We report a simple, inexpensive, rapid, and one-step method for the fabrication of a stable and biocompatible superhydrophobic and superhemophobic surface. The proposed surface comprises candle soot ...particles embedded in a mixture of PDMS+n-hexane serving as the base material. The mechanism responsible for the superhydrophobic behavior of the surface is explained, and the surface is characterized based on its morphology and elemental composition, wetting properties, mechanical and chemical stability, and biocompatibility. The effect of %n-hexane in PDMS, the thickness of the PDMS+n-hexane layer (in terms of spin coating speed) and sooting time on the wetting property of the surface is studied. The proposed surface exhibits nanoscale surface asperities (average roughness of 187 nm), chemical compositions of soot particles, very high water and blood repellency along with excellent mechanical and chemical stability and excellent biocompatibility against blood sample and biological cells. The water contact angle and roll-off angle is measured as 160° ± 1° and 2°, respectively, and the blood contact angle is found to be 154° ± 1°, which indicates that the surface is superhydrophobic and superhemophobic. The proposed superhydrophobic and superhemophobic surface offers significantly improved (>40%) cell viability as compared to glass and PDMS surfaces.
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IJS, KILJ, NUK, PNG, UL, UM
PEI/GF lamination and TI6AL4V alloy are often related to the poor wettability of PEI to TI6AL4V alloy at the interface layer. To overcome these problems, an in situ synthetic candle soot reinforcing ...coating on TI6AL4V alloy was added into the place of the bonding area. The mechanical properties of composite joints were evaluated by single lap shear strength (LSS) tensile test. The mechanism of strengthening TI6AL4V-PEI/GF joint by candle ash was compared.
We present a cost-effective and environmental-friendly approach to realize the robust water repellency on flexible substrate via in-situ formation of integrative hierarchical architectures, which ...eliminates the obvious interface between the micro/nano-components where the mechanical fragility normally locates. The flexible and superhydrophobic film exhibits overall improved robustness including mechanical durability, chemical resistance, and impalement resistance of high-speed water jet.
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•A superhydrophobic film was prepared by a template/solvent/fluorine-free method.•Mechanical/chemical/physical robustness was elevated by the integrative hierarchy.•The film is highly flexible with preserved superhydrophobicity during deformation.•The approach is facile and economic, with cost of ∼ USD0.87 for a 5 cm × 5 cm film.•Durability of daily wears and water-jet reveals the potential for real-world use.
Flexible superhydrophobic surfaces have recently attracted extensive interest owing to the potential for diverse curvatures and emerging flexible electronics. However, the simultaneous realization of mechanical robustness, chemical resistance, and maintained superhydrophobicity during deformation is still challenging. Herein, we introduced an environmental-friendly method to produce the integrative multi-level structures by generating the micro-cilia array in a ‘template-free’ manner, followed with in-situ thermal curing in the candle flame before the complete solidification of the micro-structured surface. Instead of weak physical adhesion (van der Waals forces), the candle soot nanoparticles penetrated into the ‘semi-cured’ micro-cilia surface, along with the high temperature to rapidly cure and generate the PDMS-connected integrative architectures, which effectively avoid the interface between the micro/nano-scaled components to eliminate the mechanical fragility. Comparative investigations confirm that the elevated robustness is attributed by the synergistic effect from the ‘semi-cured’ surface and the formation mechanism of subsequent hierarchical structures. The flexible film thus exhibits significantly improved stability against mechanical damage (ultrasonic processing, adhesive pressing, and linear abrasion), chemical corrosion, and water-jet impalement (∼10.4 m s−1 at ∼ 0.17 MPa). With the realization of co-existent features and real-life applications, the green methodology should be promising to open up an avenue that moves superhydrophobicity further to our world.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A facile method is developed for fabrication of a superhydrophobic photothermal coating based on candle soot.•The coating can resist initial bacterial adhesion and kill the residual bacteria on the ...surface under NIR irradiation, preventing long-term biofilm formation.•The coating exhibits long-term storage stability and could be deposited on diverse practical substrates.
Bacterial biofilms formed on the material surfaces have posed a series of serious problems for human health and industries. The treatment of mature biofilms is particularly difficult because they are inherently highly resistant against antibiotics and other adverse factors. The prevention is strategically advantageous over the treatment, and thus the development of innovative surfaces with capability to inhibit biofilm formation is highly demanded. In this work, we developed a superhydrophobic photothermal coating for prevention of biofilm formation, which was based on candle soot with hierarchical structure and excellent light-to-heat conversion ability. This coating was fabricated by deposition of a candle soot layer on the substrate, followed by sequential chemical vapor deposition of tetraethoxysilane and immobilization of fluorinated silane to make the coating robust and superhydrophobic. The resulted coating could repel a majority of bacteria from the surface at the early stage, and then eradicate a small number of bacteria remained on the surface under a short-term irradiation of near-infrared laser. The combination of anti-adhesive property and photothermal bactericidal property endowed the coating with good antibiofilm property to prevent biofilm formation for at least 2 weeks. This coating is facile for deposition on various substrates with good storage stability, showing great potential for diverse practical applications to solve the biofilm-associated problems of materials and devices.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Double layered superhydrophobic PDMS-CS coating with mechanical robustness was prepared.•The PDMS-CS coating maintains its super-water-repellency even under 350 °C•The low frequency impedance ...modulus |Z|0.01 Hz was remarkably improved.•Rct of superhydrophobic PDMS-CS coating increased by six orders of magnitude.•The fabricated PDMS-CS coating exhibits long-term corrosion resistant properties.
Nature-inspired superhydrophobic coatings with typical Cassie-Baxter contacts garner numerous interests for multifunctional applications. However, undesirable poor mechanical and thermal stability are still crucial bottlenecks for real-world employment. This work introduces a cost-effective, fluorine free and versatile strategy to achieve double-layered PDMS agglutinated candle soot coating with superior water-repellent superhydrophobicity. The surface morphologies, chemical compositions and wettability behaviors were investigated in detail. The mechanical stability, chemical stability and durable corrosion resistance of the fabricated PDMS-CS coating were evaluated through friction, calcination and electrochemical impedance spectroscopy. The results demonstrate a remarkably enhanced mechanical robustness and corrosion resistance, indicating PDMS units can act as an effective agglutinating agent between candle soot and underlying substrate. The synergistic effect of PDMS agglutination, porous network nanostructures and extremely low surface energy of incomplete combustion induced candle soot deposition contribute to the eventually robust corrosion resisting coating, which greatly increases the possibility for practical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Emerging evidence supports that mitochondrial dysfunction contributes to systemic lupus erythematosus (SLE) pathogenesis. Here we show that programmed mitochondrial removal, a hallmark of mammalian ...erythropoiesis, is defective in SLE. Specifically, we demonstrate that during human erythroid cell maturation, a hypoxia-inducible factor (HIF)-mediated metabolic switch is responsible for the activation of the ubiquitin-proteasome system (UPS), which precedes and is necessary for the autophagic removal of mitochondria. A defect in this pathway leads to accumulation of red blood cells (RBCs) carrying mitochondria (Mito+ RBCs) in SLE patients and in correlation with disease activity. Antibody-mediated internalization of Mito+ RBCs induces type I interferon (IFN) production through activation of cGAS in macrophages. Accordingly, SLE patients carrying both Mito+ RBCs and opsonizing antibodies display the highest levels of blood IFN-stimulated gene (ISG) signatures, a distinctive feature of SLE.
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•HIF2α degradation promotes UPS activation and mitophagy during human erythropoiesis•Defective HIF2α degradation leads to accumulation of Mito+ RBCs in SLE patients•Uptake of opsonized Mito+ RBCs by macrophages induces IFN production via cGAS/STING•Highest ISG scores define SLE patients with Mito+ RBCs and opsonizing antibodies
A subgroup of SLE patients fail to engage HIF-regulated metabolic and proteasomal pathways causing the accumulation of mitochondria-containing red blood cells. These cells, when engulfed by macrophages, activate cGAS/STING-dependent inflammation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Corrosion susceptibility is a critical obstacle for Mg alloy usage in harsh environments. Bioinspired superhydrophobic surface (SHS) affords a new way to combat corrosion. However, problems, e.g., ...water vapor condensation and air dissolution, ceaselessly hurdle practical usage of SHS for long-term corrosion inhibition. In this report, targeting the corrosion inhibition of Mg alloy in seawater, a refreshable self-polishing superhydrophobic coating is bound onto AZ31 Mg alloy bridging via a ceramic/paraffin buffer layer to solve the two problems encountered by traditional SHS. Firstly, the liquid paraffin is injected into the porous ceramic structure constructed by micro-arc oxidation (MAO). Then, carbon soot (CS) is grown onto the ceramic/paraffin layer via a combustion method. The internal CS layer is firmly bonded due to the molten paraffin. Meanwhile, the external superhydrophobic CS layer is soft and floppy to perform self-polishing property under dynamic water flow condition. The refreshable feature endows the regeneration of SHS. Using water jet flush (5.8 m/s) and immersion test up to 168 h, Mg alloy covered ceramic layer and carbon soot (MMAO-CS) coating demonstrates excellent stability. Using diatoms as target organisms to illustrate seawater anti-biofouling property, a few diatoms are found on MMAO-CS even after immersion for 10 d due to the low modulus and self-polishing of the external superhydrophobic layer invaded by the water phase and bio-organisms. For prohibiting corrosion in seawater environment, MMAO-CS coating possesses prominent resistance with |Z|0.01 Hz (2.82 ×107 Ω cm2) of 6 orders of magnitude larger than bare AZ31 (42.9 Ω cm2), enabling its potential usage in marine environment.
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•A refreshable super-hydrophobic coating is bound onto AZ31.•Superhydrophobic candle soot demonstrates self-polishing.•Self-polishing carbon soot highly inhibits corrosion and biofouling.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Superhydrophobic surface which mimics respiration plastrons.•Regenerative capability due to underlying geometry of porous nanochannels.•Durable against tap water jet with speeds up to ...10 m/s.•Superhydrophobicity unaffected against saltwater, chemicals, and frost-defrost cycles.•Superhydrophobic to organic liquids and self-cleaning to fine-particulate flour.
Despite substantial advancements in development of artificially engineered superhydrophobic surfaces, durability and regenerative aspect of such surfaces remain elusive. Harsh working condition, especially extreme exposure to water or humidity deteriorates plastron property of superhydrophobic surfaces rendering them inappropriate for prolonged under-water applications. We report a systematic approach for creating a durable superhydrophobic surface by first plasma-treating a fabricated porous nanochannel geometry on a silicon substrate followed by infusion-depletion of silicon oil and coating a layer of carbon derived from candle soot. The surface is capable of maintaining water contact angle (WCA) of nearly 160° and roll off angle (ROA) less than 5° after undergoing 20 different tests including mechanical (tap water jet up to 10.3ms-1, tape peeling test up to 12 cycles), chemical (saline and solvents immersion), thermal (high temperature exposure and condensation heat transfer), self-cleaning tests, organic compatibility (honey, soy sauce, chocolate syrup, all-purpose flour) and superoleophilic test, thus exhibiting potential real-world applications. The surface retains stable plastron with negligible change in WCA and ROA even after being under 10cm of water for 30 days, similar to respiration plastrons seen on some aquatic insects. Regenerative capability of the surface is demonstrated by restoring its superhydrophobicity from a forced degraded state.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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