Ultrahigh Flux Research Articles

Facile fabrication of 2D MOF-Based membrane with hierarchical structures for ultrafast Oil-Water separation

The surface chemical composition and building unit structures of membrane are the key factors to realize highly-efficient oil–water separation. Here we report the synthesis of Cu-CAT-1 metal–organic frameworks (MOFs) with unique two-dimensional (2D) hierarchical structures grown directly on copper mesh (Cu-CAT-1@CM) for oil–water separation. The Cu-CAT-1@CM membrane with micro/nano- architecture exhibits robust superhydrophilicity and underwater superoleophobicity characteristics, allowing gravity-driven oil–water separation by achieving ultrahigh flux up to 329 kL∙m−2∙h−1. The membrane shows excellent separation performances by testing various oils, particularly actual crude oil and xylene, which are considered as the notorious pollutants in the water. The residual oil contents of six samples are all less than 24.6 mg∙L-1. The mechanism analysis demonstrated that the appropriate hierarchical structures of the membrane surface is the code for the extreme wettability that remarkably improved the separation efficiency. Moreover, such a membrane with high performance can be readily synthesized by electrochemical method at room temperature in only 20 min, which shows the advantages of facile and environmentally friendly fabrication process as well as low cost. Overall, the membrane with energy-saving of gravity-driven and ultra-high permeability allows the rapid separation of oil–water mixture, showing the potential applications for resolving the problem of oil pollution.

New graphitic carbon nitride-based composite membranes: Fast water transport through the synergistic effect of tannic acid and tris(hydroxymethyl) aminomethane

Graphitic carbon nitride nanosheets can be assembled into two-dimensional layered separation membranes due to their unique structure; however, the narrow interlayer channels (0.32 nm) cause strong transmembrane mass transfer resistance. In this study, we expanded the interlayer spacing by intercalating tris(hydroxymethyl) aminomethane (Tris) molecules as supports while introducing high-affinity and adhesive tannic acid (TA) molecules to suppress the disordered stacking of Tris molecules. The two were stably anchored between the layers through hydrogen bonding to form an interlayer channel of 0.83 nm. While maintaining the high rejection performance (>99%) for EB dyes, the improved composite membrane possessed an ultrahigh water flux (170 ± 6 L h−1 m−2 bar−1) that was more than ten times higher than that of the pristine g-C3N4 membrane. We also studied the acid-base resistance, organic solvent resistance and mechanical stability of the composite membrane.

Molecular and structural design of polyacrylonitrile-based membrane for oil-water separation

Herein, a durable superhydrophobic/superoleophilic membrane with micro-/nano-hierarchical structure was achieved through molecular and structural design of fluorinated polyacrylonitrile-based membrane. In which, the introduction of perfluorooctanol acrylate into copolymer chain and usage of electrospinning/electrospraying technology followed by heat post-treatment provided low surface energy and durable hierarchical structure, respectively. The resultant membrane demonstrated superhydrophobicity and superoleophilicity with water contact angle of 160° and oil contact angle of 0° in air, which endowed the membrane with excellent separation ability for oil/water mixture with separation efficiency above 99% and ultrahigh flux beyond 8000 L/m 2 /h. Furthermore, the obtained membrane maintained its superhydrophobicity after exposure to broad pH, organic solvents, high temperature and ultrasonic treatment, ascribed to the chemical reaction of cyano groups on the surface of fibers and particles during the heat post-treatment. This work provides a promising strategy to fabricate superwetting membrane to remove trace amount of water in oil. A durable and robust membrane with micro-/nano-hierarchical structure was achieved through molecular and structural design of polyacrylonitrile-based membrane for efficient separation of various oil/water mixtures. • A novel fluorinated polyacrylonitrile copolymer was synthesized. • Membrane with micro-/nano-scale structures was constructed by using the copolymer. • The fibers and particles in membrane were integrated by chemical interactions. • Durable superhydrophobicity of membrane was achieved. • The membrane showed excellent separation efficiency for oily wastewater.

Fabrication of a superhydrophilic/underwater superoleophobic stainless steel mesh for oil/water separation with ultrahigh flux

Fabrication of a superhydrophilic/underwater superoleophobic stainless steel mesh for oil/water separation with ultrahigh flux

High flux composite membranes based on glass/cellulose fibers for efficient oil-water emulsion separation

It is a challenge to develop an oil-water separation membrane that simultaneously meets the requirements of environmentally-friendly, low-cost, high flux, high wet strength, and excellent separation efficiency. Herein, composite membranes based on glass and cellulose fibers were prepared by a series of steps including cellulose fiber skeleton construction, maleic anhydride (MA) modification, and plasma treatment. The micro-sized beaten cellulose fibers and nano-sized bacterial nanocellulose (BC) are interlaced with each other during the layer upon layer deposition via vacuum filtration, thus effectively fixing the glass fibers. Combined with MA crosslinking, the wet strength of the composite membrane is greatly increased to 6.55 N·m/g. Besides, the underwater superoleophobicity of the composite membrane (UOCA＞150°) was realized by constructing the micro- and nano-scale roughness through plasma treatment. When used for oil-water emulsion separation, an ultrahigh flux up to 12, 070 L/m2·h with the separation efficiency of ≥ 98.1% were achieved for the composite membranes solely under the driving of gravity. Micro- and nano-scale fibers are used to synergistically increase strength, and the hierarchical roughness is generated as an inherent property of the membrane. The unique structure resulting underwater superoleophobic composite membrane is of practical interest for oily wastewater treatment.

Metal-organophosphate biphasic interfacial coordination reaction synthesizing nanofiltration membranes with the ultrathin selective layer, excellent acid-resistance and antifouling performance

Phytate as a natural strongly charged organophosphate has recently attracted much attention in diverse fields including membrane separations towards water-energy-food nexus. However, the ideal phytate-based nanofiltration membrane with defect-free and ultrathin selective layer for highly-efficient water treatment is still much challengeable due to the typical aggregation of metal ions and uncontrolled reaction between metal ion and organophosphate via conventional coating method. Herein, metal-organophosphate biphasic interfacial coordination reaction is proposed to construct ultrathin (13.4 nm) selective layer of phytate-based nanofiltration membranes with high permeance and excellent stability by controllable coordination assembly. Iron acetylacetonate (Fe(acac)3) as an organic phase monomer with powerful electron-gaining ability is exploited to avoid the aggregation of traditional Fe(III) in aqueous phase, which can also coordinate with phytic acid (PA) to ensure a defect-free ultra-thin selective layer. The architecture of the phytate-based selective layer can be well regulated by optimizing the coordination metal source, the concentration of PA and Fe(acac)3, reaction time, so as to achieve the ultrahigh permeation flux of 190 L m−2 h−1 with excellent dye rejection (99.6%). Most interestingly, our phytate-based nanofiltration membranes with plenty of hydrophilic phosphate groups on the surface and high binding energy of P–O–Fe bond (−315.1 kJ mol−1) exhibited the long-term separation stability, excellent acid-resistance and anti-pollution ability, realizing the stable membrane separation process under harsh conditions.

Graphene nanofiltration membrane intercalated with AgNP@g-C3N4 for efficient water purification and photocatalytic self-cleaning performance

Low water flux and heavy membrane fouling hinder the use of graphene-based membranes for water purification and molecular sieving. To the end, a novel graphene-based membrane, intercalated with Ag nanoparticles anchored g-C3N4 (AgNP@g-C3N4) as pillars and photocatalysts, was fabricated through a mixed-dimensional assembly strategy. The uniform loading of Ag nanoparticles on g-C3N4 can greatly improve the photocatalytic ability of g-C3N4 while creating more water transport channels between reduced graphene oxide (rGO) and g-C3N4 laminates. The resultant rGO/AgNP@g-C3N4 nanofiltration membrane displayed efficient water permeability, superior photocatalytic self-cleaning performance, and owned excellent flexibility and structural stability. The water permeability of the rGO/AgNP@g-C3N4 membrane was considerably improved (210.9 L∙m−2∙h−1∙bar−1) compared to the pure rGO membrane (78.4 L∙m−2∙h−1∙bar−1) due to the larger interlayer spacing and rough surface. After 1 h of visible light irradiation, the decrease of flux produced by pollutant molecule adsorption can recover with a ultrahigh flux recovery ratio (FRR) of 98.1%. Moreover, the high flux of the rGO/AgNP@g-C3N4 membrane remained stable in a cross-flow photocatalytic nanofiltration device. Membrane separation, photocatalytic regeneration, and pollutant degradation by ·OH and ·O2− radicals are proposed as effective cooperation mechanisms.

Ultrahigh Emulsion Separation Flux and Antifouling Performance of MIL‐100(Fe)@Graphene Oxide Membrane Enabled by its Superhydrophilicity and Self‐Cleaning Ability

AbstractThe development of microfiltration (MF) membranes with a high separation flux and antifouling ability is an ultimate goal for the purification of emulsified oily wastewater by MF techniques. Herein, a dual‐functional MIL‐100(Fe)@graphene oxide (MIL‐100(Fe)@GO) membrane is fabricated by in situ growth of MIL‐100(Fe) with a graphene oxide (GO) nanosheet. The porous MIL‐100(Fe)@GO composite endows the MF membrane with superhydrophilicity and demulsification functions. The MIL‐100(Fe)@GO membrane achieves an outstanding water permeation flux of 12 457 L m−2 h−1 bar−1, as encouraged by the versatility of MIL‐100(Fe) in enabling superhydrophilicity of the MIL‐100(Fe)@GO membrane and providing rich water permeation channels. An impressive emulsion separation efficiency of >99% and maximum emulsion separation flux of 5529 L m−2 h−1 bar−1 are thus delivered by the MIL‐100(Fe)@GO membrane. Moreover, a 131% recovery ratio of emulsion separation flux (7135 L m−2 h−1 bar−1) is attained with this system after regeneration by ethanol. In virtue of the demulsification of MIL‐100(Fe), the rational design of the MIL‐100(Fe) hybrid membrane exhibits a self‐cleaning effect on the emulsion separation. The demonstrated high performance of the membrane system opens up new avenues for the development of membranes with antifouling abilities and ultrahigh flux for emulsion separation.

Graphene-based melamine sponges with reverse wettability for oil/water separation through absorption and filtration

To achieve oil/water separation using both absorption and filtration regardless of the oil/water density relationship, the super-hydrophilic/underwater super-oleophobic graphene oxide coated melamine sponge (GO@MS) and super-hydrophobic/super-oleophilic reduced graphene oxide coated melamine sponge (rGO@MS) were prepared via dip-coating of graphene oxide (GO) sheets onto melamine sponge (MS) and subsequent chemical reduction, respectively. The structures of the GO@MS and rGO@MS were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectra, and X-ray diffraction (XRD). Both GO@MS and rGO@MS can preserve their original wettability in harsh environments containing acidic, alkaline, saline, and hot waters. The GO@MS and rGO@MS show excellent capability for selective absorption of water and oil respectively, with high capacities of 72.3–136.5 g g−1 and excellent recyclability. The compressed GO@MS and rGO@MS also exhibit high separation efficiency of about 99% and ultra-high permeation flux above 1.62 × 105 L m−2 h−1 for separating different oil/water mixtures containing light and heavy oils through filtration driven by gravity, respectively. Furthermore, a bidirectional separation setup assembled with the compressed GO@MS and rGO@MS was constructed, which demonstrates high efficiency for continuously separating different oil/water mixtures of any oil density.

Collagen fiber membrane as multi-functional support enabled rational design of ultrahigh-flux separation membrane for the remediation of oil contamination in water

Membrane separation is a promising approach for the remediation of oil contamination in water. High-flux separation of membrane relies on the rational design of ultrathin active layer to significantly reduce mass transfer distance for achieving high separation flux, while the ultrathin active layer is usually fragile with poor mechanical strength, which has to be supported on a support. Herein, we employed collagen fiber membrane (CFM) as multi-functional support for the in-situ growth of polyacrylonitrile (PAN) layer by electrospinning to prepare the high-performance PAN/CFM composite membrane. Due to the amphiphilic nature and strong capillary effect, CFM played the role as multi-functional support to provide separation effectiveness and boosted separation flux. The PAN/CFM composite membrane enabled ultrahigh separation flux (e.g., 51751.59 L m−2 h−1 bar−1) to a variety of oil-in-water emulsion, which was one order of magnitude higher than that of commercial polyethersulfone membrane and 1.86-fold to that of cellulose acetate membrane. Furthermore, the PAN/CFM composite membrane retained high separation flux (e.g., 11046.97 L m−2 h−1 bar−1) during the 5th separation cycle, providing appreciable anti-fouling capability. Therefore, our findings provided a promising way to effectively resolve the problem of oil contamination in water.

MOFs decorated sugarcane catalytic filter for water purification

MOFs nanoparticles decorated sugarcane-based cellulose hierarchical porous framework as a free-standing catalytic filter for water purification. • ZIF-67 are in-situ immobilized on sugarcane to achieve ZIF-67@SC catalytic filter. • The ZIF-67@SC shows high catalytic activity and treatment flux for MB degradation. • The amount of ZIF-67 loaded regulates the catalytic performance of ZIF-67@SC. • Dominant free radicals (SO 4 - · and ·OH) during MB degradation are verified. • Proof-of-concept continuous-flow water purification devices are demonstrated. Developing high-performance catalytic filter with both high removal efficiency and ultra-high flux, especially under gravity-driven conditions, is of great significance yet still a fundamental challenge in organic wastewater purification. Herein, a high-efficiency gravity-driven catalytic filter, ZIF-67 decorated sugarcane that is denoted as ZIF-67@SC sponge, is successfully constructed by the in-situ growing ZIF-67 nanoparticles inside the channels of biomass sugarcane skeleton. Pretreatment of cellulose fibers with alkali can set the nucleation sites for the ZIF-67 nanocrystals decoration on the sugarcane skeleton, which originates from the ion exchange between Co 2+ and Na + . The effect of the perforated plate structures of sugarcane on fluid obstruction and the widely distributed ZIF-67 nanoparticles can synergistically enhance the contraction between organic pollutants and ZIF-67 nanoparticles. The resultant ZIF-67@SC sponge therefore exhibits the superior removal efficiency up to 86.99 % for methylene blue (MB) in water with the water treatment flux of ∼ 2720 L m -2 h −1 under the activation of peroxymonosulfate (PMS). Importantly, the ZIF-67@SC sponge catalytic filter can be readily regenerated by a simple methanol washing, maintaining the removal efficiency of 82.09 % after even 10 continuous regeneration cycles. Furthermore, the ZIF-67@SC sponge catalytic filter can be facilely engineer as a continuous-flow catalytic reactor like a water purifier for high throughout wastewater purification. It’s believed that relying on the outstanding catalytic performance of metal–organic frameworks (MOFs) and the unique skeletons of sugarcane and other biomass materials, the present outcomes can be promising by extended to the large-scale water remediation.

Robust graphene/poly(vinyl alcohol) aerogel for high‐flux and high‐purity separation of water‐in‐oil emulsion and its computational fluid dynamic simulation

AbstractDue to the trade‐off between purity and flux, the development of high‐purity, high‐flux oil–water separation materials is still an arduous challenge. Herein, to achieve emulsion separation with high purity and high permeability, fluorinated graphene/poly(vinyl alcohol) aerogel (FGPA) with strong honeycomb was obtained via a facile freeze‐drying method, and the separation mechanism was investigated via computational fluid dynamics (CFDs) simulation. The as‐prepared FGPA exhibited superhydrophobicity‐superoleophobicity and cyclic compression stability. Under the complex pore and superhydrophobicity, FGPA could separate water‐in‐oil emulsions with droplet sizes several times smaller than their own aperture only under gravity with ultrahigh flux (3255 L m−2 h−1) and ultrahigh purity (99.9%). Also, the separation process as visualized using simulations revealed that the vortex accelerates the demulsification behavior and promotes the gathering of water droplets rebounding on the superhydrophobic surface, so that the water droplets are intercepted. Therefore, FGPA has broad practical application potential in high‐flux and high‐purity oil–water emulsion separation.

Oil/water separation membranes with stable ultra-high flux based on the self-assembly of heterogeneous carbon nanotubes

Due to the problem of membrane fouling, the preparation of oil/water separation membranes with stable ultra-high flux is still a challenge. At present, ultra-hydrophilicity is the main antifouling strategy, which indeed renders ultra-high base flux and high flux recovery rate. However, the flux usually declines to a low level during the real oil/water separation. With the assist of low surface energy (LSE) strategy, the flux stability can be remarkably enhanced, but at the cost of the reduced base flux. In order to combine the advantages of hydrophilic and LSE strategies, and avoid the undesired side effects of the LSE strategy, the distribution of hydrophilic and LSE microdomains on membrane surfaces is rationally designed and accurately manipulated in this study. Membranes are prepared by the vacuum-assisted self-assembly of heterogeneous carbon nanotubes (HCNTs), which consist of fluorinated multi-walled carbon nanotubes (FMCNTs), amino multi-walled carbon nanotubes (AMCNTs) and carboxylic single-walled carbon nanotubes (CSCNTs). AMCNTs and CSCNTs form great-area continuous and high porous hydrophilic microdomains through membranes, providing high base flux. FMCNTs form discrete linear LSE microdomains, providing good flux stability via LSE antifouling strategy. Except for the ultra-hydrophilic strategy, this study provides a reasonably and accurately manipulated LSE strategy in the energy-efficient membrane water treatment.

Forward-looking insights in laser-generated ultra-intense \u03b3-ray and neutron sources for nuclear application and science

Ultra-intense MeV photon and neutron beams are indispensable tools in many research fields such as nuclear, atomic and material science as well as in medical and biophysical applications. For applications in laboratory nuclear astrophysics, neutron fluxes in excess of 1021 n/(cm2 s) are required. Such ultra-high fluxes are unattainable with existing conventional reactor- and accelerator-based facilities. Currently discussed concepts for generating high-flux neutron beams are based on ultra-high power multi-petawatt lasers operating around 1023 W/cm2 intensities. Here, we present an efficient concept for generating γ and neutron beams based on enhanced production of direct laser-accelerated electrons in relativistic laser interactions with a long-scale near critical density plasma at 1019 W/cm2 intensity. Experimental insights in the laser-driven generation of ultra-intense, well-directed multi-MeV beams of photons more than 1012 ph/sr and an ultra-high intense neutron source with greater than 6 × 1010 neutrons per shot are presented. More than 1.4% laser-to-gamma conversion efficiency above 10 MeV and 0.05% laser-to-neutron conversion efficiency were recorded, already at moderate relativistic laser intensities and ps pulse duration. This approach promises a strong boost of the diagnostic potential of existing kJ PW laser systems used for Inertial Confinement Fusion (ICF) research.

Robust reduced graphene oxide composite membranes for enhanced anti-wetting property in membrane distillation

The application of membrane distillation (MD) has been severely limited by membrane wetting, particularly when treating feed solutions having contaminants with low surface energy. Herein, inspired by the special anti-wetting properties of the graphene-based membrane, a simple and scalable approach has been developed to fabricate the anti-wetting composite membranes with a reduced graphene oxide (rGO) skin layer and a microporous polytetrafluoroethylene (PTFE) substrate. The anti-wetting mechanism of rGO was investigated using a quartz crystal microbalance with dissipation and also fluorescence microscope. The prepared rGO-PTFE composite membrane exhibited outstanding MD performance with high water flux of about 60 L·m−2 h−1, excellent salt rejection (>99.9%) and robust anti-wetting properties when desalinating a 3.5 wt% NaCl feed solution with 0.8 mM sodium dodecyl sulfate (SDS) for 66 h at the temperature difference of 40 °C. Moreover, the rGO-PTFE composite membrane achieved an ultrahigh water flux of about 149 LMH and perfect salt rejection (100%) at a temperature difference of 60 °C, which is 1.2–3.5 times as high as the flux of the reported MD membranes. Our research provides a robust rGO composite membrane with high flux and anti-wetting properties in MD and offers some insightful understanding about the anti-wetting mechanism of rGO against SDS and water.

Spider-web-inspired membrane reinforced with sulfhydryl-functionalized cellulose nanocrystals for oil/water separation

The cellulose nanocrystals (CNC) has attracted widespread attention in reinforced materials. However, the application of CNC in electrospinning has been limited due to its self-polymerization. Herein, a cobweb-like nanofibrous membrane was fabricated by electrospinning the polyacrylonitrile (PAN) and sulfydryl-functionalized CNC (SC). The SC content could reach to 48 wt% after the thiolation modification. The membrane with ultrafine fibers and interlaced nets possessed outstanding porosity (91.7%) and underwater superoleophobicity. An ultrahigh permeation flux of 1244 L·m−2·h−1 with a separation efficiency of >99.9% was achieved driven by gravity. The mechanical properties also enhanced significantly with the increase of SC. When the addition amount of SC was 48 wt%, the maximum tensile stress was 2.9 MPa, which was 3.4 times than that of the PAN membrane. The antifouling performance and chemical stability endowed the SC(48)/PAN membrane with intriguing reusability, thus making it exhibit enormous potential in oil/water separation.

Facile strategy for the construction of a robust underbrine superoleophobic membrane for highly efficient oil-brine separation

Developing an effective and sustainable method for the separation of oil and brine mixture is highly necessary for the restoration of environmental pollution caused by the loss of organic solvents during the lithium extraction process from brine. Herein, we report a facile and cost-efficient method to fabricate an underbrine superoleophobic mesh by one-step hydrothermal method. The synthesized CrOx(OH)3–2x/nickel mesh possesses flower-like nanostructure, exhibiting superior superhydrophilicity/underbrine superoleophobicity for different ratios of tributyl phosphate and sulfonated kerosene mixtures. Simultaneously, the CrOx(OH)3–2x /nickel mesh manifests high efficiency for oil and brine separation with an ultrahigh permeation flux (78136 L∙m−2∙h−1) and excellent oil rejection efficiency (>99.17%). Furthermore, the as-prepared mesh exhibits high chemical stability, outstanding salt tolerance, and excellent mechanical properties. Importantly, the surface wettability can be changed from superhydrophilicity to superoleophobicity for several times only by ignition of the CrOx(OH)3–2x/NM on an alcohol burner for 10 s or modified by OTS. Altogether, the CrOx(OH)3–2x/nickel mesh has tremendous potential in practical oil-brine applications.

Anchoring metal organic frameworks on nanofibers via etching-assisted strategy: Toward water-in-oil emulsion separation membranes

The zeolitic imidazolate framework-71/poly(vinylidene fluoride-hexafluoropropylene) (ZIF-71/PVDF-HFP) nanofibrous membrane was fabricated via anchoring ZIF-71 on PVDF-HFP nanofibrous membrane with targeted sites assisting. The ZIF-71 facilitated demulsification with increasing hydrophobicity. Eventually, the ZIF-71/PVDF-HFP nanofibrous membrane exhibited excellent separation performance for water-in-oil emulsions. • Etching-assisted strategy is used to anchor ZIF-71 nanoparticles on nanofibers. • The ZIF-71 increased roughness and hydrophobicity (162.1°). • Ultrahigh flux (4827.97 L m -2 h −1 ) and high efficiency (>99%). • The membranes exhibited excellent antifouling and cyclic stability. Efficiently separating water-in-oil emulsions is urgent demand and still worldwide challenge. Nanofibrous membranes with super-wetting surface have drawn wide concern to solve it. Herein, under-oil superhydrophobic zeolitic imidazolate framework-71/poly(vinylidene fluoride-hexafluoropropylene) (ZIF-71/PVDF-HFP) nanofibrous membranes were prepared via electrospinning and etching-assisted in-situ growth strategy for water-in-oil emulsions separation. ZnO was etched to create adsorption sites, ensuring the dispersed ZIF-71 nanoparticles firmly anchoring on nanofibers. The membranes showed under-oil superhydrophobicity with under-oil water contact angle 162.1°. The membranes could effectively separate a variety of water-in-oil emulsions (such as dichloromethane, chloroform, and toluene) by gravity. The separation efficiency of all emulsions was higher than 99% and the flux of water-in-chloroform without surfactant reached up to 6577.68 L m -2 h −1 . Moreover, the membranes exhibited excellent cyclic stability and anti-fouling. Therefore, the MOF/nanofibrous membranes fabricated by etching-assisted strategy are promised candidates for efficient oil/water separation.

Robust multifunctional fluorine-free superhydrophobic fabrics for high-efficiency oil-water separation with ultrahigh flux.

The limited robustness and complex preparation process greatly hinder the large-scale use of superhydrophobic surfaces in real life. In this work, we adopt a simple method to prepare robust fluorine-free superhydrophobic cotton fabrics by a facile dip-coating method based on silica microparticles and titanium dioxide nanoparticles. Microparticles and nanoparticles are used to build a suitable rough hierarchical structure, while strong bonds are formed between fabric and particles by a silane coupling agent. The cross-linking reaction between the isocyanate group of trimers of hexamethylene diisocyanate (HDI) and the hydroxyl group of each component in the condensation reaction further increases the bonding between the coating and the cotton fabric. In addition, polydimethylsiloxane (PDMS) is used as a low-surface-energy material to modify the fabric surface. The resulting coating shows excellent superhydrophobic properties with a water contact angle of 161.7°. Meanwhile, the prepared superhydrophobic fabric exhibits excellent durability and stability after sandpaper wearing, washing, and UV radiation, as well as treatment with various organic solutions, boiling water and different pH solutions. Moreover, the superhydrophobic fabric displays excellent UV protection performance and high oil-water separation efficiency (>99% after 30 cycles) with ultrahigh flux up to 20 850 L m-2 h-1.

Hydrophobic Ti3c2tx/Pu Sponge Prepared from Commercial Amphiphilic Pu Sponge for Oil/Water Separation with Ultrahigh Flux

Hydrophobic Ti3c2tx/Pu Sponge Prepared from Commercial Amphiphilic Pu Sponge for Oil/Water Separation with Ultrahigh Flux