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[Display omitted] • Hydrophobic coating with dew suppression shows 50 ± 13 % reduction in soiling loss. • Hydrophobic coating without dew suppression shows 31 ± 15 % reduction in soiling loss. • Coating decreases the deposition of 10 to 30 μm particles by 60.0 ± 8.1% (mass) • Multiple dew events cause more milli-scale non-uniformity on the glass. The deposition of particulate matter (PM) on PV surfaces reduces energy generation, which results in huge losses to the PV industry. Hydrophobic coatings are known to reduce PM deposition on PV surfaces. Covering panels during the night is expected to reduce the PM deposition as well as suppress the dew formation on the surface. The objective of the present study is to compare the soiling on the hydrophobic coating with and without dew suppression. Uncoated and hydrophobic coated slides were kept for PM deposition in a 70-day field study. The dew formation was suppressed on some of the uncoated and coated slides by covering them from sunset to sunrise. The results show that the % reduction in soiling of coated slides under dew suppression is higher (50 ± 13%) compared to the coated slides without dew suppression (31 ± 15%) (statistically different; two-tailed p-value < 0.05). In addition, the particle size analysis using optical microscopy shows that the hydrophobic coating (under dew suppression) reduces the particles deposition by 60.0 ± 8.1% (mainly 10 to 30 μm range) compared to the uncoated slides (under dew suppression) over the entire sampling period. However, the dust potency (soiling loss per unit deposited mass loading) for uncoated and coated samples is found to be statistically similar (5 to 6 % g−1 m2; two-tailed p-values > 0.05). Overall, the present study advances the understanding of the impact of dew on hydrophobic coating, thereby adding to the existing knowledge of soiling mitigation approaches for solar PV industries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic surface treated HKUST-1 (HHK-x) is manufactured. • High stability in continuous exposure to moisture containing air condition. • Sacrificial hydrolysis reaction of hydrophobic layer protects the structure. • Water sorption resistance is enhanced by 50.2 % compared to pristine HKUST-1. Imparting water resistance is important for structures which is vulnerable to moisture to maintain the performance. In this study, octadecyltrimethoxysilane (ODTMS), which forms a hydrophobic surface through polymerization on the surface of the material, was used to enhance the hydrophobicity of HKUST-1 (HHK-x). This self-assembled structure reacts as sacrificial barrier to continuously penetrating H 2 O molecules and this effect is evaluated with detection of O–H peak (3323 cm−1) in FT-IR spectra. The gas adsorption performance is conducted with CO 2 gas and the adsorption amount was reduced by 20 % (from 5.77 to 4.62 mmol/g at 25 °C, 1 bar) compared with the pristine HKUST-1 following the trend of specific surface area. However, water adsorption amount was reduced by 50.2 %, which is 2.5 times higher than the decrease in CO 2 adsorption capacity. In addition, when the N 2 adsorption and cycle adsorption performances were compared after exposing the sample to air for five days, it was confirmed that HHK-40 maintained its microporous structure and stable performance. The manufactured materials exhibited higher durability in a cyclic vapor sorption test depending on the loading amount of ODTMS and exhibits different tendency depending on the rate of humidity. These results experimentally indicate that accessible self-assembly process of ODTMS on water-vulnerable materials to be sustainable and stable in humid air conditions. [ABSTRACT FROM AUTHOR]

The development of hydrophobic surfaces is an important factor for clean energy production from solar arrays, enabling their operation at the highest possible efficiencies for the longest possible time, without the need for physical intervention. This work reports the development of hydrophobic Y 2 O 3 thin films on a range of transparent glass substrates. The growth of the Y 2 O 3 films from the mono-hydrate yttrium (III) complex of 1,3-diphenyl-1,3-propanedione [Y(dbm) 3 (H 2 O)] is studied using the aerosol-assisted chemical vapor deposition (AACVD) technique. The qualitative evaluation of the deposited films and their hydrophobicity is assessed using several materials characterization techniques, such as scanning electron microscopy, grazing incident X-ray diffraction, Fourier-transform infrared, X-Ray photoelectron spectroscopy, in addition to a surface free energy and water contact angle measurements. This work demonstrates experimentally a relationship between the Y 2 O 3 wettability and its physico-chemical characteristics in terms of surface energy, chemical composition, and morphology which is controlled by the type of glass support used. The water contact angle of the hydrophobic Y 2 O 3 coating grown on the F-doped tin oxide glass reached 128°; currently the first deposited on transparent glass. This film exhibits the highest WCA reported up to date without the need for performing post-reaction surface treatment processes. The hydrophobic nature of the transparent Y 2 O 3 films marks a significant leap forward in the field of anti-soiling coatings suitable for photovoltaic technology. [Display omitted] • New AACVD protocol for synthesis of hydrophobic Y 2 O 3 coating was developed. • The Y 2 O 3 films grown on the glass substrates were hydrophobic and exhibited WCAs of 128, 120 and 104°. • Strong substrate growth control in the AACVD process of the Y 2 O 3 was demonstrated. • Clear relationship between the Y 2 O 3 wettability, its surface chemical composition and physico-chemical properties is provided. [ABSTRACT FROM AUTHOR]

Currently, an increasing number of studies focus on the applications of hydrophobic surfaces for underwater drag reduction. However, the drag reduction mechanisms of hydrophobic coatings with controllable wettability still lack systematic understanding. Herein, nano-SiO 2 composite coatings with different contact angles were fabricated using air spraying techniques. The relationship between the hydrophobicity of these coatings and their drag reduction performance under different Reynolds numbers was further investigated. The results showed that the uniformed distributed air layer and low depinning force significantly contributed to drag reduction performance. The coating with a contact angle of 140° achieved a maximum reduction rate of 58 % at a Reynolds number of 750. However, the coatings with contact angles of 150° and 155° exhibited diminished drag reduction effects due to the uneven distribution of the air film. This study highlighted that the hydrophobicity of the coatings and the uniform microstructures are essential for sustaining effective drag reduction performance. • Different hydrophobic coatings were used for drag reduction experiments. • The surface of the hydrophobic coating exhibited a low depinning force. • Highly hydrophobic coating exhibited the best drag reduction performance. • The impact of air film distribution on drag reduction was clarified. [ABSTRACT FROM AUTHOR]

A series of polymethylhydrosiloxane modifying acrylic resins (PSi-AR resins) have been designed and synthesized. Their properties have been studied by varying the relative content of the two components. Firstly, polymethylhydrosiloxane (PHMS) was modified with divinylbenzene (DVB) via electrophilic addition to endow it with the reactive functional groups. Then the modified PHMS (D-PHMS) was blended with acrylic monomers, initiator, and the mixed solvent, and the PSi-AR resins were obtained via solution polymerization. The structure and the thermodynamic properties of the resins, and the interface character, mechanical and anticorrosion properties of the corresponding coatings were studied systematically. In particular, the self-stratification properties of the PSi-AR resins have been studied in detail. Since the D-PHMS component tended to float on the top layer of the coating, the surface of the coating showed hydrophobic properties, with which the contact angle of the coatings was >100° and increased with the content of D-PHMS. With excellent mechanical and anticorrosion properties, the coatings demonstrate excellent performance, which can be potentially employed in paints for metal corrosion protection. • Knitting a polymer with carbon bonds to synthesize a self-stratification resin, stable in a wide pH range. • The cured self-stratifying coatings exhibit hydrophobicity, heat resistance, and corrosion resistance. • The characteristic of low surface tension endows the coating with excellent anti-fouling properties. [ABSTRACT FROM AUTHOR]

Biobased packaging materials derived from carbon-neutral feedstocks are sustainable alternatives to conventional fossil-based polymers. In this study, a method was developed to prepare paper-sheets derived from Miscanthus × giganteus cellulose fibers for potential food contact applications. The papers were hydrophobized with modified lignin from Miscanthus × giganteus biomass and commercial Kraft alkali lignin through hydroxyethylation with ethylene carbonate, followed by esterification with propionic acid. The esterified lignin (10 % w /w) and cellulose acetate (5 % w/w, based on lignin content) were dissolved in acetone and applied as a coating on the miscanthus paper sheets. The esterified lignins were characterized using FTIR, NMR, DSC, TGA, and elemental analyses. The uncoated and coated paper-sheets had contact angle values 52.4° and >130°, respectively, indicating an increased surface hydrophobicity of the coated paper samples. The water vapor transmission rate decreased significantly from 213.7 (uncoated paper-sheet) to 63.3 g/m2.d (coated paper-sheet). The tensile strength of the coated paper (64.6 MPa) was higher than the uncoated counterpart (57.1 MPa). Results from this study suggest that the esterified lignin coated miscanthus paper is a promising hydrophobic food packaging material alternative to conventional fossil-based thermoplastics. [Display omitted] • Lignin from miscanthus biomass was hydroxyethylated followed by esterification. • Extracted cellulose fibers from miscanthus were used to fabricate paper-sheet. • Esterified lignin-cellulose acetate coating was applied on the paper-sheet. • Coated paper-sheet exhibited an excellent hydrophobicity (contact angle ˃134°). • Coating significantly increased tensile strength and moisture barrier of the paper-sheet. [ABSTRACT FROM AUTHOR]

Rare earth oxides (REOs) and metals as an important class of materials have generated global interest in modern technology. Here, eight REOs (R 2 O 3 , R = Yb, Er, Sm, Eu, Y, Gd, Dy, and Ce) are identified those are mostly used in diverse chemical and industrial sectors. In this concise review the applications of these REOs in corrosion protection, thermal barrier coating, hydrophobic coating, catalytic reactions, refrigeration, photoactivity, environmental, and tribological sector are briefly summarized, which are sparsely documented in the existing literature review. In what follows, recently published relevant literature is systematically evaluated and key insights are addressed. The use of REOs as nonstoichiometric compounds or as doping agents to enhance the system performance of specific applications is commendable. Related lab-scale studies, therefore, will invoke the potential exploitation of individual or blended REOs for large-scale commercialization. However, phase transformation and high energy consumption in the thermal coating, multi-step fabrication of hydrophobic coating, the building of aromatic pollutants in catalysis, magnetic entropy shift in refrigeration, and photo corrosion are some of the inherent hindrances of these oxides. These issues warrant prompt actions from the scientific community to deliver cost-effective, efficient, and environmentally sustainable applications. Regardless, this review is expected to provide critical insights into REOs for contrasting industrial applications and encourage interested researchers to dig deeper in finding the best strategic solutions to counter prevalent challenges. [Display omitted] • Catalysis: REOs enhanced photocatalytic dye degradation activity. • Tribological: REOs enhance wear properties of hybrid composites. • Coating: REOs are potential for thermal barrier & corrosion-resistance coating. • Sustainability: REOs' contribution to recycling materials and water treatment. • Prospect: REOs possess great potential in eco-friendly applications. [ABSTRACT FROM AUTHOR]

Slippery liquid-infused porous surfaces (SLIPSs) based on polymer matrices impregnated with liquid lubricants are multifunctional and provide a wide range of useful properties such as low adhesion of water and other liquids, selectivity, high corrosion resistance, etc. However, these properties vanish quickly due to the gradual depletion of lubricant from the matrix. This issue could be resolved by attaching lubricant molecules to the matrix as flexible, liquid-like sidechains. In the present work, thin silicone films with grafted sidechains are fabricated. The uniform coatings are obtained in "eco-friendly" pressurized (subcritical) CO 2 on smooth silicon wafers as well as on rough porous substrates such as carbon aerogels. The possibility of applying films by the traditional dip-coating method is also demonstrated on titanium slides. The coatings demonstrate low sliding angles for water and water/alcohol solution droplets. Coated aerogels preserve high porosity. It is demonstrated that initially hydrophilic aerogels become highly hydrophobic after coating and selectively absorb oil from water/oil mixtures. The tests of obtained coatings on titanium substrates demonstrate a significant increase in corrosion resistance. The proposed technique has a wide range of potential applications where such slippery coatings should be applied on complex rough substrates: from filtration materials production to textile finishing. [Display omitted] • Novel thin silicone film coatings with grafted sidechains are synthesized. • A one-step deposition from "eco-friendly" pressurized CO 2 solutions on smooth and rough porous substrates is proposed. • The non-monotonic dependence of slippery properties on sidechains amount is observed. • Coated aerogels have high porosity and can be used for selective oil/water separation. • Coated titanium electrodes exhibit increased corrosion potential and 1.5 orders of magnitude decreased corrosion current. [ABSTRACT FROM AUTHOR]

A highly hydrophobic and self-recoverable sponge was prepared with cellulose nanofibrils (CNFs), N-alkylated chitosan (NCS), and poly (vinyl alcohol) (PVA), which was then endowed with hydrophobic properties via simple thermal chemical vapor deposition (CVD). The three-dimensional (3D) interconnected microstructure of the prepared CNF/NCS/PVA sponge was found to have 96% porosity, ultra-low density (16.61–50.91 mg/cm3) and high hydrophobicity (water contact angle of 147°), which can absorb various organic solvents with an absorption capacity of 19.05–51.08 times of its original weight. Besides, the sponge could bear 80% strain and be cyclically compressed 50 times under the strain of 50%. The sponge can effectively separate oil/water mixtures and water-in-oil emulsions with high separation efficiency and fluxes. Moreover, the sponge could keep its good stability in various acidic, saline and mechanical abrasion conditions. The green preparation and good separation efficiency suggest a potential application of recyclable and versatile CNF/NCS/PVA sponges in oil/water separation. [Display omitted] • The hydrophobic and self-recoverable sponge based on polysaccharides was prepared via a green way. • The sponge could withstand a good recoverable deformation under the strain of 80%. • The sponge possessed good stability under harsh conditions. • The sponge exhibited excellent selective and versatile oil/water separation. [ABSTRACT FROM AUTHOR]

A range of bio-based, biodegradable, and edible straw options have emerged as eco-friendly alternatives to combat plastic straw pollution. These innovative solutions utilize materials such as polysaccharides (e.g., starch, cellulose, and seaweed) and polylactic acid (PLA). Despite their positive environmental impact, these alternatives face challenges and limitations compared to traditional, durable plastic straws. Consequently, extensive research is underway to bolster their performance and refine manufacturing technology. This comprehensive review delves into recent strides in bio-based biodegradable straw development. It covers the spectrum from raw materials to manufacturing methods, including rolling-up, screw extrusion, directional diffusion assembly, and drill method. The exploration extends to targeted enhancement techniques, such as the creation of fiber composites and the development of hydrophobic coatings or surfaces. Additionally, a detailed discussion on the challenges faced by biodegradable straws, touching on nanotoxicity, raw material sourcing, cost, and degradation efficiency, adds depth to the analysis. While existing processing methods cater to the preparation of biomass straws, a pressing concern is the lack of comprehensive and standardized evaluation criteria for biodegradability/composability. This gap contributes to confusion in assessing these alternatives. Addressing this issue emerges as a crucial step forward. This review emphasizes that breakthroughs in cutting-edge technologies will heighten the market competitiveness of various biodegradable straw types. The conclusive insights and perspectives offer the aim to steer the design and fabrication of eco-friendly food tableware and packaging. [Display omitted] • Progress in degradable straw: from raw materials to preparation/reinforcement methods. • Challenges from material sources, technology, cost, and degradation of straws. • Future straw development trends linked to performance and environmental/human impact. [ABSTRACT FROM AUTHOR]

This study first self-made TMP-IPDI tetramer, and then prepared a fluorine-modified silicon dioxide double shell isocyanate type self-healing microcapsule (CBS-X/TMP-IPDI@PU@F-SiO 2) using TMP-IPDI tetramer, fluorescent agent 4,4-bis (2-disulfonic acid sodium styrene) biphenyl (CBS-X) as the core material, polyurethane (PU) as the single shell, and fluorine modified silicon dioxide (F-SiO 2) as the double shell using interfacial polymerisation method. Then, it was added to waterborne polyurethane (WPU) to prepare self-healing coatings and coatings. The chemical structure, microstructure, self-healing self detection, and mechanical properties of TMP-IPDI, CBS-X/TMP-IPDI@PU@F-SiO 2 , and composite coatings were characterized by infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), scanning electron microscopy (SEM), particle size analysis (PSA), X-ray electron spectroscopy (XPS) analysis, contact angle testing, tensile testing, electrochemical impedance testing, and Ultraviolet photograph. The results showed that the TMP-IPDI tetramer was successfully prepared. The average particle size of CBS-X/TMP-IPDI@PU@F-SiO 2 prepared is 29 μm. The contact angle, tensile strength, low-frequency impedance and Nyquist curve radius of the repaired spots increased with the increase of the amount of CBS-X/TMP-IPDI@PU@F-SiO 2 in WPUs; the increasing trend slowed down when the amount of CBS-X/TMP-IPDI@PU@F-SiO 2 was >5 %. When the CBS-X/TMP-IPDI@PU@F-SiO 2 dosage is 5 %, the WPU coating has good self-repair and self-detection performance. The stress before and after repair were 12.89 MPa and 20.11 MPa, respectively, with a repair rate of 80.3 %. The contact angle at the repair site can reach 100.8°, and the coating has good corrosion resistance. The microcapsules prepared based on fluorine-modified silica (F-SiO 2) as the wall material have good self-healing performance for WPU coatings, achieving secondary protection of the repaired material. • Preparation of trifunctional isocyanate-based microcapsule cores to improve the self-healing efficiency of microcapsules. • Double-shell microcapsules were prepared from SiO 2 produced by hydrolysis of ethyl orthosilicate using sol-gel method. • Modification of SiO 2 with tridecafluorooctyl trimethoxy silane to enhance the densification of microcapsules. • The incorporation of double-shell microcapsules renders the coating self-repairing and self-detecting. [ABSTRACT FROM AUTHOR]

• The MS sample surface was treated by a novel thin-film based on europium (Eu) oxide. • Using STA molecules, a hydrophobic layer was constructed on the Eu treated sample. • Tafel curves evidenced the i corr reduction to 0.71 μA.cm−2 after 48 h steel subjection. • Theoretical results ensured the Eu 2 O 3 /stearic acid adsorption on the metallic surface. Metal's corrosion is an important parameter affecting the steel lifetime. Nowadays, because of the widespread industrial applications of mild steel, the corrosion protection of this material has become a challenging item. The modification of the metal surface (i.e., mild steel, MS) via thin hydrophobic layers is one of the most efficient/promising protocols for the improvement of the metal's anti-corrosion properties. In this work, the MS sample surface was treated by a novel thin-film based on the europium (Eu) oxide. Using stearic acid (STA) and palmitic acid (PAA) molecules, a hydrophobic layer was constructed on the Eu-treated sample. The EDS and GIXRD tests were utilized for the analysis of the elemental/phase compositions of the treated and untreated samples. The FE-SEM and AFM tests were used for studying the surface morphology and topography of the treated and untreated samples. The corrosion protection durability of the coated metals was checked via electrochemical approaches, i.e., EIS and potentiodynamic polarization. The EDS/Mapping analysis demonstrated that the europium conversion coating (EuCC) was successfully deposited on the MS surface. Besides, a high concentration of the Eu-containing compounds in the GIXRD patterns proved the sufficient Eu-based conversion coating formation on the sample. The contact angle (CA) measurements displayed that after surface modification with the hydrophobic layer, the CA was drastically improved by about 40%. The FE-SEM micrographs ensured the precipitation of a uniform protective layer without obvious cracks on the MS surface. The Tafel curves illustrated that the EuCC-STA could diminish the steel corrosion by mixed anodic and cathodic inhibition mechanisms. The EIS reports evidence that the existence of the EuCC-STA hydrophobic film could diminish about 66% of corrosion activities during 24 h of iron exposure to the harsh 3.5% chloride media. [ABSTRACT FROM AUTHOR]

In the present work, G-TiO 2 and G-ODA-TiO 2 hybrids were prepared by concurrent surface functionalization and reducing of graphene oxide (GO) using octadecylamine (ODA). The G-TiO 2 and G-ODA-TiO 2 powders were deposited on the copper surface by electrophoretic deposition (EPD) technique. The wettability of coatings revealed the preferable hydrophobic characteristic of G-ODA-TiO 2 compared to G-TiO 2 and bare copper with water contact angles of 130°, 101°, and 87°, respectively. The anti-corrosion performance of specimens in a 0.5 M H 2 SO 4 solution was appraised by the potentiodynamic polarization (Tafel analysis), which clearly showed that G-TiO 2 and G-ODA-TiO 2 coatings can act as a great barrier for copper in the corrosive H 2 SO 4 solution. The corrosion inhibition of G-TiO 2 and G-ODA-TiO 2 was about 2 and 15 times higher than bare copper. Moreover, the hydrophobic G-ODA-TiO 2 coating on copper reached a much lower interfacial contact resistance (ICR) than the other samples. • G-TiO 2 and G-ODA-TiO 2 composite powders are hydrothermally synthesized. • The G-TiO 2 and G-ODA-TiO 2 powders are used for coating on Cu surface by EPD. • G-ODA-TiO 2 film has superior hydrophobic properties compared to G-TiO 2 and bare Cu. • Corrosion inhibition of G-ODA-TiO 2 film is 15 times higher than that of bare Cu. • ICR of G-ODA-TiO 2 coated copper has reached the lowest interfacial contact resistance. [ABSTRACT FROM AUTHOR]

• Hydrophobic anti-icing emulsified asphalt was prepared. • The effect of hydrophobic agent roughness, dosage and incorporation method on hydrophobic effect was analyzed. • Anti-icing and anti-skidding properties of hydrophobic coating were tested. • An indoor simulated anti-icing test was designed and the evaluation criteria for anti-icing performance were proposed. • The adhesion and durability between hydrophobic coating and asphalt pavement were improved by interfacial agent. Icing on asphalt pavement may lead to potential hazards for driving safety. To reduce the security risk, this paper aims at preparing a hydrophobic emulsified asphalt coating on asphalt pavement by adding a hydrophobic agent (HPA, Polytetrafluoroethylene powder) to emulsified asphalt. Considering the factors influencing hydrophobic effect, such as roughness of hydrophobic agent, dosage and incorporation method, the ice-repellency of hydrophobic emulsified asphalt coating was characterized by means of contact angle. It was found the hydrophobic properties of emulsified asphalt were significantly affected by roughness, dosage and incorporation methods of HPA and the highest contact angle was 94.3° when the HPA with 1250 meshes and dosage of 15% was added by the external addition method. Through the interlayer shear test and the indoor anti-icing test, hydrophobic asphalt pavement could reduce the bond strength between pavement and ice so that the ice layer could be easily broken and cleared, and the bond strength could be reduced by about 40% at 0.3 kg/m2 dosage of hydrophobic emulsified asphalt. It was proved that the skid resistance performance of the hydrophobic emulsified asphalt coating could conform to the requirements of the specification. The addition of interfacial agent can significantly improve the adhesion between emulsified asphalt and aggregates. These findings demonstrated the potential of using hydrophobic emulsified asphalt coating on highways in adverse weather to provide better anti-icing performance and contribute to traffic safety in winter. [ABSTRACT FROM AUTHOR]

Highlights • The dynamic icing process on the rotating spinner with hydrophobic coating is experimentally investigated. • The ice accretion on rotating surface is analyzed based on the droplet impingement, heat and mass transfer, and force. • The effects of the airflow temperature and rotating speed on the ice accretion on rotating spinner are studied. • The freezing delay and icephobicity on the hydrophobic coating on rotating spinner are evaluated. Abstract Ice accretion on aero-engine inlets is a serious threat to the inflight safety. As an important part of the engine inlet components, the rotating spinner has special icing phenomena compared with the stationary ones. An experimental study is conducted to investigate the ice accretion on a rotating aero-engine spinner in the icing wind tunnel. A full-scale engine spinner model is used in the experiments operated under different conditions. The hydrophobic nanoparticle-polymer composite coating is applied to cover on the aluminum-based spinner and then to examine its anti-icing performance. The dynamic icing processes and the final ice shapes on the rotating spinner surface are captured. The experimental results reveal that the ice growth and ice shape are basically determined by the airflow temperature and slightly affected by the rotating speed when the airflow velocity and icing cloud parameters are constant. The ice fracture and shedding are greatly dependent on the rotating speed when the icicle length is large enough. The freezing delay on the hydrophobic coating is inconspicuous and there is even no effect on the ice growth. However, the ice shedding on the coating happens, especially in the mixed icing condition with a higher rotating speed, demonstrating its icephobicity. Meanwhile, the dynamic icing processes and the effects of the airflow velocity and rotating speed on the ice growth are analyzed based on the mechanism of the supercooled droplet impingement characteristics, heat and mass transfer, force analysis on the rotating surface. The surface wettability is introduced to evaluate the freezing delay and icephobicity on the hydrophobic coating. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Hydrophobic PE-coated cotton (PE-CC) was fabricated by using recycled waste material (PE gloves). • The PE-CC exhibits hydrophobicity (WCA <144°) and superoleophilicity (OCA = 0°). • The PE-CC exhibited high absorption selectivity for oils and solvents. • The PE-CC shows excellent oil/water separation efficiency and recyclability. Abstract In this study, we report the fabrication of hydrophobic cotton fibers via simple and cost-effective one step easy fabrication approach by utilizing waste recycled polyethylene (PE) gloves. Also, we prepared silres-modified cotton fibers with hydrophobic and oleophilic properties via a simple dip coating process. The resultant both coated cotton (PE and silres) fibers exhibited high repellency towards the water with water contact angle < 135° and superoleophilicity with an oil contact angle ˜ 0°. Due to such special wettability, the as-prepared cotton fibers exhibited high selective oil absorption capacity when used as absorptive materials for separating various oil/water mixtures under acidic, alkaline, and salt aqueous solutions. It was observed that oil/organic solvents absorption capacity of the PE coated cotton fibers was better (16.8–59.7 %, depending on the type of oil) than that of silres modifications. The fabricated PE fiber shows oils and organic solvents absorption ability in the range of 22–61 times their weight as well as good reusability in oil/water separation even after ten absorption-desorption repeated cycles by simple squeezing method. Thus, the utilization of PE waste materials provides an extremely low cost and better approach in the fabrication of promising surfaces for oil/water separation applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Dental caries, i.e., tooth decay mediated by bacterial activity, is the most widespread chronic disease worldwide. Carious lesions are commonly treated using dental resin composite restorations. However, resin composite restorations are prone to recurrent caries, i.e., reinfection of the surrounding dental hard tissues. Recurrent caries is mainly a consequence of waterborne and/or biofilm-mediated degradation of the tooth-restoration interface through hydrolytic, acidic and/or enzymatic challenges. Here we use amphipathic antimicrobial peptides to directly coat dentin to provide resin composite restorations with a 2-tier protective system, simultaneously exploiting the physicochemical and biological properties of these peptides. Our peptide coatings modulate dentin's hydrophobicity, impermeabilize it, and are active against multispecies biofilms derived from caries-active individuals. Therefore, the coatings hinder water penetration along the otherwise vulnerable dentin/restoration interface, even after in vitro aging, and increase its resistance against degradation by water, acids, and saliva. Moreover, they do not weaken the resin composite restorations mechanically. The peptide-coated highly-hydrophobic dentin is expected to notably improve the service life of resin composite restorations and to enable the development of entirely hydrophobic restorative systems. The peptide coatings were also antimicrobial and thus, they provide a second tier of protection preventing re-infection of tissues in contact with restorations. Statement of Significance We present a technology using designer peptides to treat the most prevalent chronic disease worldwide; dental caries. Specifically, we used antimicrobial amphipathic peptides to coat dentin with the goal of increasing the service life of the restorative materials used to treat dental caries, which is nowadays 5 years on average. Water and waterborne agents (enzymes, acids) degrade restorative materials and enable re-infection at the dentin/restoration interface. Our peptide coatings will hinder degradation of the restoration as they produced highly hydrophobic and antimicrobial dentin/material interfaces. We anticipate a high technological and economic impact of our technology as it can notably reduce the lifelong dental bill of patients worldwide. Our findings can enable the development of restorations with all-hydrophobic and so, more protective components. [ABSTRACT FROM AUTHOR]

Abstract Anode flooding is one of the critical issues in developing a proton exchange membrane (PEM)-based electrochemical hydrogen pump. Improving the hydrophobicity of the gas diffusion layer (GDL) has been studied as an approach to mitigating anode flooding in electrochemical pumps. A mixture of Nafion™ and oxidized carbon nanotubes (O-CNT) has been applied to the porous gas diffusion medium in the hydrogen pump cell. The coating renders the GDL hydrophobic with an effective contact angle of 130°. Electrochemical pump testing has shown that, with the help of the coating, the flood-recovery performance of the hydrogen pump was greatly improved. A hydrogen pump cell with an uncoated GDL was not able to recover from a flooded state, while a hydrogen pump cell with a coated GDL was able to recover its performance in about 100 s. Highlights • Anode flooding is a critical issue in low-temperature electrochemical hydrogen pumps based on proton exchange membranes. • Coating the gas diffusion medium with a mixture of Nafion and oxidized carbon nanotubes (O-CNT) renders it highly hydrophobic. • The Nafion/O-CNT coating effectively eliminated anode flooding. [ABSTRACT FROM AUTHOR]

Abstract AZ31 magnesium alloy is a promising implant metallic material for the process of healing hard tissue in the human body. However, it is susceptible to degradation when exposed to physiological fluid. To address this issue, we modified the surface of AZ31 to enhance its degradation resistance and corrosion resistance. The surface modification involved hydrothermal treatment, immersion into oleic acid, and subsequent heat treatment. When the alloy experienced hydrothermal treatment and immersion into oleic acid, it showed Mg(OH) 2 phase and slight hydrophobicity. There were both Mg(OH) 2 and MgO in the alloy experienced only hydrothermal treatment and in the alloy experienced hydrothermal treatment + immersion into oleic acid + subsequent heat treatment. The surface modification process significantly enhanced both degradation resistance and corrosion resistance of the AZ31 magnesium alloy. Highlights • Modified AZ31 surface drastically increases its degradation resistance. • Subsequent heat treatment further improves the corrosion resistance. • Coating produced by in-situ conversion has strong adhesion to the substrate. [ABSTRACT FROM AUTHOR]

Abstract Hydrolyzed fluorinated alkyl silane (FAS) containing well-dispersed fluorinated-decyl polyhedral oligomeric silsesquioxane (FD-POSS) was used to form a thin coating layer on AA6061 alloy. Its performance was evaluated by the electrochemical measurements and surface analysis technology. The FD-POSS/FAS film shifted the corrosion potential (E corr) of AA6061 alloy to a positive value, and suppressed significantly the anodic and cathodic corrosion reactions. Corrosion current density was decreased by one order of magnitude after FD-POSS/FAS coating treatment. The coating was hydrophobic with a water contact angle of 130°. It was highly transparent and had excellent stability and reasonable adhesion with AA6061. The coating also showed a remarkable self-healing ability to auto-repair from both chemical and physical damages. This self-healing FD-POSS/FAS coating may provide an effective protection toward aluminum alloys for power transmission applications. Highlights • Hydrolysis of fluorinated alkyl silane to form a protective coating on aluminum alloy surface. • The coating shows self-healing activity. • The stable coating exhibits hydrophobic behavior. [ABSTRACT FROM AUTHOR]

Abstract Non-thermal plasma is getting more popular in industrial applications, mainly treatment of material surfaces. Hydrophobic coatings often suffer mechanical instability and do not function well after abrasion/scratching. In this study, non-thermal plasma jet generated at atmospheric pressure in ambient condition was applied to the hydrophobic treatment of glass surface using two precursors. Tetramethylsilane (TMS) was used to promote hydrophobicity and (3-Aminopropyl)triethoxysilane (APTES) was used to get durable mechanical strength of the coating although it is hydrophilic in character. An alternating current (AC) high voltage (operating frequency: 11.5 kHz) was used to generate plasma jet for producing a coating layer onto the soda-lime glass sample. Water contact angle of 139° and a stable mechanical strength were achieved at an optimal TMS/APTES ratio of 4.8. The coating thickness, strength and water contact angle were varied by changing treatment time, applied voltage, and carrier gas (argon) flow rate. The coating layer were characterized by atomic-force microscopy (AFM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), water contact angle (WCA), scratch test and UV/visible spectroscopy. Highlights • Robust coating on the glass by APPJ conjugated with two precursors • Coating strength depended on the flow rate, voltage, time and TMS/APTES ratio. • The coating exhibited good durability, mechanical strength and thermal stability. [ABSTRACT FROM AUTHOR]

Traditional electrically conductive coatings applied to the field of connectors would cause electrical signal crosstalk or even short circuits due to their excellent electrical conductivity. Meanwhile, the traditional waterproof coatings were difficult to achieve excellent electrical conductivity due to their high contact resistance. Therefore, there was a long-standing contradiction between electrical conductivity and waterproofing in the field of connectors. Based on the conductive effect of electronic tunnel, a new design concept of electrically conductive and waterproof coating was proposed. An ultra-thin and highly cross-linked hydrophobic coating was manufactured onto a dense electrically conductive coating so as to create a bifunctional coating. Simultaneously, the hydrophobic coating was thin enough so that it did not destroy the conductive response of electronic tunnel. Concretely, the electrically conductive coating (polyaniline) was in-situ polymerized on the substrate by plasma initiation, and then another ultra-thin hydrophobic coating (polysiloxane) was also polymerized onto the initial conductive coating by a similar method. The contact conductivity of the bifunctional coating was up to 2.08 × 107S/m. The plasma firstly initiated the dissociation of reactive monomers, and then polymerization. Consequently, these two monomers with different polarity (aniline and hexamethyldisiloxane) can sequentially polymerize to form a dense coating. Importantly, the interface between the conductive coating and hydrophobic coating were connected by chemical bond without delamination failure. Interestingly, the surface of the bifunctional coating exhibited a protrusion like structure of cedar leaves, resulting in the water contact angle to reach 133.3°. This work provided clear guidance and a strong impetus for the development of contact electrical conductivity and waterproofness for the connector field. • An ultra-thin and highly cross-linked hydrophobic coating was manufactured. • The bifunctional coating had a protrusion structure of cedar leaves-like. • The bifunctional coating can perfectly protect the Cu-substrates in a 30-day corrosion test. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preferentially 5–20 µm particles dominate mass loading on hydrophobic coated glass. • Particles between 15 and 25 µm dominate mass loading on uncoated glass. • Fine fraction (3–10 µm) contributes to ∼50 % of total soiling loss for coated glass. • For uncoated glass, fine fraction only contributes to ∼27 % of total soiling loss. • No significant difference in the mineralogy of the dust samples in ∼210 km2 area. Hydrophobic-coated glass (CS) on PV surfaces is known to reduce particulate matter (PM) accumulation. However, there is no comparative study on the % reduction in soiling loss (% RSL) on CS with respect to uncoated glass (UCS) for clean and polluted environments (higher atmospheric PM). The present field study (∼210 km2 in Gujarat, Western India) focuses on the evaluation of particle-size distribution of PM on CS and UCS, quantification of size-resolved soiling due to PM accumulation on CS and UCS, and comparison of % RSL of CS in cleaner and polluted environments. The findings show that 3 to 10 µm particles contribute to ∼21 % and ∼12 % of the total mass accumulated on CS and UCS, respectively. The observations are also validated using the theoretical adhesion model and critical rebounding velocity. Moreover, this particle-size fraction contributes to ∼50 % of the total soiling loss for CS against only ∼27 % soiling loss for UCS. Therefore, CS surfaces under polluted environments are expected to have a higher % of finer particle-size fraction in accumulated PM, which contributes significantly to the total soiling loss of CS and reduces the difference in % soiling loss between CS and UCS. Although CS reduces PM accumulation in both clean and polluted regions, the % RSL using CS is comparatively less in a polluted environment. The observations from the present study provide greater insight into the soiling aspect of solar PVs and have significant economic implications in deploying PV surfaces with hydrophobic coated glass. [ABSTRACT FROM AUTHOR]

• The optimal design of RPUF raises its fire safety and mechanical performances. • The bio-nanosheets exhibit remarkable catalytic carbonization capacity on RPUF. • The coatings endow RPUF with excellent fire resistance and char-formation ability. • The coatings show high resistance against hydrolysis. • The coated RPUF nanocomposite possesses superior thermal insulation properties. The adoption of rigid polyurethane foam (RPUF) in construction and rail transit offers energy conservation and emissions reduction benefits, but its inherent flammability presents challenges. Traditional fireproofing methods often disrupt foaming balance, ultimately compromising flame retardancy and mechanical properties. While flame retardant coatings preserve the bulk physical properties of materials, it tends to be sensitive to moisture. In this study, we propose to address the issues by employing a combined approach of nano-reinforcement and surface treatment. The results demonstrate that the addition of 3 wt.% bio-based Phosphorus-Nitrogen-containing nanosheet (HACP-PA) to RPUF increases its yield strength and compressive strength (at 60% strain) by 63% and 86%, respectively. Subsequently, the surface coating comprising of polydopamine-encased ammonium polyphosphate (APP@PDA), polyethyleneimine (PEI) and 1-octadecanethiol-wrapped polydopamine (PDA@ODT) imparts the RPUF nanocomposite with remarkable properties, including an LOI as high as 42.5%, a satisfactory V-0 rating in the UL94 test, 44% reduction in PHRR, 30% reduction in THR, 507% increase in residues, and a water contact angle of 137° More importantly, this method does not affect the excellent thermal insulation properties of the RPUF. In summary, this advancement tackles the challenges associated with RPUF's flammability and provides a bio-based, low-cost, and eco-friendly approach for developing multifunctional flame retardant RPUF with superior comprehensive properties. [ABSTRACT FROM AUTHOR]

To improve the hydrophobicity of polysaccharide-based films, hydrophobic carnauba wax-based particles were prepared by Pickering emulsion. The influence of the different size of the particles on the structure and hydrophobicity of the chitosan coating films were investigated. The results showed that micro-scale particles (average particle size 25.04 μm) with nano-scale (5–10 nm) TiO 2 uniformly distributed on the surface of the particles were formed by Pickering emulsion. The chitosan coating films showed higher contact angle and lower sliding angle compared to the control due to the hierarchical structure, hydrophobicity and arrangement of the particles. In addition, the small particle (23–48 μm) coating film showed higher hydrophobicity than the large particle coating film (48–70 μm) due to the small particle size and the formation of more small gaps. The gaps were conducive to form "air cushion" which reduced the contact area between water and the coating films and thus increased contact angle and decreased sliding angle. The coating films showed high chemical stability and low residual rates of liquid food. The results suggest that Pickering emulsion is an effective method to create wax-based particles with hierarchical structure and the particles have potential to be used as hydrophobic coating materials. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Activated carbon fabric (ACF) is hydrophobically out-coated by urethane reaction. • The hydrophobic out-coated ACF maintains a hierarchical structure and microporosity. • The coating exhibits anti-moisture adsorption and selective CWAs adsorption. • The hydrophobic ACF shows efficient protection performance as CWAs protective suit. Personal protective equipment (PPE) comprising activated carbon fabrics (ACFs) is required to protect an individual against chemical warfare agents (CWAs) used as chemical weapons. ACFs has micropores, high surface area, and oxygen functional groups. The nucleophilic oxygen functional groups assist electrophilic CWAs adsorption by H-bonding and nucleophilic interaction. Due to many oxygen functional groups, ACF exhibit excellent CWAs adsorption performance. However, they are sensitive to moisture and difficult to selectively adsorb because of their characteristics, which limit their practical use and storage. Herein, we report a hydrophobic out-coating method that imparts hydrophobicity to only the ACF surface while maintaining the inherent structure and microporosity. The hydrophobic out-coated ACF (NML-F) is prepared by self-assembling hydrophobic agents on the ACF surface through a selective urethane reaction with the water affinity groups. NML-F is prepared by immersing ACF in a precursor solution. NML-F has a hydrophobic surface without blocking the microporous structure of ACF by controlling the reaction time. The hydrophobic surface of NML-F enables anti-moisture adsorption and selective adsorption. NML-F as PPE shows excellent comfort and effective protection against sulfur mustard (HD) in high humid condition. [ABSTRACT FROM AUTHOR]

This study investigates the wettability of ZnO tetrapod (ZnO-T) coatings in relation to surface morphology and protective diamond-like carbon nanocomposites with SiO x (DLC:SiO x) film parameters. Randomly distributed ZnO-Ts with different leg lengths were observed to have varying degrees of wettability, which also changed keeping samples in the dark at room temperature. DLC:SiO x films significantly increase the hydrophobicity of ZnO-T coatings, and their thickness influences the surface roughness and hydrophobicity of the coating, moreover DLC:SiO x films show protection not only from the abrasion but also passivate the ZnO-T coatings from light-induced effects. The results indicate that the largest size ZnO-T fraction with a 40 nm thickness of DLC:SiO x film can provide the best hydrophobicity represented by a water contact angle of 148°, while the smallest ZnO-T fraction with a 120 nm thickness of DLC:SiO x film can provide better mechanical durability. We expect that the detailed analysis of ZnO-T coatings with protective DLC:SiO x films conducted in this study will be advantageous for other nanostructures with protective coatings application in wettability control. [Display omitted] • ZnO-T coating wettability depends on morphology: shorter legs lead to CA increase. • Even 20 nm DLC:SiO x film passivates the ZnO-T from light-induced effects. • ZnO-T with DLC:SiO x combined has higher hydrophobicity than each of them separately. • Multifunctional coating obtained: transparent, durable, UV protective with CA of 148°. [ABSTRACT FROM AUTHOR]

Porous superhydrophobic materials with high mechanical stability have a significant amount of potential for oil-water separation in practice. In this study, a superhydrophobic material with strong hydrophobic coating adhesion was developed using a polyurethane sponge. The interior and exterior surfaces of the porous polyurethane material were coated using a two-step technique. The sponge was treated with poly (dopamine) to modify its skeleton, allowing the second layer to adhere readily. The second layer of silica applied to the surface of the sponge functions as a superhydrophobic layer. The modified sponge's water contact angle was approximately 156.2° ± 5°, compared to 78° ±2° for the original sponge, demonstrating its superhydrophobic nature. The fabricated sponge is capable of separating and absorbing 43.3–51 times of its initial mass from an oil-water mixture, depending on the type of oil used in the test. Fifteen cycles of oil-water separation were followed by chemical cleaning of the hydrophobic sponge. After undergoing these cycles, the hydrophobic nature and absorption capacity of the produced sponge were preserved. Over a broad pH range, the hydrophobicity of the superhydrophobic sponge was studied, and the results indicated that hydrophobicity was substantially maintained even under harsh pH operating conditions. The water contact angle of the sponge was measured to be 145° ± 1° and 140° ± 1°, respectively, after 12 h of immersion in strong acids and bases. [Display omitted] • A simple immersion method has been used to fabricate highly superhydrophobic PU-PDA-SiO 2 sponges. • The superhydrophobic PU-PDA-SiO 2 sponge efficiently separates oil and water with relatively high separation efficiency. • Superhydrophobic PU-PDA-SiO2 sponges shown excellent absorption capacity and reusability in oil-water separation processes. • A large-scale 3D oil pollution absorbent, the superhydrophobic PU sponge was stable in harsh pH operation conditions. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Graphene and carbon nanotubes introduced superhydrophobicity to naturally hydrophilic wood. • The coating was performed by simple inexpensive and industrially viable methods. • "Rose petal" effect based model was proposed to explain wettability of CNM coated wood. • Water repellant, CNM coating on wood particles may also find applications in wood based composited. Abstract Carbon nanomaterials (CNMs) have recently been used to form superhydrophobic coatings on metals, synthetic polymers or textiles. Here we investigate the possibility of using carbon black (CB), graphene (Gr) and carbon nanotubes (CNTs), as water repellent agents on naturally hydrophilic wood. We show that it is possible to form homogeneous CNM coatings on any type of wood via simple methods of drop casting and dip coating, using CNMs dispersed in organic solvents or water. Contact angle measurements of wood coated with only 0.05 g/m2 CNTs and 0.25 g/m2 Gr gave the results exceeding 130°, indicating apparent hydrophobicity. Yet, high adhesion of the droplets was observed, simultaneously suggesting a "rose petal" type of superhydrophobic behavior. That may be explained by the formation of micro-nano architectures in which low surface energy CNMs deposited on microrough surface of wood cause superhydrophobicity. Yet, due to heterogeneity of wood, some part of hydrophilic surface is still uncovered, resulting in high adhesion of water. Finally, although Gr and CNT were only physically bond to wood surface, the hydrophobic properties of CNM coatings were maintained after sandpaper abrasion test. Moreover, wood fibers and particles covered with Gr showed the decrease of water absorption equal 98% and 87%, respectively. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Prepared ZnO nanoparticles using P. guajava leaf extract by green synthesis. • Comparative assessment of various synthesis parameters prepared ZnO Nps done. • ZnO Nps physico-chemical properties tuned with respect to parameter dependence. • Enhanced functional properties of cotton fabrics. Abstract In recent times, treatment of natural fibres, like cotton, with antimicrobial finishing using nanoparticles has become increasingly high due to the possibility of anticipated property and their tuneable nature. In this study, using the phytoconstituents of leaf extract of Psidium guajava , Zinc acetate was reduced to obtain ZnO nanoparticles using three different synthesis routes namely sonication, wet-chemical and hydrothermal methods. To evaluate and get a broader understanding about the influence of processing parameter over the ZnO nanoparticles, physico-chemical, biological and photocatalytic property, a comparative assessment was performed. The ZnO nanoparticles were subjected to X-ray diffraction, particle size analysis and scanning electron microscope to ascertain its structure/morphology. The comparative studies reveal that hydrothermal method of ZnO synthesis yields smaller particle size (12 nm), with higher photocatalytic activity (94%), higher antibacterial activity against Escherichia coli (27.4 mm) and Staphylococcus aureus (29.3 mm) and lower structural defects comparing to ZnO synthesised via other methods of synthesis. Furthermore, the most effective ZnO nanoparticles (hydothermal method) was incorporated in chitosan and coated over the cotton fabric to functionalise cotton fabrics for better antimicrobial and water repellent property. Along with the same line, the ZnO nanocomposite coated fabrics exhibit better hydrophobic (157 ± 0.1°) (superhydrophobicity) and higher antibacterial activity (30.58 ± 0.3 mm (99%) (S. aureus) and 24 ± 0.5 mm (96%) (E. coli)), which could be attributed to ZnO particle size and favourable structural morphology. Thus, the study not only reveals the tuneable nature of the ZnO nanoparticles with respect to processing parameters and also shows the potential role in coating these nanoparticles over the cotton fabrics to impart an effective antimicrobial and hydrophobic finishing for biomedical applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract A novel hydrophobic passivation coating was fabricated on the surface of electrolytic manganese by stearic acid (SA) and oleic acid diethanolamide (ODEA). ODEA, which forms micelles in aqueous solution, can promote largely dissolution of insoluble stearic acid to form stable passivation solution. A series of influence parameters were investigated and the optimized process conditions were as follows: the concentration of SA and ODEA were 3 g/L and 10 g/L, respectively; and the immersion time was 5 min. Under the optimized condition, the anti-corrosion properties of the coating were characterized by electrochemical impedance spectroscopy and polarization test. The results showed that the corrosion potential and corrosion current density decreased obviously, and the polarization resistance at 0.01 Hz increased from 20.89 to 467.74 Ohm cm2. FT-IR spectroscopy and Gaussian calculations showed that SA and ODEA simultaneously acted on the surface of manganese to form a hydrophobic coating, which increased the contact angle from 41° to 113°. [ABSTRACT FROM AUTHOR]

Relative Humidity (RH) sensors based on Fiber Bragg Grating (FBG) technology have been fabricated by polymer functionalization, using hygroscopic material, namely agar. The sensor is specifically intended to monitor moisture in stones of cultural heritage buildings and monuments, in particular to be positioned under hydrophobic coatings used for protecting stones from absorption of water and dissolved chemicals, thus providing early warning of coating deterioration by RH monitoring. The performance of the prototype was first tested exposing the sensors in controlled environment and then assessed for the application simulating “in field” operating conditions, with sensors installed on marble and travertine tiles. Results show that the proposed sensor is able to monitor the presence of moisture inside the stones. [ABSTRACT FROM AUTHOR]

• A rough micro-structure was obtained utilizing powder adhesion in laser cladding. • The coating surface became hydrophobic when it absorbed organics in the atmosphere. • The hydrophobicity of the coating was improved by stearic acid modification. Much attention has been paid to hydrophobic coatings in metal surface engineering. In this study, a rough micro-structure was formed on the coating by utilizing powder adhesion during laser cladding. Upon adsorption of hydrocarbons and their derivatives with low surface energy present in the atmospheric environment, the coating showed hydrophobic behavior. After the coating was modified by a stearic acid solution, the water contact angle of the coating surface increased from 137.2 ± 2.8° to 149.1 ± 3.3°, indicating that the hydrophobicity of the coating was further improved. According to the electrochemical results, the modified coating exhibited improved anti-corrosion performance. [ABSTRACT FROM AUTHOR]

Long transport distances and extended storage of biomass pellets especially in humid environments provide a suitable setting for enhanced degradation in the form of moisture sorption, cracking and attrition. We developed an optically transparent, low-cost and environmentally friendly coating to reduce moisture sorption and storage degradation of pellets. The developed coating is a hybrid sol–gel, based on tetraethoxysilane (TEOS) and 3-glycidoxypropyl-trimethoxysilane (GPTMS) precursors. We coated two types of untreated and one type of torrefied wood pellets and stored them in a climate chamber during 1 month simulating a ship's hold, at a constant condition of 40 °C and 85% relative humidity. After 1 month of storage, the mean water contact angle increased by a factor of two compared to the uncoated ones. The lower wettability of the sol-gel coated untreated pellets compared to the non-coated torrefied pellets might provide an alternative to torrefaction. • GPTMS/TEOS sol-gel is compatible with the heterogenous composition of biomass pellets. • The coating offers a sealing function reducing the mean apparent depth of the cracks. • After 1 month of storage, the coated pellets retained their hydrophobic behavior. [ABSTRACT FROM AUTHOR]

• The setup analyzed the changed water sloshing behaviour on sidewalls involving wave forms, impacts and free surface deformations. • An experimental investigation has been carried out in order to understand the surface properties effects for sloshing on rectangular tank using various filling level of water and oscillation frequencies configurations. • The hydrophobicity creates different wave forms and free surface deformations. • Smaller pressure impact is observed when the tangential velocity of flow is more dominant compared to the normal velocity impact under hydrophobic effect. The wave impingement on the side walls due to the oscillation of a rectangular tank under harmonic sway motion is analysed experimentally with hydrophobic coated and uncoated tank surfaces. Impact pressures and free surface deformations are compared in three water filling levels over an excitation frequency range encompassing the first natural frequency. The reduced hydrodynamic loads acting on the tank walls are observed under hydrophobic effects and discussed in detail. Experimental observations clearly indicate that there is a strong effect of the solid surface properties on the free surface elevation, wave generation and pressure distribution. In particular, major changes have been traced around the resonance frequency due to more dominant tangential flow and altered wave form, which results in lower peak pressure values with increased water movement within the tank under the hydrophobic effects. [ABSTRACT FROM AUTHOR]

Herein, bi-layer coatings were prepared through a superposition combination method, which contains polystyrene (PS) topcoat and polyaniline (PANI)/polymethyl methacrylate (PMMA) primer. PS topcoats prepared by different preparation methods show diverse microstructures, hydrophobicity, anti-medium permeability and corrosion resistance. In order to study the anti-corrosion mechanism of (PANI/PMMA primer − PS topcoat) coating system, Q235 carbon steel covered with bi-layer coatings were immersed in 3% NaCl solution for 720 h. And the anti-corrosion properties of samples were studied by open circuit potential, visual observations, electrochemical impedance spectroscopy and Tafel polarization test. Electrochemical techniques confirm that collocation of PS topcoat and PANI/PMMA primer could give full play to the shielding performance of topcoat and anodic protection performance of PANI/PMMA primer. Observed results show (PANI/PMMA primer − PS topcoat) coating system prepared by spray method has the best anti-medium permeability and outstanding corrosion protection property, which is attributed to the special microstructure. [ABSTRACT FROM AUTHOR]

Aluminium based materials undergo natural process of deterioration on exposure to corrosive environment. Among the strategies of corrosion control, sol-gel coatings have become popular as they have successfully replaced toxic hexavalent chromate coatings used hitherto. The adherent ability of sol-gel coatings combined with their ability to prevent the access of electrolyte thereby has made sol-gel coatings a promising and valuable method of corrosion control. In the present work, 3-aminopropyltrimethoxysilane (APTMS) was used as a precursor for silane based sol-gel coatings. In order to improve the active protection of metal, 1,3-diphenylthiourea (DPTU) was introduced into the sol-gel system. The nature of the coatings was studied using FT-IR, SEM and EDX. Thermogravimetric analysis (TGA) showed the thermal stability of the sol-gel coating. The inhibitor doped sol-gel coating increased the hydrophobic nature of the coating. For comparative studies, Thiourea (TU) was doped over APTMS sol-gel matrix and evaluated using electrochemical studies. EIS results of 0.1 M DPTU doped APTMS sol-gel coated Al surface showed better anti-corrosion properties than 0.1 M TU doped in 3.5 wt% NaCl medium. DPTU doped APTMS sol-gel coating forms an adherent layer over metallic surface which acts as significant physical barrier against the attack of corrosive ions in neutral medium which may be the reason for the improved corrosion resistance. [ABSTRACT FROM AUTHOR]

This study presents the preparation and characterization of natural waste material (orange peel) derived low cost, bio-based, recyclable, highly hydrophobic/superoleophilic magnetic sorbents to treat environmental pollution caused by oils and organic contaminants from water. Orange peels were dried, powdered and converted into magnetic and highly hydrophobic/superoleophilic sorbents by the incorporation of Fe 3 O 4 nanoparticles using co-precipitation approach and subsequently modifying with low surface energy polydimethylsiloxane (non-fluorinated hydrophobic reagent) layers. SEM, EDS, XRD, FTIR, XPS, TGA, VSM and contact angle measurements analysis were used for characterization of the developed materials. The as-prepared sorbents exhibit strong magnetic behavior with saturation magnetization (Ms) value of 14.9 emu/g, excellent hydrophobicity with water contact angle of 149.2° and very high capacity for the selective absorption of various oils and organic solvents from oil contaminated water. It has high absorption capacity up to 5.11 and 6.90 times its original weight for diesel oil and engine oil respectively, along with high recyclability of more than eight cycles and the advantage of magnetic separation from water surface after absorption of oils. Thus, the orange peel waste derived absorbent with magnetic and high hydrophobic properties is a promising alternative for the capture of oil and organic pollutants from water. [ABSTRACT FROM AUTHOR]

This study investigates the surface protection treatment of hydrophobic acrylate-based polymers with built-in carboxylic acid groups produced using a controlled Reversible Addition Fragmentation chain Transfer (RAFT) polymerization. The synthesized polymers are dissolved in a water-organic solvent mixture and afterwards deposited on lead substrates by immersing them in the solution. The coatings produce a hydrophobic film, which slows down the lead corrosion processes. The protective properties of the coatings are analyzed using non-destructive odd random phase multisine electrochemical impedance spectroscopy (ORP-EIS) in an acetic acid corrosive solution containing tertbutylammonium bromide (TBAB) supporting electrolyte. The impedance data and electron images of the coatings demonstrate that the coating thickness, pore formation, diffusion and electrolyte uptake profile depend on the polymer’s acrylic acid content and the molecular weight. All these parameters have a clear impact on the inhibition of the corrosion process. [ABSTRACT FROM AUTHOR]

Uncontrolled massive hemorrhage is a crucial cause of death, and developing efficient hemostatic materials are of great medical importance. Herein, we prepared a halloysite-chitosan-collagen composite sponge by directional freeze-drying method and coated the sponge with hydrophobic polydimethylsiloxane coating for rapid and effective hemostasis. The aligned channel structure of the sponge with a pore size of ~30 μm was beneficial for the transport of blood. Morphology and spectrum results suggested that chitosan and collagen are capable of adsorbing on the outer surface of HNTs due to the hydrogen bonding and electrostatic attractions. The directional freeze-dried sponge absorbed the majority of the blood within 10 s, and that process essentially was completed in 30 s, which are faster than its non-directional counterpart. The composite sponges exhibited high antibacterial properties towards E. coli and S. aureus , and they are non-cytotoxic towards mouse fibroblasts and have high hemocompatibility. The hemostatic dressing avoided unnecessary blood loss because of excessive blood absorption. In vivo experiments of rats also confirmed the ability of the asymmetric sponges to rapidly clot and reduce reducing blood loss. This work developed a high-performance and hemostatic dressing by material design and processing technique, which shows a promising application in wound healing. [Display omitted] [ABSTRACT FROM AUTHOR]

With wood regaining substantial interest as a construction material due to sustainability concerns and aesthetics trends, efficient and safe protection methods are needed to prevent the discouloration and the loss of mechanical properties of this renewable and UV-sensitive material. In this study, sustainable coatings comprising 0 to 20 wt% biocarbon (BC) dispersed in tung oil were developed for wood protection. BC particles were added as ultraviolet (UV) absorbers and were produced by various carbonization routes. The BC powders were characterized in terms of particle size and surface functional groups by Fourier-Transform infrared, and the UV and visible absorbance of dispersed BC powders in water solutions were related to these characteristics. Two wooden substrates (beech and oak) were coated with the developed coatings and the samples underwent six months of onsite weathering. While the total colour change of uncoated samples and tung oil-coated substrates without BC kept increasing over time and resulted in a clear alteration of the wood surface aesthetics, an increased BC content in the coatings led to enhanced colour stability, with alteration of the colour close to 2 for both wood species after six months of weathering for 10 and 20 wt% BC. Coating with tung oil made the wooden substrates, initially hydrophilic, become hydrophobic, and the further introduction of biocarbon increased hydrophobicity. However, the increase in BC content was not correlated with an increase in water repellence, the highest water contact angle being observed for 5 % BC, and no further improvement in hydrophobicity was observed with higher BC content. The weathering negatively affected the water repellence of all the samples (i.e., reference samples and coated samples with various BC content). However, the introduction of 20 % BC best protected the decrease in water repellence induced by the onsite weathering. • Biocarbon particles are good light absorbers in the ultra-violet and visible range. • Absorbance of biocarbon particles is proportional to their concentration in solution. • An increased biocarbon content in tung oil coatings led to enhanced colour stability. • Introduction of biocarbon in tung oil-based coatings increased their hydrophobicity. • Coatings with 20 wt% biocarbon preserved most their water repellence post-weathering. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new green route to prepare lignin thermosets, based on benzoxazine chemistry. • The type of amine used to close the oxazine ring drives the materials properties. • Stearylamine leads to easy-to-cast hydrophobic lignin-based coatings. • Furfurylamine confers fire resistance and self-extinguishable materials. • Ethanolamine affords dynamic exchange and internally catalysed vitrimer properties. The meaningful concept of circular economy has prompted the scientific community to re-think the design of materials. In this work, lignin-based benzoxazines (LBZs) thermosets with tuneable properties were synthesized in agreement with the principles of Green Chemistry, following a straightforward two-step synthetic route. The reactivity of a soda lignin was enhanced by its esterification with phloretic acid, a naturally occurring phenolic acid. Thereafter, the resulting structure enriched in phenolic rings with no ortho substituents, was used to prepare LBZs precursors with a bio-based primary amine via a Mannich-like ring-closure reaction. The structure and properties of each LBZ precursor were confirmed by multiple NMR techniques, Fourier transform infrared spectroscopy, elemental analysis, gel permeation chromatography, differential scanning calorimetry, rheology, and solubility assays. Lignin-based polybenzoxazine with high lignin mass fraction (between 46 and 66 wt.%) were obtained following curing via a vacuum compression molding manufacture process. Lignin-based thermosets exhibit a single-phase confirmed by X-ray computed tomography analysis, a T g ranging from 136 to 197 °C, and storage moduli from 0.5 to 3.1 GPa. The features of each lignin-based precursor were tuned depending on the structure of the bio-based primary amine used to close the oxazine ring. Stearylamine confers good processability and yields hydrophobic coatings with a water contact angle reaching 91°. Furfurylamine-based LBZs generate high-T g (197 °C) and fire-resistant materials with a peak of heat release rate of no>47 W.g−1. Finally, ethanolamine produces lignin-based thermosets capable of internally catalysed bond exchange via transesterification, providing vitrimeric properties such as fast stress relaxation (τ* 200 °C = 233 s) and a complete circularity. [ABSTRACT FROM AUTHOR]

The newly developed interface-free capillary electrophoresis-nanospray/mass spectrometry system (CE-nESI/MS) was applied for rapid analysis of the cardioprotective drug dexrazoxane and its hydrolysed form ADR-925 in deproteinized blood plasma samples. The aim of this study was to test the simplest possible CE-nESI/MS instrumentation for analyses of real samples. This interface-free system, utilizing single piece of a narrow bore capillary as both the electrophoretic separation column and the nanospray emitter, was operated at a flow rate of 30 nL/min. Excellent electrophoretic separation and sensitive nanospray ionization was achieved with the use of only one high voltage power supply. In addition, hydrophobic external coating was developed and tested for additional stability of the nanospray ionization. To our knowledge this is the first study devoted to the analysis of dexrazoxane and ADR-925 by capillary electrophoresis-mass spectrometry. [ABSTRACT FROM AUTHOR]

Heat stabilization of wheat bran aims at inactivation of enzymes which may cause rancidity and processability issues. Such treatments may however cause additional unanticipated phenomena which may affect wheat bran technological properties. In this work, the impact of toasting on wheat bran hydration capacity and hydration kinetics was studied. Hydration properties were assessed using the Enslin–Neff and drainage centrifugation water retention capacity methods, thermogravimetric analysis and contact angle goniometry, next to more traditional methods. While equilibrium hydration properties of bran were not affected by the heat treatment, the rate at which the heat treated bran hydrated was, however, very significantly reduced compared to the untreated bran. This phenomenon was found to originate from the formation of a lipid coating during the treatment rendering the bran surface hydrophobic. These insights help to understand and partially account for the modified processability of heat treated bran in food applications. [ABSTRACT FROM AUTHOR]

A hydrophobic coating with a static contact angle of 147° was obtained using an aluminate coupling agent on an aluminum (Al) surface, and aluminate coupling agent was first used to create hydrophobic surface. The surface energies of both neat Al and of hydrophobic coating surfaces were determined by both static and dynamic contact angle measurements. Frost formation and deposition on neat Al and hydrophobic coating surfaces were observed using an optical microscope and camera. The experimental results showed that the hydrophobic coating surface obviously restrained frost growth. The variation in frost thickness with time on the surfaces of both neat Al and hydrophobic coating surfaces was measured, and it was found that the frost deposition on hydrophobic coating surface was delayed for 60 min, when compared to a neat Al surface. Fatigue testing was also used to investigate the interfacial durability of the hydrophobic coating on an Al surface. Static contact angle studies in conjunction with fatigue testing revealed that aluminate coupling agent coatings on an Al surface exhibited strong and stable interfacial adhesion. [ABSTRACT FROM AUTHOR]

In this study, a hydrophobic coating on glass surfaces was fabricated by application of a silicone oil lubricant and activated using a microwave atmospheric plasma jet. Optimization of the treatment was done by variation of the working gas flow rates, input microwave power and plasma treatment time, based on contact angle measurements. In comparison with the untreated glass (37.6°), results show that at best discharge conditions of 600 W microwave power, 5/0.5 LPM Ar/N 2 flow rate and 10 s treatment time, the plasma-treated glass obtained a water contact angle of 105.7°. Surface energy of the glass also decreased from 45.07 mN/m for the untreated to 27.97 mN/m after plasma treatment. Atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy results suggest that increased root-mean-square roughness and introduction of hydrophobic species may have been responsible for the hydrophobicity of the glass surface. [ABSTRACT FROM AUTHOR]

Hydrophobic/superhydrophobic metallic surfaces prepared via chemical treatment are encountered in many industrial scenarios involving the impingement of spray droplets. The effectiveness of such surfaces is understood through the analysis of droplet impact experiments. In the present study, three target surfaces with aluminum (Al-6061) as base material–acid-etched, Octadecyl Trichloro Silane (OTS) coated, and acid-etched plus OTS-coated–were prepared. Experiments on the impact of inertia dominated water drops on these chemically modified aluminum surfaces were carried out with the objective to highlight the effect of chemical treatment on the target surfaces on key sub-processes occurring in drop impact phenomenon. High speed videos of the entire drop impact dynamics were captured at three Weber number ( We ) conditions representative of high We ( We > 200) regime. During the early stages of drop spreading, the drop impact resulted in ejection of secondary droplets from spreading drop front on the etched surfaces resembling prompt splash on rough surfaces whereas no such splashing was observable on untreated aluminum surface. Prominent development of undulations (fingers) were observed at the rim of drop spreading on the etched surfaces; between the etched surfaces the OTS-coated surface showed a subdued development of fingers than the uncoated surface. The impacted drops showed intense receding on OTS-coated surfaces whereas on the etched surface a highly irregular receding, with drop liquid sticking to the surface, was observed. Quantitative analyses were performed to reveal the effect of target surface characteristics on drop impact parameters such as temporal variation of spread factor of drop lamella, temporal variation of average finger length during spreading phase, maximum drop spreading, time taken to attain maximum spreading, sensitivity of maximum spreading to We , number of fingers at maximum spreading, and average receding velocity of drop lamella. Existing models for maximum drop spreading showed reasonably good agreement with the experimental measurements on the target surfaces except the acid-etched surface. [ABSTRACT FROM AUTHOR]

Highlights: [•] Development of GPTMS based sol–gel coating for protection of Al. [•] Doping of N,N-dimethylthiourea into GPTMS based sol–gel matrix. [•] The doping of DMU enhanced the hydrophobic nature of the GPTMS sol–gel coating. [•] The protective nature of the coating was revealed by EIS, PDS, SEM and XRD studies. [Copyright &y& Elsevier]

In this study, low-cost, environmentally friendly and porous agar/PVA aerogel sorbent materials with highly hydrophobic property were fabricated for the selective separation of oily substances and organic solvents from water by (i) the cross-linking reaction, (ii) freeze drying process and (iii) surface coating treatment. The characterization of agar/PVA aerogels was performed by water solubility, contact angle, SEM, EDX, mapping and XPS measurements. SEM and porosity results revealed that the increase of PVA amount within aerogel matrix led to a decrease in the pore structure of aerogel material. Agar/PVA (100:0) aerogel had good absorption capacity values (19.0–48.1 g·g−1) for various oily substances and organic solvents. All aerogels had excellent separation efficiency (≥99.3%) for chloroform-water mixture. For chloroform-water mixture and emulsion, the flux value of agar/PVA (100:0) aerogel was found to be 4273 L·m−2·h−1 and 3094 L·m−2·h−1, respectively. New agar/PVA aerogels are promising materials for the effective separation of oil-water or organic solvent-water mixtures and the cleaning of oil-spills from water. [Display omitted] [ABSTRACT FROM AUTHOR]