Organic and inorganic nanomaterials: fabrication, properties and applications.

Nanomaterials and nanoparticles are a burgeoning field of research and a rapidly expanding technology sector in a wide variety of application domains. Nanomaterials have made exponential progress due to their numerous uses in a variety of fields, particularly the advancement of engineering technology. Nanoparticles are divided into various groups based on the size, shape, and structural morphology of their bodies. The 21st century's defining feature of nanoparticles is their application in the design and production of semiconductor devices made of metals, metal oxides, carbon allotropes, and chalcogenides. For the researchers, these materials then opened a new door to a variety of applications, including energy storage, catalysis, and biosensors, as well as devices for conversion and medicinal uses. For chemical and thermal applications, ZnO is one of the most stable n-type semiconducting materials available. It is utilised in a wide range of products, from luminous materials to batteries, supercapacitors, solar cells to biomedical photocatalysis sensors, and it may be found in a number of forms, including pellets, nanoparticles, bulk crystals, and thin films. The distinctive physiochemical characteristics of semiconducting metal oxides are particularly responsible for this. ZnO nanostructures differ depending on the synthesis conditions, growth method, growth process, and substrate type. A number of distinct growth strategies for ZnO nanostructures, including chemical, physical, and biological methods, have been recorded. These nanostructures may be synthesized very simply at very low temperatures. This review focuses on and summarizes recent achievements in fabricating semiconductor devices based on nanostructured materials as 2D materials as well as rapidly developing hybrid structures. Apart from this, challenges and promising prospects in this research field are also discussed.

An overview on human exposure, toxicity, solid-phase microextraction and adsorptive removal of perfluoroalkyl carboxylic acids (PFCAs) from water matrices.

Perfluoroalkyl carboxylic acids (PFCAs) are sub-class of perfluoroalkyl substances commonly detected in water matrices. They are persistent in the environment, hence highly toxic to living organisms. Their occurrence at trace amount, complex nature and prone to matrix interference make their extraction and detection a challenge. This study consolidates current advancements in solid-phase extraction (SPE) techniques for the trace-level analysis of PFCAs from water matrices. The advantages of the methods in terms of ease of applications, low-cost, robustness, low solvents consumption, high pre-concentration factors, better extraction efficiency, good selectivity and recovery of the analytes have been emphasized. The article also demonstrated effectiveness of some porous materials for the adsorptive removal of the PFCAs from the water matrices. Mechanisms of the SPE/adsorption techniques have been discussed. The success and limitations of the processes have been elucidated.

Impact of Hybrid Fillers on the Properties of High Density Polyethylene Based Composites.

The main objective of this work is to develop a variety of hybrid high-density polyethylene (HDPE) micro- and nanocomposites and to investigate their thermal, mechanical, and morphological characteristics as a function of number of fillers and their contents percentage. In this study, 21 formulations of the composites were prepared using fillers with different sizes including micro fillers such as talc, calcium carbonate (CaCO3), as well as nano-filler (fumed silica (FS)) though the melt blending technique. The morphological, mechanical, and thermal properties of the composite samples were evaluated. The morphological study revealed negligible filler agglomerates, good matrix-filler interfacial bonding in case of combined both CaCO3 and FS into the composites. Sequentially, improvements in tensile, flexural and Izod impact strengths as a function of fillers loading in the HDPE matrix have been reported. The maximum enhancement (%) of tensile, flexural and impact strengths were 127%, 86% and 16.6%, respectively, for composites containing 25% CaCO3 and 1% FS without any inclusion of talc filler; this indicates that the types/nature, size, quantity and dispersion status of fillers are playing a major role in the mechanical properties of the prepared composites more than the number of the used fillers.

Nanomolar detection of food additive tert-butylhydroquinone in edible oils based on novel ternary metal oxide embedded ß-cyclodextrin functionalized carbon black.

It is pivotal to precisely detect food preservatives to ascertain food quality and safety. In this work, we report the sensitive electrochemical detection of widely used cytotoxic food preservative tert-butylhydroquinone (TBHQ). A novel nanocomposite was sonochemically prepared by embedding ternary metal oxide (TMO) comprising ZnO, CuO, and MgO in ß-cyclodextrin (ß-CD) functionalized carbon black (CB). The properties of the prepared nanocomposite were evaluated by employing multiple characterization methods. The nanocomposite fabricated on a screen printed carbon electrode exhibited exceptional electrocatalytic activity towards TBHQ detection, evident from the resultant very low detection limit of 1 nM and high sensitivity of 22.67 µA µM-1 cm-2. Moreover, the developed TBHQ sensor evinced all the important traits of a good electrochemical sensor including excellent selectivity, stability, reproducibility, and repeatability. Furthermore, for validating practical feasibility of TBHQ detection, we successfully determined this food additive in edible oils.

Ultrasensitive detection of food colorant sunset yellow using nickel nanoparticles promoted lettuce-like spinel Co3O4 anchored GO nanosheets.

Synthetic food colorants are extensively used across the globe regardless of the fact that they induce deleterious side effects when used in higher amounts. In this work, a novel electrochemical sensor based on nickel nanoparticles doped lettuce-like Co3O4 anchored graphene oxide (GO) nanosheets was developed for effective detection of sulfonated azo dye sunset yellow widely used as a food colorant. Hydrothermal synthesis was adopted for the preparation of lettuce-like spinel Co3O4 nanoparticles and Ni-Co3O4 NPs/GO nanocomposite was prepared using ecofriendly and economical sonochemical method. The prepared ternary nanocomposite meticulously fabricated on a screen-printed carbon electrode exhibited remarkable electrocatalytic activity towards sunset yellow determination. This is apparent from the resultant well-defined and intense redox peak currents of Ni-Co3O4 NPs/GO nanocomposite modified electrode at very low potentials. The developed sunset yellow sensor exhibited a high sensitivity of 4.16 µA µM-1 cm-2 and a nanomolar detection limit of 0.9 nM in the linear range 0.125-108.5 µM. Furthermore, experiments were conducted to affirm excellent stability, reproducibility, repeatability, and selectivity of proposed sensor. The practicality of sunset yellow determination using the developed sensor was analyzed in different varieties of food samples including jelly, soft drink, ice cream, and candy resulting in recovery in the range of 96.16%-102.56%.

Bi-functional renewable biopolymer wrapped CNFs/Ag doped spinel cobalt oxide as a sensitive platform for highly toxic nitroaromatic compound detection and degradation.

Nanomolar-level detection of priority toxic pollutant 4-nitrophenol (4-NP) in environment using a novel ternary nanocomposite based electrochemical sensor and its photocatalytic degradation is reported in this paper. A non-toxic and renewable natural biopolymer, chitosan wrapped carbon nanofibers was embedded with Ag doped spinel Co3O4 to prepare the bi-functional ternary nanocomposite. Economical and ecofriendly sonochemical method was employed in preparation of this porous nanocomposite. We used one-pot aqueous solution approach to synthesize Ag-Co3O4 nanoflowers and ultrasound-assisted method was utilized to prepare CS-CNFs. Morphological and structural properties of synthesized materials were analyzed using different characterization techniques. Electrochemical investigations using cyclic voltammetry and differential pulse voltammetry carried out with prepared ternary nanocomposite modified carbon electrode revealed its outstanding electrocatalytic activity in 4-NP quantification. The developed 4-NP sensor showcased excellent sensitivity of 55.98 µAµM-1cm-2 and nanomolar detection limit of 0.4 nM. Moreover, reproducibility, repeatability, stability, and selectivity were evaluated to confirm reliability of developed sensor. Further, real sample analyses were conducted using domestic sewage, underground water, and tomato to affirm the practical feasibility of 4-NP detection using the proposed sensor.

Analysis of non-Newtonian magnetic Casson blood flow in an inclined stenosed artery using Caputo-Fabrizio fractional derivatives.

BACKGROUND AND OBJECTIVE: Arterial diseases would lead to several serious disorders in the cardiovascular system such as atherosclerosis. These disorders are mainly caused by the presence of fatty deposits, cholesterol and lipoproteins inside blood vessel. This paper deals with the analysis of non-Newtonian magnetic blood flow in an inclined stenosed artery. METHODS: The Casson fluid was used to model the blood that flows under the influences of uniformly distributed magnetic field and oscillating pressure gradient. The governing fractional differential equations were expressed using the Caputo Fabrizio fractional derivative without singular kernel. RESULTS: The analytical solutions of velocities for non-Newtonian model were then calculated by means of Laplace and finite Hankel transforms. These velocities were then presented graphically. The result shows that the velocity increases with respect to Reynolds number and Casson parameter, while decreases when Hartmann number increases. CONCLUSIONS: Casson blood was treated as the non-Newtonian fluid. The MHD blood flow was accelerated by pressure gradient. These findings are beneficial for studying atherosclerosis therapy, the diagnosis and therapeutic treatment of some medical problems.

Magnetic/Polyetherimide-Acrylonitrile Composite Nanofibers for Nickel Ion Removal from Aqueous Solution.

In this study, a magnetic/polyetherimide-acrylonitrile composite nanofiber membrane with effective adsorption of nickel ions in an aqueous solution was created using a simple electrospinning method. Iron oxide nanoparticles (NPs) were stirred and ultrasonically dispersed into a polyetherimide-acrylonitrile solution to create a homogenous NPs suspension, which was placed in an electrospinning machine to produce a uniform and smooth nanofiber composite membrane. Nanoparticle incorporation into this membrane was confirmed using scanning electron microscope, energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and NPs aqueous stability from a leaching test. The high adsorption capability of the membrane on nickel ions was attributed to the combination of magnetic NPs, polyetherimide-acrylonitrile matrix, and the nanostructure of the membrane. A membrane containing magnetic NPs demonstrated the maximum adsorption capabilities (102 mg/g) of nickel ions in an aqueous solution. Various kinetic and isotherm models were applied to understand the adsorption behavior, such as pseudo-second-order kinetic and Langmuir isotherm models. A polyetherimide-acrylonitrile composite nanofiber membrane containing magnetic NPs could be used as an environmentally friendly and nontoxic adsorbent for the removal of nickel ions in an aqueous medium due to its ease of preparation and use and stability in aqueous mediums.

A novel graphene oxide-based ceramic composite as an efficient electrode for capacitive deionization.

In this study, N-doped and TiO2-decorated graphene oxides were developed as efficient nonprecious electrodes for capacitive deionization. The activity of this new material was evaluated in situ and in vivo. The performance of the synthesized material was measured in different saline solutions (0.1, 0.5 and 1.0 M NaCl) as an electrolyte. The results showed that the new material exhibits very good performance (157 F/g at 5 mV/s and 1.0 M NaCl compared to 19.5 F/g for pure graphene oxide). In the desalination test, which was performed in batch mode, the salt adsorption capacity and the efficiency of salt removal were 9.2 mg/g and 98%, respectively. To check the stability, the desalination test was repeated several times, and no change in the performance was observed. The results provide evidence that the newly synthesized material is a potential electrode material for CDI water desalination with satisfactory salt removal ability.

Addition of Graphite Filler to Enhance Electrical, Morphological, Thermal, and Mechanical Properties in Poly (Ethylene Terephthalate): Experimental Characterization and Material Modeling.

Poly(ethylene terephthalate)/graphite (PET/G) micro-composites were fabricated by the melt compounding method using a minilab extruder. The carbon fillers were found to act as nucleating agents for the PET matrix and hence accelerated crystallization and increased the degree of crystallinity. TGA showed that carbon fillers improved the resistance to thermal and thermo-oxidative degradation under both air and nitrogen atmospheres. However, a poor agreement was observed at higher loadings of the filler where the composites displayed reduced reinforcement efficiency. The results demonstrate that the addition of graphite at loading >14.5 wt.% made electrically conductive composites. It was calculated that the electric conductivities of PET/graphite micro-composites were enhanced, above the percolation threshold values by two orders of magnitudes compared to the PET matrix. The minimum value of conductivity required to avoid electrostatic charge application of an insulating polymer was achieved, just above the threshold values. The addition of graphite also improved thermal stability of PET, accelerated its crystallization process and increased the degree of crystallinity. Microscopic results exhibit no indication of aggregations at 2 wt.% graphite, whereas more agglomeration and rolling up could be seen as the graphite content was increased in the PET matrix (in particular, above the percolation threshold value). Furthermore, based on the mechanical experimental characterization of the PET/graphite micro-composites, a large deformation-based mathematical model is proposed for material behavior predictions. The model fits well the experimental data and predicts other mechanical data that are not included in the parameter identification.

NiSn nanoparticle-incorporated carbon nanofibers as efficient electrocatalysts for urea oxidation and working anodes in direct urea fuel cells.

Synthesis of NiSn alloy nanoparticle-incorporated carbon nanofibers was performed by calcining electrospun mats composed of nickel acetate, tin chloride and poly(vinyl alcohol) under vacuum. The electrochemical measurements indicated that utilization of tin as a co-catalyst could strongly enhance the electrocatalytic activity if its content and calcination temperature were optimized. Typically, the nanofibers prepared from calcination of an electrospun solution containing 15 wt% SnCl2 at 700 °C have a current density almost 9-fold higher than that of pristine nickel-incorporated carbon nanofibers (77 and 9 mA/cm2, respectively) at 30 °C in a 1.0 M urea solution. Furthermore, the current density increases to 175 mA/cm2 at 55 °C for the urea oxidation reaction. Interestingly, the nanofibers prepared from a solution with 10 wt% of co-catalyst precursor show an onset potential of 175 mV (vs. Ag/AgCl) at 55 °C, making this proposed composite an adequate anode material for direct urea fuel cells. Optimization of the co-catalyst content to maximize the generated current density resulted in a Gaussian function peak at 15 wt%. However, studying the influence of the calcination temperature indicated that 850 °C was the optimum temperature because synthesizing the proposed nanofibers at 1000 °C led to a decrease in the graphite content, which dramatically decreased the catalyst activity. Overall, the study opens a new venue for the researchers to exploit tin as effective co-catalyst to enhance the electrocatalytic performance of the nickel-based nanostructures. Moreover, the proposed co-catalyst can be utilized with other functional electrocatalysts to improve their activity toward oxidation of different fuels.

Composite nanofibers membranes of poly(vinyl alcohol)/chitosan for selective lead(II) and cadmium(II) ions removal from wastewater.

The nanofibers membranes were fabricated by poly(vinyl alcohol)/chitosan (PVA/Chi) using an electro-spun technique for selective and high adsorption of lead (Pb(II)) and cadmium (Cd(II)) ions based on the solution acidity. The PVA/Chi NFs membranes were characterized systematically using several instrumentations. In addition, several experimental parameters such as initial metal ions concentration, interaction time, adsorbent dosage, solution pH and the effects of competing ions on Pb(II) and Cd(II) adsorption were evaluated. The adsorption data were also clarified that the PVA/Chi NFs membranes were exhibited high kinetic performances towards the both toxic ions at the optimum conditions. The adsorption data were manipulated using different kinetics models, and it was confirmed that only pseudo-second-order model obeyed the adsorption kinetics for Pb(II) and Cd(II) ions. Similarly, the equilibrium data were well fitted with the Langmuir adsorption isotherms model, and the maximum adsorption capacity was 266.12 and 148.79 mg/g for Pb(II) and Cd(II) ions, respectively. The Pb(II) and Cd(II) ions adsorptions were also measured to know the selectivity with simulated environmental solution, and the data were confirmed the high selectivity to Pb(II) and Cd(II) ions at the optimum condition and the nanofibers membrane shown the potentiality for possible use in efficient removal of the selected toxic ions from waste samples. Thus, the PVA/Chi NFs are considered to be effective and promising materials for Pb(II) and Cd(II) ions from wastewaters with high efficiency.