The Gemini imidazoline surfactants were synthesized from a series of saturated fatty acids. Electrochemical impedance spectroscopy (EIS), polarization curve, and quantum chemistry methods were used to study the corrosion inhibition behavior of Gemini imidazoline surfactants for X70 carbon steel in NaCl solution. Results reveal that such kind of surfactants has an outstanding inhibition effect on carbon steel X70 in NaCl solution and that the restrained efficiency of Gemini imidazoline in an alkaline solution is better than that in a neutral solution. The shorter the carbon chain length, the higher the suppressive efficiency. The higher the concentration of Gemini imidazoline surfactant, the better the inhibition effect.
1 May 2020 in International Journal of Electrochemical Science
This study examined a novel ethoxy-segment-regulated hydrophobic associative amphiphilic copolymer, P(AA-AAEOn), and systematically evaluated its solution self-assembly behavior and enhanced oil recovery (EOR) performance. The influence of ethylene oxide (EO) chain length and polymer concentration on particle size distribution and aggregation morphology was analyzed using dynamic light scattering (DLS). The results revealed a concentration-dependent transition from intramolecular to intermolecular association, accompanied by a characteristic decrease followed by an increase in hydrodynamic diameter. At a fixed AA:AAEOn molar ratio (400:1), increasing EO segment length increased aggregate size and improved colloidal stability. Viscometric analysis showed that longer EO chains markedly increased molecular chain flexibility and solution viscosity. Interfacial tension measurements demonstrated superior interfacial activity of P(AA-AAEOn) compared to polyacrylic acid (PAA), and longer EO chains further reduced oil–water interfacial tension. Emulsification tests verified its strong ability to emulsify crude oil. Sandpack flooding experiments and micromodel studies demonstrated effective conformance control and high displacement efficiency, achieving up to 30.65% incremental oil recovery. These findings offered essential insights for designing hydrophobic associative polymers with tunable interfacial properties for EOR applications.
The electronic properties of TiO2 nanotubes are strongly governed by the local atomic configurations of native defects and incorporated dopants. Establishing this structure–property relationship is difficult because experimental measurements generally reflect ensemble-averaged behavior, while atomic-scale energetic and electronic properties are often investigated using idealized models of nanotubes, anatase, or rutile TiO2. This review examines how defect location, charge state, dopant position, local chemical environment, and lattice relaxation influence defect stability, dopant–defect association, and electronic reconstruction. Experimental findings and calculations specific to TiO2 nanotubes are discussed together with studies examining individual defect configurations in anatase and rutile TiO2. The discussion distinguishes defect formation from dopant–defect association and considers how these processes modify localized electronic states, charge compensation, and polaronic behavior. Previous studies show that coupled dopant–defect configurations can generate localized electronic states, shift or passivate pre-existing defect states, and redistribute charge across neighboring lattice sites. These configuration-induced electronic changes directly affect carrier trapping, polaron migration, and nonradiative recombination pathways. Quantitative relationships between specific atomic configurations and finite-temperature carrier kinetics are still not well established for TiO2 nanotubes.
Barium disilicide (BaSi2) was identified as a promising silicon-based photovoltaic absorber due to its near-optimal bandgap, strong optical absorption, and earth-abundant composition. However, the performance of BaSi2 thin-film solar cells was severely restricted by structural defects and interfacial instabilities that introduced localized electronic states and facilitated non-radiative recombination. These imperfections degraded carrier lifetime, mobility, and open-circuit voltage. This review systematically examined the formation, energetics, and electronic roles of intrinsic and extrinsic defects in BaSi2 thin films, and evaluated nanoscale passivation strategies developed to mitigate defect-induced losses. Chemical, dielectric, and interfacial approaches were critically analyzed with emphasis on their underlying mechanisms, limitations, and integration potential. The convergence of in situ characterization, first-principles modeling, and data-driven process optimization was expected to enable predictive defect control and rational interface design, thereby advancing BaSi2-based photovoltaics toward practical implementation.
Efficient utilization of agricultural residues plays an important role in advancing sustainable bioenergy development in China. This study established a multi-criteria evaluation framework integrating energy quality, economic performance, and environmental impact to assess three representative straw-to-energy pathways: direct combustion for power generation, anaerobic digestion for biogas production, and lignocellulosic ethanol production. The Analytic Hierarchy Process (AHP) was applied to determine indicator weights and calculate composite scores using operational and pilot-scale data obtained for each pathway. The results showed that anaerobic biogas achieved the highest overall performance (composite score 0.41), with balanced performance in economic viability, energy utilization efficiency, and environmental performance. Direct combustion demonstrated favorable economic performance (0.37) but exhibited higher process emissions, whereas lignocellulosic ethanol showed superior environmental performance but suffered from low energy conversion efficiency and negative economic returns (0.00). Sensitivity analysis confirmed the stability of the pathway ranking and highlighted the dominant influence of economic and energy-related indicators on the overall sustainability assessment. The study demonstrated that anaerobic biogas exhibited the most balanced performance among the evaluated pathways under the investigated technological and economic conditions, while integrated biorefining approaches, such as co-production of ethanol and biogas, showed potential for further enhancing resource efficiency and sustainability.