Search Results (24)

During aviation operations, low temperatures can cause fuel freezing and icing on 6061 aluminum fuel lines, threatening flight safety. To mitigate this, a surface treatment combining FeCl₃ etching and an ORMOSIL sol–gel coating was proposed to construct a superhydrophobic functional layer. FeCl₃ etching generated a hierarchical micro/nanostructure on the aluminum surface, while the ORMOSIL layer, formed by the co-hydrolysis and condensation of PFOTES and HDTMS, built Si-O-Si networks and introduced C-F groups to reduce surface energy and enhance stability. The modified surface showed a high water contact angle of 161.44°, confirming excellent superhydrophobicity. AFM analysis revealed a significant increase in surface roughness (Sa = 0.844 μm), confirming the formation of a hierarchical micro/nanostructure. Electrochemical measurements showed a positive shift in corrosion potential from −0.723 V to −0.652 V, demonstrating enhanced corrosion resistance. More importantly, after 120 h of immersion in aviation fuel, the coating maintained a high contact angle of 156.73° and preserved its Si-O-Si network and fluorinated functional groups, confirming outstanding fuel resistance and long-term stability. These results demonstrate that the proposed ORMOSIL coating is a promising protective strategy for aviation fuel systems operating under low-temperature and corrosive conditions. Full article

Wood’s inherent flammability, arising from its cellular organic composition, demands effective protective strategies. This study aimed to develop a multifunctional bio-based wood coating simultaneously integrating flame retardancy, optical transparency, moisture-triggered self-healing, and surface hydrophobicity within a single formulation. An intumescent flame retardant (PAGHR) was synthesized via ionic assembly of a phytic acid–phosphorylated polyethylene glycol conjugate (PgP) with a piperazine–etidronic acid salt (HEPHR), subsequently blended with gelatin (G) and surface-finished with fluorosilane. The optimized coating (G/PAGHR-4) achieved a limiting oxygen index (LOI) of 37.2% and passed the UL-94 V-0 rating. Cone calorimetry demonstrated reductions of 75.1% in peak heat release rate (pHRR) and 50.0% in total heat release (THR) relative to the neat gelatin control. Char yield at 700 °C increased substantially from 17.8 wt% to 41.0 wt%, confirming effective condensed-phase char promotion. Beyond fire performance, the coating maintained high visible-light transmittance, preserved natural wood aesthetics, and achieved macroscopic scratch healing within 40 min upon ambient water contact. Fluorosilane finishing elevated the water contact angle to 122°. These results establish a scalable, environmentally friendly strategy for multifunctional bio-based protective coatings applicable to wood, textiles, and polymer substrates. Full article

Direct current (DC) surface flashover on polystyrene (PS) remains a critical bottleneck that impedes its reliable application in high-voltage insulation apparatus. To circumvent the protracted processing durations and stringent film-forming conditions inherent in conventional surface modification techniques, this study proposes a novel “liquid-film-assisted in situ rapid plasma curing” strategy. By harnessing atmospheric-pressure dielectric barrier discharge (DBD) technology within an argon ambient, the rapid (<6 min) and efficient deposition of a fluorosilane (FAS-13) functional coating onto the substrate was achieved. Microscopic characterizations coupled with isothermal surface potential decay (SPD) measurements reveal that this coating substantially mitigates the detrapping and surface migration of charge carriers. Macroscopic DC flashover testing corroborates that, under the optimal modification ratio, the surface breakdown voltage of PS is elevated to 14.04 kV, yielding an insulation gain of 26.94%. To elucidate the underlying physical mechanisms, density functional theory (DFT) calculations were conducted, revealing that the energy band misalignment between the wide-bandgap fluorinated layer and the substrate facilitates the construction of a high-density deep trap network (with a depth of ~0.8 eV) at the coating–substrate interface. By robustly anchoring primary electrons and inducing the formation of a homopolar space charge shielding layer, these deep traps physically arrest the evolution of the secondary electron emission avalanche (SEEA). Consequently, this work not only establishes a viable engineering framework for the rapid, large-scale surface reinforcement of DC insulation equipment but also provides profound quantum chemical insights into interfacial trap regulation within all-organic dielectrics. Full article

Amidst the high global reliance on petroleum, this study addresses energy inefficiency in beam-pumping units used for oil extraction. We developed a tubular solid–liquid triboelectric nanogenerator (TENG) based on fluorinated polydimethylsiloxane (PDMS) films. Self-assembled surface modification with fluorosilane molecular chains enhanced charge transfer, achieving a 2.7-fold increase with 13F-PDMS. The enclosed tubular design utilizes periodic liquid-electrode contact to generate a volumetric effect. Experiments investigated the influence of liquid composition and device configuration on performance. Using a 1.69 mol/L FeCl₃ solution with four series-connected units, the TENG reached 29 V and 263 nA, powering 150 LEDs. This demonstrates its potential for harvesting reciprocating mechanical energy from pumping units to reduce operational energy consumption. Full article

The fall armyworm (FAW), Spodoptera frugiperda, poses a major threat to global maize production. Reliance on synthetic pesticides has contributed to pest resistance and environmental degradation, underscoring the need for sustainable alternatives. In this study, ethanolic extracts of neem (Azadirachta indica) and moringa (Moringa oleifera), together with maize-associated bacterial isolates, were evaluated for their biocontrol potential against fall armyworm. Gas chromatography-mass spectrometry (GC-MS) analysis for bioextract identification revealed tissue-specific chemical diversity, identifying eight key phytochemicals, including octadecanoic acid, trimethyl fluorosilane, and hexadecanoic acid in neem, and trimethyl fluorosilane, ethyl oleate, ethyl (9Z,12Z), octadecanoic acid, and benzenedicarboxylic acid in moringa extracts. Eighty-nine bacterial isolates were screened for extracellular enzyme activities (cellulase, chitinase, glucanase, and protease) and siderophore production, among which four strains, DR-55 (Bacillus subtilis), HL-7 (Bacillus cereus), HL-37 (Bacillus cereus), and DR-63 (Enterobacter sp.), exhibited >50% biocontrol efficacy under greenhouse conditions. A strong correlation (r = 0.88) was observed between in vitro antagonistic activity and greenhouse performance, validating the screening approach. Fall armyworm mortality was the highest in larvae (up to 80%), moderate in pupae (15–17%), and the lowest in adults (6–7%), respectively. Overall, plant bio-extracts and maize-associated microbial isolates represent a promising, non-hazardous strategy for sustainable fall armyworm management while preserving maize plant health. Full article

9,10-Disila-9,10-dihydroanthracenes have attracted significant attention due to their unique electronic structures, characterized by an extended π-system facilitated by σ-π conjugation. Here, we report the synthesis of 9,10-bis(p-methoxyphenyl)-9,10-disila-9,10-dihydroanthracene, which serves as a crucial precursor for the preparation of the corresponding difluoro derivative. This conversion is achieved through a selective deanisyl-fluorination at the silicon centers using HBF₄. A key finding is the successful isolation of the cis-isomer of 9,10-difluoro-9,10-disila-9,10-dihydroanthracenes as a crystalline compound. This allowed for definitive structural characterization by single-crystal X-ray diffraction (SC-XRD) analysis, providing precise geometric insights into this electronically fascinating framework. Full article

Commercial hydrophobic membranes encounter severe problems such as membrane wetting and membrane fouling under extreme conditions, which affect membrane separation performance. To enhance the anti-fouling abilities of hydrophobic membranes, a composite membrane with omniphobic characteristics was fabricated successfully in this paper. Titanium dioxide (TiO₂) nanoparticles were in-situ grown via the hydrothermal synthesis method, and then fluorosilane with low surface energy was grafted on polyvinylidene fluoride (PVDF) membranes. Subsequently, the morphologies, chemical compositions, wetting properties and structural parameters of composite membranes were characterized systematically. Various contaminants were added to the feed to investigate the anti-fouling and anti-wetting performances of the composite membrane in membrane distillation tests. The results showed that butyl titanate was first hydrolyzed to form titanium hydroxide (Ti(OH)₄) and then it was dehydrated to form TiO₂ in the hydrothermal environment. TiO₂ crystals continued to grow and formed rough morphology with micro-nano synergistic distribution, which is similar to a “sunflower” disk composed of cubic clusters and nanopillars. Meanwhile, fluorosilane successfully was grafted onto TiO₂. The contact angles of deionized water, 0.4 mM sodium dodecyl sulfate (SDS) solution and 0.2% v/v mineral oil emulsion on the composite membrane surface were 167.3°, 162.0° and 158.5°, respectively, endowing the composite membrane with excellent omniphobic features. In direct contact membrane distillation (DCMD) tests, the composite membrane exhibited a relatively stable membrane permeate flux, and the salt rejection rate almost reached 100%. The mixture, consisting of inorganic salts, organic substances, surfactants and oil emulsions, was used as feed. In contrast, the commercial PVDF membrane flux decreased drastically and even dropped to 0 due to the membrane fouling and wetting. As for the pristine PVDF membrane, the membrane surface was covered with pollutants and membrane pores were blocked. Therefore, it was proved that the omniphobic composite membrane possesses outstanding anti-fouling and anti-wetting performance. Full article

The hybrid inorganic–organic material concept plays a bold role in multifunctional materials, combining different features on one platform. Once varying properties coexist without cancelling each other on one matrix, a new type of supermaterial can be formed. This concept showed that silver nanoparticles can be embedded together with inorganic and organic surface coatings and silicon quantum dots for symbiotic antibacterial character and UV-excited visible light fluorescent features. Additionally, fluorosilane material can be coupled with this prepolymeric structure to add the hydrophobic feature, showing water contact angles around 120°, providing self-cleaning features. Optical properties of the components and the final material were investigated by UV-Vis spectroscopy and PL analysis. Atomic investigations and structural variations were detected by XPS, SEM, and EDX atomic mapping methods, correcting the atomic entities inside the coating. FT-IR tracked surface features, and statistical analysis of the quantum dots and nanoparticles was conducted. Multifunctional final materials showed antibacterial properties against E. coli and S. aureus, exhibiting self-cleaning features with high surface contact angles and visible light fluorescence due to the silicon quantum dot incorporation into the sol-gel-produced nanocomposite hybrid structure. Full article

A superhydrophobic surface with hierarchical micro/nano-array structures was successfully fabricated on 6061 aluminum alloy through a combination of femtosecond laser etching and anodic oxidation. Femtosecond laser etching formed a regularly arranged microscale “pit-protrusion” array on the aluminum alloy surface. After modification with a fluorosilane ethanol solution, the surface exhibited superhydrophobicity with a contact angle of 154°. Subsequently, the anodic oxidation process formed an anodic oxide film dominated by an array of aluminum oxide (Al₂O₃) nanopores at the submicron scale. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses revealed that the nanopore structures uniformly and continuously covered the laser-ablated layer. This hierarchical structure significantly increased the surface water contact angle to 162°. Wettability analysis showed that the prepared composite coating formed an air layer accounting for 91% of the surface area. Compared with the sample only treated by femtosecond laser etching, the presence of the Al₂O₃ nanopore structure significantly enhanced the mechanical durability, superhydrophobic durability, and corrosion resistance of the superhydrophobic surface. The proposed multi-step fabrication strategy offers an innovative method for creating multifunctional, durable superhydrophobic coatings and has important implications for their large-scale industrial use. Full article

This research presents the development of a surface treatment for AZ91D magnesium alloy that exhibits both superhydrophobic and anticorrosive properties. Initially, a zinc-based phosphate film was deposited on the magnesium alloy surface. Subsequently, a composite coating with superhydrophobic properties was produced by surface modification using a fluorosilane-ethanol solution. The composite coating’s microstructure, chemical composition, wettability, self-cleaning, and anti-corrosion properties were evaluated using scanning electron microscopy, a contact angle measurement instrument, and an electrochemical workstation. The results demonstrated that the main components of the composite coating were P, O, Zn, F, and C. The static contact angle reached 158°, providing superior self-cleaning and acid and alkali corrosion resistance. Additionally, the charge transfer resistance and coating resistance of the composite coating were significantly higher than those of the magnesium alloy substrate, effectively preventing corrosion and preserving the surface from fouling. Full article

Corrosion of structural parts not only reduces the service life of the equipment but also causes safety accidents, so building a long-lasting anti-corrosion coating on its surface is the key to solving this problem. Under the action of alkali catalysis, n-octyltriethoxysilane (OTES), dimethyldimethoxysilane (DMDMS), and perfluorodecyltrimethoxysilane (FTMS) hydrolyzed and polycondensed co-modified graphene oxide (GO), modified to synthesize a self-cleaning superhydrophobic material fluorosilane-modified graphene oxide (FGO). The structure, film morphology, and properties of FGO were systematically characterized. The results showed that the newly synthesized FGO was successfully modified by long-chain fluorocarbon groups and silanes. FGO presented an uneven and rough morphology on the substrate surface, the water contact angle was 151.3°, and the rolling angle was 3.9°, which caused the coating to exhibit excellent self-cleaning function. Meanwhile, the epoxy polymer/fluorosilane-modified graphene oxide (E-FGO) composite coating adhered to the carbon structural steel’s surface, and its corrosion resistance was detected by the Tafel curve and EIS impedance. It was found that the current density of the 10 wt% E-FGO coating (I_corr) was the lowest (1.087 × 10⁻¹⁰ A/cm²), which was approximately 3 orders of magnitude lower than that of the unmodified epoxy coating. This was primarily due to the introduction of FGO, which formed a continuous physical barrier in the composite coating and gave the composite coating excellent hydrophobicity. This method might provide new ideas for advances in steel corrosion resistance in the marine sector. Full article

The hydrophobicity of metal–organic frameworks (MOFs) is critical in enhancing the separation process in membrane distillation. Herein, a new superhydrophobic University of Oslo 66 (UiO-66) MOFs was successfully constructed on the top of alumina hollow fibre (AHF) membrane for desalination purposes. The fabrication methodology of the membrane involved in situ growth of pure crystalline UiO-66 on top of AHF and post-synthetic modification by fluorosilane grafting. The resultant membrane was characterised to study the physicochemical properties of the pristine and modified membrane. A superhydrophobic UiO-66 with a contact angle of 163.6° and high liquid entry pressure was obtained by introducing a highly branched fluorocarbon chain while maintaining its crystallinity. As a result, the modified membrane achieved 14.95 L/m²∙h water flux and 99.9% NaCl rejection with low energy consumption in the direct contact membrane distillation process. Furthermore, the high surface energy contributed by UiO-66 is maximised to produce the maximum number of accessible sites for the grafting process. The synergistic effect of surface hydrophobicity and porous UiO-66 membrane in trapping water vapour shows great potential for desalination application. Full article

Sansevieria trifasciata fibre (STF) is a lignocellulosic material which could be utilised for reinforcement composites. Surface modification is often needed to improve the compatibility of hydrophilic STF and hydrophobic resin. In this study, treatments for natural fibres to attain superhydrophobic properties were carried out using silica nanoparticles and fluorosilane. Sansevieria trifasciata fibres (STF) were subjected to treatment by deposition of silica (SiO₂) nanoparticles which were prepared by the sol-gel method, then followed by modification with fluorosilane, namely 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane (PFOTS). The presence of SiO₂ nanoparticles and PFOTS were evaluated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The crystallisation properties and thermal behaviour of STF were studied through X-ray diffraction (XRD) and thermogravimetric (TGA) analysis, respectively. The hydrophobicity of STF was determined by water contact angle (WCA) measurement. The results show that nanoscale SiO₂ particles were deposited on the STF surface, and PFOTS were covalently linked to them. The SiO₂ nanoparticles provide surface roughness to the fibres, whereas the long-chain fluorine on PFOTS lowered the surface free energy, and their combination in these treatments has successfully modified the STF surface from hydrophilic into superhydrophobic with a WCA of 150° and sliding angle of less than 10°. Altogether, a non-toxic, simple, and promising method of imparting hydrophobicity on natural fibres was developed, opening new opportunities for these fibres as reinforcement for composite parts. Full article

Metal corrosion causes huge economic losses and major disasters every year. Inspired by the lotus leaf and nepenthes pitcher, the superhydrophobic surfaces (SHS) and the slippery liquid-infused porous surfaces (SLIPS) were produced as a potential strategy to prevent metal corrosion. However, how to prepare stable water-repellent coatings that can prevent the intrusion of corrosive ions remains to investigate. In this work, we first fabricated a micro/nano hierarchical structure on the aluminum surface by femtosecond laser processing. Then, the SHS was prepared on the above structure by fluorosilane modification. Finally, the SLIPS was fabricated on the SHS by coating lubricant. The morphology and wettability of the fabricated samples were evaluated by scanning electron microscopy and contact angle measurements. Furthermore, the corrosion resistance properties of SHS and SLIPS in simulated seawater were characterized by electrochemical measurements. From the comparison of the electrochemical parameters of different immersion times, both water-repellent coatings are effective in protecting the aluminum alloy from corrosion in simulated seawater due to reduced contact area between the metal substrate and corrosive solution. In comparison with the SHS, the SLIPS has a corrosion inhibition efficiency of up to 99.95% and it maintains long-term stability in the corrosive solution. This work also provides a promising method for the water-repellent coatings by femtosecond laser processing for metal corrosion prevention in practical industrial applications. Full article

Biofouling has destructive effects on shipping and leisure vessels, thus producing severe problems for marine and naval sectors due to corrosion with consequent elevated fuel consumption and higher maintenance costs. The development of anti-fouling or fouling release coatings creates deterrent surfaces that prevent the initial settlement of microorganisms. In this regard, new silica-based materials were prepared using two alkoxysilane cross-linkers containing epoxy and amine groups (i.e., 3-Glycidyloxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane, respectively), in combination with two functional fluoro-silane (i.e., 3,3,3-trifluoropropyl-trimethoxysilane and glycidyl-2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononylether) featuring well-known hydro repellent and anti-corrosion properties. As a matter of fact, the co-condensation of alkoxysilane featuring epoxide and amine ends, also mixed with two opportune long chain and short chain perfluorosilane precursors, allows getting stable amphiphilic, non-toxic, fouling release coatings. The sol–gel mixtures on coated glass slides were fully characterized by FT-IR spectroscopy, while the morphology was studied by scanning electron microscopy (SEM), and atomic force microscopy (AFM). The fouling release properties were evaluated through tests on treated glass slides in different microbial suspensions in seawater-based mediums and in seawater natural microcosms. The developed fluorinated coatings show suitable antimicrobial activities and low adhesive properties; no biocidal effects were observed for the microorganisms (bacteria). Full article