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In this study, a noble robust superhydrophobic and highly oleophobic polyurethane (PU)–SiO 2 nanoparticle (NP) coating is specially designed using sol-gel process. For this purpose the effective parameters on surface tension and durability of the synthesized coating investigated and optimized. This new superhydrophobic and highly oleophobic coating exhibits good pensile hardness as high as 6H with adhesive force grade of 5B and repels water and oil with contact angles (CAs) of 159° and 140°, respectively. The synthesized PU-SiO 2 composite also retains an excellent amphiphobicity after a 7 days immersion in water with water and oil with CAs of 150° and 130°. Facile fabrication of PU–SiO 2 coating with enhanced amphiphobicity and durability provides a novel pathway to the development of a high performance superamphiphobic surfaces. The outstanding properties of synthesized PU–SiO 2 coating are mainly due to (i) reduction of surface energy by fluoroalkylsilanes, (ii) formation of hierarchical micro- and nanometer scale roughness structures on the coating surface, (iii) stable adhesion of SiO 2 NPs into PU resin after cross-linking with isocyanate, and (iv) improving the chemical bonding and electrostatic interactions between film and substrate. [ABSTRACT FROM AUTHOR]

ABSTRACT: The fabrication of novel hydrophobic, superhydrophobic, and oleophobic surfaces on glass using nanosilica particles modified with polymer brushes prepared via surface initiated Cu(0)‐mediated reversible‐deactivation radical polymerization was demonstrated. Monomers including n‐butyl acrylate, 2,2,2‐trifluoroethyl methacrylate, and 1,1,1,3,3,3‐hexafluoroisopropyl acrylate were used to synthesize a series of nanosilica–polymer organic/inorganic hybrid materials. Products were analyzed using infrared spectroscopy, thermogravimetric analysis, scanning and transmission electron microscopy. The coated nanosilica showed core–shell structures that contains polymer brushes up to 67 wt %. The application of these particles for modifying surface wettability was examined by covalently attaching them to glass via a recently developed one‐pot “grafting to” methodology using “thio‐bromo click” chemistry. Atomic force microscopy topographic images show up to 25 times increase in roughness of the coated glass compared to blank glass sample. Contact angle measurements showed that nanosilica coated with PBA and PTFEM produced hydrophobic glass surfaces, while a superhydrophobic and oleophobic surface was generated using nanosilica functionalized with PHFIPA. This novel methodology can produce superhydrophobic and oleophobic surfaces in an easy and fast way without the need for tedious and time‐consuming processes, such as layer‐by‐layer deposition, high temperature calcination, and fluorinated oil infusion. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 [ABSTRACT FROM AUTHOR]

Abstract: The paper reports an optimized process to obtain transparent and highly hydrophobic sol‐gel coatings with further oleophobic behavior at high temperatures. Polyorganosiloxane sols were prepared incorporating an organic based precursor, 1H,1H,2H,2H Perfluorooctyltriethoxysilane (POTS), into a silica‐based hybrid sol and deposited on soda‐lime glass‐slides. The coating surfaces show high water contact angle (WCA) around 120 ± 1° and oil contact angle (OCA) of 70 ± 1° after curing at temperatures between 350 and 400°C. The coatings thickness changed between 300 and 2000 nm depending on sol composition and curing temperature. Easy‐to‐clean tests were performed, the results showing excellent anti‐stick and easy‐to‐clean properties compared to non‐coated samples. Atomic force microscopy (AFM) revealed the presence of rippled surfaces with morphology similar to “lotus leaf surface,” this explaining the properties. These hybrid fluoroalkylsilane sol‐gel coatings are a good alternative to provide anti‐stick and easy‐to‐clean properties to glass substrates being quite easy to scale up. [ABSTRACT FROM AUTHOR]

Membrane distillation is a thermal membrane technology, commonly used for desalination. The industrial breakthrough of the technology requires high performing and inexpensive membranes. In this paper, an alternative for the traditional hydrophobic membrane materials has been explored through the deposition of a hydrophobic coating on a commercial hydrophilic membrane with a microporous structure. The coatings enable obtaining the required hydrophobicity and prevent membrane wetting. The effect of the surface chemistry and structure on the membrane distillation performance was investigated for 5 different coatings. The coatings were applied only on the top surface or on the entire membrane cross-section and the effect of this difference in morphology was investigated. The atmospheric toplayer coating and vacuum plasma coating on the entire cross-section were selected for further optimization. The stability of the coating and the relation of the membrane structure and performance at different salinities were also investigated using direct contact membrane distillation. [ABSTRACT FROM AUTHOR]

In order to improve the hydro- and oleo-phobic properties of anti-fingerprint coating, novel oligosiloxane intermediate bearing perfluorodecyl/octyl and triethoxy silylethylene groups were synthesized; then, a series of nano-hybrid perfluoroalkyl oligosiloxane resins (FSi@SiO2) were synthesized using the hydrolysis and condensation of FVPS with tetraethylorthosilicate. The chemical structure, morphology, and performance of FSi@SiO2 were investigated. The results indicate that the FSi@SiO2 is a nano hybrid fluorinated polysiloxane resin with mean particle sizes of 200-400 nm. And under nanoparticles and perfluoroalkyl groups bonded in the resin, FSi@SiO2 not only showed a micro rough morphology in atomic force microscopy observation but also could provide the treated substrates with excellent hydro- and oleo-phobicity. As a result, the water and oil contact angles reached 120.3° and 87.5° on the treated glass, respectively; meanwhile, fingerprints were easily cleaned without any stains. [ABSTRACT FROM AUTHOR]

Oil-water separation is a worldwide concern due to the increasing emissions of oil-contaminated industrial water, frequent oil spills and the general shortage of clean drinking water. In this study, hydrophilic/underwater superoleophobic stainless steel (SS) meshes were fabricated via a one-step solution-based coating method using methyltrimethoxysilane (MTMS). The dimensions of the meshes were varied to study their effect on wettability and separation efficiency. Coated meshes were then used for gravity-driven oil/water separation with oil-water mixtures and oil-water emulsions in which water passed through the meshes while oil was retained. Contact angles, fluid flux and separation efficiency were evaluated to determine the optimum mesh dimensions. XPS and ATR-FTIR were performed on the coated stainless steel surface to confirm the presence of silanol groups that are accountable for the resultant unique wetting properties. After sand impact durability testing, the treated meshes were still able to separate oil-water mixtures with high separation efficiency and water recovery rates, despite the presence of residual sand particles. [ABSTRACT FROM AUTHOR]

In this work, a magnetic, superhydrophilic/oleophobic (MSHO) sponge was prepared by a facile one-step dipping method. It not only showed excellent capacity for oil-water separation but also could selectively absorb and continuously remove water from bulk oil, which is probably owing to the combination of its high porosity, superhydrophilic and oleophobic nature, as well as its capillary action. The magnetic property of the MSHO sponge made it easily being removed with a magnet. It was believed that the MSHO sponge had potential application prospect in industrial oil products purification and oil spill cleanup. [ABSTRACT FROM AUTHOR]

A new class of alkyl- and perfluoroalkyl-containing urea and amide derivatives was synthesized from amino acid derivatives. Most of these compounds showed excellent gelation behavior in organic solvents at low concentrations. A few organogelators selected from the initial screening were used for surface modification of fibrous substrates to create hydrophobic and oleophobic composites. The hydrophobic and oleophobic behaviors of these composites were ascribed to a combination of increased surface roughness and the alkyl/fluorinated functionalities present in the gelator backbone.

The utilization of solar steam generator via photothermal conversion is a sustainable and highly sufficient solution for addressing long-standing water scarcity. Due to its extensive optical absorption, dopamine has been considered as a promising photo-thermal conversion material. In this work, by co-depositing Fe3+ and 3-glycidyloxypropyltrimethoxysilane (KH550) with polydopamine (PDA), a high-performance, low-cost, and scalable modified membrane (called PVDF/PDA@KH550@Fe3+) with superior oil resistance was developed. Under one sun illumination, the resulting PVDF/PDA@KH550@Fe3+ membrane generated solar steam with a high efficiency of 90.33% and a high evaporation rate of 1.40 kg m−2 h−1. More importantly, the evaporation rate still performs well even in oil-contaminated water due to the improvement of hydrophilicity and anti-fouling capabilities of the modified membrane. In oil-in-water emulsion, the evaporation rate approaches 1.33 kg m−2 h−1 and the evaporation efficiency reaches 85.49%. This study demonstrated that solar steam generation using PVDF/PDA@KH550@Fe3+ membrane could be a viable option for seawater and oily wastewater purification. [Display omitted] • A PDA@KH550@Fe3+ coating was generated on PVDF membranes by one-step co-deposition. • High light absorption of modified membranes caused a water evaporation rate as high as1.40 kg m−2 h−1. • The hydrophilicity and anti-fouling properties of the modified membrane were improved. • The PVDF/PDA@KH550@Fe3 + membrane was applied for oil wastewater and seawater desalination. [ABSTRACT FROM AUTHOR]

[Display omitted] • A method for preparing glass fibre media with good oleophobic properties and mechanical strength was developed. • Trends in pressure drop and droplet penetration ratio of combined filters over time were investigated systematically. • Filter with decreasing pore size gradient had low pressure drop and best comprehensive performance for submicron droplets. • A mechanism of filter with increasing pore size gradient to improve filtration efficiency for submicron droplets was proposed. • A drainage layer was conducive to capturing re-entrained micron droplets. Pore size is a key factor that influences the removal of oil mist droplets by a coalescence filter. However, the influence of the pore size distribution among different filter layers on filtration performance has not been thoroughly explored. In this work, a method for preparing glass fibre filtration media with a specific structure as well as good oleophobic properties and mechanical strength was developed by combining the wet-spinning method and immersive modification. The prepared single-layer media were combined in various three-layer structures with increasing pore size gradient, decreasing pore size gradient and uniform pore size distribution. The trends in the pressure drop and droplet penetration ratio of the resulting combined filters over time were analysed systematically. The results demonstrated that in the combined filter, the first layer material had a significant influence on the filtration process and steady-state performance. Throughout filtration, the pressure drop of the filter with a decreasing pore size gradient had layering characteristics, which was conducive to capturing droplets within different particle size intervals in different stages and thereby relieving the operational pressure on different layers. Hence, the filter with a decreasing pore size gradient had a relatively low steady-state pressure drop and the best comprehensive filtration performance for submicron droplets. However, the filter with an increasing pore size gradient had the highest separation efficiency for submicron droplets and its concentration of steady-state downstream droplets was 19% lower than that in the filter composed of three layers of minimum pore size materials. The proposed mechanism by which the filter with the increasing pore size gradient improved the coalescence filtration efficiency for submicron droplets was based on capillary theory. [ABSTRACT FROM AUTHOR]

Transparent liquid repellent coatings with exceptional wear and abrasion resistance are very demanding to fabricate. The most important reason for this is the fact that majority of the transparent liquid repellent coatings have so far been fabricated by nanoparticle assembly on surfaces in the form of films. These films or coatings demonstrate relatively poor substrate adhesion and rubbing induced wear resistance compared to polymer-based transparent hydrophobic coatings. However, recent advances reported in the literature indicate that considerable progress has now been made towards formulating and applying transparent, hydrophobic and even oleophobic coatings onto various substrates which can withstand certain degree of mechanical abrasion. This is considered to be very promising for anti-graffiti coatings or treatments since they require resistance to wear abrasion. Therefore, this review intends to highlight the state-of-the-art on materials and techniques that are used to fabricate wear resistant liquid repellent transparent coatings so that researchers can assess various aptitudes and limitations related to translating some of these technologies to large scale stain repellent outdoor applications. [ABSTRACT FROM AUTHOR]

In this study, cylindrical pillars with varying diameters between 10 μm to 100 μm, seperation distances between 5 μm to 10 μm, constant heights of 40 μm ± 2 and solid area fractions [ f s C B ( g e o ) ] between 0.349 to 0.712 were prepared by deep reactive ion etching process and all surfaces were hydrophobized/oleophobized by coating with perfluoro-styrene (TM/S) random copolymer that was synthesized in CO 2 -expanded monomer. It was found that, oleophobic behaviors of the patterned surfaces were affected from the type of the hydrocarbon liquids used and with the increase of hydrocarbon liquid chain lengths cylindrical pillar surfaces exhibited more oleophobic behavior. Pattern sizes also affected both oil and water drop CA values however oil and water drops behaved oppositely on the pillar surfaces. Applicability of Cassie-Baxter equation on cylindrical pillar surfaces was also investigated and was found that CA values of both water and hydrocarbon liquids were not obeying Cassie-Baxter theory however in the case of hydrocarbon liquids deviations from the theory were much more larger. [ABSTRACT FROM AUTHOR]

Here, we report for the first time the use of the Staudinger-Vilarrasa reaction to synthesize perfluorinated 3,4-propylenedioxythiophene (ProDOT) monomers for preparing hydrophobic/oleophobic surfaces. The efficiency of this reaction is shown with various perfluorinated chains. The prepared monomers are nicely polymerized to form homogeneous perfluorinated surfaces. The study of these surfaces reveal extremely high hydrophobic features with para and superhydrophobic properties (high and low water adhesion). Using different organic probe liquids (diiodomethane and hexadecane), it has been shown that the surfaces present also high oleophobic features. This work also shows a nice impact of the perfluorinated chain length on the surface morphologies. [ABSTRACT FROM AUTHOR]

In this paper, we reported a very interesting replication method to fabricate various kinds of chemically stable and mechanically durable superhydrophobic and highly oleophobic polymer surfaces by using hierarchical aluminum (H-Al) as the template. The H-Al template that consisted of microsteps and nanoplatelets was obtained by acid etching and subsequent boiling water treatment. Five polymers including acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS), and polyurethane (PU) were demonstrated to successfully replicate the hierarchical morphology of the H-Al. When coated with PDES, the final hierarchical polymer surfaces showed excellent superhydrophobicity and much improved oleophobicity to hexadecane. Most importantly, these polymer duplicates with coating displayed outstanding chemical stability and excellent mechanical durability. The resultant polymer surfaces showed stability even when immersed in HCl/NaOH solutions for as long as 144 h, exposed to organic solvent immersion for 168 h, irradiated with UV-light for 24 h, and placed under air condition for 8 months. The surfaces also impressively presented good mechanical durability after being severely scratched by sharp blade, multiply peeled by adhesive tape, and circularly rubbed under quantitative weight. This strategy can also be applied to any other dissolvable polymers. It is believed that this work provides a simple replicating method to create hierarchical polymer surfaces, and then further realize superhydrophobicity and oleophobicity. Specially, the excellent stability and durability of the resultant surfaces are believed to find promising outdoor applications. [ABSTRACT FROM AUTHOR]

Highly hydro and oleophobic materials applied to needs of the marine environment represent a relatively young field achieving growing interest as innovative solution, where technological and ecological aspects allow to be merged, taking into account the limitations imposed by international laws in terms of environmental protection. In this work a superhydrophobic (SH) coating for seawater applications has been characterized and tested in both laboratory and field conditions, since investigations in real seawater are crucial to evaluate the behaviour of SH surfaces because of a complexity not reproducible in laboratory. Taking into account the real conditions where the surface can operate oleophobicity can be investigated in presence of organic and inorganic pollution. The amphiphobic surface has been also studied to simulate those applications where the surface undergoes to thermal stress like pipelines and desalination plants affected by biofouling. The preliminary wearing test shows the effective resistance to a continuous low velocity impact of micrometric particles of the coating investigated here. Finally, time durability in field tests has been studied as a function of immersion angle in real seawater environment to investigate the role of the coating on early stages of biofilm growth. [ABSTRACT FROM AUTHOR]

Here, we report the synthesis of original hydrocarbon/perfluorocarbon mixed chain azides for surface post-functionalization. The use of mixed side chain allows to get fluorine properties with reduced amount of fluorine. The synthetized azide are grafted on surface using the Huisgen reaction. Post-modified surfaces were then investigated for their wettability, morphologies and roughness. [ABSTRACT FROM AUTHOR]

Chemical grafting of small molecule reagents onto polymeric fibrous materials, like paper, has been used to modify their wetting properties. Several reagents like trichlorosilanes, which can react with water or hydroxyls, have been used with the expectation that a monolayer, single molecule or polymerized single-molecule layer, is formed on the paper fiber surface. Presence of adsorbed water, however, would complicate the formation of a monolayer, especially in case of polyvalent reagents. We hypothesized that adsorbed water is a good co-monomer for polyvalent water-reactive reagents, therefore chemical grafting with polyvalent molecules would give polymeric gels instead of a monolayer. Reaction of trivalent reagents with paper in vacuo leads to formation of polymeric gels. By optimizing surface energy mismatch, through felicitous choice of chemical moieties on the monomer, self-assembly leads to formation of nano- to micro particles on the surface of paper fibers. We observe that, as expected, the wetting properties correlate well with the size and distribution of particles. We conclude that the recently reported ultra-hydrophobicity of chemically modified paper is not only due to inherent roughness of the paper fibers, but also due to a secondary roughness introduced by surface polymerization. Using this technique, we prepared amphi-phobic biomimetic surfaces inspired by the namib beetle. This talk will also address potential utility of such surfaces. [ABSTRACT FROM AUTHOR]

During the last years, emerging research has focused on the development and design of novel materials that can successfully repel oils and other liquids. In order to achieve such properties, different fabrication strategies can be followed. Up to now, several reviews have been published that focus and investigate each of these concepts individually without giving an entire overview of all the existing approaches for achieving oil-repellency. In this review pertaining to advances and developments since 2011, we summarise progress on fabrication, design and understanding of all the existing concepts for obtaining materials that are oil-repellent including smooth oleophobic materials, textured superoleophobic and superomniphobic surfaces, and lubricated porous/textured substrates. In each of these categories, we highlight the most successful methods to produce oil-repellent surfaces while their applications are also demonstrated. Finally, recent studies and new trends focusing on the development of oil-repellent materials by following more environmentally friendly routes such as the use of short-chain or even no perfluorinated compounds, but also fabrication methods that do not involve the use of hazardous or flammable solvents, are also discussed. [ABSTRACT FROM AUTHOR]

Superhydrophobic coatings as a surface modification method for copper substrates can improve their corrosion resistance and self-cleaning properties to extend their many industrial applications. A rapid one-step electrodeposition process was used to fabricate superhydrophobic nickel coatings with a hierarchical structure on copper substrates. Various surfaces with mushroom-like structures were obtained by adjusting the deposition voltage. The chemical composition of the coatings was nickel and nickel myristate. Contact angle measurement with three different liquids was performed to evaluate the surface energy of the coatings according to the Wu equation. All coatings were highly oleophobic representing high contact angles up to 172.3° and facile droplet rolling off. The effect of voltage on the distribution of clusters has led to different results for contact angle and corrosion performance. The highest charge transfer resistance (2370 kΩ·cm2) was obtained at an applied voltage of 35 V due to the uniform dispersion of pores and clusters. The coatings were highly durable as proved by EIS measurements in 3.5 % NaCl solution and aging in the air, which at the end of the period still had contact angles higher than 120°. The self-cleaning properties of the obtained surfaces were excellent due to the low surface energy and trapped air cushions. [Display omitted] • Ni films with different CAs up to 171.3° were electrodeposited at various voltages. • Mushroom-like structure obtained at 35 V provided the highest superhydrophobicity. • The 35 V prepared coating was highly oleophobic with high self-cleaning properties. • Long-term stability was proved by immersion in saline solution and storage in air. • During immersion, coating wettability was preserved by a change from lotus to petal. [ABSTRACT FROM AUTHOR]

Solar steam generation (SSG) with efficient interface-evaporation manner has recently emerged as one of the promising approaches to produce fresh water. In this work, halloysite-based SSG (H1) with aligned channels was prepared from halloysite (Hal) and chitosan (CS) by directional freezing and simple carbonization. Then modified the sides and lower surface of H1 to obtain oleophobic generator H2. The as-prepared H1 possess high light absorption (Ca.97.4), excellent thermal insulation (0.086 W m−1 K−1 in dry state), and abundant porosity (75.6%). Furthermore, the halloysite based evaporator H1 with unique aligned channels can ensure timely water transportation. As a result, leading to a high evaporation rate of 1.58 kg m−2 h−1 with an excellent photothermal conversion efficiency of 95.5% under 1 kW m−2 illumination. In addition, the hydrogel-based evaporation H1 also exhibits superior salt-resistant performance for solar desalination in high concentration brine, and the purified water from artificial seawater can achieve the WHO's standard for ion concentration of drinking water. Moreover, after modification the oleophobic H2 exhibit an excellent evaporation performance in oily water, and can reach to a high conversion efficiency of 86.0%. The halloysite-based evaporation devices have promise to be ideal candidates for efficient SSG and may further expanding the scope of their practical applications. [Display omitted] • H-SSGs has high light absorption, rich porosity and unique aligned channels. • The unique channels make H-SSGS promising in different water environments. • H-SSGs effectively expand the practical application range of SSG. [ABSTRACT FROM AUTHOR]

Hierarchical nanostructures of CuO nanoflowers on nanograss were investigated for self-cleaning and surface plasmonic applications. We achieved the hierarchical nanostructures using one-step oxidation process by controlling the formation of flower-like nanoscale residues (nanoflowers) on CuO nanograss. While the nanograss structure of CuO has a sufficient roughness for superhydrophobic characteristics, the additional hierarchy of nanoflowers on nanograss leads to a semi-reentrant structure with a high repellency even for a very small droplet (10 nL) of low surface tension liquid such as 25 % ethanol (~35 mN/m), thus providing non-wettable and self-cleaning properties. Furthermore, the CuO hierarchical nanostructure serves as a substrate for surface-enhanced Raman spectroscopy (SERS). Both of the CuO nanograss and nanoflower provide many nanoscale gaps that act as hot-spots for surface-enhanced Raman signal of 4-mercaptopyridine (4-Mpy), thus enabling a non-destructive detection in a short analysis time with relatively simple preparation of sample. Especially, the CuO nanoflower has larger number of hot-spots at the nanogaps from floral leaf-like structures, thus leading to three times higher Raman intensity than the CuO nanograss. These multifunctional results potentially provide a path toward cost-effective fabrication of a non-wettable surface for self-maintenance applications and a SERS substrate for sensing applications. [ABSTRACT FROM AUTHOR]

Hydrophobic and oleophobic materials have an important role in daily-life and industry. The hydrophobic and oleophobic property is mainly ascribed to the low surface energy materials and the roughness surface. The hydrophilicity and oleophobicity surface can be achieved by surface modification methods, such as electrodeposition, sol-gel process, chemical vapour deposition and spray deposition. In this paper, the properties of hydrophobic and oleophobic materials are introduced. The principles, characteristics and applications of surface modifications in hydrophobic and oleophobic materials are reviewed. [ABSTRACT FROM AUTHOR]

Superhydrophobic and oleophobic rubbery coatings were prepared by spraying perfluoroalkyl ethyl acrylate (Zonyl TA-N) grafted styrene butadiene rubber (SBR) solution in toluene after addition of hydrophilic and hydrophobic fumed silica powders onto glass. Grafting onto SBR has been performed by free radical copolymerization in toluene using different Zonyl TA-N feed compositions. Molecular weights of the graft copolymers were determined by GPC and intrinsic viscosity measurements. Thin films of Zonyl TA-N grafted SBR copolymers were prepared by dip coating glass slides into toluene solutions of SBR- g -Zonyl TA-N with varying fluoromonomer contents and their surface free energies were determined by contact angle measurements. The increase in Zonyl TA-N content resulted in a considerable decrease of the total surface free energy of the grafted SBR film. Later, superhydrophobic and oleophobic surfaces were prepared by adding hydrophilic and hydrophobic fumed silica powders into graft copolymer solutions and spraying onto glass. The effect of the Zonyl TA-N content in the graft copolymer, type of silica and its weight concentration in the solution on the water and hexadecane contact angle values, on the surface morphology and mechanical durability of the coatings were investigated. The highest water contact angle of the SBR- g -Zonyl TA-N/SiO 2 hybrid coatings was determined to be 162° and hexadecane contact angle 147° after adjusting the silica type, solids content and fluoroacrylate/SBR composition of the graft copolymer spray solution. [ABSTRACT FROM AUTHOR]

Several products are on the market to realize water-, oil-, and soil-repellent properties on textiles or textile-related materials. To make an adequate and fast rating of repellent properties of finished textiles, different drop tests according to AATCC and ISO standards are commonly used. For evaluation of the repellent properties of solid substrates against different liquids often contact angle measurements are performed. The aim of the work presented here is to determine and evaluate the repellent effects gained by the application of three different finishing agents on three different substrates, such as polyester fabric, artificial leather, and leather. The main questions are at that point: It is possible to gain similar repellent effects with the same finishing product applied on different substrates? Do the different testing methods lead to comparable results? Is there a relation to the repellency against everyday consumer products as red wine, ice tea, or coffee? This article should help the reader to evaluate different testing methods and the influence on common substrates. [ABSTRACT FROM AUTHOR]

Fluoro-containing ORMOSIL (organically modified silicate) sols were prepared by a one-pot sol-gel Stöber route by co-condensation of tetraethylorthosilicate (TEOS) and fluorinated alkyl silane [ 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilanes, (POTS)] using isopropanol as dispersant and ammonia as catalyst. Antireflective (AR) coatings from these sols were prepared by dip coating. It was found that isopropanol not only played as dispersant but also grafted to the surface of colloidal silica particles, and therefore gave the fluoro-free AR coating an almost superhydrophobic property. By increasing the molar ratio of POTS to TEOS, the oleophobicity of AR coatings increased gradually. As the molar ratio of POTS to TEOS is 0.05, the AR coating had the advantages of excellent hydrophobicity, improved oleophobicity and high transmittance. The water, CHI and polydimethyl siloxane contact angles are 143°, 119° and 85°, respectively. The water contact angle was further increased to be higher than 150° by a further surface hydrophobic modification with hexamethylisilazane. The coated glass substrates (BK-7) had very high transmittance of up to 99.8 % at a determined wavelength and had good AR stability to the hydrophilic and oleophilic pollutants. By exposing to humid environment (about 95 % humidity) for 2 months, the transmittance of fluoro-free AR coating decreased from 99.9 to about 99.5 % while that of superhydrphobic and oleophobic AR coating decreased from 99.8 to 99.6 %. Being placed in a vacuum chamber which had organic pollutants volatilized from vacuum pump oil, the transmittance of fluoro-free silica AR coating decreased seriously from 99.9 to 97.8 % while that of fluoro-containing ORMOSIL AR coating decreased slightly from 99.8 to 99.1 %. Graphical Abstract: Fluoro-containing ORMOSIL antireflective coating with resistance simultaneously to hydrophilic and oleophilic pollutants was prepared by sol-gel process.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

[Display omitted] • A room-temperature coating method was developed for anti-fingerprint application. • The coating is superhydrophobic and oleophobic with high light transmittance. • The anti-fingerprint property and self-cleaning capability are evaluated. • The coating possess excellent adhesion with the polymeric substrates. Mechanical robustness is required for a wide range of protective coatings for their long-term usage. It is particularly crucial for the coatings on polymeric substrates to maintain the surface free of contamination such as dust and fingerprint. Here, we have developed an effective fabrication method to prepare amphiphobic anti-fingerprint coating on polycarbonate (PC) substrates. Thin films with porous silicon dioxide (SiO 2) nanoparticles were deposited via pulse laser deposition on plasma pre-treated PC substrate. After the coating is applied, trichloro(1H,1H,2H,2H-perfluorooctyl) silane (PFTS) was assembled on the silica surface. The as-prepared PFTS-treated silica coating is superhydrophobic with water contact angle at 155.2 ± 1.8° and highly oleophobic with a contact angle of 133.6 ± 3.3° with diiodomethane. The coating also displays excellent adhesion with the PC substrate. The developed room temperature deposition process makes it potentially applicable for other low melting point polymeric substrates towards a wider range of functional surface applications. [ABSTRACT FROM AUTHOR]

The fluoropolymer–SiO 2 hybrid nanocomposite consisting of core–corona fluoropolymer-grafted SiO 2 nanoparticle (NP) and poly(dodecafluoroheptyl methacrylate) (PDFHM) was obtained by radical solution polymerization of the vinyl trimethoxy silane (VTMS)-treated SiO 2 NP with DFHM in this work. In H 2 O/tetrahydrofuran (THF) solution, PDFHM self-assembles into dendritic micelle and the increase in H 2 O volume is favorable for fluoropolymer-grafted SiO 2 NPs to create dense fluoropolymer corona layer. It also shows that the addition of H 2 O to the THF suspension of fluoropolymer–SiO 2 nanocomposite could cause a transfer for surface morphology of cast film from smooth film-covered aggregation to bare-exposed flaky aggregation and microsphere aggregation, which results in an increase in surface RMS roughness of cast film and induces a superhydrophobicity. Oleophobicity of cast film can be improved by thermal annealing, because strong surface self-segregation of PDFHM chains during thermal annealing process arouses a marked increase in surface fluorine content. [ABSTRACT FROM AUTHOR]

We developed a simple and inexpensive method to prepare the superhydrophobic and oleophobic copper meshes with rough structures fabrication and chemical modification. The achieved surfaces displayed liquid-repellent toward water and several organic liquids (such as hexadecane), which possessed much lower surface tension than that of water. Liquid repellency of the fabricated superhydrophobic copper mesh was demonstrated by visible experiment results and contact angle measurements. Even if the superhydrophobic copper mesh was rolled up, it still kept the superhydrophobicity. The mechanical durability was investigated by finger touch and mechanical abrasion tests. The results indicated that the copper mesh can maintain its superhydrophobicity against an abrasion length of 300 cm under a high pressure (77.2 kPa). The superhydrophobicity and oleophobicity, combined with mechanical durability, would promote the superhydrophobic surface to practical application in industry in the future. [ABSTRACT FROM AUTHOR]

Plasma nanotexturing, i.e. plasma etching with simultaneous roughening in the nano to micron scale, is used to create roughness on PMMA plates or glass slides coated with PMMA films. Mimicking nature, we use this roughness to create "smart" surfaces, with controlled optical and wetting properties. We present results that show combined antireflectivity, superhydrophobicity and superamphiphobicity for optimal plasma treatment time of only one-side of the samples (better results are expected for two-side treatment). In particular, using only 1.5 min of plasma nanotexturing and etching of PMMA in oxygen plasma, followed by vacuum deposition of a perfluorinated self-assembled monolayer, a reduction of reflectivity by 30% (compared to its initial value), superhydrophobicity and superamphiphobicity were achieved for liquids with surface tension more than 50 mN/m. [ABSTRACT FROM AUTHOR]

In this research, a two-component sol-gel inorganic-organic hybrid coating was prepared on a cotton fibre surface. An equimolar sol mixture of the precursors 1H,1H,2H,2H-perfluorooctyltriethoxysilane (SiF) and P, P-diphenyl- N-(3-(trimethoxysilyl)propyl) phosphinic amide (SiP) was applied to cotton fabric samples using the pad-dry-cure method. The surfaces of the untreated and coated cotton fibres were characterised using scanning electron microscopy, Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight-secondary ion mass spectrometry. The functional properties of the coated cotton fabric samples were investigated using static contact angle measurements with water and n-hexadecane, the ice-releasing test, antibacterial testing against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, thermogravimetric analysis in an air atmosphere, and vertical flammability tests. The results reveal the formation of a nanocomposite two-component inorganic-organic hybrid polymer network that is homogenously distributed over the cotton fibre surface. The presence of the SiP component in the two-component inorganic-organic hybrid coating did not hinder the functional properties imparted by the presence of the SiF component and vice versa, illustrating their compatibility. The cooperative action of the SiF and SiP components in the two-component coating provided the cotton fabric with exceptional multifunctionality, including simultaneous superhydrophobicity and high oleophobicity, passive antibacterial activity, and improved thermo-oxidative stability. [ABSTRACT FROM AUTHOR]

Liquid-floated rotor gyroscopes can provide high accuracy at small volume and low cost. In rotor gyroscopes, the rotating speed of rotor can significantly affect the detection accuracy. This work presents a new kind of liquid-floated rotor gyroscope using super-oleophobic surface processing, which can improve the performance of driving system. In this work, an unconventional anodization in oxalic-acid electrolyte under high current was employed to fabricate diverse nanostructured alumina surfaces. The top-view SEM image shows the nanowire pyramid structure on the surface of processed sample. Modification of the rough surfaces was achieved by dipping substrates in 0.5 wt% 1H,1H,2H,2H-perfluoro-octadecyltrichlorosilane-in-hexane and then curing then at 120 °C for 1 h. The maximum contact angle (CA) of the aluminum rotor with nanowire pyramid structure was measured to be 156° in average. The oleophobicity of the rotor surface was used to reduce the resistance in the floating liquid. The test results show that, under the normal working state, the rotating speed of super-oleophobic rotor can be reached up to 3200 rpm. While a similar system without the micro-nano composite structure can only reach 2860 rpm. Thus, the nanostructured super-oleophobic alumina surface processing can greatly increase the rotating speed, thereby improving the performance of the gyro system. [ABSTRACT FROM AUTHOR]

In the present study, an attempt has been made to design an oleophobic surface through chemical graft copolymerization of methyl methacrylate (MMA) onto polytetrafluroethylene (PTFE) film. The PTFE films were grafted with MMA resulting in PTFE-g-MMA grafts using benzoyl peroxide (BPO) as initiator in aqueous media. Optimum conditions pertaining to maximum percentage of grafting were evaluated by varying time, temperature, initiator, and monomer concentration. The maximum graft yield 9.47% was obtained at [BPO] = 0.03 M, [MMA] = 10%V/V, [reaction temperature] = 50°C and [reaction time] = 120 min. Methyl iodide was used to measure the contact angle, which revealed the oleophobic nature of grafted PTFE-g-MMA film. Maximum contact angle 95.5° of PTFE-g-MMA film was observed at optimum grafting conditions. The surface morphology of PTFE-g-MMA films was studied by Field emission scanning electron microscopy (FE-SEM) and x-ray diffraction (XRD) analysis confirmed the change in structure of PTFE after MMA grafting. [ABSTRACT FROM AUTHOR]

Highlights: [•] Perfluoro methacrylate and styrene were copolymerized in CO2-expanded monomer phase. [•] Flat and micro/nano hierarchical rough surfaces were prepared using perfluoroalkyl polymers. [•] Superhydrophobic surfaces were obtained, when micro/nano hierarchical surface are formed. [•] Particle diameters decreased with the increase of methanol content of the copolymer solution. [Copyright &y& Elsevier]

Highlights: [•] Fabrication of transparent pillar or pit grating covered acrylate coatings by UV-moulding. [•] Improved hydrophobic and oleophobic properties by modification with fluorosilane. [•] The submicron-structured coatings possessed anti-reflective and anti-wettable properties. [•] Both grating features demonstrated broadband antireflection over the visible spectrum. [ABSTRACT FROM AUTHOR]

[Display omitted] • A AgNPs@alumina bead sensor is developed for the application to POC SERS detection. • The bead surface is partitioned chemically to control AgNPs aggregation. • Aggregation-induced hot spots allow the detection of APDS at 10−15 M. • The sensor beads are successfully used to analyze food colorants in candies. • The sensor is easy to make, ultrasensitive, and satisfactory in real sample tests. Solid-state SERS sensors are desirable point-of-care tools due to their portability. However, the level of SERS sensitivity achieved in liquid phase is rarely duplicated in the solid phase. We report herein the fabrication of a SERS sensor using alumina beads as the solid support and demonstrate its high SERS sensitivity with the model analyte 4-aminophenyl disulfide (4-APDS). The key to sensitivity is a hydrophilic-hydrophobic surface gradient constructed by sequentially coating with the surfactant cetyltrimethylammonium bromide and fluorous 1H,1H,2H,2H-perfluorooctyltriethoxysilane. The surface gradient, together with chloride etching, allows the detection of 4-APDS at the low concentration of 10−15 M. The practicality of the sensor beads is evidenced by successfully tracking the SERS fingerprints of five food colorant standards in the SERS spectra of a popular candy product. These SERS sensor beads are easy to prepare, convenient to use, and highly responsive as a SERS platform for the analysis of colorants. [ABSTRACT FROM AUTHOR]

The treatment of wastewater polluted by oils and organic solvents has becoming a global environmental issue. Superhydrophobic separation materials have been widely developed to solve the problems, these materials are easily fouled by high viscosity oil fouling, causing the decrease of separation efficiency. Developing the materials with high hydrophilicity and oleophobicity in air via a facile and inexpensive approach is vital to address the oily water problems. Herein, a guar hydroxypropyltrimonium chloride-perfluorononanoate/kaolin (GHTC-PFN/KL) coated nylon textile (NT) was fabricated via a facile dip-coating approach. The obtained textiles reveal good superhydrophilicity, high oleophobicity in air, and low oil adhesion. By virtue of their special wettability, the functionalized textiles without any pre-wetting allow water to pass but preventing the passage of oils, which enables the textiles to be utilized for the selective separation to water/oil mixtures. The separation efficiencies for different oils are more than 96.7%. The modified textiles are capable of separating the oils employed with acidic, alkaline, salty solutions and hot water. Especially, a large quantity of water underoil is able to be continuously separated in situ via the multilayered textile tube at vacuum system. Simple preparation steps, scalable process and low cost make the as-prepared textile an ideal candidate for dealing with oily wastewater and purifying water-containing oil. [Display omitted] • A cationic guar gum-perfluorononanoate/kaolin sprayed nylon textile was prepared. • The obtained textile exhibits good high oleophobicity in air and superhydrophilicity. • The textile without water-prewetting allows water to permeate but repelling oil. • The textile can be used to continuously separate water in oil by vacuum pump. [ABSTRACT FROM AUTHOR]

Highlights: [•] Flat and transparent surfaces were successfully prepared using longer perfluoroalkyl chains of copolymers. [•] Increase in hydrocarbon chain length caused an increase in contact angle results of flat copolymer films. [•] Δcos θ values of copolymers depend on both wt.% Zonyl-TM content and also hydrocarbon chain length of liquids. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrids were synthesized using polymethylhydrosiloxane, 2,2,3,4,4,4 hexafluorobutylmethacrylate and tetraethyl orthosilicate with a platinum catalyst. The resulting hybrids formed transparent thin films on glass substrate by spin coating. The functional groups, molecular structure, surface morphology and chemical composition of the hybrids were analyzed by H nuclear magnetic resonance spectroscopy (NMR), Si MASNMR spectroscopy, high resolution scanning electron microscopy with energy-dispersive X-ray spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The thermal stability, mechanical scratch resistance, static and advancing/receding dynamic contact angles were measured by thermogravimetry, the pencil hardness test and a drop shape analysis system. The prepared hybrid thin films exhibited good transparency, hydrophobicity, as well as good mechanical and anti-stain properties. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: The layer-by-layer (LBL) adsorption technique has potential for controlling the surface wettability. In this study, we controlled surface wettability between “superhydrophobic and oleophobic” and “hydrophobic and oleophilic” by LBL process on TiO2 nanoparticle with hydrophobic polymer and hydrophilic polymer. From the cast coating with LBL process on TiO2 nanoparticle, the surface showed “superhydophobic and oleophobic” when the top surface was hydrophobic polymer, on the other hand, the surface showed “hydrophobic and oleophilic” when the top surface was hydrophilic polymer. The LBL process also affected to the structure of TiO2 nanoparticle/polymer composite, and TiO2 nanoparticle were aggregated with polymers in LBL process. In the condition of the aggregated diameter of TiO2 nanoparticle/polymer composite around 10μm in solution, the oleohobicity of spray coated film was enhanced with its hierarchical structure (static contact angles of rapeseed oil of 150° and hexadecane of 145°) “Superhydrophobic and high oleophobic” surfaces generated from all water-based dispersions are expected for application in technologies that need to avoid organic solvents. [Copyright &y& Elsevier]

Abstract: Superhydrophobic and oleophobic polydimethylsiloxane (PDMS)–silica nanocomposite double layer coating was fabricated by applying a thin layer of low surface energy fluoroalkyl silane (FAS) as topcoat. The coatings exhibited WCA of 158–160° and stable oleophobic property with oil CA of 79°. The surface morphology was characterized by field emission scanning electron microscopy (FESEM) and surface chemical composition was determined by energy dispersive X-ray spectrometery (EDX) and X-ray photoelectron spectroscopy (XPS). FESEM images of the coatings showed micro-nano binary structure. The improved oleophobicity was attributed to the combined effect of low surface energy of FAS and roughness created by the random distribution of silica aggregates. This is a facile, cost-effective method to obtain superhydrophobic and oleophobic surfaces on larger area of various substrates. [Copyright &y& Elsevier]

Hydrophobic and oleophobic surfaces with multi-scale structures were prepared on epoxy coating surfaces by using a facile process with fluorosilicone copolymer and SiO2 nano-particles. The fluorosilicone copolymers were synthesized using perfluoroalkyl acrylate (FA), vinyltriethoxysilane (VTES) and styrene (St) as comonomers via radical emulsion polymerization. In this paper, the surface properties of epoxy coating modified by fluorosilicone copolymer and SiO2 nano-particles were analyzed by using the contact angle measurement. The results showed that the modified epoxy coating surface exhibited not only excellent hydrophobicity but also oleophobicity, the water contact angle reached as high as 149° and the oil (atoleine) contact angle 101°, respectively. [ABSTRACT FROM PUBLISHER]

The presented study reports on differently modified silica sols for coating applications on leather. Silica sols are prepared by acidic hydrolysis of tetraethoxysilane and modified by silane compounds with fluorinated and non-fluorinated alkyl groups. In contrast to many earlier investigations regarding sol-gel applications on leather, no acrylic resin is used together with the silica sols when applying on leather. The modified silica particles are supposed to aggregate after application, forming thus a modified silica coating on the leather substrate. Scanning electron microscopy investigation shows that the applied silica coatings do not fill up or close the pores of the leather substrate. However, even if the pores of the leather are not sealed by this sol-gel coating, an improvement of the water repellent and oil repellent properties of the leather substrates are observed. These improved properties of leather by application of modified silica sols can provide the opportunity to develop sol-gel products for leather materials present in daily life [ABSTRACT FROM AUTHOR]

Abstract: Superhydrophobic sol–gel nanocomposite coatings with improved oleophobic property were obtained by incorporation of a perfluoroalkylmethacrylic copolymer in a hybrid sol–gel matrix containing fumed silica nanoparticles. The coatings exhibited a water contact angle (WCA) of 158° and contact angle of 146° for ethylene glycol and 113° for lubricant oil. Though the sol–gel nanocomposite coatings in the absence of fluoropolymer were superhydrophobic with WCA of 155°, they were oleophilic with oil contact angle of <10°. The enhanced oleophobicity can be attributed to the further lowering of surface energy by the presence of fluoropolymer. FESEM images of the coating showed a highly porous structure with random distribution of aggregates of silica nanospheres. The coatings were characterized using FTIR, EDX and XPS. These studies indicated adsorption of fluoropolymer on the coating surface. The method is simple and cost-effective and can be used for preparing multifunctional water- and oil-repellent self-cleaning coatings on large areas of different kinds of substrates like glass, metal and composites. [Copyright &y& Elsevier]

Abstract: This work explores the use of templated silica films as scaffolds for encapsulating surface-segregating functional organic moieties as a mesoscopically dispersed phase with the goal of imparting sustained functionality. Block copolymer surfactant templated hydrophobic–oleophobic fluorinated silica films were synthesized via sol–gel co-condensation and coated on glass substrates. Fluorosilane and surfactant template concentrations were varied, and coating surface properties measured before and after abrasion of the top surface. Surface physical and chemical properties were investigated using XPS and contact angle measurements. Nitrogen adsorption porosimetry and TEM were used to examine the effect of templating and fluorosilane encapsulation on the surrounding silica framework. The results show that surfactant template concentration may be used to tune the dispersion of the fluorosilane-rich phase within the silica film in order to allow exposed surfaces to maintain much of the original functionality of the pristine top surface. [Copyright &y& Elsevier]

A series of hyperbranched poly (urea-urethane) s (HPUs) containing short fluoroalkyl chain and reactive groups (HPUFs) capable as hydrophobic and oleophobic coating materials were synthesized. The obtained polymers were characterized by FTIR (fouier transform-infrared spectroscopy ), ¹ H NMR (nuclear magnetic resonance), 13C NMR, 19F NMR, GPC(gel permeation chromatography), TGA ( thermogravimetric analyzer ), and XPS (X-ray photoelectron spectroscopy) analyses. Highly hydrophobic and oleophobic cotton fabrics could be achieved from these fluorinated hyperbranched polymers by solution-immersion coating method. The static contact angles reached to 143°, 114°, and 92° for water, hexadecane, and decane, respectively. The water and oil repellency ratings were 90 and 6, respectively, and still kept 80 and 5, respectively, after 10 soaping cycles at 50 °C. [ABSTRACT FROM AUTHOR]