvinyl Chloride Membranes

AbstractPolyvinyl chloride (PVC)/copper oxide (CuO) nanocomposite membranes were fabricated at different CuO nanoparticles loading levels using the phase inversion method. The fabricated membranes were tested through two filtration cycles in a submerged membrane system to remove bovine serum albumin (BSA) from water. Results showed that the hydrophilicity and porosity of the nanocomposite membranes were enhanced with an increase of CuO nanoparticles loading. The field emission electron microscopy images from the membrane surface demonstrated that the number and size of pores increased with addition of CuO nanoparticles. The atomic force microscopy test displayed that all nanocomposite membranes showed lower surface roughness in comparison to neat PVC membranes. The obtained results from membrane performance indicated that the irreversible fouling ratio for neat PVC membranes in the first and second cycles of filtration decreased for PVC/CuO‐1.5 membranes. Compared with the neat PVC membrane, the membrane containing CuO exhibited better capabilities such as the enhanced permeation flux, higher BSA rejection rate, and better antifouling properties.

Corrosion behavior and microstructure of Al–10Zn alloy with nano CuO addition

The present study explores the preparation of Al–10wt.%Zn alloy by the casting process. Nano CuO was prepared by the Co-precipitation method. The effect of adding nanostructure of (1wt.% CuO) to Al–10Zn alloy was studied the corrosion effects as-cast and with different aging temperatures (423, 443, and 463 K) for 2 h in 3.5% NaCl aqueous solution after homogenized for 2 h at 500 K at room temperature. Electrochemical measurements (OCP, Tafel, and EIS) were performed to determine the corrosion rate (C.R.) and corrosion current density (Icorr.) to find out corrosion behavior. In addition, microstructures of Al–10Zn and Al–10Zn–1CuO were observed using a scanning electron microscope, EDX mapping, and the optical microscope to investigate the effect of the nanoparticle’s addition before and after aging and the corrosion test. The average crystal size and the dislocation density were calculated from the XRD pattern. The results show that the appropriate addition of CuO nanoparticles can refine the Al–10Zn alloy and shift the Al–10Zn alloy to a more noble direction.

Influence of Nanoparticles and Magnetic Field on the Laminar Forced Convection in a Duct Containing an Elastic Fin

In the present paper, an investigation of the effect of a magnetic field and nanoparticles suspended in pure water on the forced flow in a duct containing an elastic rectangular fin is performed. The nanofluid, i.e., CuO nanoparticles suspended in water, flow in the duct with an inlet fully developed velocity profile and a cold temperature. The lower boundary of the duct is kept at a hot temperature, while the upper boundary is adiabatic. According to the ALE formulation, numerical simulations of the laminar flow are carried out, by employing the software package Comsol Multiphysics, to solve the governing equation system: mass, momentum, energy, and deformation. The behavior of the Nusselt number, of the temperature and velocity fields as well as of the stress profiles are presented and interpreted. As a result, the addition of CuO nanoparticles to pure water improves the local and global heat transfer rate by up to 21.33% compared to pure water. On the other hand, it causes an additional deformation of the elastic fin as well as the increase of the stress due to the presence of the nanoparticles, leading to an increase of its maximum displacement of 34.58% compared to the case of pure water flow. Moreover, the enhancement of the flexibility of the fin (and thus its deformation) leads to a relative reduction in terms of convective heat transfer rate, especially downstream of the fin.

Does the addition of nanoparticles always lead to heat transfer enhancement? Numerical solution enriched by artificial neural network

In this study, the effects of loading CuO nanoparticles on heat transfer and pumping power of CuO/liquid paraffin nanofluid were discussed. Although the presence of CuO nanoparticles can increase the thermal conductivity but by increasing the viscosity, the heat transfer may be reduced. Also, the pumping power may not change significantly, depending on the application of the nanofluid and the material for base fluid. Numerical analysis revealed that for NTU greater than five, there is no chance for heat transfer between fluid and tube. In this study, a new figure of merit (FOM) is introduced, and the effect of the presence of nanoparticles in laminar and turbulent regimes at the constant volume/mass flow rate has been examined for CuO/Paraffin nanofluid in tubes. The presence of nanoparticles boosts the density (positive effect) and simultaneously diminishes the specific heat (negative effect). Under the constant mass flow rate, the negative effect of CuO nanoparticles is predominant, and therefore the addition of CuO nanoparticles reduces heat transfer up to 4.8%. A general negative effect of nanoparticles is to increase pumping power. Based on calculations, in the laminar flow regime, the sensitivity of the pumping power to the presence of CuO nanoparticles is higher, so in laminar flow, the pumping power increased more than in the turbulent regime. Defining temperature, mass fraction, and the ratio of nanofluid properties to the base fluid as input variables to the artificial neural network (ANN), it can estimate the FOM to affirm whether adding nanoparticles is useful or not by a maximum error of less than 1%.

The responses and detoxification mechanisms of dark septate endophytes (DSE), Exophiala salmonis, to CuO nanoparticles.

To understand the tolerance mechanisms of dark septate endophytes (DSE), Exophiala salmonis, to CuO nanoparticles (CuO-NPs) with different sizes (40 and 150nm), we investigated the morphology, antioxidant response, Cu subcellular distribution, and the melanin gene expression in the mycelia of E. salmonis. E. salmonis was cultured in liquid and solid media under the stress of increasing CuO-NP concentrations (0, 50, 100, 150, and 250mg/L). Results showed that (1) E. salmonis showed good CuO-NP tolerance, and the tolerance to CuO-NPs at 150nm was stronger than that at 40nm. A large number of agglomeration structures were observed on the mycelia surface with the exception of 50mg/L CuO-NPs with a diameter of 150nm. (2) CuO-NP stress significantly stimulated the production of antioxidant enzymes, particularly the CuO-NPs with small particle size (40nm). (3) Cu uptaken by E. salmonis increased proportionally with the increase of CuO-NP concentration in the medium. More than 80% Cu was absorbed in cell wall of mycelia treated with a small particle size (40nm). (4) FTIR analysis revealed that hydroxyl, amine, carboxyl, and phosphate groups were associated with CuO-NP binding regardless of particle size. (5) Fungal melanin content increased with the addition of CuO-NPs; the increase of melanin induced by CuO-NPs with small particle size (40nm) was more significant. (6) The expression of 1,3,6,8-tetrahydroxynaphthalene reductase (Arp2) in the melanin synthesis pathway increased under the stress of CuO-NPs, and CuO-NPs with a small particle size (40nm) caused a significant change in the expression level of Arp2 gene than those with a large particle size (150nm). In conclusion, E. salmonis had a strong tolerance to CuO-NPs and mitigated the toxic effects of CuO-NPs through the antioxidant system, the expression of genes related to melanin synthesis, and the synthesis of melanin.

The effect of different enclosure materials and NePCMs on performance of battery thermal management system

A battery thermal management system (BTMS) with nano-enhanced phase change material (NePCM) is a favorable system because of its sustainable lifespan and high-latent heat in the absence of needing any external pumping power like air/liquid cooling in electric vehicles. However, some improvements and investigations are needed to improve the system. Hence, this current study has been conducted numerically to analyze the effect of different materials of the enclosure including copper (Cu), aluminum (Al), and acrylic (Acr) on thermal performance of a cylindrical lithium-ion BTMS by utilizing CuO nanoparticles and n-eicosane PCM. Additionally, the impact of various CuO nanoparticles volume fractions of NePCM (2 % and 4 %) on battery surface temperature and Nusselt number have been investigated. The battery is considered under the full discharge condition at a 3C current rate within 20 min. Furthermore, two different initial and ambient temperatures (300 K and 305 K) have been considered to study the thermal performance of BTMS in solid and solid/liquid phases of NePCM. The numerical results presented that using Cu enclosure in BTMS keeps the battery surface temperature at the lowest level and also causes to delay in melting the NePCM. Moreover, with the addition of CuO nanoparticles to pure n-eicosane and an increase in nanoparticles volume fraction, the battery surface temperature and onset melting time of NePCMs decreases and increases, respectively. Finally, the Nusselt number investigation illustrates that by adding nanoparticles to pure n-eicosane and increasing the nanoparticles volume fraction, the Nusselt number decreases slightly.

Responses of Prorocentrum cordatum (Ostenfeld) Dodge, 1975 (Dinoflagellata) to copper nanoparticles and copper ions effect.

In the present study, changes were determined in morphological, structural-functional, and fluorescent parameters of Prorocentrum cordatum with the addition of CuO nanoparticles (NPs) and copper ions (CuSO4). A stimulating effect of low Cu2+ concentrations (30μg L-1) on algal growth characteristics was observed. HigherCu2+ concentration of 60-600μg L-1 and CuO NPs concentration of 100-520μg L-1 inhibited algal growth. Ionic copper is more toxic to P. cordatum than NPs. After 72h of algae cultivation in the medium supplemented with CuSO4 and CuO NPs, EC50 values (calculated based on cell abundance) were of 60 and 300μg L-1 (in terms of copper ions), respectively. Reduction in algal growth rate is due to disruption in cell cycle, changes in nuclear morphology, chromatin dispersion, and DNA damage. The studied pollutants slightly affected the efficiency of P. cordatum photosynthetic apparatus. Addition of the pollutants resulted in an increased production of reactive oxygen species (ROS). At a concentration of Cu2+ of120μg L-1 and a concentration of CuO NPs 0-300μg L-1 of CuO NPs increase in ROS production is short-term with a decrease at later stages of the experiment. This is probably due to the activation of antioxidant mechanisms in cells and an increase in the concentration of carotenoids (peridinin) in cells. The high values of ROS production persisted throughout the experiment at sublethal copper concentrations (400-600μg L-1 of CuSO4 and 520μg L-1 of CuO NPs). Sublethal concentrations of pollutants caused restructuring of cell membranes in P. cordatum. Shedding of cell membranes (ecdysis) and formation of immobile stages (temporary or resting cysts) were recorded. The pronounced mechanical impact of NPs on the cell surface was observedsuch as-deformation and damage of a cell wall, its "wrinkling" and shrinkage, and adsorption of NP aggregates.

Performance, Emission, and Study of DI Diesel Engine Running on Pumpkin Seed Oil Methyl Ester with the Effect of Copper Oxide Nanoparticles as an Additive

The usage of petroleum fuels in IC engines is hazardous to humans, plants, and agriculture since they exhaust poisonous pollutants into the environment. Substantial research is now being conducted to identify an alternative to petroleum fuel and to enhance its quality. Nanoparticles are a relatively new technology that may be used to improve the properties of fuel. Engine tests were performed on conventional CI engines using a diesel and biodiesel blend under different running circumstances. The purpose of this study is to investigate the performance, emissions, and combustion characteristics of a pumpkin seed oil methyl ester diesel blend (PSOME20) in a diesel engine with the help of a copper oxide nanoparticle. CuO nanoparticles in varying concentrations (50 and 100 ppm) were dispersed in the PSOME20 fuel. The results showed that the BTE of the PSOME20CuO100 fuel is 2.3% higher than that of the PSOME20 fuel, but the reduction in BSFC is 6.4%. Engine HC, CO, and smoke emissions were being significantly minimized when CuO nanoparticles were mixed with PSOME20. The addition of CuO nanoparticles to PSOME20 enhanced combustion behaviors such as HRR and cylinder pressure.

Using nanoparticles in solar collector to enhance solar-assisted hot process stream usefulness

In this study, focusing on building energy usage (BEU) reduction, a solar system was added to HVAC system to reduce its energy demand. The evaluation of the usefulness of incorporating the solar system for three climatic zones in Saudi Arabia (Najran, Sharorah and Taif) was studied. The annual calculations showed that solar collectors filled with water-EG (70:30 wt%) reduced BEU by 14,790 kWh (for Najran), 16,440 kWh (Shrorah) and 12,420 kWh for Tiaf climate regions. This means under the climate of Sharorah, solar collectors were more efficient than others. The addition of CuO nanoparticles improved the performance of collectors in all three regions. In Sharorah, the energy saving in the presence of CuO (at 25 ppm) was calculated to be 18,730 kWh, and with the addition of more alpha, the energy-saving reached 19,440 kWh (at 50 ppm) and 20,430 kWh (at 100 ppm). Finally, it was found that owing to using a solar system equipped with CuO nanoparticles, BEU reduced by 45.1% (for Najran), 35.7% (for Sharorah) and 38.4% (for Taif) under the best conditions.

Investigation on the effect of CuO nanoparticles on the IFT and wettability alteration at the presence of [C12mim][Cl] during enhanced oil recovery processes

In the current study, the effect of CuO nanoparticles (CuO-NPs) at the presence of dodecyl-3-methylimidazolium chloride ([C12mim][Cl]) is investigated on the interfacial tension (IFT) reduction, wettability alteration, and even tertiary oil recovery. Since the prepared solutions with CuO-NPs are completely dark and it is impossible to measure the IFT of these solutions in the presence of crude oil using the pendant drop method (since one of the phases must be transparent for IFT measurement using the pendant drop method), n-heptane (representative of saturates) and toluene (representative of aromatics) are used only for IFT measurement of solutions prepared by CuO-NPs, while rest of the experiments are performed using crude oil. The obtained results reveal that CuO-NPs are not stable in the aqueous solution in the absence of surfactant which means fast precipitation of CuO-NPs and a high risk of pore plugging. In this way, the stability of CuO-NPs is investigated at the presence of dodecyl-3-methyl imidazolium chloride ([C12mim][Cl]) as an effective surfactant for stabilizing the CuO-NPs in the aqueous solution (more than 1 month without precipitation using 1000 ppm of IL). Further measurements reveal that although the presence of IL in the aqueous solution can reduce the IFT of oil/aqueous solution system, especially for the aqueous solutions prepared by formation brine (0.65 mN.m−1), the presence of CuO-NPs has no considerable effect on the IFT. On the other hand, not only the contact angle (CA) measurements reveal the considerable effect of IL on the wettability alteration toward water-wet condition (68.3° for IL concentration of 1000 ppm) but also the addition of CuO-NPs can significantly boost the wettability alteration toward strongly water-wet condition (23.4° for the concentration of 1000 ppm of CuO-NPs). Finally, several core flooding experiments are performed using different combinations of chemicals to find the effect of these chemicals on the tertiary oil recovery factor. The results reveal that the presence of CuO-NPs can enhance the oil recovery of injected chemical slug (aqueous solution prepared by dissolution of IL with an oil recovery factor of 10.1% based on Original oil in place (OOIP)) to 13.8, %, 16.9%, and 21.2% based on OOIP if 500, 1000, 2000 ppm of CuO-NPs existed in the solution concomitant with 1000 ppm of [C12mim][Cl].

Study of thermophysical properties of chloride salts doped with CuO nanoparticles for solar thermal energy storage

As heat storage and heat transfer medium, molten salt plays a vital role in achieving high heat transfer efficiency in concentrating solar power (CSP) plants. In this study, ternary chloride salts (NaCl–KCl–MgCl 2 ) is considered as the base salt and the nanocomposites doped with different mass fractions of CuO are synthesized using the solution evaporation method. The thermophysical properties of the nanocomposites, including melting temperature, phase change enthalpy, specific heat, thermal diffusivity, and thermal conductivity are investigated. The experimental results indicated the melting temperature of the nanocomposites is very close to that of the base salt. The specific heat of the nanocomposite in the liquid phase region is 10.51% higher than that of the base salt when the mass fraction of CuO was 0.7%. The addition of CuO nanoparticles significantly increase the thermal diffusivity and thermal conductivity of the base salt. The thermal diffusivity and thermal conductivity of the nanocomposites are increased by 10.95–37.23% and 15.85–39.55% compared to the base salt, respectively. The nanocomposites doped with CuO nanoparticles exhibit good application prospects and excellent thermal energy storage performance for high-temperature CSP systems. To improve the heat transfer characteristics of chloride salts, nanocomposites doped with 0.2, 0.7, and 2.0 wt% CuO nanoparticles were synthesized. The nanocomposites showed excellent TES performance for high-temperature CSP systems. • Nanocomposites doped with CuO exhibited excellent thermal energy storage performance. • Specific heat in liquid phase region had an enhancement of 10.51% by doping 0.7 wt% CuO nanoparticles. • Thermal diffusivity of nanocomposites increased with increasing temperature. • Thermal diffusivity and thermal conductivity of base salt can be increased by adding CuO nanoparticles. • The mechanism of the enhancement of thermophysical properties of nanocomposites was investigated.

Mechanical and Thermal Properties of Epoxy Polymer Composites Reinforced with CuO

Polymer nano composites using CuO as filler material and epoxy as matrix materials were prepared with different concentrations of CuO nano particles (1-5 wt%) by shear mixing followed by ultra-sonication process. The mechanical properties such as compressive strength and modulus were characterized using ASTM standards. It was found that the addition of CuO nano particles both compressive strength and modulus increased. As the CuO content increased in epoxy matrix the moduli values found to increase and were further analyzed using micromechanical models. The analytical models discussed correlate well with experimental values. The models discussed include Nicolais – Narkis, Turcsanyi, Piggot – Leidner and Nielsen models for the tensile strength values and for tensile modulus the models discussed include Halpin Tsai, Kerner and Sato – Furukawa models. These micromechanics models predict stiffness of nanocomposites with both aligned and randomly oriented fillers. XRD pattern revealed the interaction between CuO nanoparticles and epoxy matrix. The thermal decomposition behaviour revealed that there is an enhancement of onset of decomposition temperature by 28oC for 5wt% CuO filled epoxy than that of pure epoxy

Thermal performance of heat sink using nano-enhanced phase change material (NePCM) for cooling of electronic components

Present experimental study reports the thermal performance of nano-enhanced phase change material (NePCM) based thermal energy storage system for cooling of electronic components. The NePCM based heat sink (HS) cooling is a passive cooling technique that can eliminate the fan-based conventional cooling technique. A plate heater was used to impersonate the heat generated by microelectronics. Here, copper oxide (CuO), paraffin wax, and aluminum are considered as nanoparticle, phase change material (PCM), and HS material, respectively. Different HS configurations such as HS with no fin (HSNF), HS with rectangular plate fins (HSRPF), HS with square pin fins (HSSPF), and HS with circular pin fins (HSCPF) are studied for a fixed volume fraction of fin material. The performance of various HS configurations are analyzed for different nanoparticle concentration (∅=0.5–3.0), and heat flux values (q′′=1.5–3.0 kW/m2). For ∅= 3.0, thermal conductivity and viscosity of NePCM are found to increase by 150% and 100%, respectively. The HSSPF involving PCM/NePCM exhibits better thermal performance compared to other HS configurations. The maximum reduction in temperature is found to be 13 °C and 15 °C for HSSPF involving PCM and NePCM (∅= 0.5), respectively. The highest enhancement ratio of 5.0 is obtained for HSSPF at q″= 2.0 kW/m2 for SPT of 65 °C. The addition of CuO nanoparticle beyond ∅=0.5 decreases the HS performance considerably.

Development of novel electrochemical sensor for the detection of biological warfare agents: enzyme, antibody, and DNA free

There is an urgent need to develop a novel sensor that can quickly and accurately detect biological warfare agents (BWAs). A novel electrochemical sensor was specially designed and developed for Staphylococcus aureus as a potential BWAs without using any enzyme, antibody, or genetic material. Cyclic voltammetry (CV), linear resistance polarization (LRP), chronoamperometry, impedance spectroscopy, and Differential Pulse Voltammetry (DPV) techniques were used for fast and accurate detection of BWAs. Co-precipitation technique was used for the synthesis of CuO nanoparticles (NPs) for their use in the electrochemical sensor. The effect of temperature, stirring and addition of CuO NPs was thoroughly investigated. The storage, stability, and performance of electrochemical sensor was tested for 45 days. The current response of the electrochemical sensor was found linear with the correlation coefficient, R2 = 0.991. The major advantage of this novel electrochemical sensor is that immobilization of enzyme, antibody, or DNA is not required in sensing technology as the immobilization process makes biosensors a highly specific. The novel electrochemical sensor was very quick, accurate, non-specific, and provide reliable results in the qualitative and quantitative estimation of pathogenic bacteria as a potential BWAs. A novel electrochemical sensor was specially designed and developed for the detection of Staphylococcus aureus pathogenic bacteria as a potential BWAs without using any enzyme, antibody, or genetic material. Cyclic voltammetry, linear resistance polarization, chronoamperometry, impedance spectroscopy, and Differential Pulse Voltammetry (DPV) experiments were carried out for fast and accurate detection of BWAs. Storage, stability, and reusability of the electrochemical sensor was tested for continuous 45 days. The current response of the electrochemical sensor was found to be linear with the correlation coefficient, R2 = 0.991. The major advantage of this novel sensor is that immobilization of enzyme, antibody, or DNA is not required in sensing technology as the immobilization process makes biosensor a highly specific. The novel electrochemical sensor was proved to be very quick, accurate, non-specific, and provide reliable results in the qualitative and quantitative estimation of pathogenic bacteria as a potential BWAs.

Significantly enhanced electromagnetic interference shielding effectiveness of montmorillonite nanoclay and copper oxide nanoparticles based polyvinylchloride nanocomposites

In the present study, montmorillonite (MMT) nanoclay and copper oxide (CuO) nanoparticles (NPs) reinforced polyvinylchloride (PVC) based flexible nanocomposite films were prepared via solvent casting technique. Using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA), the structural, morphological and thermal properties of PVC/MMT/CuO nanocomposite films with various loadings of CuO NPs and MMT were investigated. These studies suggested that by the addition of dual nanofillers in the polymer matrix some structural modifications occurred owing to the homogenous dispersion of MMT and CuO NPs within the PVC matrix. The TGA results reveal that the addition of CuO NPs and MMT considerably improved the thermal stability of the nanocomposites. The EMI shielding effectiveness (SE) of nanocomposites was examined in the X-band (8–12 GHz) and Ku-band (12–18 GHz) frequency regions. The EMI SE values were found to be −30 dB (X-band) and −35 dB (Ku-band) for nanocomposites containing 0.3 wt% of CuO NPs and 4.7 wt% of MMT respectively while the shielding was found to be absorption dominant. These results emphasize that PVC/MMT/CuO nanocomposite films can be used as a potential EMI shielding material.