Langmuir最新文献

The flotation process of low-grade ilmenite faces considerable challenges, primarily due to its small particle size and large specific surface area. The introduction of nanobubbles (NBs) offers an effective approach to enhancing the flotation of fine particles. In this study, NBs produced via hydrodynamic cavitation were introduced into the flotation of -20 μm ilmenite. The results showed that NBs significantly enhanced ilmenite flotation and extended the recovery difference between ilmenite and forsterite to 49.37% at a 20 mg/L collector. NBs selectively adhered on the ilmenite surface and enhanced the hydrophobic interaction between ilmenite surfaces in the presence of collector, thereby improving the flotation performance of microfine ilmenite.

Utilizing density functional theory (DFT) computational techniques, this paper examines how dissolved gases (CO, H₂, CH₄, C₂H₂, and C₂H₄) in transformer oil adhere to HfSe₂ monolayers enhanced with metal oxides (ZnO, TiO₂). The results demonstrate that the pristine HfSe₂ monolayer exhibits weak physisorption for all five gases, characterized by small adsorption energies and long adsorption distances. Upon modification with ZnO and TiO₂, the adsorption performance improves significantly, particularly for CO, C₂H₂, and C₂H₄. These improvements are reflected in stronger adsorption energies, reduced adsorption distances, and increased charge transfer, indicating stronger interactions and, in some cases, chemisorption. Among the two modified systems, ZnO-HfSe₂ demonstrates superior gas sensing potential compared to that of TiO₂-HfSe₂. The adsorption capacity follows the order C₂H₄ > C₂H₂ > CO > CH₄ > H₂ for ZnO-HfSe₂ and C₂H₂ > C₂H₄ > CO > CH₄ > H₂ for TiO₂-HfSe₂. Analysis of the electronic properties reveals that ZnO modification enhances electrical conductivity, while TiO₂ modification reduces it. Recovery time analysis suggests that both modified materials are unsuitable for H₂ and CH₄ detection due to their extremely short recovery times. However, they are promising candidates for CO, C₂H₂, and C₂H₄ sensing, with recovery times that can be optimized by adjusting the temperature. This study offers theoretical foundations for creating advanced gas sensors that utilize metal-oxide-modified HfSe₂ to identify dissolved gases present in transformer oil.

With increasing water production in mature oil and gas reservoirs, the development of effective water shutoff agents is of critical importance. In this work, a superhydrophobic mesoporous silica (SiO₂)-based water shutoff agent is developed to overcome the limitations of conventional chemical agents under harsh reservoir conditions or to exhibit poor selectivity. To further verify that the mesoporous structure provides advantages over conventional solid nanoparticles in water shutoff, computational simulations are conducted to compare their pressure distributions during the blocking process. The results show that mesoporous particles exhibit higher and broader pressure regions, indicating superior water shutoff performance relative to solid particles. The modified SiO₂ is then prepared into a stable oil-in-water (O/W) emulsion for efficient transport into the reservoir. The characterization results confirm the retention of the mesoporous structure after modification, with a water contact angle of 148.5°, showing excellent thermal and rheological stability. Core flooding experiments demonstrate water shutoff efficiencies of 97.13-99.09% and oil blocking ratios of only 25.00-28.50% in cores with 300-1000 mD permeability under conditions of 100 °C and 35,000 mg/L salinity. These results indicate that the developed system offers a high conformance control performance with robust thermal and salinity tolerance.

High-speed data transmission requires the formation of fine and smooth Cu wiring, which inevitably causes a decline of interfacial bonding strength between Cu and the insulating dielectric layer. In this work, 4-aminothiophenol (4-ATP) is used as a bifunctional promoter for the interfacial adhesion between a Cu foil and a widely used Ajinomoto build-up film (ABF) without coarsening the Cu surface. It is found that the introduction of ascorbic acid (AA) accelerates the self-assembly process of 4-ATP on Cu surface, as monitored by in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and examined by cyclic voltammetry (CV). Peel strength tests and morphology analyses reveal that the AA-assisted 4-ATP SAM significantly enhances the interfacial adhesion between Cu and ABF, which is of practical significance in advanced packaging.

Catechol (CC), also known as 1,2-dihydroxybenzene, is a hazardous industrial pollutant that poses significant environmental and health risks, including skin irritation and vision damage. Developing an efficient sensing material for catechol detection is a critical challenge. This study employs first-principles density functional theory (DFT) to investigate the catechol-sensing performance of pristine and a biaxially strained BeN₄ monolayers, which are recently synthesized two-dimensional Dirac semimetal. When compressive strain is applied to the BeN₄ monolayer, the catechol adsorption energy increases from -0.90 to -0.98 eV, and the amount of charge transfer enhances from 0.01e to 0.02e, indicating improved interaction strength and sensitivity. The density of states and reduced density gradient (RDG) plots provide important insights into the interaction between CC and the BeN₄ monolayer. CC binding is due to charge transfer from the oxygen 2p orbital of the CC molecule to the BeN₄ nanosheet. Ab initio molecular dynamics (AIMD) simulations confirm the thermal stability of the nanosheet at 500 K. The CC recovery time from the strained BeN₄ nanosheet under visible light is 70.5 s at 300 K. This theoretical study is of significant importance for the design of efficient catechol-sensing devices.