Search

[Display omitted] • A controllable hydrophilic/superhydrophobic patterned coating is reported. • The superhydrophobic pattern presents rough ridge-like microstructures and opaque state. • The hydrophilic pattern exhibits water-triggered opaque to translucent transition. • The patterned coating is successfully applied in optical information encryption/decryption. • The information revealing demonstrates long-term stability and great reusability. Anti-counterfeiting technologies are crucial for securing the authenticity and proof of commodities, in which the optical information encryption/decryption has attracted extensive attention for its overriding advantages of visibility and convenience. Inspired by the unique transparency transformation phenomenon of Diphylleia grayi petals, a controllable hydrophilic/superhydrophobic patterned coating with water-triggered opaque to translucent transition is proposed through the construction of a superhydrophobic coating, subsequent air plasma etching under a mask, and final hydrophilic modification to introduce stable invisible patterns. The superhydrophobic region exhibits great water repellency with a water contact angle (WCA) at 157°, while the hydrophilic region quickly absorbs water with a WCA at 61°. The patterned coating presents an opaque state for the serious light scattering induced by the rough microstructure and large refractive index difference between the coating and air, while the hydrophilic patterns on the coating transform to translucent after water infiltration for the reduced roughness and close refractive indexes of the coating and water. The information revealing is rapid and reversible, and demonstrates heat and long-term stability and great reusability. The findings conceivably stand out as a new methodology to fabricate controllable superwettable coatings with optical information encryption/decryption capability for application in anti-counterfeiting. [ABSTRACT FROM AUTHOR]

Recently, the membrane separation materials show promising applications in the fields of crude oil removal because of their low energy consumption and less secondary pollution. However, the membrane separation materials suffer problem of low separation efficiency due to the high viscosity of crude oil. Here, a superhydrophobic material with Joule heat and photothermal effect was prepared by decorating the delignified wood with reduced graphene oxide (GSH) and vinyl terminated polydimethylsiloxane (V-PDMS) through thiol-ene click reaction. The prepared PDMS@GSH wood exhibited stable superhydrophobicity with a water contact angle of 156°. Meanwhile, the GSH layer provided promising electrothermal effect that endowed the PDMS@GSH wood with excellent crude oil/water separation capability under the Joule heat with a surface temperature of 139 °C and separation rate of 1.78 × 105 kg m−3 h−1. Besides, the PDMS@GSH wood displayed a good photothermal effect that assisted with the Joule heat to heat the wood for crude oil removal to save energy. More importantly, the PDMS was crosslinked with GSH on the wood via thiol-ene click reaction, leading to the stable superhydrophobicity and electrical conductivity in strong acid or alkali environment. This material has broad application prospects in crude oil clean-up due to its high separation speed and easy large-scale production. [Display omitted] • A new strategy for fabricating superhydrophobic wood with heating property is proposed. • The wood presents stable superhydrophobicity and electrical conductivity. • The wood shows excellent Joule heat and photothermal effect. • The wood exhibits high separation rate for viscous crude oil wastewater. [ABSTRACT FROM AUTHOR]

Self-cleaning films with superhydrophobicity and photocatalytic capability have attracted considerable interest in recent years for the synthetical chemical and physical self-cleaning performance to overcome individual inherent limitations. In the present work, a dual-functional self-cleaning film is proposed through the design of polydimethylsiloxane (PDMS) nanopillar array, swelling absorption of anatase-typed TiO 2 nanoparticles, and final low-surface-energy modification of 1 H ,1 H ,2 H ,2 H -perfluorodecyltrimethoxysilane (PFDTS). Benefiting from the hierarchically mountain-like structure constructed by the PDMS nanopillar array and swelling absorbed TiO 2 nanoparticles, the self-cleaning film presents a robust superhydrophobicity to resist chemical and mechanical damages (e.g. solvent/acid/alkali immersion, stretching, water impact, and sand abrasion). Combining the photocatalytic activity with adequate loading of TiO 2 nanoparticles, the self-cleaning film demonstrates a great degradation capability of organic pollutants with a degradation efficiency over 98 %. Importantly, owing to the superhydrophobicity repairability induced by the migration of fluorocarbon chains, the self-cleaning film can highly recover the water repellency with a water contact angle (WCA) of 155o even after long-term irradiation under UV light. The findings conceivably promote the development and application of the self-cleaning materials with superhydrophobic and photocatalytic properties. [Display omitted] • A superhydrophobic and photocatalytic self-cleaning film is reported. • The film is based on the structure of TiO 2 -modified nanopillar array. • The film exhibits durable superhydrophobicity to resist various damages. • The film demonstrates effective photocatalytic degradation of organic pollutants. • The damaged film can repair superhydrophobicity via chain rearrangement. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials possess prospective applications of oily wastewater treatment due to their high efficiency and easy operation. Nevertheless, most superhydrophobic materials are difficult to separate oil-water emulsion, especially for highly viscous water-in-crude oil emulsion. Herein, a superhydrophobic wood with excellent Joule heat and demulsification was proposed by chemically treating the natural wood and subsequent coating of the carboxyl-modified carbon nanotubes (cCNTs) for providing conductive pathways, polyethylenimide (PEI) for supporting demulsification and polydimethylsiloxane (PDMS) for hydrophobic modification. The fabricated superhydrophobic PDMS@PEI-cCNTs wood displayed a water contact angle of 155o and great compression property with a nearly undamaged structure at a strain of 40 % after 50 compression tests, which could separate and recover oil from the oil-water mixture via absorption-extrusion process. Besides, due to the filtration and electrostatic interaction of the PDMS@PEI-cCNTs wood, the water-in-oil emulsion was demulsified quickly with a separation efficiency greater than 99.7 %. Meanwhile, the PDMS@PEI-cCNTs wood showed a good Joule heat capability, and the surface temperature reached 160 °C at 35 V of voltage within 120 s, which largely reduced the viscosity of water-in-crude oil emulsion. Thus, the PDMS@PEI-cCNTs wood was successful in separating the water-in-crude oil emulsion via Joule heat capability with a separation rate of 4.33 × 104 kg·m−3·h−1 and a separation efficiency of 93.4 %. The material developed in this study has wide range of applications in treating the stable crude oil-water emulsion with high viscosity. [Display omitted] • A new strategy for fabricating superhydrophobic wood for various oil-water emulsions separation is proposed. • The wood presents stable superhydrophobicity and good electrical conductivity. • The wood shows excellent demulsification capability via charge action, absorption and gathering. • The wood exhibits great Joule heat to promote separating viscous water-in-crude oil emulsion. [ABSTRACT FROM AUTHOR]

Superhydrophilic/underwater superoleophobic coatings that effectively prevent viscous oil contamination have been of considerable interest for the great potential in oil spill remediation and oilfield wastewater treatment. In the present work, a protonated cross-linkable nanocomposite coating with robust underwater superoleophobicity and intensified hydration capability is proposed through the synthesis of active polymeric nanocomplex (PNC), cross-linking reaction between PNC and hydrophilic chitosan (CS), and final protonation to further improve water affinity. Benefiting from the hierarchical structure and strong hydration capability induced by electrostatic interactions and hydrogen bondings, the nanocomposite coating coated textile exhibits excellent superhydrophilicity (within 0.28 s with water contact angle reaching 0°), underwater superoleophobicity (underwater crude oil contact angle at 160°), and ultralow oil adhesion even to highly viscous silicone oil. Moreover, the nanocomposite coating presents a robust chemical resistance, mechanical tolerance, and storage stability. Simultaneously, the nanocomposite coating adapts well to various porous substrates (e.g., stainless steel mesh and Ni sponge) with great anti-oil-fouling and self-cleaning performances. Importantly, the coating coated textile is successfully applied in crude oil/water separation with excellent efficiency and repeatability. The findings conceivably stand out as a new methodology to fabricate superhydrophilic/underwater superoleophobic materials with outstanding anti-viscous oil-fouling property for practically treating oily wastewater. [Display omitted] • A protonated cross-linkable nanocomposite coating with underwater superoleophobicity is reported. • The PPNC-CS coating presents an outstanding hydration capability induced by charges. • The PPNC-CS coating exhibits ultralow oil adhesion even to viscous silicone oil. • The PPNC-CS adapts well to various porous substrates with great anti-oil-fouling performance. • The PPNC-CS coated textile is successfully applied in crude oil/water separation. [ABSTRACT FROM AUTHOR]

Natural wood, with its unique porous structure, has been widely modified for separating oil-water mixtures. However, the separation efficiency is often unsatisfactory, and little attention is focused on mitigating secondary pollution after its usable lifespan. Here, a superhydrophobic material consisting of delignified wood coated with titanium dioxide (TiO 2) and polydimethylsiloxane (PDMS) was prepared. The resulting PDMS@TiO 2 wood possessed outstanding superhydrophobicity, with a water contact angle of 160o. Owing to its longitudinal channels and excellent water repellency, the wood was successfully used to separate oil-water mixtures, with a high permeation flux of up to 6111 L·m−2·h−1 and separation efficiency of up to 93.4%. Importantly, PDMS and other oil pollutants were capable of being largely degraded after use via photocatalysis of the TiO 2 layer, and the degradation reached 8.56 wt% within 30 days. The results from this study provide a method for fabricating functional superhydrophobic wood with photocatalytic degradation ability for efficient oily wastewater treatment. [Display omitted] • A new strategy for fabricating superhydrophobic wood with anisotropic porous structure is reported. • The wood presents excellent separation flux in oil-water separation. • The wood exhibits great photocatalytic degradation ability for post-treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fully organic and biodegradable superhydrophobic sponge is rationally constructed. • All of raw materials are derived from cheap renewable natural resources. • The sponge presents great separation performance for immiscible oil/water mixtures. • Multi-layer compressed porous structure achieves gravity-driven high-flux emulsion separation. Facile fabrication of functional superhydrophobic porous materials with full biodegradability for efficient removal of oily pollutants from water has been of considerable interest for its great significance in environmental protection. Herein, a fully organic and biodegradable superhydrophobic sponge is fabricated with carnauba wax (CW) via dip-coating, nonsolvent induced phase separation and spraying processes on a freeze-dried pomelo peel. The as-fabricated sponge was covered with flower-shaped patterns aggregated by CW nanosheets, and presented great water repellency with a contact angle of 154°. Thanks to the 3D porous architecture and superhydrophobicity/superoleophilicity, the sponge exhibited great oil absorptive capacity, oil selectivity, separation efficiency and reusability for immiscible oil/water mixtures. Interestingly, the multi-layer compressed sponges realized gravity-driven surfactant-stabilized water-in-oil emulsion separation with high permeation flux of up to 5729 L·m−2·h−1 and excellent efficiency of oil purity larger than 99.9%. Importantly, the superhydrophobic sponge was derived from cheap renewable natural resources, and capable of being completely biodegraded after discarding. The findings conceivably stand out as a new tool to fabricate superhydrophobic materials with sustainability and biodegradability for oil accidents and industrial sewage emissions. [ABSTRACT FROM AUTHOR]

Superhydrophobic material has great potential applications in the field of anti-icing due to its special wettability. However, the poor wear resistance of the material has restricted its practical applications. Based on this, a simple two-step spray method was used to prepare a self-healing and robust superhydrophobic coating with excellent photothermal/electrothermal effect for anti-icing using epoxy modified ethylene octene copolymer (POEG) resin as the substrate layer and the fluorinated carbon black as the top coating. Results showed that the obtained composite coating showed multi-level rough structure and possessed excellent superhydrophobicity toward water droplets with different pH. Meanwhile, the composite coating could resist abrasion and kept superhydropbobicity even 250 cycles abrasion test with a water contact angle higher than 150o. When the surface was subjected to the intense abrasion, the rough structure and the superhydrophobic property of the surface were destroyed. However, it could be restored by the abrasion of the rougher surface. In addition, the scratches on the surface could be completely repaired by the heat treatment, indicating the good self-healing performance of the composite coating. Due to the existence of the carbon black particles, the superhydrophobic coating had good photothermal/electrothermal effects, which endowed the surface with excellent anti-icing performance of removing the icing under the conditions of electrothermal and light. This paper provides a simple and convenient way to prepare functional self-healing superhydrophobic coating, and a new idea for the preparation of anti-icing coating. [Display omitted] • The stable superhydrophobic coating showed excellent abrasion resistance performance. • The damaged composite coating could be easily repaired by heating self-healing. • The superhydrophobic coating possessed excellent electrothermal/photothermal effects. • The superhydrophobic coating showed excellent anti-icing performance. [ABSTRACT FROM AUTHOR]