Low Surface Energy Research Articles

Atomic Layer Deposition of Ru Nanoparticles on Low Surface Energy Carbon Supports for Alkaline Hydrogen Evolution Reaction

Platinum group metals such as Pt, Ru, Pd, Ir, etc., have superior performance for various catalytic applications.[1] Due to their scarcity, efforts were being made to reduce or replace these noble metals. Atomic Layer Deposition (ALD) is one among the best technique to facilitate lowering of loading mass on a support of interest.[2],[3] Furthermore, ALD is the most suitable technology that can decorate high aspect ratio and high surface area substrate architectures by noble metal nanoparticles.[4] Due to the governing surface energy variations between noble metals and support surfaces, the growth initiates as nanoparticles (NP) and with a further increase in ALD cycles the agglomeration among NP’s dominates over the individual NP size increase, thus developing thin films of relatively higher thickness. The surface energy variations are also known to increase the nucleation delay of noble metals especially for Ru considerably. In this regard our efforts were laid to improve the functionality with pretreatments on carbonaceous supports which were shown promising to reduce the nucleation delay of ALD deposited Ru.For electrocatalytic applications, it is important to choose the right substrates. Among available substrates, carbon papers (CP) and titania nanotube (TNT) layers are best choices considering their physio-chemical properties, availability, vast literature, and low costs incurred using these as support substrates in electrocatalysis and photocatalysis. Several surface modifications for CP’s and variations on morphological aspects of TNT layers had received a great attention form applied fields due to their improved surface area, conductivity and stability.[5]–[8] Uniformly decorating these CP’s and TNT layers by NPs or thin films of catalysts proved to be highly efficient with no boundaries on applications.[9] The presentation will introduce and describe the synthesis of different noble metal NPs by our ALD tool (Beneq TFS 200) on various aspect ratio TNT layers and CP substrates. It will also include the corresponding physical and electrochemical characterization and encouraging results obtained with alkaline hydrogen evolution reaction.

Enhancement of hydrophobicity in natural rubber vulcanizates using diatomaceous earth

This study discusses an approach that gives the Natural Rubber (NR) vulcanizates an elevated hydrophobic character. The method used a chemically treated filler called diatomaceous earth (DE) to deliver the hydrophobic characteristics to NR. DE has a nanoscale roughness. It was chemically treated with hexadecyltrimethoxy silane to obtain low surface energy. The combination of nanoscale roughness and low surface energy gave superhydrophobic properties to DE. A series of treated-DE was made with varying silane percentages to find an optimum silane to DE ratio to get the maximum possible hydrophobicity. The optimum ratio was recorded as 38% w/w, and the treated DE displayed a superhydrophobic water contact angle (WCA) of 152°. The treated-DE was added to the rubber as a filler during the compounding process. The filler was added in varying amounts of 5 phr, 10 phr, 15 phr, and 20 phr to observe the changes in the hydrophobic property. The wettability and morphology of developed vulcanizates were measured using WCA measurements and scanning electron microscope (SEM) analysis, respectively. NR compounded with 20 phr filler exhibited an enhanced WCA of 136°, compared to the WCA of 92° of the NR vulcanizate with no treated-DE, and displayed improved tensile, and tear properties.

Impact of rGO modified with FAS on corrosion protection performance of inorganic phosphate bonded coating

In this paper, inorganic phosphate bonded coatings (IPBCs) via embedding reduced graphene oxide (rGO) modified with heptadecafluoro-1,1,2,2-tetradecyl trimethoxysilane (FAS) were prepared through sol-gel method. Aim of this paper is to research the corrosion resistance of IPBCs with the addition of rGO modified with FAS. Firstly, the Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman) and surface morphology of GO and rGO modified with and without FAS were characterized. Results indicated that the hydrophobic –CF2– and –CF3 groups were successfully introduced into GO and rGO after modification. And IPBCs with rGO-FAS exhibited higher hydrophobicity and corrosion resistance than IPBCs with the addition of GO or GO-FAS. That is because the hydrophobicity and the introduction of low surface energy material is conducive to overcoming the interaction of rGO itself, thus rGO can be better utilized and played, which resulting the excellent corrosion performance of IPBC@rGO-FAS.

Optimization of PDMS Surface Treatment Using Atmospheric Pressure Plasma for Microfluidic Applications

Abstract Polydimethylsiloxane (PDMS) is widely used for microfluidic and biomedical applications because of its chemical inertness and affordability. However, its low surface energy limits its adhesion properties, thus necessitating mandatory surface activation, via plasma treatments or chemical processing, especially for improving its hydrophilicity. In this study, we employed an atmospheric pressure plasma jet (2 W) in order to enhance the PDMS surface adhesion for application in microfluidic devices. Treatment variables, including exposure and recovery time and adhesion quality, were investigated. It was possible to achieve a minimum exposure time of 15 s/cm2 for thin PDMS (sheet, 250 μm) and 30 s/cm2 for thick (resin, 3 mm) PDMS. A robust and efficient methodology for scaling the jet system treatment of larger areas was developed. Additionally, we examined the effect of ambient humidity on the plasma treatment. Results showed that water adsorption on PDMS-treated surfaces indicated a difference between the well-established contact angle method for determining surface hydrophilicity (and thus, its adhesion) and the real adhesion properties of the treated surfaces.

Facile preparation of durable superhydrophobic DTMS@HKUST-1 wood membrane for continuous oil-water separation in harsh conditions

Manufacturing durable wood membranes that demonstrate both high efficiency and ultra-high flux for continuous oil-water separation utilizing scalable and cost-effective processes remains a serious challenge. In this study, a facile two-step approach is employed to prepare a novel superhydrophobic/oleophilic wood-based MOF (metal-organic framework) membrane. This method involves in-situ anchoring of the octahedral Cu-HKUST-1 (copper benzene-1,3,5-tricarboxylate) onto the wood sponge (WS), which inherently features internal micro-channels. The structure is then modified using the eco-friendly hydrophobic long-chain coupling agent dodecyltrimethoxysilane (DTMS). Due to its unique micro/nanoscale rough surface morphology and low surface energy, the functional wood membrane (DTMS/HKUST-1@WS) exhibited a high contact angle of 162.98±1.10° for water and was able to effectively separate various immiscible oil/water mixtures. Notably, the DTMS/HKUST-1@WS membrane can be integrated into a pump drive system, serving as an advanced filter element for the sustained and efficient oil-water constituents. Results showed that this membrane possesses attractive permeability toward CCl4 (56689.34 L·m−2·h−1) and toluene (47241.12 L·m−2·h−1), achieving separation efficiencies over 99.0%. Furthermore, this novel membrane exhibits remarkable resistance to physical damage, high/low temperatures, and corrosive solutions, thereby showcasing stable superhydrophobic and superoleophilic interfaces suitable for oily wastewater treatment in harsh environments. Thus, this work offers an innovative approach for designing functional wood-based MOF membranes to achieve highly efficient continuous oil-water separation.

Near-field electrospinning of PTFE/ZnO membrane with regular pore geometry and its photocatalytic performance

Poly(tetrafluoroethylene) (PTFE) membrane is remarkable due to its impressive comprehensive properties. However, the PTFE membrane’s chemical inertness and low surface energy make it difficult to achieve pore geometry regulation and functional modification. In this work, the PTFE/ZnO photocatalytic fiber membrane with regular membrane pore geometry was prepared by Near-filed electrospinning (NFES) technology. The precursor Zn(Ac)2 was added to the PTFE/poly(ethylene oxide) (PEO) spinning solution to introduce the ZnO seed layer. Then ZnO was grown in situ by hydrothermal method to prepare the NFES PTFE/ZnO membrane. The effects of the mass ratio of the PTFE/PEO spinning solution and the additional amount of Zn(Ac)2 on the membrane morphologies were investigated, and the effects of different membrane pore geometries on the photocatalytic degradation of methylene blue (MB) dye wastewater were discussed. The results showed that when the mass ratio of PTFE/PEO was 5:1 and the addition amount of Zn(Ac)2 was 15 wt%, the membrane had the optimal morphology. Compared with the PTFE/ZnO membrane prepared by electrospinning, the NFES PTFE/ZnO membrane with regular membrane pore geometry had more catalyst loading, and the dynamic MB removal rate reached 97.6% after 4 h of UV irradiation. After 5 cycles of testing, the degradation rate of MB can also reach 70.8%.

The effect of surface energy on the wettability of graphene-coated copper: A comparison of different single and multilayer graphene

The present research investigated the effect of different types of graphene layers including a slow cooling rate single-layer graphene (SSLG), a high cooling rate single-layer graphene (HSLG), and a multilayer graphene (MLG) on the wettability and surface energy of the copper substrate, which was synthesized using a chemical vapor deposition (CVD) process. Results revealed an increasing trend in surface roughness of the substrate by applying the graphene layer which is mostly due to the formation of step bunches (SBs) during the synthesis process, and the highest surface roughness is obtained for the MLG. Moreover, despite the expectations the results of surface energy indicated that applying the graphene layer in all cases has increased the surface energy. However, the lowest surface energy is related to SSLG among the coated samples. On the contrary, the wettability of the coated-samples was diminished and the lowest wettability was obtained for the SSLG.

Unveiling Oxygen Evolution Reaction on LiCoO2 Cathode: Insights for the Development of High‐Performance Aqueous Lithium‐ion Batteries

AbstractAqueous lithium‐ion batteries (ALIBs) are attracting significant attention as promising candidates for safe and sustainable energy storage systems. This paper delves into the crucial aspects of ALIB technology focusing on the interaction between LiCoO2 (lithium cobalt oxide) cathode material and water electrolytes, with a specific emphasis on the Oxygen Evolution Reaction (OER) process. Fundamental understanding of the electrochemical behavior of LiCoO2 in aqueous electrolytes is crucial for enhancing the performance, safety, and longevity of ALIBs using LiCoO2 as the cathode material.Through a comprehensive periodic density functional analysis of the LiCoO2‐water at the cathode interface, the potential catalytic contributions to the OER mechanism of LiCoO2 are explored. The catalytic properties of LiCoO2 towards OER are investigated considering different steady states of the lowest energy surfaces of LiCoO2 and three different Li concentrations. Our results do not predict the formation of oxygen gas due to the expected large overpotentials, although the exergonic water decomposition to hydroxyl by means the first proton‐electron transfer is predicted at equilibrium potential. This work contributes to the fundamental understanding of LiCoO2 as cathode for aqueous lithium‐ion batteries, reporting the pros and cons of one of the most common cathode materials for traditional non‐aqueous batteries.

Investigation of hydroxyl-terminated polydimethylsiloxane-modified epoxy resin

Epoxy resin coatings are characterized by a high concentration of hydroxyl groups, making them inherently hydrophilic and prone to corrosion. Additionally, the brittleness of epoxy resin limits its practical uses. In this study, epoxy resin (EP-51) was modified using hydroxyl-terminated polydimethylsiloxane (HTPDMS), which possesses a low surface energy due to its -Si-O- bonds, to improve the hydrophobicity and toughness of the coating. The effect of varying HTPDMS concentrations on the properties of epoxy resin was evaluated in terms of mechanical, thermodynamic, and electrochemical properties, as well as contact angle measurements. The findings reveal that as the HTPDMS content increases, the tensile strength of the modified EP diminishes, while the elongation and impact strength are enhanced. However, higher HTPDMS levels lead to reduced compatibility with EP, causing phase separation and the formation of an “island structure”. The glass transition temperature of the EP declines with added HTPDMS, resulting in an increased swelling rate and reduced pencil hardness and adhesion grade of the coatings. Notably, the hydrophobicity of the EP improved significantly, with its contact angle rising from 74.8° to 99.0° post-modification. Electrochemical impedance spectroscopy and polarization curve analyses revealed optimal protective performance of the coating at an epoxy resin to HTPDMS mass ratio of 8:2.

Porous Polyethylene Supports in Reinforcement of Multiblock Hydrocarbon Ionomers for Proton Exchange Membranes.

Hydrocarbon (HC)-based block copolymers have been recognized as promising candidates for proton exchange membranes (PEMs) due to their distinct hydrophilic-hydrophobic separation, which results in improved proton transport compared to that of random copolymers. However, most PEMs derived from HC-based ionomers, including block copolymers, encounter challenges related to durability in electrochemical cells due to their low mechanical and chemical properties. One method for reinforcing HC-based ionomers involves incorporating the ionomers into commercially available low surface tension PTFE porous substrates. Nevertheless, the high interfacial energy between the hydrocarbon-based ionomer solution and PTFE remains a challenge in this reinforcement process, which necessitates the application of surface energy treatment to PTFE. Here, multiblock sulfonated poly(arylene ether sulfone) (SPAES) ionomers are being reinforced using untreated PE on the surface, and this is compared to reinforcement using surface-treated porous PTFE. The PE support layer exhibits a lower surface energy barrier compared to the surface-treated PTFE layer for the infiltration of the multiblock SPAES solution. This is characterized by the absence of noticeable voids, high translucency, gas impermeability, and a physical and chemical stability. By utilizing a high surface tension PE support with a comparable value to the multiblock SPAES, effective reinforcement of the multiblock SPAES ionomers is achieved for a PEM, which is potentially applicable to various hydrogen energy-based electrochemical cells.

A multilayered antifouling coating constructed using the synthesized capsaicin-mimicking N-(4-hydroxy-3-methoxy-benzyl) acrylamide

Biofouling is a stepwise accumulation process involving participation of various molecules and marine organisms. To tackle this complex threat, development of efficient long-term antifouling coatings yet keeps elusive. Here we report a newly constructed coating with both antifouling activity and low surface energy. The special surface structure formed by silica spheres and fluorosilanes offers the coating superhydrophobicity. Capsaicin-mimicking N-(4-hydroxy-3-methoxy-benzyl)-acrylamide (HMBA) powder is synthesized via the Friedel-Crafts reaction and is used as the antifoulant additives in the coating. By the synergistic effect of surface superhydrophobicity and the dispersed antifoulant, the multilayered HMBA-silica coating effectively inhibits the adhesion of alginate, bovine serum albumin and Chlorella, their adhesion rate on the HS-3 coating is 11.9 %, 8.7 % and 3.3 % respectively. The HS-3 coating kills 96.6 % gram-negative bacteria E. coli and 99.9 % gram-positive bacteria S. aureus. Furthermore, the HMBA-silica coating significantly mitigates by its superhydrophobicity the corrosion of artificial seawater, its corrosion current density has decreased by 4 orders of magnitude compared to bare 316 L plate. In a 90 days real seawater immersion experiment, the coating shows excellent anti-fouling and anti-corrosion properties. The fabrication route of the HMBA-silica coating using the synthesized broad-spectrum antifoulant HMBA and hydrophobic silica would give insight into developing new antifouling materials for marine applications.

Mechanically stable superhydrophobic coating of crosslinked polymer composite with self-healing ability

Sustainable superhydrophobicity is of significance for practical application of superhydrophobic coatings. We fabricated a mechanically stable superhydrophobic coating with self-healing performance by spray-coating a composite suspension of poly(vinyl butyral)-hexamethylene diisocyanate and octadecylamine (PVB-HDI/ODA) on various substrates. In the as-obtained composite, PVB-HDI formed 3D self-crosslinked polymer networks which not only impart the coating with high mechanical stability but also provide strong bonding force between the coating and the substrate, and ODA formed pedal-like structures which roughened the coating surface with low surface energy. Consequently, the coating possessed superhydrophobicity with a water contact angle up to 163.9° and a sliding angle lower to 1.0°. Notably, the as-obtained coating sustained its water repellency even after being exposed to various mechanical and chemical treatments. Moreover, the coating exhibited a self-healing ability in superhydrophobicity against O2 plasma etching. Such mechanical and chemical stabilities with self-healing ability are favourable to the superhydrophobic coating to prolong the lifespan for practical applications.

Recent Progress on the Air-Stable Battery Materials for Solid-State Lithium Metal Batteries.

Solid-state lithium metal batteries (SSLMBs) offer numerous advantages in terms of safety and theoretical specific energy density. However, their main components namely lithium metal anode, solid-state electrolyte, and cathode, show chemical instability when exposed to humid air, which results in low capacities and poor cycling stability. Recent studies have shown that bioinspired hydrophobic materials with low specific surface energies can protect battery components from corrosion caused by humid air. Air-stable inorganic materials that densely cover the surface of battery components can also provide protection, which improves the storage stability of the battery components, broadens their processing conditions, and ultimately decreases their processing costs while enhancing their safety. In this review, the mechanism behind the surface structural degradation of battery components and the resulting consequences are discussed. Subsequently, recent strategies are reviewed to address this issue from the perspectives of lithium metal anodes, solid-state electrolytes, and cathodes. Finally, a brief conclusion is provided on the current strategies and fabrication suggestions for future safe air-stable SSLMBs.

Rational design and facile preparation of hybrid superhydrophobic epoxy coatings modified by fluorinated silsesquioxane-based giant molecules via photo-initiated thiol-ene click reaction with potential applications

First, several fluorinated silsesquioxane-based giant molecules (G-SQs) were easily prepared by the photo-initiated thiol-ene click reaction of octa(mercaptopropyl)silsesquioxane (SH8-SQ) with monovinyl(heptatrifluoropropyl)silsesquioxane (CF3-SQ) and perfluorohexyl ethylene with varying stoichiometric ratios. Then, G-SQs were used as low surface energy substances to modify epoxy acrylate resin (EA), which allowed adhesion to different substrates to prepare hydrophobic coatings via photo-initiated thiol-ene click reaction. The hybrid coating can impart stable superhydrophobic properties to cotton fabrics, which possess self-cleaning and oil–water separation function. The cotton fabrics coated by G-SQs-EA can perform oil–water separation very well, whose oil–water separation fluxes and efficiencies are 34,000 L m−2 h−1 and 99 %, respectively. The hybrid hydrophobic coating also provides effective corrosion protection for copper and the corrosion protection effect is further improved by increasing coating thickness. The corrosion current density, corrosion rate and impedance (0.01 Hz) reached 1.17*10−2 μA·cm−2, 0.14 μm yr−1 and 1026 kΩ cm−2, respectively. These excellent results indicate that EA coating modified by G-SQs has potential applications in many fields.

N-Type Small Molecule Electron Transport Layers with Excellent Surface Energy and Moisture Resistance Siloxane for Non-Fullerene Organic Solar Cells.

Electron transport layers (ETLs) generally contain polar groups for enhancing performance and reducing the work function. Nevertheless, the polar group with high surface energy may cause inferior interfacial compatibility, which challenges the ETLsto balance stability and performance. Here, two conjugated small molecules of ETLs with low surface energy siloxane, namely PDI-Si and PDIN-Si, are synthesized. The siloxane with low surface energy not only enhances the interfacial compatibility between ETLs and active layers but also improves the moisture-proof stability of the device. Impressively, the amine-functionalized PDIN-Si can simultaneously exhibit conspicuous n-type self-doping properties and outstanding moisture-proof stability. The optimization of interfacial contact and morphology enables the PM6:Y6-based OSC with PDIN-Si to achieve a power conversion efficiency (PCE) of 15.87%, which is slightly superior to that of classical ETL PDINO devices (15.27%), and when the PDIN-Si film thickness reaches 28nm, the PCE remains at 13.19% (≈83%), which indicates that PDIN-Si has satisfactory thickness insensitivity to facilitate roll-to-roll processing. Excitingly, after 120 h of storage in an environment with humidity above 45%, the unencapsulated device with PDIN-Si as ETL remains at 75% of the initial PCE value, while the device with PDINO as ETL is only 50%.

Fabrication of a Fluorocarbon Low Surface Energy Coating for Anti-Stain Applications.

In the long-term working state, stains such as dust, oil, and charged particles in the environment are prone to deposit on the surface of the power equipment, which has great security risks. To achieve anti-stain performance, fluorocarbon composite coating with a low surface energy was prepared and studied. In this paper, SiO2 nanoparticles were used as inorganic fillers and fluorocarbon resin was used as the substrate to form anti-stain coatings. By adjusting and optimizing the ratio of fillers and organic resins, coatings with different static contact angles were constructed. The optimum composite coating has a contact angle of 151 ± 2° and a surface energy of 9.6 mJ/m2. After high-temperature treatment (up to 200 °C), immersion in corrosive solutions (pH 3-11), and sandpaper abrasion (after 5 abrasion cycles), the coating has been proven to show good thermal, chemical and mechanical stability. Our study provides significant research and market opportunities for the anti-stain application of the fluorocarbon composite coating on power equipment.

Enhancing strategies for the activity and H2O resistance of MnCo-CMS flexible SCR catalysts and hydrophobic modification by modulating the surface energy

Melamine sponge is a flexible organic rubber-plastic foam characterized by its highly porous three-dimensional mesh structure. By optimizing the carbonization process of the melamine sponge, NH3-SCR catalysts with enhanced flexibility were developed. In this study, MnCo-CMS (Carbonized melamine sponge) catalysts were synthesized using the impregnation method. Response surface methodology (RSM) and central composite design (CCD) were employed to investigate the effects of impregnation time, loading, and calcination temperature on the mass reaction rate and N2 selectivity. The results showed that loading had the most significant influence, followed by calcination temperature and impregnation time. Under the optimal preparation conditions of 32.5 wt% loading, the calcination temperature at 420 °C, and the impregnation time for 342 min, the mass reaction rate could reach 11.02 cm3min-1g−1, and the N2 selectivity could achieve 87.4 %. Experimental validation confirmed that various preparation processes resulted in catalysts with high SCR activity (rate constant k > 9.5 cm3min-1g−1 and N2 selectivity > 80 %). The Mn-Co loading should be within the range of 28–36 wt%, the calcination temperature within the range of 380–420 °C, and the impregnation time should be 150 min or more. Materials with low surface energy could result in excellent hydrophobicity. In this study, it was found that melamine sponges could be modified into low surface energy carbon foams by temperature modulation. The change in surface energy was utilized as a modification approach to enhance the water resistance of the NH3-SCR catalyst. Importantly, the optimized process significantly improved the stability and water resistance of the catalysts.

High-performance hazardous aerogel/liquid barriers from fluffy, antibacterial superhydrophobic nanofiber membranes

Fibrous membranes have been regarded as one of the most effective barriers against hazardous matters, e.g., pathogen, airborne particulates, and liquids. However, developing multi-functional membranes with high air filtration performances, liquid barrier properties, and antibacterial activities remains challenging. Herein, a robust nanofibrous membrane with fluffy structure has been developed through a facile one-step electrospinning process. Under the synergistic effect of polyetherimide (PEI) nanofibers, low surface energy fluorinated alkyl silane (FAS), and fluorinated ZIF67 nanoparticles, the resultant PEI/FAS/F-ZIF67 composite nanofiber membrane shows superhydrophobicity with WCA of 155° and antibacterial activity with efficiency of over 99 %. The addition of FAS renders the membrane a fluffy fibrous structure, which further enhances the filtration performances with a filtration efficiency of 99.99 % and a low pressure drop of 125 Pa. Owing to the superhydrophobicity, the membrane also shows excellent liquid repellent properties with hydrostatic pressures of 60.6 kPa and 14.0 kPa to water and blood, respectively. Furthermore, benefiting from the excellent thermal stability of PEI, the composite membrane can well maintain its filtration performances at high temperature of 200 ℃. Overall, the proposed PEI/FAS/F-ZIF67 nanofiber membrane demonstrates high potential to be widely applied for air purification and medical protection applications.

Highly efficient electromagnetic interference shielding composite with excellent superhydrophobic and photothermal/electrothermal effects

With the development of communication facilities, electromagnetic pollution has become more problematic in modern society. Outdoor electromagnetic devices such as signal stations and radar units are the main source of electromagnetic pollution. Therefore, it is urgent to develop electromagnetic interference (EMI) shielding composites for outdoor applications. Meanwhile, the accumulation of ice on the surfaces of these facilities often has serious effects, especially in winter and cold areas. To this end, the Polydimethylsiloxane/Graphite/Carbon black-Polydimethylsiloxane/Fe3O4@Multi-walled carbon nanotube-Aramid paper@Ag (PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP) laminated composite was prepared by combining spraying, scraping and electroless plating techniques to enable the coordination of EMI shielding and de-icing. Through the rational design of the absorbing and conducting layers, the PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP composite has a shielding effectiveness of 31.35 dB in the X-band and an ultra-high absorption coefficient (A) of 0.9. It is worth noting that, due to the rough structure and the low surface energy of the surface layer, the composite exhibits excellent superhydrophobicity (158° ± 1°). Importantly, the PDMS/GP/CB-PDMS/Fe3O4@MWCNTs-AgP composite exhibits stable electrothermal properties, with a fast response and high-speed de-icing capability. At 0.1 W/cm2 input electrical power, ice completely melts in 210 s. And the composite shows excellent photothermal properties, with the ice completely melts within 180 s at 1 sun. The composite also shows excellent self-cleaning properties and acid-alkali resistance. This multifunctional EMI shielding composite provides a new strategy for the safe and long-term use of all-weather outdoor devices.

Novel eco-friendly bio-nano-hybridized woolen felts for effective oil/water separation

Herein, a novel eco-friendly oil/water separation membrane was fabricated by bio-nano-hybridized surface modifications of waste woolen felt, which are inexpensive and biodegradable raw material. The bio-nano-hybridized surface modification was performed by decoration of the felt with polydopamine (PDA) in the presence of TiO2 and then Ag nanoparticles loaded onto the PDA layer by in-situ reduction, followed by treating the woolen felt@PDA-TiO2-Ag with a thiol having long alkyl chain (DDT) to fabricate the woolen felt@PDA-TiO2-Ag-DDT. FT-IR, FE-SEM, TEM, AFM and XRD analyses were performed to examine the surface structure and morphology of the modified woolen felts. Results revealed that low surface energy as well as nanostructured roughness were created through the modification process. The modified felt showed superhydrophobicity with water contact angle of 155° and excellent water/oil separation performance. It was also demonstrated that the densities of the membrane can be adjusted by the bio-nano-hybridized modification and the water/oil separation capability can be enhanced.