Papers by Keyword: Nanoparticle

Abstract: In the oil and gas industry, drilling fluid plays a critical role in ensuring the safety and efficiency of hydrocarbon extraction. It serves multiple purposes, including cooling and lubricating the drill bit, transporting rock cuttings for geological analysis, and optimizing drilling performance. However, water-based muds (WBM) face significant challenges during drilling operations, such as high fluid loss into permeable formations, inadequate sealing properties, and instability of the mud structure, which can lead to sagging and settling of solids. These issues can compromise the efficiency of drilling operations and pose environmental concerns. This study aims to evaluate the impact of additives extracted from fenugreek, commercial saponin polymer, Gemini surfactant (GS), and nanoparticles on the performance of WBM. Key properties examined include plastic viscosity, gel strength, yield point, mud density, fluid loss, mud cake thickness, and interfacial tension (IFT). Notably, IFT plays a pivotal role in improving the sealing capabilities of drilling fluids, reducing fluid loss into permeable formations. IFT indirectly influences sealing properties and fluid loss by interacting with the mud cake formation process, which is the primary barrier preventing fluid invasion into permeable formations. The study achieved an optimal IFT of 22.65 mN/m and the highest yield point of 65 lb/100ft² using 1.6 g of commercial saponin, an environmentally friendly additive suitable for Malaysia's drilling conditions. These results prevent sagging and settling of solids in the drilling mud, enhancing overall performance. The optimal IFT and high yield point combination demonstrated superior effectiveness, ensuring improved sealing properties, minimized fluid loss, and enhanced mud stability compared to other tested conditions.

Abstract: Due to the super-linear growth of the number of particle (especially, proton) therapy centers in 2010–2018, many researchers forecasted the number of patients treated by proton therapy to reach 500–550 thousand before 2026. However, the real farther overall spread of hadron therapy was much slower due to its high cost, very high research intensity, and very high requirements for medical and engineering staff, so that by the end of 2026 the number of patients will reach only 410–415 thousand, clearly tending to saturation with an ever decreasing share of ion therapy and showing that the increase of the biological efficacy and safety of proton and especially heavy ion therapy is it is an urgent need of today’s time. The most promising and experimentally substantiated concept of the whole body and the highly localized combination cancer therapy was developed and tested by Japanese and Georgian researchers in 2015–2020, which clearly demonstrated the high efficiency of the highly localized multicomponent combined therapy of cancer. This paper reports in vitro and in vivo data on the relative anticancer efficacy and acute toxicity of the 50 various multicomponent nanoparticle containing anticancer combinations in comparison to the widely used anticancer drugs gemcitabine, carboplatin, cisplatin and paclitaxel systematically applied against the Non-Small Cell Lung Cancer (NSCLC), clearly showing that the newly developed combinations can be several times more efficient and have a several times less toxicity than the usually applied anticancer drugs. The obtained data also provide sufficient reasons to conclude that the significant increase in the effectiveness of combined formulations is caused by the super-additive synergistic interaction of nanoparticles and of the active components of anticancer mixtures. It is especially important that the newly developed “cocktails” reveal a 3 to 10 times increased therapeutic window due to several times increased necrotic and apoptotic activity against the cancer cells in comparison to healthy tissue cells, drastically increasing the therapeutic value of the drugs due to higher efficacy, higher safety and significantly reduced duration and costs of treatment.

Abstract: Studying the spectroscopic properties of nanomaterials and nanoparticles is essential for developing nanomaterial science and nanotechnology. Spectroscopic properties of nanoparticles of biological origin, especially pathogenic nanoparticles such as viruses, became actual after the Covid-19 pandemic, causing economic, human and social harm. Known spectra of the utmost atoms, molecules, and compositions are well used for identification. In this paper, we provide a concise review of the experimental results obtained from advanced spectroscopy techniques by various scientific groups and demonstrate the possibility of using spectra of viruses to detect and identify diseases caused by pathogens. Raman, ultraviolet (UV), and infrared (IR) spectroscopy methods for experimental study of viral materials are considered.

Abstract: In this work, it is proposed that the thermophysical properties of the composite material can be improved by modifying the binder with nanoscale additives. It is proved that the introduction of nanoparticles into oligomers at concentrations around 1% increases the thermal conductivity by 1.3–1.6 times. Macrosized particles were also used for comparison. It was found that this effect is achieved due to a decrease in thermal resistance at the interface in result of the formation of outer surface layers. Such modified binders are effective for creating various materials and coatings based on them with a wide range of characteristics.

Abstract: Inherent magnetic features of engineered nanoparticles are quite important parameters for biomedical application. In this study, trying to process Bengawan Solo iron sand into a material that has potential for cobalt ferrite (CFO-NPs) and silver-cobalt ferrite (AgCFO-NPs) were synthesized by aqueous extract of tumeric. To modify the physical properties, annealing treatment was carried out at non-annealing temperatures and 500°C. The characterized by various instrument, and utilized for biomedical application with antibacterial activity. These are characterized XRD with showing results particle size was calculated by the Scherrer formula, which is around 19 nm to 25 nm. The results of FTIR peak adsorption at 400 and 600 cm^-1 it shows the characteristics of spinel ferrite and the presence of vibrations at tetrahedral and octahedral sites. The coerciveness field (Hc) while those subjected to annealing temperature treatment increased from 46 Oe to 136 Oe. Nanoparticles cobalt ferrite (CFO-NPs) and silver-cobalt ferrite (AgCFO-NPs) can be used as antibacterial application. The AgCFO-NPs material has an antibacterial function as seen in the antibacterial test. AgCFO-NPs showed a good response being able to inhibit the growth of Staphylococcus aureus and Eschericia coli bacteria. By the obtained result it can be claimed that material nanoparticles will be useful model for biomedical applications if they are explored at advance level.

Abstract: This study investigates an enhancement of carbon-based materials, including multi-walled carbon nanotubes (MWCNTs) and graphite, through Ion Assisted Reaction (IAR) and metal nanoparticle deposition using Physical Vapor Deposition. The IAR process employed Ar⁺ ion beams in reactive gas environments, effectively introducing hydrophilic functional groups such as hydroxyl (-OH) and carboxyl (-COOH) on the MWCNT surfaces. This modification significantly improved dispersion behavior of the treated MWCNTs, particularly in non-polar solvents like N-Methyl-2-pyrrolidone (NMP). Results indicated that the treated MWCNTs demonstrated a slower sedimentation rate compared to untreated samples, with enhanced stability over 120 minutes in NMP. Graphite was modified with copper nanoparticles on its surface using magnetron sputtering in PVD system, leading to a uniform distribution of the modified graphite in matrix. SEM analysis revealed that this modification enhanced the surface roughness of the graphite, facilitating stronger interfacial adhesion with polymer epoxy resin. Composites incorporating these nanoparticle-coated graphite fillers (NPP graphite) exhibited superior thermal and mechanical properties. For instance, a 15% increment in thermal conductivity was observed in epoxy resin composites containing NPP graphite compared to those with untreated graphite. This improvement was attributed to the metallic Cu nanoparticles acting as thermal bridges, effectively transferring heat within the composite matrix. Mechanical properties were evaluated by blending modified fillers into polymer matrices, including polyvinyl chloride (PVC) and polyethylene (PE), with filler concentrations varying from 5 vol% to 15 vol%. Tensile testing and SEM analysis of the fractured surfaces indicated that NPP graphite composites achieved uniform dispersion, reduced agglomeration, and improved interfacial bonding. This study demonstrates that physical surface modification techniques such as IAR and PVD effectively overcome limitations associated with conventional chemical methods. This approach not only improves the dispersion and interfacial adhesion of carbon-based fillers but also enhances their thermal and mechanical performance.

Abstract: In this study, zinc oxide (ZnO) and copper-doped zinc oxide nanoparticles (Cu-ZnO NPs) were synthesized using a green method that employed Rosmarinus officinalis leaf extract as a reducing agent. Copper was incorporated as a dopant at concentrations of 3% and 5%. Zinc acetate dihydrate and copper acetate served as the precursors and dopants, respectively. The synthesized samples were characterized utilizing a range of techniques, including XRD, SEM, EDX, Raman spectroscopy, UV-visible spectroscopy, and PL spectroscopy. XRD and Raman spectroscopy analyses validated the effective incorporation of Cu²⁺ ions into the ZnO wurtzite structure. SEM analysis indicated that the nanoparticles displayed a spherical morphology, while EDX analysis confirmed the presence of zinc (Zn), copper (Cu), and oxygen (O), thereby validating the sample's purity. UV-visible spectra revealed a reduction in the optical band gap with increasing Cu concentration. Photoluminescence peaks observed at 383 nm and 565 nm were ascribed to electron transitions from deep donor levels, particularly from Zn interstitials to Zn and oxygen vacancies. The 5% Cu-doped ZnO NPs demonstrated the highest photocatalytic activity, achieving 90% degradation of Rhodamine B (RhB) dye under UV irradiation in 135 minutes. They also exhibited significant antibacterial activity, particularly against Gram-positive bacteria (Staphylococcus aureus) compared to Gram-negative bacteria (Escherichia coli).

Abstract: This study explores the utility of reduced graphene oxide (rGO) as a support material for gold nanoparticles (AuNPs) synthesized via an economically efficient and environmentally friendly electrochemical deposition method conducted at room temperature. Employing a chronoamperometry (CA) method, we successfully synthesize AuNPs in aqueous solutions without additional stabilizing agents. We investigate the influence of substrate and electrodeposition duration on the growth of AuNPs, on indium tin oxide glass substrates and rGO, with electrodeposition durations for comparison. This research highlights the straightforward and rapid one-step synthesis of AuNPs in an aqueous medium and explores the correlation between Au particle size and electrocatalytic performance. We evaluate the electrochemical performance of rGO-supported AuNPs in the context of methanol oxidation reaction (MOR) using cyclic voltammetry in an aqueous medium with an alkaline electrolyte. Notably, AuNPs supported by rGO, featuring an average particle size of 46 nm, exhibit superior electrochemical performance compared to their counterparts with an average particle size of 165 nm when employed as catalysts for the MOR. This superior performance is characterized by a 15 mV more negative oxidation potential (54 mv compared to 39 mV) and over 2.5 times higher oxidation peak current (0.064 mA compared to 0.025 mA), underscoring their efficiency as electrocatalysts for MOR.

Abstract: This paper presents the synthesis of metallic silver (Ag) nanoparticles immobilized on silica (SiO₂) particles. Ag immobilization was carried out via the Ag mirror reaction using two types of reducing reagents: D-glucose and formaldehyde (HCHO). The effects of Ag immobilization conditions, such as Ag nitrate concentration, SiO₂ concentration, reaction time, and reducing reagent concentration, were investigated. The particle morphology is related to the ionic strength of the solution. As a result, Ag immobilization was successfully performed while minimizing the formation of large metallic Ag nanoparticles and/or the aggregation of metallic Ag nanoparticles in the HCHO system with a reaction time of 5 min and HCHO concentration of 1.5×10^-4 M, producing SiO₂ particles (92.5±7.3 nm) immobilized with metallic Ag nanoparticles 5–15 nm in size.

Abstract: Calcium hydroxide (Ca (OH)₂) is an intracanal medicament used as a disinfectant in cases of tooth inflammation with ad dubia prognosis. The success of root canal treatment depends on the ability of intracanal medicaments to eliminate pathogenic bacteria present in the walls of narrow and complex root canals by releasing calcium and hydroxyl ions at the closest contacts. This study aimed to evaluate the effect of particle size on the ability to penetrate Ca (OH)₂ in the coronal, middle, and apical root canals. Fifteen mandibular premolars extracted for orthodontic and periodontal purposes were collected and cut to produce root canals with a length of 12 cm. The root canals were then prepared with a Protaper SX-F3 needle and irrigated using a solution of 2.5% NaOCl, NaCl, and 17% EDTA as lubrication at each needle change. Ca (OH)₂ with different particle sizes in paste form was manipulated with distilled water at a concentration of 0.8 g/mL then the paste was applied to the prepared tooth root canals and covered with a temporary filling. The samples were then stored in an incubator at 37 °C for 7 days. Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) was performed on the transverse surfaces of the coronal 1/3, middle 1/3 and apical 1/3 of the tooth. The maximum penetration depth was evaluated by measuring the maximum distance between the dentin canal wall and Ca (OH)₂ present in the dentinal tubules. In all three zones, the Ca (OH)₂ nanoparticles had a greater penetration depth than the Ca (OH)₂ nanoparticles (P<0.001). In both groups, the penetration depth increased from the apical to the coronal section. All differences in the penetration test ability of the Ca (OH)₂ nanoparticles and Ca (OH)₂ microparticles at all depths of the surface. Ca (OH)₂ nanoparticles penetrate deeper into the dentinal tubules than Ca (OH)₂ microparticles do.