Nanoscience & Nanotechnology-Asia - Volume 14, Issue 1, 2024

Background: The applications of nanocomposite materials require stable and high electrical performance for the potential conductive applications. Objectives: This study aimed to present the effect of introducing different compositions of nanomaterials and to obtain the highly conductive composite composition and its relative analysis. Methods: The XRD, SEM, and TEM tests were conducted to study different characteristics related to the characterization and composition of the nanomaterials. Results: The laboratory results show that the conductivity test revealed that Sample-6 (Rk-6) exhibited the lowest impedance value of 15.26 Ω, indicating its superior conductivity among the samples tested. These findings significantly contribute to the field of graphene research, providing valuable insights into the potential of GZS nanocomposites for applications that require enhanced conductivity. Conclusion: With the proposed composition of the synthesis of GZS nanocomposites using graphene, zinc oxide, and silica, the study successfully demonstrated improved storage capabilities and can be well suited for low-power applications in the fabrication of nanorods, polymers, and polyester resin.

Introduction: Oil spill incidents caused by human activities can cause major habitat damage and pose serious threats to all living organisms living on and within sources of water and soil. Finding a solution for oil spills is necessary to protect ecosystems, the environment, and health. Nanotechnology seems to be an interesting tool in many applications, such as soil and water remediation and oil recovery. Nanoparticles are a good alternative since they are not as expensive as chemicals used to remove oil. Objective: The prime purpose of this research work was the comparison of the additional displacement of sunflower oil from a single fracture using ferrofluids prepared with bare and novel covalent functionalized magnetic nanoparticles. Experiences were performed at constant nanoparticle concentration and variable flow rate and at constant flow rate and variable nanoparticle concentration. The novel ferrofluid stability and its recovery properties related to a low-cost process were explored. Methods: Tests were carried out by image analysis. Stable ferrofluids were prepared using magnetic nanoparticles (MNPs) and novel covalent functionalized magnetic nanoparticles (MSMs). Their ability to displace the residual oil in a single fracture model previously invaded by an aqueous brine solution was tested. A flow channel of a single fracture by a typical transparent Hele-Shaw cell with 12% of its area covered by a random distribution of obstacles was modeled. Oil recovery was performed at three different flow rates: 0.36, 1.80, and 3.60 mL min^-1, using relatively low ferrofluid concentrations (0.0125 wt%). Oil recovery was also carried out with MSM ferrofluid at a constant flow rate of 1.80 and 3.60 mL min^-1 at different nanoparticle concentrations (0.00625, 0.0125, and 0.025 wt%). Results: Ferrofluids prepared with MSMs were more effective for oil recovery than those prepared with bare nanoparticles due to their surfactant behavior for all flows studied here. A 7.86% extra percentage of oil was removed after brine flooding. Oil recovery using MSM ferrofluid at a constant flow rate of 1.80 and 3.60 mL min^-1 increased linearly with nanoparticle concentration. Magnetic nanoparticles can be efficiently recovered and reused in at least three oil displacements for the fracture model used as covalent functionalization promotes ferrofluids' stability. Conclusion: The characteristics of the MSM amphiphilic novel coating cause the nanoparticles to be attracted to both water and oil, enhancing oil displacement. These results indicate that this novel material, whose structure stability is related to the covalent bonding of organic coating, can be considered for remediation and oil recovery in fractured media.

Background: In this paper, graphene and copper oxide nanoparticles and graphene-based copper oxide nanoparticles have been produced by means of a pulsed laser ablation process (PLA) in a deionized water solution. Methods: The composition ratio of materials has been investigated in the structure of the prepared materials and their optical properties. The absorbance of the samples was obtained by the UV-VIS single beam spectrophotometer in the wavelength range of 290 to 800 nm. Spectroscopic ellipsometry method was used to investigate the linear optical properties of the samples including the real and imaginary parts of refractive index and dielectric function of the samples. The preferred model in the dielectric function modeling was Tauc-Lorentz. Also, the energy band gap of the samples has been calculated using Tauc relation. In addition, the nonlinear optical properties of graphene based copper oxide have been studied by Z-scan technique. Structure of the samples was studied using TEM image. Results: The most and the least absorbance at 532 nm wavelength, and also band gap energy belong to 1.4 ml Gr-0.6 ml Cu and copper oxide, respectively. Conclusion: The band gap energies of the samples were calculated between 3.30 eV and 3.43 eV. The real and imaginary parts of the complex refractive index were obtained in the order of 10^-8cm²/W and 10^-5cm/W. The results for nonlinear properties show that these samples are suitable for all-optical switching devices.

Background: As the size of the field effect transistors is reduced down to nanometers, the performance of the devices is affected by various short-channel effects. To overcome these effects, various novel devices are used. Tunnel Field Effect Transistors (TFET) are novel devices in which the drain current needs to be improved. Gate engineering and III-V compound materials are proposed to improve the ON current and reduce the leakage current along with its ambipolar behaviour. Methods: The proposed device structure is designed with a heterojunction hetero dielectric dual material gate Tunnel Field Effect Transistor incorporating various combinations of III-V compound materials such as AlGaAsSb/InGaAs, InGaAs/Ge, InGaAs/InP and SiGe/Si. As in III-V composite materials like AlGaAsSb/InGaAs, the narrower bandgap at the source channel interface helps to improve the electric field across the junction. At the same time, the wider bandgap at the channel drain junction leads to unidirectional current flow, resulting in ambipolar reduction. 2D TCAD simulation is used to obtain the electrical parameters for Hetero junction TFETs and the comparison analysis of different Hetero device structures. Results: The device's electrical parameters, such as energy band diagram, current density, electric field, drain current, gate capacitance and transconductance, have been simulated and analyzed. Besides, the dual material used in the gate, such as Metal1 (M1) and Metal2 (M2), along with HfO2/SiO2 stacked dielectric, helps improve the gate controllability over the channel and the leakage current reduction. Conclusion: An ION=10^-1A/μm, IOFF = 10^-12A/μm at drive voltage 0.5V is obtained for InGaAs/InP layer at the source channel hetero junction TFET, and ION=10^-2A/μm, IOFF =10^-14A/μm at drive voltage 0.5V is obtained for SiGe/Si layer at the source channel hetero junction TFET. Therefore, the InGaAs/InP and SiGe/Si layer TFET are more suitable for ultra-low power integrated circuits.

Background: Magnetic materials like iron, nickel, and cobalt have been a subject of interest among the scientific and research community for centuries. Owing to their unique properties, they are prevalent in the mechanical and electronic industries. In recent times, magnetic materials have undeniable applications in biotechnology and nanomedicine. Bacteria like Salmonella enterica, Clostridium botulinum, Bacillus subtilis, etc, pose a hazard to human health and livestock. This ultimately leads to huge yields and economic losses on a global scale. Antimicrobial resistance has become a significant public health concern in recent years, with the increasing prevalence of drugresistant infections posing a significant threat to global health. Many coherent studies have successfully reported magnetic metal oxide nanoparticles to be highly selective, specific, and effective in neutralizing pathogens through various mechanisms like cell membrane disruption, direct contact-mediated killing, or by generating Reactive Oxygen Species (ROS) and numerous costimulatory and inflammatory cytokines. Therefore, we explored the inhibitory effects of iron oxide nanoparticles (NPs) on various pathogenic bacteria via an in-silico approach. This method helped us to understand the active sites where the iron oxide NPs bind with the bacterial proteins. Methods: The 3D crystal structures of all the pathogenic proteins of Streptococcus pneumoniae, Pseudomonas aeruginosa, Vibrio cholerae, Salmonella enterica, Shigella flexneri, Clostridium botulinum and nanoparticles (Fe2O3 and Fe3O4) under study were downloaded from RCSB PDB and ChemSpider official websites respectively. It was followed by the in-silico molecular Docking using PyRx and AutoDock Vina and analyzed on LigPlot. Results: This study interprets the efficacy of the Fe2O3 and Fe3O4 nanoparticles against all the test bacteria. At the same time, Fe2O3 and Fe3O4 formed the most stable complexes with cholera enterotoxin subunit B and lectin II (PA-IIL) mutant S23A of Pseudomonas aeruginosa, respectively. Conclusion: As in this era of AMR, researchers have been exploring alternative strategies to combat bacterial infections, including using magnetic nanoparticles as a potential treatment. They possess unique physical and chemical properties that make them attractive candidates for antimicrobial therapy, including their ability to penetrate bacterial biofilms and selectively target pathogenic bacteria while leaving healthy cells unharmed. This study examined the inhibitory effects of iron oxide (magnetic) nanoparticles, namely Fe2O3 and Fe3O4, on various bacterial proteins involved in cell-to-cell interactions and pathogenesis.

The use of mRNA in therapeutics has lately emerged as a powerful strategy for alleviating the various viral infections and diseased conditions, along with prophylaxis. However, a key challenge in their efficient delivery is the protection of the nucleic acid from degradation followed by mRNA transport to the cells. In this regard, clinical translation of mRNA therapeutics has largely been facilitated with the advent of lipid-based nanoparticles (LBNPs). LBNPs–mRNA vaccines currently being employed for COVID-19 is one such instance substantiating and endorsing the use of lipidic nanocarriers for mRNA therapeutics. Thus, the current review article aims to furnish information on developmental challenges, different aspects of lipid-based carrier systems for mRNA delivery, their vital applications in different diseases and the future potential of LBNPs in therapeutics.