Facile Solution-immersion Research Articles

Selective Fabrication of Robust and Multifunctional Super Nonwetting Surfaces by Diverse Modifications of Zirconia-Ceria Nanocomposites.

The creation of surfaces with various super nonwetting properties is an ongoing challenge. We report diverse modifications of novel synthesized zirconia-ceria nanocomposites by different low surface energy agents to fabricate nanofluids capable of regulating surface wettability of mineral substrates to achieve selective superhydrophobic, superoleophobic-superhydrophilic, and superamphiphobic conditions. Surfaces treated with these nanofluids offer self-cleaning properties and effortless rolling-off behavior with sliding angles ≤7° for several liquids with surface tensions between 26 and 72.1 mN/m. The superamphiphobic nanofluid coating imparts nonstick properties to a solid surface whereby liquid drops can be effortlessly displaced on the coating with a near-zero tilt and conveniently lifted off using a needle tip, leaving no trace. Further, the superamphiphobic surface demonstrates good oil repellency toward ultralow surface tension liquids such as n-hexane and n-heptane. The superoleophobic-superhydrophilic surface repels oil droplets well regardless of whether it is in the air or underwater conditions. In addition, reaping the benefits of the ZrO2-CeO2 nanocomposites' photocatalysis feature, the superoleophobic-superhydrophilic coating exhibits self-cleaning ability by the degradation of color dyes. Modification of the wettability of substrates is carried out by a cost-effective and facile solution-immersion approach, which creates surfaces with hierarchical nano-submicron-scaled structures. The multipurpose coated surfaces have outstanding durability and mechanical stability. They also resist well high-temperature-high-pressure conditions, which will provide various practical applications in different fields, including the condensate banking removal in gas reservoirs or the separation of oil/water mixtures.

Fluffy intersected NiCo–OH nanosheet decorated hollow Cu(OH)2 nanotube arrays on Cu foam for high-performance Ni–Zn battery

The NiCo hydroxides nanosheets (NiCo–OH) decorated Cu(OH)2 nanotubes structure was fabricated via a facile solution-immersion and later solvothermal method. The internal 1D Cu(OH)2 nanotubes directly grown on current collector without binder using enhance conductivity, accelerating electron transport. The outer 2D NiCo–OH nanosheets provide large surface areas and considerable active sites, promoting the electrode/electrolyte contact. Beneficial from significant electrochemical synergy in conductivity and open structure, the Cu(OH)2@NiCo–OH exhibits an impressive capacity of 1.12 mAh cm−2 at 3 ​mA ​cm−2, and remarkable rate capability (71% capacity retention at 30 ​mA ​cm−2). When assembled Ni–Zn battery with Cu(OH)2@NiCo–OH as cathode and Zn plate as anode, the Cu(OH)2@NiCo–OH//Zn battery displays high energy density and power density (1.53 ​mWh cm−2, 31.6 ​mW ​cm−2). Therefore, the Cu(OH)2@NiCo–OH//Zn battery presents a tremendous charm in new-type energy-storage devices.

Surface Hydrophobic Treatment of Water-Sensitive DUT-4 Metal–Organic Framework To Enhance Water Stability for Hydrogen Storage

Water stability in acidic, neutral, and basic aqueous solutions is quite important for the potential application of metal–organic frameworks. As evidenced by X-ray diffraction and scanning electron microscopy results, the pristine DUT-4 is extremely water sensitive to acidic, neutral, and basic aqueous solutions and undergoes crystal structure and morphology transformation. The pristine DUT-4 nearly loses its porosity and H2 uptake capacity after being exposed for 6 d. A facile solution-immersion approach was employed to deposit a hydrophobic layer on the DUT-4 surface without significant loss of surface area. This layer could effectively protect DUT-4 from water molecule attack and greatly enhance water stability. After the same exposure to aqueous solutions, the hydrophobic-treated DUT-4 could basically retain their crystal structure, morphology, surface area, and H2 uptake capacity. This approach could be explored to broaden the scope of practical applications of DUT-4 and other metal–organic frameworks under water-containing environments.

Role of Hydrophilic APTES-PP Separator in Enhancing the Electrochemical Performance of Ni-Rich Cathode for Li-Ion Battery.

Polypropylene (PP) separators essentially have poor compatibility with normal liquid electrolytes, including EC/DEC, due to the low surface energies of their hydrophobic surfaces. Therefore, they have a poor ability to retain electrolyte solutions within the separators because of low absorption capacity for the liquid electrolytes, which could directly damage the AC impedance and C-rate performance of LIBs. This study aims to improve the hydrophilicity and adhesion properties using (3-aminopropyl)triethoxysilane (APTES) coating on hydrophobic PP separators. Their surfaces were treated with a thin and stable silane layer, using APTES with -NH₂ of the hydrophilic group. Hydrophilic PP separator surfaces with pore structures were fabricated by a facile solution-immersion method. The contact angle of the APTES-PP separator decreased from 102±2.5° to 60±1.5°. The electrochemical measurement results indicate that the cell using the modified PP separator showed a better initial discharge capacity of 165.79 mAh g-1 during the first cycle, at a current density of 0.1 C, as compared with the initial discharge capacity (141.61 mAh g-1) of the cell with a bare PP separator. The performances of all cells with coated PP separators were improved with regard to interfacial resistance, discharge capacity and C-rate capacity, compared to the uncoated PP separator.

Fabrication of Superhydrophobic-Superoleophobic Surfacesby Facile Solution-Immersion and Surface Coating

Fabrication of Superhydrophobic-Superoleophobic Surfacesby Facile Solution-Immersion and Surface Coating

A binder-free composite anode composed of CuO nanosheets and multi-wall carbon nanotubes for high-performance lithium-ion batteries

The energy density and operational life of lithium-ion batteries (LIBs) depend sensitively on the properties of electrode materials. Transition metal oxide based electrodes attract much attention because of their potential to offer high energy density. In this study, we report a binder-free composite anode composed of CuO nanosheets and multi-wall carbon nanotubes for LIBs. This composite anode is fabricated by a cost-effective electrophoretic deposition process followed by facile solution immersion. When tested in a LIB, this composite anode delivers a high reversible capacity of 540 mAh g−1 and maintains its capacity retention of above 78% after 50 cycles at a current density of 100 mA g−1, which is much higher than the CuO anode without carbon nanotubes. The high capacity, enhanced rate capability, low resistance, and increased operational life are attributed to the unique architecture of the hybrid electrode. The carbon nanotubes facilitate the electron transfer, enhance the structural stability of CuO nanosheets, and improve the adhesion of the CuO nanosheets to current collector. Such highly porous cross-linked network based on CuO nanosheets and multi-wall carbon nanotubes has great potential as a binder-free anode for high-performance LIBs.

Imparting surface hydrophobicity to metal-organic frameworks using a facile solution-immersion process to enhance water stability for CO2 capture.

The water sensitivity of metal-organic frameworks (MOFs) poses a critical issue for their large-scale applications. One effective method to solve this is to provide MOFs with a hydrophobic surface. Herein, we develop a facile solution-immersion process to deposit a hydrophobic coating on the MOFs' external surface without blocking their intrinsic pores. The water contact angle of the surface hydrophobic (SH) MOFs is ∼146°. The hydrophobic coating not only greatly enhances MOFs' water stability but also provides durable protection against the attack of water molecules. When exposed to liquid water, the SH samples well retain their crystal structure, morphology, surface area and CO2 uptake capacity. However, the as-synthesized (AS) samples nearly collapse and lose their porosity as well as CO2 uptake capacity after the same exposure. This study opens up a new avenue for the MOFs' application of gas sorption in the presence of water.

Synthesis of a dodecylphenylsiloxane oligomer resin/silica nanocomposite and its application to cotton fabrics

A novel dodecylphenylsiloxane oligomer resin/nanocomposite (PHDESR-SiO2) was prepared by graft copolymerization between dodecyl modified phenylsiloxane resin with pendent epoxy groups (PHDESR) and amino-functionalized silica nanoparticles (BTEPA-SiO2). PHDESR-SiO2 was then used to prepare a super hydrophobic surface on cotton fabric by a facile solution-immersion process method. Chemical structures, chemical compositions, wettability, surface morphology, and thermal properties were investigated by Fourier Transform Infrared Spectrum (FT-IR), 1H-NMR spectrum, X-ray photoelectron spectroscopy (XPS), static contact angle analyzer, scanning electron microscopy (SEM), Particle size distribution (PSD) and thermo-gravimetric analysis (TGA). The results showed that the target product PHDESR-SiO2 has an anticipative structure with many micro/nanostructure tubercles, a cross-linked network hydrophobic organosilicon resin film and many clusters of cylindrical dodecyl molecular brushes. This created super hydrophobic structure on the surface of the treated cotton fabrics. XPS analysis indicated that the long carbon chain groups had a slight tendency to enrich the film-air interface. In addition, PHDESR-SiO2 can provide good hydrophobicity for the treated fabric. As the dose of PHDESR-SiO2 increased, the hydrophobicity of the treated fabric enhanced and consequently the water static contact angle reached 152.5 °. This had little influence on the softness, color, and gas permeability of the fabrics. This makes it slightly stiff at high doses, and the super-hydrophobic cotton fabric also had good launderability.

Continuous Oil–Water Separation Using Polydimethylsiloxane-Functionalized Melamine Sponge

The development of absorbent materials with high selectivity for oils and organic solvents is of great ecological importance for removing pollutants from contaminated water sources. We have developed a facile solution-immersion process for creating polydimethylsiloxane (PDMS)-functionalized sponges for oil–water separation. Sponge materials with densities ranging from 8 to 26 mg/cm3 were investigated as candidate skeletons. After functionalization, the lowest-density melamine sponge exhibits superior superhydrophobic and superoleophilic properties, absorption capacity, oil–water selectivity, and absorption recyclability. Via suction through such a functionalized sponge, we have experimentally demonstrated that various kinds of oils can be continuously separated from immiscible liquid mixtures without any water uptake. The widely available raw materials (melamine sponge and PDMS solution) and simple synthesis steps yield a cost-effective and scalable process for fabrication of absorbent materials that can ...

A multifunctional polymeric nanofilm with robust chemical performances for special wettability

A multifunctional polymeric nanofilm of a triazinedithiolsilane compound, which can protect metallic substrates and activate the corresponding surface simultaneously, is introduced onto a copper mesh surface via facile solution-immersion approaches. The resultant interface exhibits hydrophilic features due to the existence of silanol groups (SiOH) outward and has the potential to act as a superhydrophilic and underwater superoleophobic material. As the polymeric nanofilm atop the copper mesh is modified with long-chain octadecyltrichlorosilane (OTS), the functionalized surface becomes superhydrophobic and superoleophilic. The OTS-modified polymeric nanofilm shows outstanding chemical durability and stability that are seldom concurrently satisfied for a material with special wettability, owing to its inherent architecture. These textures generate high separation efficiency, durable separation capability and excellent thermal stability. The protective ability, originating from the textures of the underlying cross-linked disulfide units (-SS-) and siloxane networks (SiOSi) on the top of the nanofilm, prolongs the chemical durability. The activating capability stemming from the residual SiOH groups improves the chemical stability as a result of the chemical bonds developed by these sites. The significant point of this investigation lies in enlightening us on the fabrication of multifunctional polymeric nanofilms on different metal surfaces using various triazinedithiolsilane compounds, and on the construction of interfaces with controllable wettable performances in demanding research or industrial applications.

A facile solution-immersion process for the fabrication of superhydrophobic gibbsite films with a binary micro-nano structure: Effective factors optimization via Taguchi method

A superhydrophobic gibbsite film composed of a binary micro-nano hierarchical structure has been fabricated on the aluminum foil via the solution-immersion method as a facile route. The gibbsite film was formed based on the reaction of ammonia and aluminum nitrate as the precursor. Taguchi L16 experimental design was used to evaluate and optimize the effective factors, such as the ammonia/Al3+ molar ratio, concentration and type of the surface modifiers, reaction time and solution. Morphology features, phase analysis, chemical composition, topography and static water contact angle (WCA) were evaluated by means of FESEM, XRD, FTIR and AFM. Results showed that the ammonia/Al3+ molar ratio was the most effective parameter to achieve higher values of WCA and superhydrophobic property. Effect of the surface modifier was studied and two different fatty acids (stearic and palmitic) were compared. ANOVA showed that stearic acid is more effective for hydrophobization. Finally, a superhydrophobic thin film of aluminum hydroxide with WCA of 164.4±0.44° and contact angle hysteresis of about 3.05° was obtained. Results indicated that a binary micro-nano structured gibbsite composed of nano plates of about 30nm thickness has been formed.

Under seawater superoleophobic PVDF membrane inspired by polydopamine for efficient oil/seawater separation

Under seawater superoleophobic polyvinylidene fluoride (PVDF) membrane inspired by mussel is successfully fabricated for both surfactant-free and surfactant-stabilized oil/seawater separation. The conventional PVDF membrane is modified by a simple solution-immersion method, which was immersed in dopamine aqueous solution for 24h. The morphology and chemistry of dopamine inspired PVDF membrane was characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), attenuated total reflectance Fourier transform infrared spectra (FTIR-ATR) and X-ray photoelectron spectroscopy (XPS) respectively. The as-prepared membrane obtained stable superoleophobicity under seawater with an oil contact angle of 152±0.3° and extremely low oil-adhesion. Separation experiments for both surfactant-free and surfactant-stabilized emulsions showed that our membrane exhibited high oil/seawater separation efficiency (oil concentration in filtrate below 80ppm) and substantially high permeability, which are several times higher than that current traditional filtration membrane. Fouling resistance to proteins was also investigated for long-term use purpose. This study provides a facile solution-immersion method to fabricate under seawater superoleophobic membrane, highlighting its great potential in practical oil/seawater separation.

Superhydrophobic CuO@Cu2S nanoplate vertical arrays on copper surfaces

The present work reports a simple method to produce hierarchical CuO architectures on copper substrate through self-generation. Subsequently, [email protected]2S composites have been successfully synthesized from the hierarchical CuO precursors via a facile solution-immersion process. These products were characterized by field-emission scanning electron microscopy, x-ray powder diffraction and x-ray photoelectron spectrum. The wettability of the products was also investigated. It was found that the wettability of the [email protected]2S composite film could be easily changed from hydrophilic to superhydrophobic with simple fluorination modification. Compared with other methods, the method herein is mild, economical and easy to create large area superhydrophobic materials on copper substrate.

Facile Approach in Fabricating Superhydrophobic and Superoleophilic Surface for Water and Oil Mixture Separation

Metal copper mesh with superhydrophobic and superoleophilic surface had been successfully fabricated via a facile solution-immersion process. The hierarchical structure was prepared on the commercial copper mesh surface by etching with the nitric acid. After being modified by 1-hexadecanethiol (HDT), the as-prepared mesh indicated both superhydrophobic and superoleophilic property simultaneously. This as-prepared metal mesh could then be applied for oil and water mixture separation. The unusual wettability of the as-prepared mesh was stable in corrosive conditions, such as acidic, basic, and salt solutions. The solution-immersion method was simple, time-saving, and inexpensive and therefore exhibited great potential application.

Preparation and characterization of slice-like Cu 2(OH) 3NO 3 superhydrophobic structure on copper foil

Superhydrophobic structure was prepared on copper foil via a facile solution-immersion method. Thus slice-like Cu 2(OH) 3NO 3 crystal was prepared on the surface of the copper foil by sequential immersing in an aqueous solution of sodium hydroxide and cupric nitrate. And the superhydrophobic structure was obtained by modifying the slice-like Cu 2(OH) 3NO 3 crystal with 1 H,1 H,2 H,2 H-perfluorodecyltriethoxysilane (FAS-17). The morphologies, chemical compositions and states, and hydrophobicity of the surface-modifying films on the copper foil substrates were analyzed by means of scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and water contact angle measurement. Moreover, the thermal stability of the slice-like structure was also evaluated using thermogravimetric analysis (TGA). It was found that roughening of the copper foil surface helped to increase the hydrophobicity to some extent, but no superhydrophobicity was obtained unless the slice-like Cu 2(OH) 3NO 3 crystal formed on the Cu substrate was modified with 1 H,1 H,2 H,2 H-perfluorodecyltriethoxysilane. Besides, the superhydrophobicity of the FAS-17-modified slice-like Cu 2(OH) 3NO 3 structure was closely related to the surface morphology. And this hydrophobic structure retained good superhydrophobic stability at elevated temperature and in long-term storage as well, which should be critical to the application of Cu-matrix materials in engineering.