No abstract

In response to the industry's difficulty in properly separating oily wastewater discharge, researchers are investigating enhanced oil/water separation materials. In this work, a cost-effective and environmentally friendly superhydrophobic textile fabric was fabricated for effective oil–water mixture and emulsion separation. A biological metal–organic framework consisting of copper as a core metal and aspartic acid as a linker (Cu-Asp MOF) was used to improve the surface roughness of the pristine textile fabric, and stearic acid was used to lower its surface energy. The thermal gravimetric analysis investigated the prepared Cu-Asp MOF's thermal stability. X-ray spectroscopy and Fourier-transform infrared spectroscopy studied the crystal orientation and chemical composition of the Cu-Asp MOF, Cu-Asp MOF@SA, pristine textile fabric, and superhydrophobic textile fabric, respectively. The surface morphology of the pristine and modified textile fabric was studied by scanning electron microscope. The wettability results showed that the prepared superhydrophobic textile fabric has a water contact angle of 158° ± 1.3 and water sliding angle of 2° ± 0.2°. The prepared superhydrophobic textile fabric showed excellent oil–water mixture and emulsion separation performance, oil absorption capacity, chemical stability, mechanical abrasion resistance, and a high flux rate. These outstanding characteristics of the prepared superhydrophobic textile fabric greatly increase the possibility for practical applications.

Effect of lupine and damsissa extracts on the corrosion of steel in 0.5 M Na2SO4 solution free from and containing 0.01 or 0.1 M NaCl were examined by potentiodynamic and electrochemical impedance spectroscopy techniques. Potentiodynamic polarization curves measurements indicated that damsissa and lupine extracts behave as anodic type inhibitors. Nyquist impedance plots showed type of distorted semicircle whose size increases with increasing concentrations of lupine or damsissa extract. Increasing chloride ion concentration in the solution led to increase of the inhibition efficiency of the extract and this behaviour was explained on the basis of co‐operative mechanism of adsorption. Kinetic–thermodynamic model was used to clarify the nature of adsorption and showed good fit to the experimental data. The results indicated that lupine extract is more effective as corrosion inhibitor for steel in neutral media containing chloride ions than damsissa extract.

Potentiostatic deposition of cobalt film and cobalt-graphene, Co-G, composite, followed by modification with low surface energy stearic acid (SA), was used to fabricate superhydrophobic films on a steel substrate successfully. A scanning electron microscope was used to analyze the surface morphology of the prepared superhydrophobic cobalt film modified by stearic acid, Co-SA, and the cobalt-graphene film modified by stearic acid, Co-G-SA. The findings show that both the fabricated films have micro-nanostructures. The Co-G-SA film shows a higher roughness due to the network structures of graphene and so exhibits higher superhydrophobicity. The Fourier transform infrared spectrophotometer, FTIR, results confirm the formation of Co-SA and Co-G-SA films on the steel surface. The wettability of the prepared films shows that they exhibit superhydrophobicity, where the Co-SA and Co-G-SA films have contact angles of 155° and 158°, respectively. The Potentiodynamic polarization results show that the value of the corrosion current density for steel coated with Co-SA (0.7094 µA) is lower than that of bare steel (0.1457 mA), while the coated steel with Co-G-SA film has the lowest value (0.1732 µA). The electrochemical impedance spectroscopy, EIS, results show that the charge transfer resistance for steel coated with Co-SA is 38 times that of bare steel, while steel coated with Co-SA is 57 times that of bare steel. Potentiodynamic polarization and EIS results show that the prepared Co-G-SA film superhydrophobic films exhibit higher corrosion resistance. Co-G-SA film has higher mechanical stability (maintains superhydrophobicity until 900 abrasion cycles), chemical stability (has superhydrophobicity in the pH range 1–13), and long-term stability (retains superhydrophobicity after 30 days in a 0.5 M NaCl solution) in 0.5 M NaCl solution.

Superhydrophobic cobalt and cobalt-graphene films were fabricated on copper bipolar plates using potentiostatic electrodeposition to improve their corrosion resistance and surface conductivity. A scanning electron microscope (SEM) was used to study the surface morphology of the prepared superhydrophobic films. The results show that the cobalt film modified by stearic acid (Co-SA) and cobalt-graphene composite modified by stearic acid, Co-G-SA, exhibit micro-nano structures. The results of the Fourier transforming infrared spectrophotometer (FTIR) confirm that the copper substrate was coated by Co-SA and Co-G-SA films. The wettability results of the prepared superhydrophobic films demonstrate that the films display superhydrophobicity, where the fabricated Co-SA and Co-G-SA films have contact angles of 159° and 165°, respectively. Chemical stability, mechanical abrasion resistance, surface conductivity, and corrosion resistance in a simulated proton exchange membrane fuel cells (PEMFC) environment are significantly higher for copper coated by Co-G-SA film. Because the copper coated with Co-G-SA has a low ICR value and a high corrosion resistance, it is thought to be a good choice for PEMFC bipolar plates.