Advances in Nanoparticles
Latest articles in this journal
Advances in Nanoparticles, Volume 10, pp 66-74; doi:10.4236/anp.2021.102005
To observation, poisonous gases in the environment, Sensors with high selectivity, high response and low operating temperature are required. In this work, pure SnO2 nanoparticles was prepared by using a simple and inexpensive technique (hydrothermal method) without a template. Various confirmatory tests were performed to characterize SnO2 nanoparticles such as energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Transition Electron Microscopy (TEM), during the detection of the gas, we found that pure SnO2 nanoparticles has a high selectivity for ethanol to 100 ppm at a low temperature (180°C) and a high response (about 27 s) and a low detection limit of 5 ppm, also it have response/recovery times about (4 s, 2 s) respectively. The distinctive sensing properties of SnO2 sensor make it a promising candidate for ethanol detection. Furthermore, the gas-sensing mechanism have been examined.
Advances in Nanoparticles, Volume 10, pp 51-65; doi:10.4236/anp.2021.102004
Ten (10) cowpea varieties exposed to alpha nano spin were evaluated during the 2019 cropping season to access the role of alpha nano spin in their growth and dry matter accumulation at the Botanical garden of Federal University, Lafia. A Randomized Complete Block Design (RCBD) with four replications was used. The fourth replication was used for the destructive sampling over time. The seed was exposed to alpha nano spin before planting at 0, 20, 40 and 60 minutes respectively. Results of the study showed that the varieties differed significantly with respect to morphological traits studied (P s such as vine length, number of leaves and above ground stems were significantly influenced by alpha nano spin bombardment. 40 mins alpha nano spin resulted in maximum accumulation of dry matter, leaf area and leaf area index. The traits evaluated were stable under alpha nano spin exposure, suggesting that they could be useful indices in creating genetic variability in each of the varieties.
Advances in Nanoparticles, Volume 10, pp 36-49; doi:10.4236/anp.2021.101003
The growing interest in functionalized nanoparticles and their implementation in oilfield applications (e.g., drilling fluids and enhanced oil recovery (EOR)) facilitate the ongoing efforts to improve their chemical functionalization performance in stabilization of water based or hydrocarbon based nanofluids. Cyclic azasilanes (CAS), substituted 1-aza-2-silacyclopentanes, possess a strained 5-member ring structure. Adjacent Si and N atoms in the ring provide opportunity for highly efficient covalent surface functionalization of hydroxylated nanoparticles through a catalyst-free and byproduct-free click reaction. In this work, hydroxylated silica, alumina, diamond, and carbon coated iron core-shell nanoparticles have been studied for monolayer CAS functionalization. Two cyclic azasilanes with different R groups at N atom, such as methyl (CAS-1) and aminoethyl (CAS-2), have been utilized to functionalize nanoparticles. All reactions were found to readily proceed under mild conditions (room temperature, ambient pressure) during 1 - 2 hours of sonication. CAS functionalized adducts of hydroxylated nanoparticles have been isolated and their microstructure, composition, solubility and thermal stability have been characterized. As a result, it has been demonstrated, for the first time, that covalent surface modification with cyclic azasilanes can be extended beyond the previously known porous silicon structures to hydroxylated silica, alumina and carbon nanoparticles. The developed methodology was also shown to provide access to the nanoparticles with the hydrophilic or hydrophobic surface functional groups needed to enable oilfield applications (e.g., EOR, tracers, drilling fluids) that require stable water based or hydrocarbon based colloidal systems.
Advances in Nanoparticles, Volume 10, pp 1-25; doi:10.4236/anp.2021.101001
This article briefly reviews how to construct an enzyme based hydrogen peroxide sensor involving nanomaterials, which has the advantages of high efficiency, good sensitivity and selectivity, fast response time and an extended range of linearity with lower detection limit. Glucose biosensor is constructed by immobilizing glucose oxidase enzyme on the polycarbonate membrane and the protective cover is then filled with a physiological phosphate buffer, pH 7.4. The novel blocking hydrophobic membrane which is only permeable to hydrogen peroxide is used to eliminate electrochemical interferences. This constructed enzyme based H2O2 biosensor is miniaturized by the involvement of nanomaterials like carbon nanotubes, platinum nanoparticles and silver nanoparticles and it can achieve the effective microscopic detection of glucose. The introduction of nanomaterials including some pure metals (Ag, Au, Pd, Ni, Pt, and Cu), metal oxide (ZnO and TiO2), bimetallic (Au/Ag and Au/Pt) and carbon (nanotubes and graphene) nanomaterials in the construction of the enzyme based H2O2 biosensor improves its sensitivity and performance by enhancing the enzymatic activity, and allows the introduction of many new signal transduction technologies in biosensors. This review article summarizes the working principles of glucose oxidase based hydrogen peroxide sensor, importance of involving nanomaterials in biosensor manufacturing, basic characteristics and components of a biosensor, generations glucose biosensors, procedure of making hydrogen peroxide based biosensor, synthesis of nanomaterials involved in hydrogen peroxide biosensor, and finally some examples of nanomaterials which intervene in hydrogen peroxide biosensor.
Advances in Nanoparticles, Volume 10, pp 26-35; doi:10.4236/anp.2021.101002
A series of colossal magneto resistance (CMR) materials with compositional formula Pr0.5Sr0.5Mn1-xCrxO3 (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by sol-gel technique using pure metal nitrates as the starting materials. These samples were characterized structurally by X-ray diffraction, FTIR and SEM. All the samples exhibit orthorhombic structure without any detectable impurities. The bulk densities for all the compositions were measured from the pellets. The Young’s and Rigidity moduli, Poisson’s ratio and Debye temperature of all the compositions were calculated with the experimentally measured ultrasonic longitudinal and shear velocities at room temperature using pulse transmission technique. As the materials are porous, zero porous elastic moduli have also been calculated using a well-known Hasselmann and Fulrath model. The observed variation of elastic moduli with varying chromium doping concentration has been studied qualitatively.
Advances in Nanoparticles, Volume 9, pp 59-80; doi:10.4236/anp.2020.93005
The increasing demand for new packages with increased shelf life properties has stimulated the increase of research in the active packaging sector. The use of antimicrobial agents requires an in-depth study of their properties to avoid loss of efficiency of the polymer processing. In this context, the objective of this work was to evaluate the preparation of an 18% ethylene vinyl acetate copolymer (EVA) nanocomposite and zinc oxide (ZnO) as microbicidal nanoparticle, prepared in a monosulfon extruder. The nanoparticle was modified with octadecylamine and EVA 18 nanocomposite films were prepared and compared to the systems containing modified nanoparticle. These new materials were characterized by thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), Dynamic Mechanical Analysis (DMA), Time Domain Nuclear Magnetic Resonance (NMR) to investigate the effect of zinc oxide nanoparticles on thermal properties, EVA crystallinity and antimicrobial effect. The TGA showed a tendency of increase of the thermal stability in different proportions of ZnO. DSC results did not show significant changes in thermal parameters. The XRD analysis showed an increase in the degree of crystallinity of the nanocomposites in relation to the EVA matrix and change in the crystallinity with the increase of ZnO percentages. DMA analysis indicates change in structural organization through the variation of storage modulus, loss, and tan delta. Time domain NMR data corroborate with XRD data through the change in molecular mobility.
Advances in Nanoparticles, Volume 9, pp 81-116; doi:10.4236/anp.2020.94006
Fiber reinforced composite (FRC) requires a process of grinding, mixing and compounding natural fibers from cellulosic waste streams into a polymer matrix that creates a high-strength fiber composite. In this situation, the specified waste or base raw materials used are the waste thermoplastics and different types of cellulosic waste including rice husk and saw dust. FRC is a high-performance fiber composite achieved and made possible through a proprietary molecular re-engineering process by interlinking cellulosic fiber molecules with resins in the FRC material matrix, resulting in a product of exceptional structural properties. In this feat of molecular re-engineering, selected physical and structural properties of wood are effectively cloned and obtained in the FRC component, in addition to other essential qualities in order to produce superior performance properties to conventional wood. The dynamic characteristics of composite structures are largely extracted from the reinforcing of fibres. The fiber, held in place by the matrix resin, contributes to tensile strength in a composite, enhancing the performance properties in the final part, such as strength and rigidity, while minimizing weight. The advantages of composite materials always beat down their disadvantages. In this analysis, we tried to find out FRC advance manufacturing, recycling technology and future perspective for mankind and next generation development. This research will bring a new horizon for future science with FRC technology and every aspect of modern science which will bring a stable dimensional stability by recycling process with minimizing waste for environment and next generation science.
Advances in Nanoparticles, Volume 9, pp 23-39; doi:10.4236/anp.2020.91002
The results of this article can be useful in science and technology advancement, such as nanofluidics, micro mixing and energy conversion. The purpose of this article is to examine the impacts of nanoparticle shape on Al2O3-water nanofluid and heat transfer over a non-linear radically stretching sheet in the existence of magnetic field and thermal radiation. The different shapes of Al2O3 nanoparticles that have under contemplation are column, sphere, hexahedron, tetrahedron, and lamina. The governing partial differential equations (PDEs) of the problem are regenerated into set of non-linear ordinary differential equations (ODEs) by using appropriate similarity transformation. The bvp4c program has used to solve the obtained non-linear ordinary differential equation (ODEs). The Nusselt number for all shapes of Al2O3 nanoparticle shapes in pure water with is presented in graphical form. It has reported that the heat transfer augmentation in lamina shapes nanoparticles is more than other shapes of nanoparticle. The relation of thermal boundary layer with shapes of nanoparticles, solid volume fraction, magnetic field and thermal radiation has also presented with the help of graphical representation. It is also demonstrated that lamina shape nanoparticles have showed large temperature distribution than other shapes of nanoparticles.
Advances in Nanoparticles, Volume 9, pp 49-58; doi:10.4236/anp.2020.92004
The Zn0.5CuxMg0.5-xFe2O4 (where x = 0.0, 0.1, 0.2, 0.3 and 0.4) was prepared by sol-gel route and characterized in detail in terms of their structural, morphological, elemental and optical properties as a function of Cu concentration. X-ray diffractometer (XRD) results confirmed the formation of cubic spinel-type structure with average crystallized size in the range of 30.56 to 40.58 nm. Lattice parameter was found to decrease with Cu concentration due to the smaller ionic radius of Cu2+ ion. The HR-SEM images show morphology of the samples as prismatic shaped particles in agglomeration. The elemental dispersive X-ray Spectroscopy (EDX) confirmed the elemental composition of the as-prepared spinel ferrite material with respect to the initial concentration of the synthetic composition used for the material. The Fourier transform infrared (FTIR) spectroscopy confirmed the formation of spinel ferrite and showed the characteristics absorption bands around 463, 618, 876, 1116, 1442, 1622 and 2911 cm-1. The energy band gap was calculated for the samples were found to be in the range of 4.87 to 5.30 eV.
Advances in Nanoparticles, Volume 9, pp 41-48; doi:10.4236/anp.2020.92003
Synthesis of silver nanoparticles using seeds of Nigella sativa as a capping agent was evaluated in this study. Different concentrations of the aqueous extract of N. sativa with silver nitrate solution were exposed to sunlight; as a force for acceleration of the formulation. Then the silver nanoparticles were characterized by UV-Vis, scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. Antibacterial activity of the nanoparticles was investigated against Staphylococcus aureus and Escherichia coli by the disc diffusion method. The characterization of nanoparticles was detected by the change in color to yellow-brown which indicated the formulation of silver nanoparticles. Irregular shapes within range of nanoscale were detected using SEM and XRD techniques. The finding suggests that silver nanoparticles may be effectively used as antibacterial agent.