Search Results (152)

Due to the complex mineral composition, low clay content, and strong heterogeneity of the mixed sedimentary shale in the Xinjiang Salt Lake Basin, the wettability characteristics of the reservoir and their influencing factors are not yet clear, which restricts the evaluation of oil-bearing properties and the identification of sweet spots. This paper analyzed mixed sedimentary shale samples from the Lucaogou Formation of the Jimsar Sag and the Fengcheng Formation of the Mahu Sag. Methods such as petrographic thin sections, X-ray diffraction, organic matter content analysis, and argon ion polishing scanning electron microscopy were used to examine the lithological and mineralogical characteristics, geochemical characteristics, and pore space characteristics of the mixed sedimentary shale reservoir. Alternating imbibition and nuclear magnetic resonance were employed to quantitatively characterize the wettability of the reservoir and to discuss the effects of compositional factors, lamina types, and pore structure on wettability. Research findings indicate that the total porosity, measured by the alternate imbibition method, reached 72% of the core porosity volume, confirming the effectiveness of alternate imbibition in filling open pores. The Lucaogou Formation exhibits moderate to strong oil-wet wettability, with oil-wet pores predominating and well-developed storage spaces; the Fengcheng Formation has a wide range of wettability, with a higher proportion of mixed-wet pores, strong heterogeneity, and weaker oil-wet properties compared to the Lucaogou Formation. TOC content has a two-segment relationship with wettability, where oil-wet properties increase with TOC content at low TOC levels, while at high TOC levels, the influence of minerals such as carbonates dominates; carbonate content shows an “L” type response to wettability, enhancing oil-wet properties at low levels (<20%), but reducing it due to the continuous weakening effect of minerals when excessive. Lamina types in the Fengcheng Formation significantly affect wettability differentiation, with carbonate-shale laminae dominating oil pores, siliceous laminae contributing to water pores, and carbonate–feldspathic laminae forming mixed pores; the Lucaogou Formation lacks significant laminae, and wettability is controlled by the synergistic effects of minerals, organic matter, and pore structure. Increased porosity strengthens oil-wet properties, with micropores promoting oil adsorption through their high specific surface area, while macropores dominate in terms of storage capacity. Wettability is the result of the synergistic effects of multiple factors, including TOC, minerals, lamina types, and pore structure. Based on the characteristic that oil-wet pores account for up to 74% in shale reservoirs (mixed-wet 12%, water-wet 14%), a wettability-targeted regulation strategy is implemented during actual shale development. Surfactants are used to modify oil-wet pores, while the natural state of water-wet and mixed-wet pores is maintained to avoid interference and preserve spontaneous imbibition advantages. The soaking period is thus compressed from 30 days to 3–5 days, thereby enhancing matrix displacement efficiency. Full article

Polymer brushes (PBs) are transformative surface-modifying nanostructures, yet their synthesis via controlled methods like copper-mediated surface-initiated atom-transfer radical polymerization (Cu⁰-SI-ATRP) faces reproducibility challenges due to a lack of understanding of parameter interdependencies. This study systematically evaluates the Cu⁰-SI-ATRP process for polyacrylamide brushes (PAM-PBs), aiming to clarify key parameters that influence the synthesis process. This evaluation followed a step-by-step characterization that tracked molecular changes through infrared spectroscopy (IR) and surface development by contact angle (CA) through two different mixing methods: ultrasonic mixing and process simplification (Method A) and following literature-based parameters (Method B). Both methods, consisting of surface activation, 3-aminopropyltriethoxysilane (APTES) deposition, bromoisobutyryl bromide (BiBB) anchoring, and polymerization, were analyzed by varying parameters like concentration, temperature, and time. Results showed ultrasonication during surface activation enhanced siloxane (1139→1115 cm⁻¹) and amine (1531 cm⁻¹) group availability while reducing APTES concentration to 1 Vol% without drying sufficed for BiBB anchoring. BiBB exhibited insensitivity to concentration but benefited from premixing, evidenced by sharp C–Br (~1170 cm⁻¹) and methyl (3000–2800 cm⁻¹) bands. Additionally, it was observed that PAM-PBs improved with Method A, which had reduced variance in polymer fingerprint regions compared to Method B. Adding to the above, CA measurements gave complementary step-by-step information along the modifications of the surface, revealing distinct wettability behaviors between bulk PAM and synthesized PAM-PBs (from 51° to 37°). As such, this work identifies key parameter influence (e.g., mixing, BiBB concentration), simplifies steps (drying omission, lower APTES concentration), and demonstrates a step-by-step, systematic parameter decoupling that reduces variability. In essence, this detailed parameter analysis addresses the PAM-PBs synthesis process with better reproducibility than the previously reported synthesis method and achieves the identification of characteristic behaviors across the step-by-step process without the imperative need for higher-cost characterizations. Full article

Polyaryletherketone (PAEK) polymers inherently exhibit low surface activity, leading to poor adhesive bonding performance when using epoxy-based adhesives. In this study, low-temperature plasma surface modification was conducted on carbon fiber-reinforced polyetherketone ketone (CF/PEKK) composites to investigate the influence of plasma treatment parameters on their lap shear strength. Surface characterization was systematically performed using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle analysis to evaluate morphological, chemical, and wettability changes induced via plasma treatment. The results demonstrated a significant enhancement in lap shear strength after plasma treatment. Optimal bonding performance was achieved at a treatment speed of 10 mm/s and a nozzle-to-substrate distance of 5 mm, yielding a maximum shear strength of 28.28 MPa, a 238% improvement compared to the untreated control. Notably, the failure mode transitioned from interfacial fracture in the untreated sample to a mixed-mode failure dominated by cohesive failure of the adhesive and substrate. Plasma treatment substantially reduced the contact angle of CF/PEKK, indicating improved surface wettability. SEM micrographs revealed an increased micro-porous texture on the treated surface, which enhanced mechanical interlocking between the composite and adhesive. XPS analysis confirmed compositional alterations, specifically elevated oxygen-containing functional groups on the plasma-treated surface. These modifications facilitated stronger chemical bonding between CF/PEKK and the epoxy resin, thereby validating the efficacy of plasma treatment in optimizing surface chemical activity and adhesion performance. Full article

Titanium has specific uses due to its cost, which is counterbalanced by its extraordinary chemical and physical properties. Submarine hulls and nuclear power plant pipes have been made of titanium since the last century due to its high corrosion resistance, and the aircraft industry has also exploited its remarkable properties, such as lightness and high melting point. Surface modifications by plasma electrolytic oxidation (PEO) may increase its corrosion resistance, roughness and wettability. Furthermore, greater corrosion resistance is a rather attractive property in nuclear power plant pipes, although the increased roughness and wettability are disadvantageous downsides as they favor the attachment of marine organisms. Nonetheless these new features are particularly interesting for biomedical applications. In this study, PEO films were produced on commercially pure titanium substrates using different electrolytes, one of which contains zirconium dioxide and the other consisting of tantalum pentoxide, in addition to a third one composed of a combination of the former two. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses were performed in addition to contact angle and roughness measurements, and electrochemical tests were carried out to comparatively characterize the different film compositions. The results revealed that excellent corrosion resistance was achieved by mixing oxides in the electrolyte. Full article

The primary challenge associated with stainless steel in fuel cell operation is its susceptibility to corrosion, which leads to increased contact resistance and subsequent degradation of electrochemical performance. In general, the protective layers have been loaded onto the metal surface by widely used traditional techniques such as physical vapor deposition (PVD), or cathode arc ion plating. However, the above sputtering and evaporation ways require a high-vacuum condition, complicated experimental setups, higher costs, and an elevated temperature. Therefore, herein the achievement for uniform coatings over a large surface area has been realized by using a cost-effective strategy through a complete wet chemical process. The synergistic regulation of two conductive components and a plastic additive has been employed together with the entrapment of a surfactant to optimize the microstructure of the coating surface. The assembly of layered graphite and a polystyrene sphere could maintain both the high corrosion resistance feature and excellent electrical conductivity. In particular, the intrinsic vacant space in the above physical barriers has been filled with fine powders of indium tin oxide (ITO) due to its small size, and the interconnected conductive network with vertical/horizontal directions would be formed. All the key technical targets based on the U.S. Department of Energy (DOE) have been achieved under the simulated operating environments of a proton exchange membrane fuel cell. The corrosion current density has been measured as low as 0.52 μA/cm² (for the sample of graphite/mixed layer) over the applied potentials from −0.6 V to 1.2 V and its protective efficiency is evaluated to be 99.8%. The interfacial contact resistance between the sample and the carbon paper is much less than 10 mΩ·cm² (3.4 mΩ·cm²) under a contact pressure of 165 N/cm². The wettability has been investigated and its contact angle has been evolved from 48° (uncoated sample) to even 110°, providing superior hydrophobicity to prevent water penetration. Such an innovative approach opens up new possibilities for improving the durability and reducing the costs of carbon-based coatings. Full article

The need to find sustainable solutions to conventional plastics has driven research into alternative materials, including bioplastics, which represent a promising option for reducing pollution and enhancing the value of renewable resources. In this study, bioplastics made from polyvinyl alcohol (PVA) and proteins extracted from the larvae of Black Soldier Fly (BSF), an insect capable of converting organic waste into high-value biomass, were produced and characterized. The proteins were obtained by hydrolysis of defatted BSF larvae with superheated water, avoiding harsh chemical reagents. Next, polymer films were fabricated by mixing PVA and hydrolyzed BSF proteins in different proportions and analyzed for morphological, physical-chemical, mechanical and biodegradability characteristics. The results obtained show that as the BSF protein content increases, the films show a reduction in thermal stability and mechanical properties, and also, they exhibit higher biodegradability, correlated with higher wettability, solubility and ability to absorb moisture. This research highlights the value of using organic waste-fed insects as a resource for bioplastic production, offering an alternative to traditional polymers and contributing to the transition to sustainable materials. Full article

The controllable transport of droplets on solid surfaces is crucial for many applications, from water harvesting to bio-analysis. Herein, we propose a novel droplet transport controlling method, reconfigurable orbital electrowetting (ROEW) on inclined slippery liquid-infused porous surfaces (SLIPS), which enables controllable transport and dynamic handling of droplets by non-contact reconfiguration of orbital electrodes. The flexible reconfigurability is attributed to the non-contact wettability modulation and reversibly deformable flexible electrodes. ROEW graphically customizes stable wettability pathways by real-time and non-contact printing of charge-orbit patterns on SLIPS to support the continuous transport of droplets. Benefiting from the fast erase-writability of charges and the movability of non-contact electrodes, ROEW enables reconfiguration of the wetting pathways by designing electrode shapes and dynamically switching electrode configurations, achieving controllable transport of various pathways and dynamic handling of droplet sorting and mixing. ROEW provides a new approach for reconfigurable, electrode-free arrays and reusable microfluidics. Full article

Shale oil is abundant in geological reserves, but its recovery rate is low due to its unique characteristics of ultra-low porosity, ultra-low permeability, and high clay content. This study investigated the effect of mixed-charge surfactants (PSG) on enhanced oil recovery (EOR) in high-temperature shale reservoirs, building on our previous research. The results indicate that PSG not only has outstanding interfacial activity, anti-adsorption, and high-temperature resistance but can also alter the wettability of shale. After aging at 150 °C for one month, a 0.2% PSG solution exhibited minimal influence on the viscosity reduction and oil-washing properties but significantly altered the oil/water interfacial tension (IFT). Compared to field water, the 0.2% PSG solution enhances the static oil-washing efficiency by over 25.85% at 80 °C. Moreover, its imbibition recovery rate stands at 29.03%, in contrast to the mere 9.84% of field water. Because of the small adhesion work factor of the PSG solution system, it has a strong ability to improve shale wettability and reduce oil/water IFT, thereby improving shale oil recovery. This study provides the results of a laboratory experiment evaluation for enhancing shale oil recovery with surfactants. Furthermore, it holds significant potential for application in the single-well surfactant huff-n-puff process within shale reservoirs. Full article

Honeycomb-structured, mixed-wettability surfaces have attracted significant attention due to their potential for tailoring surface properties and controlling fluid dynamics at the nanoscale. However, the underlying mechanisms governing droplet spreading and wettability modulation remain insufficiently understood. This study, using molecular dynamics simulations, reveals that periodic hydrophilic–hydrophobic areas within honeycomb structures induce unique oscillatory spreading behaviors and allow the precise modulation of equilibrium contact angles. The findings demonstrate that honeycomb designs can effectively transition surfaces between hydrophilic and hydrophobic states, with practical applications in boiling heat transfer, thermal management, and advanced materials development. Full article

Recently, there has been a rapid growth in the use of biodegradable polymers as alternatives to petroleum-based polymers, particularly in the packaging sector, to reduce environmental pollution. In this scenario, the aim of this work was to study the use of different amounts of Natamycin on two polymer systems: one that is non-biodegradable but widely known in the field of packaging and one that is biodegradable and is emerging as a possible replacement, in order to accelerate progress toward the achievement of the sustainable development goals. Both systems were produced through melt mixing followed by compression moulding. Subsequently, they were fully characterized by rheological, morphological, mechanical, thermal, and wettability analyses. Natamycin release was evaluated in water at 4 °C by UV-Vis measurements. The antifungal activity of both polymeric systems containing Natamycin was assessed in vitro against three strains of undesirable filamentous fungi of food interest. The results show that PCL with 5% Natamycin represents an effective biodegradable alternative to EVA for inhibiting undesirable filamentous fungi. More specifically, both systems at 5% showed comparable inhibition zones of about 30 mm. Full article

Optimizing oil recovery from mature reservoirs remains a key challenge in the petroleum industry. This study evaluates the efficiency of CO₂-WAG injection compared to continuous CO₂ and water flooding using a sector model of the X Oil Field. A compositional reservoir simulator was employed to analyze oil recovery under water-wet and mixed-wet conditions, incorporating three-phase relative permeability and wettability effects. The results show that continuous CO₂ flooding yields the highest oil recovery, with water-wet systems outperforming mixed-wet reservoirs. CO₂-WAG injection provides a balanced approach, enhancing recovery while enabling CO₂ sequestration, but remains less effective than continuous CO₂ flooding. Water flooding, though the least efficient in terms of oil recovery, demonstrates long-term production stability. The gas–oil ratio (GOR) is notably higher in CO₂-WAG, indicating gas breakthrough challenges. These findings emphasize the significant role of wettability in enhanced oil recovery (EOR) and suggest that continuous CO₂ flooding is the most effective technique for maximizing production in heterogeneous reservoirs. This study contributes valuable insights for optimizing injection strategies, improving hydrocarbon recovery, and supporting sustainable reservoir management. Full article

CO₂-enhanced tight oil production can increase crude oil recovery while part of the injected CO₂ is geologically sequestered. This process is influenced by factors such as gas injection rate, oil/gas viscosity ratio, and contact angle. Understanding how these factors affect recovery during CO₂ non-mixed-phase substitution is essential for improving CO₂-enhanced tight oil production technology. In this study, three-dimensional pore structure was numerically simulated using physical simulation software. The effects of three key parameters—the gas injection rate, contact angle and viscosity slope—on flow displacement during a CO₂ non-mixed-phase drive were analyzed. In addition, the study compares the fluid transport behavior under mixed-phase and non-mixed-phase conditions at the pore scale. The simulation results show that increasing the replacement velocity significantly expands the diffusion range of CO₂ and reduces the capillary fingering phenomenon. In addition, the saturation of CO₂ increases with the increase in the viscosity ratio, which further improves the diffusion range of CO₂. The wetting angle is not simply linearly related to the drive recovery, and the recovery is closely related to the interfacial tension and capillary force under the influence of wettability. The recoveries under mixed-phase conditions were slightly higher than those under unmixed-phase conditions. During the mixed-phase replacement process, CO₂ is dissolved into the crude oil, resulting in oil volume expansion, which improves the distance and extent of CO₂ permeation. Full article

Immiscible displacement in porous media is a crucial microscale flow phenomenon in many fields, necessitating an understanding of the flow mechanisms under dynamic injection velocity and mixing wettability to predict and affect this flow accurately. Initially, a dynamic injection velocity method and a computational domain model considering non-dominant/dominant wetting angles were proposed. Then, microscale flow phenomena were modeled in a pore throat structure and doublet geometry under mixed wetting conditions. Finally, the influence of dynamic injection velocity and mixed wettability on microscale flow were investigated using numerical simulations. The results indicate that when stepwise and piecewise linear changes in injection velocity are observed, unlike continuous injection, two preferential displacement pathways are predominantly formed in the porous media. As the difference between the maximum and minimum injection velocity increases, the recovery efficiency initially decreases and then increases. Recovery efficiency is higher under piecewise linear injection velocity changes. The non-dominant wetting angle determines the distribution and flow of oil-water two-phase systems in porous media. With a dominant controlling wetting angle of 45°, as the non-dominant wetting angle increases, the flow phenomenon changes from one preferential pathway in the back region (30°, 45°) to two preferential pathways (60°, 90°, 120°) and then to one preferential pathway in the middle porous media (150°). As the degree of the non-dominant wetting angle increases, the recovery efficiency first increases and then decreases, with a maximum and minimum difference of 13.6%. Full article

Stockpiled end-of-life tires (ELTs) pose a serious environmental concern. In the current investigation, ELT pyrolysis oil (i.e., pyro-oil) was studied as a potential additive to conventional motor oil. The pyro-oil samples were mixed in different concentrations of 10 to 50 wt.% with commercial virgin motor oil to obtain a lubricant mixture. Chemical analyses were performed for the tire-recycled derivative material, as a potential route to utilize pyro-oils, valorize ELT waste, and reduce production costs of motor oil lubricants. Rheological examinations were performed to explore the impact of the pyro-oil on the rheological properties of the motor oil under several shearing rates and temperatures. Tribological analyses of the lubricant mixtures and the pure motor oil were accomplished to study the influence of the pyro-oil additive on the tribological behavior of motor oils. Lastly, thermal stability and wettability examinations were executed to assess the thermal and wetting properties of lubricant mixtures. The obtained results showed that adding a low concentration of the pyro-oil (≤10%) will sustain the motor oil’s chemical, wettability, thermal stability, rheological, and tribological properties, signifying a viable application of recycled ELTs and helping to reduce their environmental and economic impact. These findings offer a feasible route of use in the future to obtain low-cost oils with market specifications, utilizing pyro-oil as a sustainable and environmental oil additive. Full article

Aluminum 7075 alloys are widely utilized in aerospace, transportation, and marine industries due to their high strength and low density. However, further research is needed to understand their mechanical, thermomechanical, and vibrational behaviors when reinforced. This study focuses on the development of Al 7075 composites reinforced with zirconium silicate (ZrSiO₄), processed via sand stir casting. The mechanical properties, including tensile, compression, and impact strength, as well as thermomechanical and vibrational behaviors, were thoroughly investigated. A planetary ball mill was used to mix ZrSiO₄ with a wettability agent, and the results indicated that the addition of ZrSiO₄ with the wettability agent significantly enhanced the mechanical properties. Fourier Transform Infrared Spectroscopy (FTIR) was employed to identify the compounds formed after adding the reinforcement and wettability agent. Scanning Electron Microscope (SEM) images and Energy-dispersive X-ray (EDX) analysis revealed a uniform distribution of the particles within the matrix. The tensile, compression, and impact strengths increased by 20%, 21%, and 19%, respectively, with the addition of 8 wt% ZrSiO₄; however, strain decreased. Additionally, heat treatment further enhanced the mechanical properties of the composites. The thermomechanical properties showed improvement even at elevated temperatures, and the damping factor was enhanced with the addition of ZrSiO₄. The elemental composition of the reinforced composites was analyzed using EDX, confirming the presence of the reinforcement. This research highlights the potential of Al 7075-ZrSiO₄ composites for improved performance in various applications. Full article