PU Sponge Research Articles

Preparation of Superhydrophobic and Multifunctional Sponges for Oil/Water Separation and Oil Absorption.

For settling the recycling problem of waste polyurethane sponges (PU) and environment pollution of oil spills simultaneously, this work exploited the multifunctional superhydrophobic PU materials via the dip-coating method, which were prepared by anchoring modified Fe3O4 and expandable graphite (EG) on PU sponges under the adhesion effect of polydimethylsiloxane (PDMS). The water contact angle and sliding angle of as-prepared PU sponges reached 154.1 ± 1.6 and 8°, respectively. Most importantly, the superhydrophobic PU sponges were endowed with the multipath oil treatment ability, which consisted of magnetically driven, gravity-driven, peristaltic pump-driven, and photothermally driven modes. Besides, the light oil absorption capacity, separation flux, and efficiency for superhydrophobic PU sponges reached 23.9 g/g, 27779 L m-2 h-1, and 99.5%, respectively. Owing to the photothermal conversion ability of Fe3O4 and EG, the temperature of superhydrophobic PU sponges was raised to 71.5 °C within 233 s under 1.2 solar irradiation (1200 W/m2), demonstrating its absorption potential for high-viscosity crude oils. In addition, the prepared sponges exhibited good chemical/mechanical stability, self-cleaning, and flame retardancy. In a nutshell, this article has evolved an environmentally benign and practical method for fabricating the multifunctional materials in oil spill treatment, which will efficiently accomplish the targets of low carbon and environmental management.

Preparation of temperature-responsive smart sponge and its application in oil-water separation and dye adsorption

At present, researchers are committed to studying new intelligent response materials to deal with severe water pollution problems. Using PU sponge as the substrate, dopamine was first modified to construct a rough surface while introducing active groups. The monomer N-isopropylacrylamide (NIPAM) and itaconic acid (IA) were grafted and polymerized onto the polydopamine coating on the sponge surface by vinyltrimethoxysilane (VTMS). The obtained DINA-PU sponge has good temperature response and switchable wettability characteristics, and has good adsorption-desorption cycle function. Moreover, a micro-filtration device was designed to separate heavy (light) oil-water mixtures. The separation efficiency can reach more than 95% and 99% for heavy and light oil-water, respectively. In addition, the adsorption capacity of the material for methylene blue (MB) can reach 660mg·g-1. The separation efficiency in the oil-water separation-dye adsorption integrated separation experiment can reach more than 99%.

Carbon Ink Enhanced Calcium Alginate-Based Hydrogel with Response Surface Methodology Optimized for Solar-Driven Salt-Tolerant Desalination.

The global shortage of freshwater resources is becoming more and more serious; therefore, it is necessary to obtain freshwater by desalinating seawater resources. Solar-driven interfacial photothermal evaporation, which is an environmentally friendly and energy-efficient technology, has been used to desalinate seawater for water purification and production. Herein, the IPCA hydrogel with abundant pores consisting of carbon ink as a photothermal conversion material and PU sponge loaded with calcium alginate as a water transport medium was successfully prepared and used to obtain portable water. The parameters of the synthesized IPCA are optimized by Response Surface Methodology analysis, and it was found that the IPCA exhibits a high evaporation efficiency of 3.779 kg m-2 h-1 and up to 95.98% of photothermal conversion capacity under one solar intensity. It maintains a high evaporation efficiency and salt resistance after 10 cycles of evaporation in actual seawater. Moreover, IPCA shows a high removal of various organic dye pollutants in wastewater. The results suggest a new approach for the preparation of simple, efficient, and green solar evaporators in practical application.

Simultaneous removal of nitrate, manganese, zinc, and bisphenol a by a biofilm reactor with β-CD modified corn stover biochar and PU sponges: Performance and microbial community response

In the present study, a biofilm reactor with manganese (Mn) redox cycling was established to remove nitrate (NO3−-N), bisphenol A (BPA), zinc (Zn(II)), and Mn(II) using β-cyclodextrin (β-CD) modified corn stover biochar (BC) and polyurethane sponges loaded with Cupriavidus sp. HY129 and Pantoea sp. MFG10. At C/N = 2.0, HRT = 6 h, Mn(II) = 10.0 mg L−1, and BPA and Zn(II) concentrations = 1.0 mg L−1, the removal efficiencies of NO3−-N, Zn(II), BPA, and Mn(II) were 81.5%, 86.5%, 87.9%, and 75.5%, respectively. The outcomes demonstrated the success that the addition of β-CD could accelerate electron transfer activity and the denitrification process. The remediation of BPA and Zn(II) was mainly through the adsorption of bioprecipitation generated by reactor operation. The bioreactor could preserve the stability of the biological community and the expression of pertinent functional genes under the coercion of BPA and Zn(II).

Electrically conductive polyaniline: Graphite composite on porous polyurethane sponge with enhanced sensitivity of humidity

AbstractRecent advancements in organic materials based sensor technology created a prospective field in designing sensors that are both cost‐effective and environment friendly. In view of that an electronic material system has been prepared depositing a uniform layer of graphite‐infused Polyaniline (PANI) onto the sponge framework using a straightforward physical vapor deposition technique. The prepared active materials were studied for the composition, morphology, optical properties, and charge transport characteristics. In the current context of rapidly growing sensor technology, this works describes an innovative approach of improving the response of the prepared electronic system of PANI/Gr composites, integrated into porous PU sponge substrates. Incorporation of graphite in PANI improved the electrical conductivity of the composite and porous structure of PU increased the interaction surface area. The performance of the prepared materials in humidity detection was evaluated by studying their resistive response under varying humidity levels, which was measured through current‐voltage (I‐V) characteristics. The higher interaction sites of the reported active sensing system leads to inspiring humidity sensitivity of 0.522–26.22 kΩ/% RH with reasonable response and recovery time of 572 and 416 sec respectively. Additionally, the reported sensor system consisting of degradable materials will offer a useful way of reducing electronic garbage.

Facile and sustainable upcycling of fly ash into multifunctional durable superhydrophobic coatings

Fly ash (FA), a hazardous byproduct of coal combustion in power plants, poses significant environmental and health risks due to improper disposal and utilization. This study introduces a facile, sustainable, and cost-effective method for converting FA into a robust superhydrophobic material for various substrates. -FA particles are modified with polydopamine (PD) in water and covalently grafted with octadecylamine (ODA) via the Michael Addition-Schiff Base reactions, resulting in robust superhydrophobic FA (SH-FA) with a water contact angle (WCA) of 163° (±3.1). When applied as a coating to jute, cotton, polyester fibers, PU sponge, and wood, they became superhydrophobic, with WCAs ranging from 154.7 to 161.2° except for the wood substrate, which achieved a WCA of 132° (±3°). The coated polyester fabric exhibited remarkable durability, retaining consistent WCA values after 70 abrasion cycles, 75 adhesive tape peelings, and 20 detergent washing cycles. It also showcased excellent self-cleaning properties, effectively repelling dust and various liquids. Additionally, the coated PU sponge demonstrated exceptional performance in separating oil from different oil/water mixtures, achieving rapid separation of organic solvents within seconds and maintaining a separation efficiency of over 98% even after 12 reuse cycles. These results indicate the potential for transforming FA through effective management.

Theranostic nano-enabled polyurethane eso-sponges coupled to surface enhanced Raman scattering for detection and control of bacteria killing

Herein, a facile approach toward converting a three-dimensional polyurethane sponge (PUS), employed in endoluminal vacuum-assisted closure (endo-VAC) therapies, in a theranostic material able to detect and to inhibit bacteria growth, has been reported. The endo-VAC PUS presented sensitivity to Gram-positive and Gram-negative bacterial species thanks to its functionalization with gold and silver antibacterial nanoparticles (NPs). PUS with chitosan-stabilized Au-NPs achieved 5.26 ± 0.17 logs and 2.78 ± 0.34 logs of reduction of bacteria growth, whereas the sponges functionalized with phenolated lignin Ag-NPs offered slightly inferior values (4.77 ± 0.36 logs and 2.03 ± 0.37 logs, respectively), against Escherichia coli and Staphylococcus aureus pathogens, respectively, after the application of photothermal ablation. The in vitro antimicrobial studies were contrasted with the in-situ monitoring of bacteria localization and inactivation with excitation lasers of 532 and 785 nm wavelengths, respectively, in the Raman equipment. The novel theranostic nano-enabled antimicrobial PU sponges offer unprecedented possibilities for the improvement of the endo-VAC treatments and extrapolation of the methodology to other plastic-based implants to combat antimicrobial resistances.

Superhydrophobic octadecylamine-modified MIL-101(Cr)@polyurethane sponge composite as an oils/organic solvents sorption material

The pollution due to oil spills causes diverse problems such as water pollution, destruction of habitats, and health issues. An easy process to solve this problem is fabricating hydrophobic sorbents. Metal-organic frameworks (MOFs)@polyurethane (PU) sponges in 3D structures are promising candidates to remove pollutants through sorption due to their intrinsic characteristics of MOFs and PU sponges, including porosity, low density, and mechanical strength. In this research, some novel MOFs@PU sponges were fabricated by incorporating MIL-101(Cr) or octadecylamine (ODA)-modified MIL-101(Cr), m-MIL-101(Cr), into PU sponges using PDMS (polydimethylsiloxane) as an adhesive agent. The prepared materials were investigated by various techniques including Fourier transform infrared (FT-IR), x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive x-ray (EDS) mapping, water contact angle (WCA), and BET (Brunauer–Emmett–Teller) analyses. The WCA increased from 106.36° for the pristine PU to 145.06° and 157.98° for the as-prepared MIL-101(Cr)@PU and m-MIL-101(Cr)@PU, respectively. The uptake efficiency of the as-obtained sorbents for some oils (olive oil, sesame oil, sunflower oil, hydraulic oil, and diesel) and organic solvents (toluene, dichloromethane, ethyl acetate, chloroform, and n-hexane), as well as the ability of the m-MIL-101(Cr)@PU sponge for separation of diesel oil, chloroform, and toluene from water, were studied. The maximum sorption capacity was 79.83 g g−1 and 97.50 g g−1 for sesame oil and chloroform, respectively, using m-MIL-101(Cr)@PU as sorbent, which was higher than the efficiency of the pristine PU adsorbent. Additionally, the m-MIL-101(Cr)@PU sponge composite exhibited proper reusability of up to 7 cycles (∼52.88 g g−1). Overall, the as-obtained m-MIL-101(Cr)@PU sorbent exhibits promising potential to uptake oil and organic solvent contaminants.

A portable self-powered biosensor for monitoring artistic gymnastics techniques

The development of self-powered smart biosensors has attracted great attention due to their potential applications in human motion monitoring and energy collection systems. Here, a newly designed triboelectric nanogenerator (PSP-TENG) composed of the PU sponge, polytetrafluoroethylene, and polydimethylsiloxane for monitoring rear leg rotation motion in artistic gymnastics has been developed. The PSP-TENG can monitor the buffering and stretching time of rear leg rotation and identify the angle between the hip, knee, and ankle during the stretching stage. Furthermore, the PSP-TENG has the function of converting measured signals into power signals, which can convert collected human motion mechanical energy into electrical energy to power wearable devices. The development of PSP-TENG has made contributions to the field of human motion monitoring, providing ideas for new energy and technologies to improve the environment and promote a virtuous ecological cycle.

Preparation and characterization of a polyurethane-based sponge wound dressing with a superhydrophobic layer and an antimicrobial adherent hydrogel layer

Bacterial infection poses a significant impediment in wound healing, necessitating the development of dressings with intrinsic antimicrobial properties. In this study, a multilayered wound dressing (STPU@MTAI2/AM1) was reported, comprising a surface-superhydrophobic treated polyurethane (STPU) sponge scaffold coupled with an antimicrobial hydrogel. A superhydrophobic protective outer layer was established on the hydrophilic PU sponge through the application of fluorinated zinc oxide nanoparticles (F-ZnO NPs), thereby resistance to environmental contamination and bacterial invasion. The adhesive and antimicrobial inner layer was an attached hydrogel (MTAI2/AM1) synthesized through the copolymerization of N-[2-(methacryloyloxy)ethyl]-N, N, N-trimethylammonium iodide and acrylamide, exhibits potent adherence to dermal surfaces and broad-spectrum antimicrobial actions against resilient bacterial strains and biofilm formation. STPU@MTAI2/AM1 maintained breathability and flexibility, ensuring comfort and conformity to the wound site. Biocompatibility of the multilayered dressing was demonstrated through hemocompatibility and cytocompatibility studies. The multilayered wound dressing has demonstrated the ability to promote wound healing when addressing MRSA-infected wounds. The hydrogel layer demonstrates no secondary damage when peeled off compared to commercial polyurethane sponge dressing. The STPU@MTAI2/AM1-treated wounds were nearly completely healed by day 14, with an average wound area of 12.2 ± 4.3 %, significantly lower than other groups. Furthermore, the expression of CD31 was significantly higher in the STPU@MTAI2/AM1 group compared to other groups, promoting angiogenesis in the wound and thereby contributing to wound healing. Therefore, the prepared multilayered wound dressing presents a promising therapeutic candidate for the management of infected wounds. Statement of significanceHealing of chronic wounds requires avoidance of biofouling and bacterial infection. However developing a wound dressing which is both anti-biofouling and antimicrobial is a challenge. A multilayered wound dressing with multifunction was developed. Its outer layer was designed to be superhydrophobic and thus anti-biofouling, and its inner layer was broad-spectrum antimicrobial and could inhibit biofilm formation. The multilayered wound dressing with adhesive property could easily be removed from the wound surface preventing the cause of secondary damage. The multilayered wound dressing has demonstrated good abilities to promote MRSA-infected wound healing and presents a viable treatment for MRSA-infected wound.

Construction of lignin/CaCO3/CS superhydrophobic coating with excellent heat resistance, abrasion resistance, UV resistance and oil-water separation

Superhydrophobic coatings are developed rapidly due to the eye-catching versatility, but still suffer from problems of insufficient environmental protection, poor heat resistance, and weak UV resistance. Here, a stable and versatile lignin/calcium carbonate (CaCO3)/chitosan (CS) superhydrophobic coating on the wood (beech) could be successfully prepared by simple one-step spay. In the coating system, enzymolysis lignin was employed as the main materials to construct surface rough structure, which was enhanced with both CaCO3 and CS, methyltrimethoxysilane (MTMS) and hexadecyltrimethoxysilane (HDTMS) as the hydrophobic modifiers and polydimethylsiloxane (PDMS) as the adhesive. The resulted coating shows good superhydrophobicity (water contact angle of 161.1° and sliding angle of 8°), as well as excellent heat resistance (superhydrophobicity still maintaining under 200 °C), UV resistance (10 h of high-intensity UV irradiation). In addition, when PU sponge was used as the substrate, the stable oil-water separation could be achieved. In view of the good performance and simple preparation, the superhydrophobic coating displays a good application prospect.

Study on the Influence of the Reduced Graphene Oxide Coating on the Hydrophobicity of PU Sponge for Oil Recovery

In order to produce a hydrophobic material for oil removal from surface waters, in this study, the reduced graphene oxide coated PU sponges (rGO@PU) were prepared by ultrasonication of PU sponges with suspension of rGO in ethanol. The chemical structure of the rGO coatings was investigated by X-ray diffraction and FT-IR spectroscopy methods. The surface morphology of the obtained materials was also examined by SEM. The influence of the rGO loadings and the number of coatings on the hydrophobicity of the materials was investigated. The testing on the surface hydrophobicity indicated that the water drops were remained on the surface of rGO@PU for 4.5 - 5 hours. The results indicated that the best hydrophobic sponge was obtained at the rGO loading of 3 mg/mL and after three times of coatings. The water contact angle (WCA) of the optimal rGO@PU was up to 119°. The kerosene oil absorption capacity of the rGO@PU in 5 minutes is 32.34 g/g. Besides, the oil-water separation ability of the material was also investigated by passing the kerosene-water mixture through a filter funnel containing the synthesized porous material rGO@PU. The result indicated that the separation efficiency of the material was 85%. The recyling test was conducted by squeezing the saturated absorbed sponges and applying the desorbed sponges for the next cycle tests. After 10 times of recycling, the amounts of kerosene absorption on the rGO@PU were maintained from 4.39 - 5.33 g, implying the excellent recyclability of the material.

The effect of chemical bond and solvent solubility parameter on stability and absorption value of functionalized PU sponge

Seawater pollution from various sources such as industrial effluents, ship washing at sea, and oil spills harm humans and the marine environment. Therefore, finding ways to eliminate this pollution is crucial. This study successfully modified a polyurethane sponge through a simple dip-coating method with functionalized graphene oxide incorporating octadecylamine and oleic acid, resulting in a hydrophobic sponge capable of absorbing crude oil and various organic solvents. Characterization analyses confirmed the synthesis. The absorption capacity of the modified sponges was examined, for example, the PU sponge has absorbed 4 g/g engine oil, while the modified GO-ODA-PU sponge has increased its absorption to 36 g/g. The GO-ODA-PU sponge demonstrated great reusability compared to the GO-OA-PU sponge owing to the strong covalent bond formed between GO and ODA, which is superior to the weak hydrogen bond formed between GO and OA. The absorption capacity of the GO-OA-PU sponge decreased by 30%. The contact angle test showed that GO-ODA-PU and GO-OA-PU sponges had contact angles of 131° and 115°, respectively. Additionally, the GO-ODA-PU sponge performed optimally for semi-polar solvents in the solubility parameter range of 18–19, with its absorption capacity reaching its maximum value. The amount of oil recycling is even possible up to 98%.

Novel photothermal response intelligent polyurethane sponge with switching wettability for oil/water separation

Intelligent oil–water separation materials with stimulating response have received extensive attention. In this paper, a novel, cost-effective, and simple approach is developed to produce a photothermal-responsive smart sponge with switchable wettability. The polydopamine (PDA) and photothermal agent copper sulfide (CuS) were grafted PU sponge surface. Thermal-responsive polymers P(VTMS-co-NIPAm) and 1-octadecanethiol (ODT) are then decorated on the PDA/CuS@PU surface through free radical polymerization and Michael addition reaction. The obtained PCPO@PU exhibits rapidly switchable wettability between hydrophobicity and hydrophilicity depending on the temperature response of P(VTMS-co-NIPAm) induced by photothermal effect of CuS. The PCPO@PU showed excellent separation performance with oil absorption ratio 8–33 g·g−1 and average self-desorption efficiency of more than 70%, but also has a remarkable recycling effect. Specifically, the photothermal response of PCPO@PU does not require additional chemical initiation and both address the limitations of materials that respond to specific light species and heat. More importantly, the PCPO@PU is able to realize the fluorescent lamp-peristaltic pump model, which can be a significant step toward its widespread application for oil–water separation in nature marine environment.

A linear and large-range pressure sensor based on hierarchical structural SnO2@carbon nanotubes/polyurethane sponge

Flexible pressure sensors arouse an extensive interest in health monitoring, human-computer interaction, and wearable electronic devices. However, the preparation of pressure sensors with high sensitivity, high linearity, and wide working range continues to be challenging. In this study, a SnO2@carbon nanotubes/polyurethane (SnO2@CNT/PU) sponge pressure sensor was presented with high sensitivity in a wide linear pressure range. SnO2 was attached to CNT/PU sponge, which allowed the pressure sensor to obtain low initial current, thus increasing the sensitivity of the pressure sensor. The applied compressive strain was linearly related to the resistance since the nodes of CNT/PU sponge porous skeleton change synchronously during contact. SnO2@CNT/PU sponge pressure sensor shows a wide pressure range (3 Pa–30 kPa), while maintaining high sensitivity (53.4 kPa−1), and excellent linearity (R2 = 0.996). Furthermore, the sensor exhibited stable cycle performance (1500 cycles), fast response time (23 ms), as well as low detection limit (3 Pa). More importantly, the pressure sensor is capable of accurately detecting the human body's physiological signals, and shows promising application for health monitoring.

Adsorption Behavior and Mechanism of Cesium Ions in Low-Concentration Brine Using Ammonium Molybdophosphate–Zirconium Phosphate on Polyurethane Sponge

Salt lake brine originating from Qinghai, China has abundant cesium resources and huge total reserves. The inorganic ion exchangers ammonium molybdophosphate (AMP) and zirconium phosphate (ZrP) have the significant advantages of separating and extracting Cs+ as a special adsorbent. Nevertheless, their high solubility in water leads to a decrease in their ability to adsorb Cs+ in aqueous solutions, causing problems such as difficulty with using adsorbents alone and a difficult recovery. In this work, an environmentally friendly polyurethane sponge (PU sponge) with a large specific surface area is employed as an adsorbent carrier by physically impregnating dopamine-coated AMP and ZrP onto a PU sponge, respectively. The experiment found that under the same conditions, the AMP/PU sponge performs better than the ZrP/PU sponge for Cs+ adsorption. When the amount of adsorbent reaches 0.025 g, the adsorption capacity reaches saturation. The adsorption efficiency remains above 80% when the concentration of Cs+ is 5–35 mg/L. The kinetic calculations show that adsorption is spontaneous, feasible, and has a higher driving force at high temperatures. In addition, the power and mechanism of the interaction between adsorbent and adsorbent are explained using the density functional theory calculation. This efficient, stable, and selective Cs+ adsorbent provides design guidelines.

Superhydrophobic magnetic Fe3O4 polyurethane sponges for oil–water separation and oil-spill recovery

The effective and affordable separation of oil and water, a crucial process in the safe handling of environmental disasters such as crude oil spills and recovery of valuable resources, is a highly sought-after yet challenging task. Herein, superhydrophobic PU sponge was fabricated for the fast and cost-effective adsorptive separation of oil and different organic solvents from water. Octadecyltrichlorosilane (OTS)-functionalized Fe3O4@SiO2 core–shell microspheres were dip-coated on the surface of porous materials via a dip-coating process, thereby endowing them with superhydrophobicity. Owing to the hydrophobic interaction between OTS molecules and oil and increased capillary force in the micropores, the resulting superhydrophobic sponge served as a selective oil-sorbent scaffold for absorbing oil from oil–water mixtures, including oil–water suspensions and emulsions. Remarkably, after the recovery of the adsorbed oil via mechanical extrusion, these superhydrophobic materials could be reused multiple times and maintain their oil–water separation efficacy even after 10 oil–water separation cycles.

Fabrication of polydopamine-boehmite modified superhydrophobic coating for self-cleaning, oil-water separation, oil sorption and flame retardancy

A facile approach for fabricating multifunctional superhydrophobic coating was developed through a simple dip-coating process. The boehmite particles (BMPs) were adhered and modified onto stainless steel (SS) mesh through polydopamine (PDA), which was formed by the oxygen-induced polymerization of dopamine (DA). Therefore, the roughness structure (SS-PDA@BMPs mesh) was obtained. Meanwhile, due to the catechol group of the PDA, cetylamine (CTA) with low surface energy and amino group was grafted onto PDA via the Michael addition reaction to construct the superhydrophobic coating (CTA@PDA@BMPs). The effects of the morphology of BMPs, the ratio of BMPs to DA, the reaction time, and the concentration of CTA on superhydrophobicity of SS-CTA@PDA@BMPs mesh were discussed, which showed the water contact angle of 164° and the sliding angle of 3° for the SS-CTA@PDA@BMPs mesh fabricated under optimal conditions. The SS-CTA@PDA@BMPs mesh with great chemical stability and mechanical durability displayed excellent self-cleaning property and oil/water separation efficiency. When the PU sponge was coated with CTA@PDA@BMPs coating by the same process, the superhydrophobic PU sponge was obtained, which exhibited superior reusability and flame retardancy property. Thus, the prepared superhydrophobic materials are multifunctional and environmentally friendly.

Flexible Polyurethane@Ti3C2Tx/Silver Nanowires Composite Films with Cocontinuous Segregated Structures for Superior Electromagnetic Interference Shielding and Joule Heating

The booming development of communication technology and electronic equipment has put forward higher requirements of flexibility, electromagnetic interference (EMI) shielding performances, and service reliability for the EMI shielding materials. Herein, the flexible polyurethane@Ti3C2Tx/silver nanowires (PU@Ti3C2Tx/AgNWs) composite films with cocontinuous segregated structures are developed by a facile layer‐by‐layer hydrogen bonding assembly followed by hot‐pressing approach using PU sponge as the 3D skeleton template. Benefiting from the cocontinuous segregated structures, the flexible composite films exhibit high electrical and mechanical properties, excellent EMI shielding, and Joule heating performances. The EMI SE of the composite films can reach as high as 88 dB in X‐band (8.2–12.4 GHz). At a supplied voltage of 4.0 V, the composite films exhibit a high steady‐state Joule heating temperature up to 116.7 °C. The flexible cocontinuous segregated composite films with high working stability show great application potentials in EMI shielding and Joule heating systems in aerospace, weapon equipment, and wearable devices.

The superhydrophobic sponge decorated with Ni-Co double layered oxides with thiol modification for continuous oil/water separation

In this paper, the superhydrophobic polyurethane sponge (SS-PU) was facilely fabricated by etching with Jones reagent to bind the nanoparticles of Ni-Co double layered oxides (LDOs) on the surface, and following modification with n -dodecyl mercaptan (DDT). This method provides a new strategy to fabricate superhydrophobic PU sponge with a water contact angle of 157° for absorbing oil with low cost and in large scale. It exhibits the strong absorption capacity and highly selective characteristic for various kinds of oils which can be recycled by simple squeezing. Besides, the as-prepared sponge can deal with the floating and underwater oils, indicating its application value in handling oil spills and domestic oily wastewater. The good self-cleaning ability shows the potential to clear the pollutants due to the ultra-low adhesion to water. Especially, the most important point is that the superhydrophobic sponge can continuously and effectively separate the oil/water mixture against the condition of turbulent disturbance by using our designed device system, which exhibit its good superhydrophobicity, strong stability. Furthermore, the SS-PU still maintained stable absorption performance after 150 cycle tests without losing capacity obviously, showing excellent durability in long-term operation and significant potential as an efficient absorbent in large-scale dispose of oily water.