A superwettable functionalized-fabric with pH-sensitivity for controlled oil/water, organic solvents separation, and selective oil collection from water-rich system

Superhydrophilic and Underwater Superoleophobic Cotton Fabric for Oil–Water Separation and Removal of Heavy-Metal Ion

“…According to the Wenzel equation (as shown in eq (7)), the surface roughness reduces the water contact angle and enhances the hydrophilicity of the material.…”

“…WA WA (7) where θ WA ′ is the water contact angle of the rough surface, and r is the surface roughness factor (i.e., the roughness factor is the ratio of actual surface area to the apparent surface area; r is always larger than 1). Figure 3 shows the experimental results of wettability of the samples.…”

“…So far, many technologies have been reported for the disposal of oily wastewater, including flotation, centrifuges, oil skimmers, membrane separation, etc . The membrane separation method based on a superwetting surface has been attracting extensive attention in the field of oily wastewater treatment because of its simple operation and high separation efficiency. − Notably, oily wastewater contains other pollutants, such as organic dyes and heavy-metal ions, among which heavy-metal ions are one of the most common and harmful pollutants in water pollution. , Adsorption is one of the most commonly used methods to remove heavy metals because of its simple operation, easy recycling, and low cost. ,− A superhydrophilic membrane with functional groups for heavy-metal ion adsorption could simultaneously remove oil and heavy-metal ions from wastewater, which simplifies the purification process of oily wastewater containing heavy-metal ions and reduces the cost of wastewater treatment. − Wang et al prepared an organic-inorganic composite membrane by the electrospinning technique modified with 3-[(trimethoxysilyl) propyl]-diethylenetriamine to obtain a superhydrophilic and underwater superhydrophobic membrane. The membrane was used to treat artificial emulsified oily wastewater with the desired concentrations of heavy-metal ions Pb­(II), Cr­(III), and Ni­(II); the water flux could reach 1517 ± 53 L·m –2 ·h –1 , and the removal efficiencies of both oil and heavy-metal ions were larger than 99%.…”

Universal Rapid Demulsification by Vacuum Suction Using Superamphiphilic and Underliquid Superamphiphobic Polyurethane/Diatomite Composites

“…Various methods such as gravity separation, , local combustion, chemical demulsification, coalescence separation, , microchannel demulsification, membrane separation, − and adsorption separation , are commonly employed to treat emulsions. However, inexpensive and satisfactory emulsion treatment is difficult to achieve owing to the natural drawbacks of these conventional processes: easy choking and contamination of the membrane and coalescer by oil fouling, the high cost of operational energy consumption and the demulsifier, or frequent adsorbent replacement. − Thus, it is necessary to develop a simple, low-cost continuous emulsion separation process based on a facile, fast, stable, and efficient demulsifying separator with low energy consumption, low cost, high environmental friendliness without the use of external chemicals, and excellent oil fouling tolerance in long-term operation.…”

Green fabrication of flame retardant and superhydrophobic materials with application in oil‐water separation

“…In the past decades, water pollution and fire accidents caused by chemical leaks and oil spills have occurred frequently, and oil-water separation and flame retardancy have received widespread attention. [1][2][3] Oils and organic pollutants will reduce the dissolved oxygen in water, seriously affect the normal growth of aquatic organisms, and then destroy water resources. The carcinogenic hydrocarbons in oily wastewater will be enriched by fish and shellfish, and endanger human health through the food chain.…”