Superelastic and Durable Hierarchical Porous Thermoplastic Polyurethane Monolith with Excellent Hydrophobicity for Highly Efficient Oil/Water Separation

Abstract

A superelastic hierarchical porous thermoplastic polyurethane (TPU) monolith with excellent hydrophobicity was facilely prepared by a thermally induced phase separation method with two cooling steps. The TPU monolith as an oil absorbent is capable to selectively absorb various oils/organic solvents from oil/water mixtures with high saturated absorption capacity (5.95–40.60 g g–1) and rapid absorption rate (achieving absorption equilibrium within 15 s). More importantly, the monolith exhibits remarkable superelasticity with large reversible compressibility and outstanding fatigue resistance (1500 cycles at 80% strain), allowing it to repetitively absorb oil via simple manual squeezing. Furthermore, the monolith possesses high tolerance and durability in a wide range of pH (2–12) and temperature (0–100 °C), even in a turbulent environment. The TPU monolith can also continuously absorb and remove oil/organic solvent from the water surface by a pump-assisted system. The above-mentioned advantages of a porous TPU monolith make it become a promising and sustainable candidate for water pollution treatment.

Thiol Oxidative Coupling Synthesis of Silicone Foams for Oil/Water Separation

“…This finding could be attributed to the open-celled structure in SF-21. The acquired values of these foams are comparable to or higher than many reported SF-based absorbents and organic foams, such as the polydimethylsiloxane (PDMS) oil absorbent (4−34 g g −1 ), 22 macroporous PDMS/MWNT (multiwalled carbon nanotubes) nanocomposite (8.5−20 g g −1 ), 23 porous PDMS sponge via the paraffin oil-based emulsion technique (13.5−33.3 g g −1 ), 24 sodium alginate foams (11.2−25.9 g g −1 ), 25 thermoplastic polyurethane foams, 26,27 and poly(lactic acid) foams 28,29 (Table 2). Moreover, the SFs can be recycled by a simple treatment of compression, which is important for industrial application.…”

A Review on Oil/Water Mixture Separation Material

“…9,10 Commercially available sponge materials have aroused extensive attention because of the superiority of being easily available, low cost, developed porous skeleton, and compressibility. 11,12 Metal mesh, 13 natural textile, 14 organic synthetic polymer membrane, 15 carbonbased membrane, 16 and cellulose-based membrane material 17 are often developed to separate oil from water through the means of filtration. Furthermore, smart controllable special wettable separation material as a new kind of oil−water separation material has also been introduced here.…”

“…Among these materials, particle or powdered material exhibited obvious advantages during the treatment of a thin oil layer . Aerogel has long been a star material for the removal of floating oil from water, owing to the advantage of excellent oil adsorption performance derived from ultralight density and high specific surface area. , Commercially available sponge materials have aroused extensive attention because of the superiority of being easily available, low cost, developed porous skeleton, and compressibility. , Metal mesh, natural textile, organic synthetic polymer membrane, carbon-based membrane, and cellulose-based membrane material are often developed to separate oil from water through the means of filtration. Furthermore, smart controllable special wettable separation material as a new kind of oil–water separation material has also been introduced here. , Finally, the prospect and challenge of these materials are put forward.…”

Fabrication of New Thermoplastic Polyurethane Elastomers with High Heat Resistance for 3D Printing Derived from 3,3-Dimethyl-4,4′-diphenyl Diisocyanate

“…Nowadays, industrial TPU is mostly synthesized using polyethers, polyesters, or polycarbonates to react with toluene diisocyanate (TDI) or diphenyl methane diisocyanate (MDI). Previous studies of TPU mostly focused on TDI-based TPU, MDI-based TPU, and hexamethylene diisocyanate (HDI)-based TPU. − However, TDI and MDI show poor heat resistance because of their structural asymmetry. Para-phenyl diisocyanate (PPDI) and 1,5-naphthalene diisocyanate (NDI) are structurally symmetrical and their synthesized TPUs have relatively high heat resistance, but their reactivities are higher than expected, making it easily go out of control.…”