Papers by Keyword: Nanoparticle

Abstract: In fuel manufacturing, a catalyst is an additive added from the base material to the intermediate product, which functions to accelerate the process of forming the intermediate product. Meanwhile, an additive is a material added to the intermediate product to improve the properties of the fuel before it undergoes combustion. Keywords: additive, nanoparticle, biodiesel.

Abstract: Ag@TiO₂ core-shell nanoparticles (NPs) were synthesized through an environmentally benign, two-step method utilizing Aloe vera extract as a natural reducing and capping agent. Structural and morphological characterization via X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) confirmed the successful formation of spherical core-shell structures with a size range of 10-40 nm. Optical analysis revealed a wide bandgap of 4.8 eV, indicative of quantum confinement effects. While electrokinetic measurements suggested moderate colloidal stability (zeta potential near 0 mV), the nanoparticles exhibited potent, strain-dependent antimicrobial activity. Notably, they demonstrated superior efficacy against Gram-positive Staphylococcus epidermidis (32 mm inhibition zone) compared to Gram-negative Escherichia coli (21 mm inhibition zone). This green synthesis route presents a sustainable strategy for producing antibacterial nanoparticles with enhanced activity against Gram-positive pathogens.

Abstract: CuO/TiO₂ nanocomposites were synthesized using an economical drop-casting method and subsequently irradiated with high-energy C⁺ ions at fluence levels of 1 × 10¹⁴, 1 × 10¹⁵, 1 × 10¹⁶, and 1 × 10¹⁷ ions cm⁻². While ion irradiation of metal oxide materials is well established, the systematic investigation of C⁺ ion effects on the structural and optical properties of CuO/TiO₂ nanocomposites under these specific fluence conditions has been limited. This study therefore contributes new insight into how controlled C⁺ irradiation can tailor the behavior of this composite. These un-irradiated and irradiated nanocomposites were characterized using various techniques such as Energy Dispersive X-Ray Spectroscopy (EDX), Raman Spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Photoluminescence (PL) Spectroscopy and Diffuse Reflectance Spectroscopy (DRS) to analyze structural, morphological and optical properties of these nanocomposites. The Raman and EDX analysis confirmed the formation of pure CuO/TiO₂ nanocomposites. The SEM results represent the spherical morphology of these nanocomposites in aggregated form. PL spectra’s depicted the pure and C⁺ ions irradiated nanocomposites were the same before and after C⁺ irradiation in the Photoluminescence emission. DRS results indicated that band gap energy was decreased as the fluence rate of C⁺ ions increased up to 1 × 10¹⁷ ions cm^-2.

Abstract: Pure and silver-doped zinc oxide (ZnO) nanoparticles were synthesized via phyto-mediation using Stachytarpheta jamaicensis leaf extract to develop an eco-friendly method for synthesizing nanoparticles with enhanced properties. Zinc nitrate and silver nitrate were employed as precursors for ZnO and Ag-doped ZnO nanoparticles, respectively. The synthesized nanoparticles were characterized using Ultraviolet-Visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy (SEM-EDS) to investigate their optical and morphological properties. Results revealed that the absorption peaks of the synthesized nanoparticles confirmed the formation of nanoparticles, with Ag doping causing a red shift in the absorption spectrum. SEM images indicated a spherical morphology, with slight agglomeration in the doped samples. Doping with silver enhanced the optical properties, which could have potential applications in catalysis, sensing, and biomedical fields. Furthermore, the nanoparticle extracts were subjected to antimicrobial test against two bacterial strains (Escherichia coli and Staphylococcus aureus) using a modified disk diffusion method and compared with the antibacterial effect with the standard antibacterial drug, Ampicillin. Ampicillin only showed antibacterial activity against S. aureus and had no antibacterial effect on E. Coli. Result of this study showed that the 5% and 10% Ag-doped ZnO NPs showed strong antibacterial activity against both gram-positive (S. aureus) and gram-negative (E. coli) bacterial strains.

Abstract: This study presents a rapid method for synthesizing yttrium oxide nanoparticles (Y₂O₃-NPs) utilizing ethanol and yttrium oxide (Y₂O₃). The Y₂O₃-NPs were analyzed using Fourier transform infrared (FT-IR), ultraviolet spectroscopy (UV-Vis), atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD).The X-ray diffraction (XRD) analysis revealed that the Y₂O₃ exhibited a preferred alignment and possessed a cubic crystal structure with a (111) orientation. The Atomic Force Microscopy (AFM) findings indicated the presence of a nanoscale structure characterized by a spherical surface that exhibits excellent dispersibility. The granules were seen to have a consistent size ranging from 19 to 36 nanometers, and the surface had a roughness ranging from 38 to 78 nanometers. The aim of this paper was to examine the features of (Y₂O_3-NPs) with antifungal and antibacterial activities. Studies on Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella, Escherichia coli, and Candida have shown the effectiveness of NPs as an antibacterial and antifungal agent.

Abstract: The changes in the mechanical and physical properties of concrete prepared by incorporating various metal oxide nanoparticles into cement products used in both the oil/gas industry and construction have been analyzed in this review. The study compares the properties exhibited by transition metal oxide and some metal nanoparticles in both isolated and complex forms with polymers in concrete. Analyses were conducted primarily in the direction of changes occurring in properties due to the addition of metal oxide nanoparticles such as magnetite Fe₃O₄, TiO₂, ZnO, Fe₂O₃, Ag, CuO, TiO₂/SiO₂, Al₂O₃, ZrO₂, core/shell Fe₃O₄/SiO₂, in dispersed form as cement powder or in water. It has been showed that appropriate changes occur in properties such as compressive and flexural strength, adhesion, initial and final setting, water absorption, porosity, electrical conductivity, degradation when metal oxide nanoparticles are added to cement. The density and size of nanoparticles affect their response to various influences, alongside the fundamental properties of the material.

Abstract: One of the emerging alternatives to surfactants in crude oil dehydration is the application of nanoparticles. This review aims to assess the recent progress in the application of nanoparticles for the chemical demulsification of water-in-oil and to provide knowledge gaps for future research. This review covers the nanomodification of commercial demulsifiers and the demulsification performance of magnetic and nonmagnetic nanoparticles, along with their possible mechanisms and factors that affect their dehydration efficiency. The addition of nanoparticles improves the dehydration performance of commercial demulsifiers by improving their wettability and interfacial activity. The advantage of magnetic nanoparticles is their rapid response to a magnetic field, which allows them to be recoverable. For nonmagnetic nanoparticles, their advantage is their environmental friendliness, biocompatibility, and cost-effectiveness. Nanoparticles were able to dehydrate emulsions by modifying the interfacial properties and possibly through adsorption of asphaltenes. Factors such as dosage, temperature, pH, salinity, water content, surfactant concentration; and nanoparticle wettability, and surface chemistry significantly affect the demulsification performance. The application of nanoparticles as demulsifiers is still on a laboratory scale. However, studies on toxicity and proper handling may increase interest for field application. Studies are encouraged on the exact mechanism on the reduction of interfacial tension.

Abstract: The use of hybrid nanofluids aimed to improve the exceptional qualities of fluids, including adsorption, viscosity, stability, and interfacial tension. Although several surfactant changes utilizing hybrid nanomaterials have been documented, their wider application has been hindered by the material's stability and processing challenges. The purpose of this study is to use the liquid phase exfoliation technique and examine the properties of the recently created hybrid nanofluids. This paper investigates the mechanisms of how hybrid nanofluids (HNF) composed of Graphene nanoplatelet (GNP) & SiO₂ with various surfactants such as Gum Arabic (GA) and Sodium Carboxymethyl Cellulose (SCMC) could improve EOR through adsorption of nanoparticles, improve viscosity, Interfacial tension (IFT), and wettability contact angle. Based on the results, using the hybrid nanoparticles decreases the IFT between oil-water interface from 39.700 mN/m for brine to 38.466, 37.582, 35.609 mN/m, for Control HNF, GA HNF, and SCMC HNF respectively. The adsorption of nanoparticles mechanism occurs and peaks during a 12-hour to 24hour period. Furthermore, the findings on the performance of hybrid nanofluid have increased the viscosity from 0.317cP (brine) to 3.638cP (GA) and 3.556cP (SCMC) nanofluid. When nanoparticles are introduced into reservoirs, they interact with rocks and crude oil via rock absorption, potentially improving the recovery rate of oil by changing wettability and influencing the efficiency of water-transfer to oil in several improved oil recovery methods. The contact between the rock surface, nanofluid, and oil was shown to be reduced by 29.47% and 59.12%, as seen by the contact angle of the oil droplet on the rock surfaces. The phenomenon occurs because nanoparticles are attached to the interface of rock, oil, and brine.

Abstract: Understanding how oil and water interact at the surface level is essential for enhancing crude oil recovery, particularly in Enhanced Oil Recovery (EOR) techniques. This study explores the effects of three types of nanoparticles, aluminum oxide (Al₂O₃), zinc oxide (ZnO), and silica-coated iron oxide (Fe₃O₄@SiO₂) on key interfacial properties such as wettability and interfacial tension. Using a sand pack displacement setup under controlled flow conditions, nanofluids were prepared at concentrations ranging from 0.1 wt% to 0.5 wt% and evaluated for their dynamic viscosity and permeability characteristics. Results showed that ZnO reached the highest viscosity at 1.694 cP (0.5 wt%), while Fe₃O₄@SiO₂ recorded the lowest at 0.995 cP (0.1 wt%). Interestingly, permeability increased with viscosity, contrary to conventional expectations, with ZnO achieving a peak of 90 mD. Oil recovery also improved with higher nanoparticle concentrations. Al₂O₃ delivered the best performance at 0.5 wt%, recovering 27 mL of oil, followed by ZnO (24 mL) and Fe₃O₄@SiO₂ (15 mL). These findings underscore the importance of selecting the right nanoparticle type and concentration to improve EOR performance, with Al₂O₃ showing the most promise for enhancing both permeability and displacement efficiency.

Abstract: This paper presents a numerical study on the passive cooling of an electronic component inside a rectangular enclosure filled with phase change material (PCM). The electronic component is centrally located on a substrate and generates volumetric heat. The study utilizes the enthalpy-porosity approach and the thermal equilibrium model. Its goal is to enhance the performance of the PCM by incorporating metal foam and nanoparticles. The investigation examines the impact of varying metal foam porosity while keeping the nanoparticle volume fraction constant. The results indicate that a lower porosity (0.85) significantly improves the thermal conductivity of the PCM by 3 times, which increases the cooling efficiency of the PCM-based heat sink. Meanwhile, nanoparticles have a negligible effect when metal foam is present.