Search Results (157)

Sustainable deepwater drilling for oil and gas offers significant potential. In this work, we synthesized a nanoscale collapse-prevention agent by grafting didecyldimethylammonium chloride onto spherical nano-silica and characterized it using Fourier-transform infrared spectroscopy, thermogravimetric analysis, zeta-potential, and particle-size measurements, as well as SEM and TEM. Adding 1 wt% of this agent to a bentonite slurry only marginally alters its rheology and maintains acceptable low-temperature flow properties. Microporous-membrane tests show filtrate passing through 200 nm pores drops to 55 mL, demonstrating excellent plugging. Core-immersion studies reveal that shale cores retain integrity with minimal spalling after prolonged exposure. Rolling recovery assays increase shale-cutting recovery to 68%. Wettability tests indicate the water contact angle rises from 17.1° to 90.1°, and capillary rise height falls by roughly 50%, reversing suction to repulsion. Together, these findings support a synergistic plugging–adsorption–hydrophobization mechanism that significantly enhances wellbore stability without compromising low-temperature rheology. This work may guide the design of high-performance collapse-prevention additives for safe, efficient deepwater drilling. Full article

Aiming at the problems of insufficient natural productivity and large seepage resistance in low-permeability oil and gas reservoirs, a nano relative permeability improver based on nano SiO₂ was developed in this study. The nano relative permeability improver was prepared by the reversed-phase microemulsion method, and the formula was optimized (nano SiO₂ 5.1%, Span-80 33%, isobutanol 18%, NaCl 2%), so that the minimum median particle size was 4.2 nm, with good injectivity and stability. Performance studies showed that the improvement agent had low surface tension (30–35 mN/m) and interfacial tension (3–8 mN/m) as well as significantly reduced the rock wetting angle (50–84°) and enhanced wettability. In addition, it had good temperature resistance, shear resistance, and acid-alkali resistance, making it suitable for complex environments in low-permeability reservoirs. Full article

Hydrogel particles, renowned for their high water content and biocompatibility in drug delivery and tissue engineering, typically rely on complex, costly microfluidic systems to reach sub 5 µm dimensions. We present a vortex-based inverse-emulsion polymerization strategy in which UV crosslinking of polyethylene glycol diacrylate (PEGDA) dispersed in n-hexadecane and squalene yields tunable micro- and nanogels while delineating the parameters that govern particle size and uniformity. Systematic variation in surfactant concentration, vessel volume, continuous phase viscosity, vortex speed and duration, oil-to-polymer ratio, polymer molecular weight, and pulsed vortexing revealed that increases in surfactant level, vortex intensity/duration, vessel volume, and oil-to-polymer ratio each reduced mean diameter and PDI, whereas higher polymer molecular weight and continuous phase viscosity broadened the size distribution. We further investigated how these same parameters can be tuned to shift particle populations between nano- and microscale regimes. Under optimized conditions, microhydrogels achieved a coefficient of variation of 0.26 and a PDI of 0.07, with excellent reproducibility, and nanogels measured 161 nm (PDI = 0.05). This rapid, cost-effective method enables precise and scalable control over hydrogel dimensions using only standard laboratory equipment, without specialized training. Full article

In this work, 1,3-diketone synthesized via the Claisen condensation method and nano-copper particles modified by the Brust–Schiffrin method were added into a commercial marine medium-speed diesel engine cylinder piston oil to evaluate their effects on boundary lubrication performance. Friction and wear tests conducted on CKS-coated piston ring and cast-iron cylinder liner samples demonstrated significant reductions in both friction and wear with the addition of 1,3-diketone and nano-copper particles. Compared to the original oil without additives, the friction force was reduced by up to 16.7%, while the wear of the piston ring and cylinder liner was decreased by up to 21.6% and 15.1% at 150 °C, respectively. A worn surface analysis indicated that the addition of 1,3-diketone and functionalized nano-copper particles influenced the depolymerization and tribo-chemical reactions of the anti-wear additive ZDDP (zinc dialkyldithiophosphate) in the original engine oil. This modification enhanced the oil’s anti-friction and anti-wear properties, offering valuable insights into the development of eco-friendly lubricants for energy-efficient systems. Full article

Molecular modeling calculations for the design and improvement of next-generation additives for motor oils have reached a level that can support and improve experimental results. The regulation of insoluble sludge nanoparticle aggregations within oil and on engine pistons is a critical performance metric for lubricant oil additives. There is a general agreement regarding the mechanism of deposit formation which is attributed to the self-aggregation of nano-sized carbon rich insoluble structures. Dispersants are a primary category of additives employed to inhibit aggregation in lubricant formulations. Along with the base oil, they are crucial in dispersing and stabilizing insoluble particles to manage the formation of deposits. In this study, multiscale modeling methods were used to elucidate molecular mechanism of deposit control via polyisobutylene-bis-succinimide (PIBSI) dispersants by using density functional theory (DFT), molecular dynamics (MD) simulations of cells constructed by statistical sampling of molecular configurations, and coarse-grained (CG) simulations. The aim of this study was to understand the role of different groups such as succinimide, amine center, and two polyisobutylene (PIB) tails in PIBSI dispersants. It was demonstrated that the mechanism of deposit control by the polymer-based PIBSI dispersant can be elucidated through the interactions among various constituents, including hydrogen bonding and hydrophilic–hydrophobic interactions. We showed that sludge type nanoparticle aggregation is mitigated by intercalation of polar amine central groups of dispersant between the nanoparticles followed by the extension of two hydrophobic PIB chains into the oil phase that decreases coalesce further by forming a hydrophobic repulsive layer. Full article

Background/Objectives: Blepharitis is a condition often caused by Demodex folliculorum infestations, resulting in significant ocular discomfort and surface damage. Current treatments offer only temporary relief and fail to eliminate mites effectively. This study evaluates nano-niclosamide (nano-NCL), a lipophilic nanosuspension designed to enhance solubility and permeability, for targeting Demodex folliculorum. Methods: Nano-NCL was characterized by particle size, zeta potential, transmission electron microscopy, pH measurement, bacterial culture, and HPLC. Viable Demodex mites were collected from patients’ eyelashes and assigned to six treatment groups: DDW, F127, 0.15% nano-NCL, 0.3% nano-NCL, 20% TTO, and Okra. Mite survival was analyzed using Kaplan–Meier curves. The ocular surface safety was assessed via slit-lamp examination, corneal fluorescein staining, and in vivo confocal microscopy. Results: The nano-NCL particles are uniformly rod-shaped, approximately 291 nm in size, and exhibit good stability, remaining suspended in various media for up to 20 days. The formulation has a stable pH of 6 and demonstrated no bacterial growth, indicating sterility and suitability for clinical use. In vitro, both 0.15% (w/v) and 0.30% (w/v) nano-NCL significantly reduced Demodex survival, with mortality rates ranging from 70.6% to 92.3% within 2 h. Safety evaluations showed minimal corneal staining and inflammation. Notably, 0.15% nano-NCL displayed efficacy comparable to that of 20% tea tree oil (TTO) and Okra, which are established anti-Demodex treatments. Conclusions: Nano-NCL, particularly at 0.15%, rapidly eliminates mites while maintaining excellent ocular tolerability, making it a promising treatment for Demodex-related ocular surface diseases. Full article

The enhancement of tribological properties represents a pivotal strategy for achieving energy efficiency and environmental protection. Titanium dioxide (TiO₂) nanomaterials have been garnering significant attention due to their exemplary tribological properties and due to the abundance of titanium reserves. The present review is concerned with the study of TiO₂ nanomaterials in lubricants. The properties and various synthesis methods of TiO₂ nanomaterials are presented. The dispersion stability of these TiO₂ nanomaterials in lubricating oils is discussed in depth, as well as strategies to improve their dispersion stability, such as enhancing compatibility with base oils, reducing the dynamic light scattering (DLS) particle size, modulating the zeta potential, and optimizing the drying step. Aggregation and dispersion instability remain key challenges for TiO₂ nanomaterials, especially bare TiO₂ nanoparticles (NPs). In contrast, in situ surface-modified TiO₂ NPs show improved stability and tribological performance, offering promise for further research. The tribological performance of lubricants has been demonstrated to be enhanced by TiO₂ nanomaterials, with the observed enhancement attributed to the synergistic effect of multiple mechanisms, including rolling, patching, polishing, and the formation of a protective film. Furthermore, future research suggestions are proposed to provide a reference for the design and synthesis of high-performance TiO₂ nano-lubricants and promote their wide application. Full article

Earias insulana Boisd. (Lepidoptera: Nolidae) is a major pest of cotton and other crops in Egypt, and the widespread use of insecticides has led to resistance. This study evaluates, for the first time, the bioactivity of Croton tiglium (Malpighiales: Euphorbiaceae) oil and its nano-emulsion (CTNE) against 25 newly hatched larvae of E. insulana Boisd. We assessed their biological effects across different developmental stages and performed histological and ultrastructural examinations. Gas–liquid chromatography (GLC) identified several bioactive compounds in C. tiglium oil crushed dry seeds, including fatty acids, hydrocarbons, and sterols. CTNE showed excellent quality with a zeta potential of −17.7 mV, an average particle size of 54.28 nm, and spherical droplets of 42.42 nm in diameter. The LC₅₀ values for C. tiglium oil and CTNE were 9.02% and 2.70%, respectively. Both treatments significantly impacted the biological characteristics of E. insulana Boisd., including reduced larval and pupal weight, lower adult emergence, decreased fecundity, and increased mortality. Histologically, there was epithelial cell hypotrophy and detachment, while ultrastructural damage included chromatin condensation, nuclear envelope folding, and mitochondrial damage, indicating apoptotic degeneration. These findings suggest C. tiglium oil and CTNE as potential, safe alternatives to chemical insecticides. Full article

The aim of this study was to compare the functional properties of linseed oil powders made of three types of wall material (OSA starch + maltodextrin, OSA starch + nutriose, and OSA starch + inulin) and two types of emulsion phases (micro- and nanoemulsion). For these independent variables, the properties of the prepared emulsions (flow curves and viscosity) and the resulting powders (encapsulation efficiency, particle size distribution, water activity, bulk and tapped density, Carr’s index, color parameters, and thermal stability) were determined. The results showed that emulsion viscosity and most powder properties were affected by the emulsion type. All emulsions demonstrated Newtonian-like behavior, with viscosity values ranging from 29.07 to 48.26 mPa·s. The addition of nutriose induced the most significant variation in this parameter, with nanoemulsification leading to a 1.6-fold increase in viscosity compared to microemulsification. The application of nanoemulsification to prepare the emulsions prior to spray-drying resulted in powders with lower surface oil content (by 78.8–88.5%), tapped density (by 1.7–14.2%), and Carr’s index (by 7.6–14.0%), as well as higher encapsulation efficiency (by 5.9–17.0%). The decreased oxidative stability (by 30.9–51.1%) of powders obtained from nanoemulsified emulsions was related to 4.7–15.9-fold lower surface oil content. Powders produced using inulin as the wall material had the smallest and most uniform particle sizes, showing minimal variation between powders derived from nano- and microemulsified emulsions. Full article

Biomass, though a major energy source, remains underutilized. Biochar from biomass pyrolysis, with its high porosity and surface area, is especially useful as catalyst support, enhancing catalytic activity and reducing electron recombination in photocatalysis. Indonesia, the world’s top palm oil producer, generated around 12 million tons of empty fruit bunches (EFBs) in 2023, making EFBs a promising biochar source. This study synthesizes biochar from leftover EFB fibers at 500, 800, and 1000 °C, analyzing structural changes via infrared and Raman spectroscopy, along with particle size and surface area analysis, laying the groundwork for future biochar research. The smallest particle size and highest surface area gained was 71.1 nm and 10.6 × 10² m²/g. Spectroscopic analysis indicates that biochar produced at 1000 °C has produced nano-crystalline graphite with a crystallite size of approximately 5.47 nm. This provides higher defect density, although with lower conductivity. Other studies indicate that our biochar can be used as catalyst support for various green energy-related applications, i.e., counter electrodes, electrocatalysts, and photocatalysts. Full article

Background/Objectives: Degradation by physical and chemical agents affects the properties of essential oils; therefore, this study aimed to protect the volatile compounds present in essential oils through biopolymer encapsulation. Methods: The Achyrocline satureioides (Lam) DC. essential oil was obtained by steam distillation at 2.5 bar. The nano-sized physical coating of the active oil core resulted in an optimal polymer/oil ratio of 1:3 and particle diameter of 178 nm. The particle morphology was evaluated using scanning electron microscopy and transmission electron microscopy. The inclusion of the essential oil in the polymer was confirmed using thermogravimetric analysis. Results: The pH of the formulation remained stable for 90 days, and controlled release and encapsulation efficiencies were evaluated. Formulations were evaluated using the perfumery radar technique, which indicated a predominantly woody profile. The diffusion of fragrant compounds in the air was assessed over time and mathematically modeled. Conclusions: The produced nanostructures were efficient for the controlled release of volatile compounds from the essential oil of Achyrocline satureioides. Full article

Aim: To investigate the anti-inflammatory, antioxidant, and diabetic wound healing properties of the novel topical formulation [Ferulic acid-loaded nanoemulgel (DLMGO-G)]. Methods: Ferulic acid nanoemulsion developed with lemongrass oil is investigated in diabetic wound healing. Further nanoemulsion is incorporated into 1% carbopol^® 934 to obtain the DLMGO-G. Nanoemulsion was characterized for particle size, and polydispersity index (PDI) was obtained by Malvern Zetasizer (Zetasizer Nano ZS, Malvern, AL, USA), and morphology by TEM (JEM 1400, JOEL, Akishima, Japan). Furthermore, in vitro cell line and in vivo studies were carried out. Results: The developed nanoemulsion showed a globule size of 28.04 ± 0.23 nm and PDI of 0.07 ± 0.01. The morphology of nanoformulations by TEM confirmed the spherical and uniform nature. Further, the nanoformulation in in vitro cell line experiments revealed that the IC50 value was increased by 1.52 times compared to the drug solution. The treatment groups have shown that fibroblast morphologies were spindle-shaped, suggesting that nanoformulation was compatible with the cells and developed normally on nanoformulation. It also reduced ROS with improved internalization more than the control group. The in vitro wound healing model also revealed that nanoformulation had better wound healing activity. In the in vivo diabetic wound studies on male SD rats, the levels of inflammatory markers such as TNF-α, IL-6, IL-22, and IL-1β declined significantly when treated with DLMGO-G. IL-10 levels significantly increased compared to the diseased group, and MMP-9 levels were remarkably decreased compared to the diseased group. Furthermore, histopathological studies showed the regeneration and granulation of tissues. Conclusions: Thus, these findings indicate that FA-loaded nanoemulgel greatly accelerates the healing of wounds in diabetic rats. Full article

In recent years, slippery liquid-infused porous surfaces (SLIPSs) have gained significant attention in antifouling applications. However, their slippery performance often deteriorates in dynamic environments, limiting their service life. TC4 titanium alloy, commonly used in hulls and propellers, is prone to biofouling. SLIPSs have gained significant attention in antifouling applications. However, their slippery performance often deteriorates in dynamic environments, limiting their service life. To address these issues, a novel slippery liquid-infused surface (STASL) was developed on TC4 through the integration of hydroxyl end-blocked dimethylsiloxane (OH-PDMS), a silane coupling agent (KH550), and nano-titanium dioxide loaded with silver particles (TiO₂-Ag, anatase) and silicone oil, thereby ensuring stable performance in both dynamic and static conditions. The as-prepared surfaces exhibited excellent sliding capabilities for water, acidic, alkaline, and saline droplets, achieving speeds of up to 2.859 cm/s. Notably, the STASL demonstrated superior oil retention and slippery stability compared to SLIPS, particularly at increased rotational speeds. With remarkable self-cleaning properties, the STASL significantly reduced the adhesion of proteins (50.0%), bacteria (77.8%), and algae (78.8%) compared to the titanium alloy. With these outstanding properties, the STASL has emerged as a promising solution for mitigating marine biofouling and corrosion on titanium alloys. Full article

In this study, the design of experiments (DOE) method is used to find the optimum values of the tribological system in a 40–120 °C range with 0.1–1 wt% zirconia nanoadditives in a base oil. Significant factors were identified. The studied parameters include friction absolute integral, static friction, the wear scar diameter and the wear volume of the specimens. The measurements were carried out on a tribometer. The results were pre-estimated using statistical software; then, validation measurements were made using the estimated optimum point. The results show that the FAI value differed by 0.008, the COF value by 0.017, the WSD value by 4 μm and the WV value by 110,000 μm³. At 1 wt%, zirconia can have a positive effect at high temperatures. As temperatures increase, wear parameters decrease and friction values remain stable. Full article

High-temperature steam injection is a primary method for viscosity reduction and recovery in heavy oil reservoirs. However, due to the high mobility of steam, channeling often occurs within the reservoir, leading to reduced thermal efficiency and challenges in enhancing oil production. Foam fluids, with their dual advantages of selective plugging and efficient oil displacement, are widely used in steam-injection heavy oil recovery. Nonetheless, conventional foams tend to destabilize under high-temperature conditions, resulting in poor stability and suboptimal plugging performance, which hampers the efficient development of heavy oil resources. To address these technical challenges, this study introduces a foam system reinforced with Janus nano-graphite, a high-temperature stabilizer characterized by its small particle size and thermal resistance. The foaming agents used in the system are sodium α-olefin sulfonate (AOS), an anionic surfactant, and octadecyl hydroxylpropyl sulfobetaine (OHSB), a zwitterionic surfactant. Under conditions of 250 °C and 5 MPa, the foam system achieved a half-life of 47.8 min, 3.4 times longer than conventional foams. Janus nano-graphite forms a multidimensional network structure in the liquid phase, increasing internal friction and enhancing shear viscosity by 1.2 to 1.8 times that of conventional foams. Furthermore, the foam gel system demonstrated effective steam-channeling control in heterogeneous heavy oil reservoirs, particularly in reservoirs with permeability differentials ranging from 3 to 9. These findings suggest that the Janus nano-graphite reinforced foam system holds significant potential for steam-channeling mitigation in heavy oil reservoirs. Full article