Journal of Nanomaterials
ISSN / EISSN : 1687-4110 / 1687-4129
Published by: Hindawi Limited (10.1155)
Total articles ≅ 5,567
Latest articles in this journal
Journal of Nanomaterials, Volume 2022, pp 1-15; https://doi.org/10.1155/2022/5790074
Silicon nanowires (SiNWs) are promising structures as resonators for applications in ultrasensitive force and mass transducers. In the present work, large-scale molecular dynamics simulations were conducted to explore the effect of gold (Au), a commonly used catalyst, on the vibrational properties of [1 0 0] and [1 1 0] SiNWs. The force field was established using the modified embedded atom method (MEAM) formalism. The parameterization focused on the properties of the hydrogen-covered SiNWs doped with Au, involving the formation energy as well as the structural and vibrational characteristics. The vibrational characteristics of a clamped-clamped SiNW were examined through excitation using a sinusoidal velocity field after energy minimization and thermal equilibration. Different doping concentrations and distributions can significantly change the frequency response, quality factor , and beat phenomenon. The natural frequency decreased with increasing Au concentration, whereas the effect of the impurity distribution on was negligible. Furthermore, was sensitive to the Au concentration and distribution, and the increased concentration led to an overall increment in , accompanied by considerably increased scattering. Besides, the beat period of [1 1 0] SiNWs showed a strong positive correlation with the concentration. The vibration along the elementary axes cannot produce the beat phenomenon. Deflection of the elementary axes in a very small range would lead to a higher energy dissipation rate. In addition, owing to the considerable difference between the atomic masses of Au and Si, randomly distributed Au atoms significantly disturb the symmetry of the SiNWs. However, the elementary axes of the [1 1 0] SiNWs remained stable, even in the models with extremely radial or longitudinal impurity segregation. In contrast, we failed to capture the distinguishable elementary axes for most of the doped [1 0 0] samples. The features described above indicate that the impurity Au can effectively tune the resonant frequency of the [1 1 0] SiNWs, meanwhile, causes no large frequency shift that could be potentially caused by the deflection of the elementary coordinate system.
Journal of Nanomaterials, Volume 2022, pp 1-12; https://doi.org/10.1155/2022/3052175
Albumin is derived from plasma and it is the most abundant protein in plasma, which is an ideal material for the preparation of nanoparticles because of its good biocompatibility, noncytotoxicity, nonimmunogenicity, biodegradability, and so on. Besides, albumin can enhance the targeting of drugs, reduce the toxicity of free drugs, and enhance the water solubility of hydrophobic drugs, etc. Drug delivery systems based on albumin nanoparticles are widely used in the medical field. At present, the main methods of preparing albumin nanoparticles are desolvation, self-assembly, thermal gelation, spray-drying, double emulsification, emulsification, Nab-technology, pH coacervation, and so on. Due to the differences of principle and preparation conditions, these methods show different advantages and disadvantages. This review systematically summarizes the latest research progress of albumin nanoparticles about its methods of preparation in past five years, and it also introduces the latest applications in cancer therapy, existing difficulties. Thus, this review can fill the two gaps that few articles focus comprehensively on the application of albumin nanoparticles in tumor therapy and no article clearly points out the difficulties faced in current research of albumin nanoparticles.
Journal of Nanomaterials, Volume 2022, pp 1-11; https://doi.org/10.1155/2022/8630685
In this work, the zinc/cobalt-based zeolite imidazolate frameworks ((Co/Zn)ZIFs) were synthesized with the solvothermal method. The obtained material was characterized by utilizing scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis diffusive reflectance spectroscopy, and nitrogen adsorption-desorption isotherms. XRD and SEM analyses show that (Co/Zn)ZIFs are composed of nanocrystals with polyhedral shapes of around 50100nm and belong to the I-43m space group as those of ZIF-8 and ZIF-67. Optical studies demonstrate a red shift in the absorbance spectrum of (Co/Zn)ZIFs compared with individual components of ZIF-67 or ZIF-8. (Co/Zn)ZIF composite was utilized as photocatalytic material to treat a model aqueous solution containing rhodamine B and bacteria. It was found that (Co/Zn)ZIFs could simultaneously degrade rhodamine B and inhibit bacteria (E. coli and S. aureus). The manufactured composite could catalyze the mineralization of rhodamine B and also exhibited good antibacterial activity against Gram-negative E. coli (93.32 inhibition rate) and Gram-positive S. aureus (90.86 inhibition rate) in the visible-light region within four hours of irradiation. Gram-negative bacteria were more resistant to (Co/Zn)ZIFs than Gram-positive bacteria. (Co/Zn)ZIFs can be used as light-driven catalysts for water and environmental detoxification from organic compounds like dyes and bacteria.
Journal of Nanomaterials, Volume 2022, pp 1-16; https://doi.org/10.1155/2022/7238602
Nanomaterials have gained huge applications ever since their discoveries, especially in the field of electronics, medicine, research, and environmental cleanup. Nanomaterials have a high surface area-to-volume ratio along with high surface energies making them suitable for such wide applications. Carbon nanotubes (CNTs) and carbon nanocomposite (CNC) materials are remarkable nanomaterials that have become the backbone of most industries these days. Both materials have gained huge attention in the last decade by the scientific community. CNTs come in two variants, i.e., single-walled CNTs (SW-CNTS) and multiwalled CNTs (MW-CNTs). Due to their wider applications, CNT synthesis is currently emerging with the advancement in technology. Currently, CNTs are being synthesized by chemical as well as physical approaches. The current review article focuses on the vital research and application for the synthesis of CNTs depending on the quality of the nanotube materials. Controlled routes to their organization and assembly are also discussed in detail over here. The aim is to provide recent advances in the synthesis methods, of CNTs, their current applications, future applications, and the potential of agrowaste and industrial waste for the synthesis of CNTs and nanomaterials.
Journal of Nanomaterials, Volume 2022, pp 1-7; https://doi.org/10.1155/2022/1493066
Antifriction self-lubricating glass composite coatings of the Sic-Ni-Cu-Al-Si-C type additionally contain an aluminoborosilicate glass phase and structurally free MgC2, which forms α-graphite during thermolysis, the synergistic effect of which causes modification of the friction surface due to the formation antifriction layer. The influence of the structural components of the coating on their contribution to the antifriction properties is considered. It was clarified that an increase in the adhesive strength of the coatings was achieved by preliminary application of a sublayer of vitreous sodium silicate. The developed coatings showed high performance properties, while the means of minimizing and stabilizing wear characteristics was the presence of a thin-film antifriction layer based on α-graphite, which shields unacceptable processes of molecular-adhesive interaction.
Journal of Nanomaterials, Volume 2022, pp 1-15; https://doi.org/10.1155/2022/8560069
The current water supply situation demonstrates the predominance of contamination caused by industrial effluent runoff. Polluted waters have contributed to significant health and environmental risks, calling for an acceptable alternative to address the effects. However, diverse chemical and treatment physical stages commonly used for dye effluent processing are more cost-intensive, less effective, and time-consuming. Instead, nanomaterials have developed as a good alternative for dye removal and degradation because of their special chemical reactivity and superior surface features/properties. In this regard, the ability of modified or hybrid ferrite-based magnetically recoverable nanomaterials in dye effluent treatment has been extensively explored. The present study especially emphasizes magnetic ferrite (Fe3O4+X) or metal-doped ferrite (MFe2O4+X) nanocomposite for dye degradation (where M consists of Co, Cu, Zn, Mg, Mn, Ni, etc., and X consists of reduced graphene oxide, graphene oxide, metal, or metal oxide). Several dye degradation efficiencies of various ferrite and metal ferrite nanomaterial were discussed. Degradation is carried out using direct sunlight, and various lamps (e.g., visible light/UV-C lamp/halogen lamp/Mercury-Xenon lamp/UV lamp with UV filter for visible light) are used as a source. This review article covers the degradation of various dyes from wastewater using ferrite-based nanomaterial as an efficient catalyst and making water pollution free.
Journal of Nanomaterials, Volume 2022, pp 1-9; https://doi.org/10.1155/2022/1000859
Tensile and impact strengths of 304L SS stainless steel weldment prepared at different levels of heat treatments and with vibratory assistance were studied and compared with the conventional process of welding. The results reveal that the microstructures of weld joints after heat treatment and vibratory welded joints attained a fine grain structure, compared with the joints prepared with the conventional process of welding. By increasing the temperature of quenching and vibrations during welding, the grain size is gradually improving. Improvement in the tensile and impact is observed in the heat-treated and vibration-welded specimens. Similarity, in the weld joint properties of post weld heat treatment (PWHT) and vibratory-assisted welding (VAW) are observed. With the VAW technique, high quality weldments are produced and are more suitable than PWHT due to its less cost and time.
Journal of Nanomaterials, Volume 2022, pp 1-11; https://doi.org/10.1155/2022/5617339
Low-voltage design is a challenge for Gilbert cell-based mixers due to stacking transconductance and switching stage. This work addresses this issue by proposing a design of a low-voltage down-conversion mixer for band #1 of multiband orthogonal frequency division multiplexing (MB-OFDM) system in 180nm complementary metal oxide semiconductor (CMOS) technology. The mixer is tuned at band #1 at RF frequency of 3.432GHz and IF frequency of 264MHz. The proposed mixer uses folded cascode connection of LO and RF in order to increase headroom and to reduce the DC supply voltage for low-voltage operation. Common gate configuration is used at RF transconductance stage to enhance the input bandwidth of the mixer. RF and LO ports are matched to 50Ω using differential T and LC matching, respectively. The resistive source denegation technique is used to linearize transconductance with respect to the bias point. The common source stage is used at the IF port as a buffer cum matching circuit it. The simulation results of the mixer show the maximum conversion gain of 9.76dB, 1dB compression point (P1dB) of -16.25dBm, the third-order input intercept point (IIP3) of -4.70dBm, an SSB noise figure of 9.036dB, and S11of -19.490dB at the supply voltage of 1.2V. Excluding off chip components, proposed mixer records an active area of 926.35μm2.
Journal of Nanomaterials, Volume 2022, pp 1-10; https://doi.org/10.1155/2022/3992590
The current study investigated the formation of entropy in a nanofluid flow in a wedge with thermal radiation and convective boundary conditions. Nanoparticle aggregation is also taken into consideration. The rate of heat transmission of a water-based aggregated fluid over a wedge has been investigated due to the effects of thermal radiation. A set of nonlinear differential equations governs the flow process, and these are numerically solved using a helpful approach called the Runge-Kutta-Fehlberg scheme. This method starts by breaking down the equations into a collection of first-order equations. The RK method then solves those equations. The effects on flow and heat transmission are studied using graphical analysis. Entropy generation and Bejan number changes are also graphically displayed, and the results are discussed in detail. These equations’ answers were also incorporated into a dimensionless entropy generating equation. According to the findings, raising the radiation parameter and decreasing boundary convection minimize entropy generation, while nanoparticles boost entropy production.
Journal of Nanomaterials, Volume 2022, pp 1-13; https://doi.org/10.1155/2022/7012012
FeOOH nanoparticles have recently appealed to wide-ranging applications due to their physicochemical properties and size-tunable synthesis; however, a few studies were performed on the antimicrobial potentials of iron oxyhydroxide nanoparticles. In this regard, we aimed to design various synthesis experiments to optimize the fabrication of β-FeOOH nanorods (NRs) with a desirable size of NRs and high antimicrobial potential. For this purpose, ten experiments were designed by manipulating reaction conditions of the standard hydrolysis method, including the initial concentration of ferric ions, reaction time, reaction temperature, and different concentrations of surfactants of PEI and PEG as process control agents. The structural characteristics of prepared NRs were analyzed using FE-SEM, FTIR, and XRD. The ImageJ software was also used to measure the length, width, and aspect ratio of NRs. Five microbial species, including the Gram-positive and Gram-negative bacteria and fungi species, were applied to investigate the antimicrobial potentials of NRs. The initial concentration of ferric ions revealed a dominant effect in NRs morphology, though other reaction conditions also played essential roles. The crystal structure of NRs was preserved in all synthesis experiments (β-phase) due to using the same iron salt precursors. The synthesized NRs exhibited dose-dependent antimicrobial activities against all tested microbial species. Additionally, the presence of surfactants exhibited an excellent capability of controlling effects on the size and growth pattern of NR crystals and improving their antimicrobial potentials; PEI could also be more effective on the antimicrobial efficacy of final NRs. Besides, our findings exhibited an inverse correlation between aspect ratio and antimicrobial potentials of β-FeOOH NRs. To sum up, it seems that optimization of synthesis conditions could provide tunable size and structure patterns of β-FeOOH NRs to achieve a promising tool for biomedical applications, particularly in combat with resistant microbial species, though further studies are needed in this regard.