Self-cleaning coatings need to have a certain degree of breathability to avoid peeling due to interfacial stress. In this study, a multifunctional superhydrophobic breathable DDA-PDA@BNNS/silicon ...resin coating is successfully designed by modifying sucrose-assisted exfoliation of boron nitride nanosheets (BNNS) with dodecylamine (DDA) and polydopamine (PDA). The coating shows a contact angle as high as 153.6° and a rolling angle as low as 4.8°, which can effectively avoid the adhesion of solid and liquid contaminants and extend the freezing time of ice up to six times. Meanwhile, the porous network structure of boron nitride nanosheets hardly changes the water vapor transmission rate of the substrate material. The DDA-PDA@BNNS/silicon resin breathable superhydrophobic coating is expected to achieve practical applications in long-lasting self-cleaning and antifouling.
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•A multifunctional superhydrophobic breathable coating is designed by modifying BNNS.•The porous structure hardly changes water vapor transmission rate of the substrate.•The coating can avoid the adhesion of contaminants and extend the freezing time.•The breathability and universality of coating promise the practical applications.
Nanocellulose‐based strain sensor (NBSS) have been a subject of growing interest for wearable electronics. However, these electronic devices are susceptible to damage when they come into contact with ...water and organic contaminants. Recently, researchers have developed a superhydrophobic NBSS. Unfortunately, it does not treat organic pollutants in water when used in an underwater environment. In this paper, a new solution: a superhydrophobic photocatalytic self‐cleaning NBSS created through scrape coating and dip coating methods is proposed. This new method shows outstanding self‐cleaning capabilities against water and organic contaminants due to the synergistic effects of the superhydrophobicity and photocatalysis of MnO2 nanoparticles. Furthermore, the superhydrophobic photocatalytic self‐cleaning NBSS has an exceptional response time of 0.66 s, a fast recovery time of 0.81 s, a sensitivity ≈66.53 at a strain of 0.5%. It is expect that the superhydrophobic photocatalytic self‐cleaning NBSS can monitor human movements, including finger twists, wrist movements, elbow bends, and knee movements. Not only is the fabrication method cost‐effective and scalable, but the new NBSS holds great promise in a wide range of fields, including human‐machine interactive systems, smart systems, and human‐body monitoring. Overall, the study provides significant guidance for future designs for wearable strain sensors.
A superhydrophobic photocatalytic self‐cleaning nanocellulose‐based strain sensors (NBSS) is created through scrape coating and dip coating methods. Not only is this fabrication method cost‐effective and scalable, but the new NBSS holds great promise in a wide range of fields, including human‐machine interactive systems, smart systems. Overall, this research provides significant guidance for future designs for wearable strain sensors.
Multifunctionalization is the future development direction for microwave absorbing materials, but has not yet been explored. The effective integration of multiple functions into one material remains ...a huge challenge. Herein, an aerogel‐type microwave absorber assembled with multidimensional organic and inorganic components is synthesized. Polyacrylonitrile fibers and polybenzoxazine membranes work as the skeleton and crosslinker, respectively, forming a 3D framework, in which carbon nanotubes are interconnected into an electrically conductive network, and Fe3O4 nanoparticles are uniformly dispersed throughout the aerogel. Remarkably, the microwave absorption performances of the aerogel achieve ultralight, ultrathin (1.5 mm), and strong absorption (reflection loss of −59.85 dB) features. In particular, its specific reflection loss values considerably outperform the current magnetic–dielectric hybrids with similar components. Moreover, the aerogel possesses strong hydrophobicity and good thermal insulation, endowing it attractive functions of self‐cleaning, infrared stealth, and heat insulation that is even comparable to commercial products. The excellent multifunction benefits from the cellular structure of aerogel, the assembly of multidimensional nanomaterials, and the synergistic effect of organic–inorganic components. This study paves the way for designing next‐generation microwave absorbing materials with great potential for multifunctional applications.
A multifunctional microwave absorbing aerogel is designed and synthesized by assembling a variety of organic and inorganic components including polyacrylonitrile fibers, polybenzoxazine membranes, carbon nanotubes (CNTs), and Fe3O4 nanoparticles. This lightweight aerogel not only achieves excellent microwave absorption performances that outperform the current CNT‐based magnetic–dielectric hybrids, but also possesses self‐cleaning, infrared stealth, and thermal insulation functions.
A superelastic aerogel with fast shape recovery performance from large compressive strain is highly desired for numerous applications such as thermal insulation in clothing, high‐sensitive sensors, ...and oil contaminant removal. Fabrication of superelastic cellulose nanofibrils (CNF) aerogels is challenging as the CNF can assemble into non‐elastic sheet‐like cell walls. Here, a dual ice‐templating assembly (DITA) strategy is proposed that can control the assembly of CNF into sub‐micrometer fibers by extremely low temperature freezing (–196 °C), which can further assemble into an elastic aerogel with interconnected sub‐micron fibers by freezer freezing (−20 °C) and freeze drying. The CNF aerogel from the DITA process demonstrates isotropic superelastic behavior that can recover from over 80% compressive strain along both longitudinal and cross‐sectional directions, even in an extremely cold liquid nitrogen environment. The elastic CNF aerogel can be easily modified by chemical vapor deposition of organosilane, demonstrating superhydrophobicity (164° water contact angle), high liquid absorption (489 g g−1 of chloroform absorption capacity), self‐cleaning, thermal insulating (0.023 W (mK)−1), and infrared shielding properties. This new DITA strategy provides a facile design of superelastic aerogels from bio‐based nanomaterials, and the derived high performance multifunctional elastic aerogel is expected to be useful for a wide‐range of applications.
A dual ice‐templating assembly (DITA) strategy is proposed to fabricate a superelastic aerogel from cellulose nanofibrils. The aerogel demonstrates superelastic performance in both longitudinal and cross‐sectional directions, even in an extremely cold environment (–196 °C). In addition, multifunctionalities including superhydrophobicity, superabsorbancy, self cleaning, thermal insulation, and infrared shielding are also achieved.
Low‐cost engineered nanotemplates are used to mold flexible nanocone anti‐reflection (AR) films. Both optical reflectance measurements and photovoltaics characterizations demonstrate that the ...flexible nanocone AR films can considerably suppress device front‐side reflectance and thus improve the power conversion efficiency of high‐efficiency thin‐film CdTe solar cells. Additionally, these nanocone AR films are found to be superhydrophobic and thus possess self‐cleaning capability.
Imidacloprid (IMI) are widely used in modern tea industry for pest control, but IMI residues pose a great threat to human health. Herein, we propose a regeneration metal-semiconductor SERS substrate ...for IMI detection. We fabricated the SERS sensor through the in-situ growth of a nano-heterostructure incorporating a semiconductor (TiO2) and plasmonic metals (Au, Ag) on oxidized carbon cloth (OCC). Leveraging the high-density hot spots, the formed Ag/AuNPs-TiO2-OCC substrate exhibits higher enhancement factors (1.92 × 108) and uniformity (RSD = 7.68%). As for the detection of IMI on the substrate, the limit of detection was lowered to 4.1 × 10−6 μg/mL. With a hydrophobic structure, the Ag/AuNPs-TiO2-OCC possessed excellent self-cleaning performance addressing the limitation of single-use associated with traditional SERS substrates, as well as the degradation capability of the substrate under ultraviolet (UV) light. Accordingly, Ag/AuNPs-TiO2-OCC showcases outstanding SERS sensing and regenerating properties, making it poised for extensive application in the field of food safety assurance.
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•A heterogeneous SERS substrate of Ag/AuNPs-TiO2-OCC was developed.•The substrate was synthesized by simple photoreduction and hydrothermal routes.•Efficient SERS enhancement is achieved by the synergistic effect of EM and CT.•The reusability of substrates is obtained by the hydrophobicity and UV degradation.
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•One-step fabrication of robust superhydrophobic coatings.•Evaporation driven self-assembly of cantaloupe like hierarchical structures.•Interesting effect of spray-coating distance on ...the mechanical durability of the coatings.
Mechanically durable superhydrophobic coatings have enormous application potential in almost all aspects of our daily lives. In this study, we present a practical strategy for one-step fabrication of robust superhydrophobic coatings based on evaporation driven self-assembly of hydrophobic nanoparticles and wax into hierarchical structures. Depending on the solvent and coating distance, spray-coating a dispersion composed of alkyl-silane functionalized nanoparticles and wax results in extremely water repellent surfaces with a water contact angle of 175° and a sliding angle of 3°. The formation of hierarchically structured surfaces upon evaporation of the solvent enables fabrication of fluorine-free, highly water repellent surfaces and provides high level of structural protection against mechanical abrasion. The coating retains its superhydrophobicity even after 1000 cycles of water spray impact, 45 min of water jet impact, and 180 cm of linear abrasion. The low-cost, scalable, one-step, and fluorine-free fabrication of superhydrophobic coatings that can be applied onto virtually any type of material surface with a satisfactory mechanical robustness based on eco-friendly and industrially available materials presents promising avenues for practical applications.
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•Co3O4/NCDs-PVDF (CN-PVDF) membrane was first applied in membrane distillation.•Effect of photo-Fenton on the physical and chemical properties of HA-Ca2+ was studied.•Effect of ...photo-Fenton on the interaction mode between HA-Ca2+ and the membrane was studied.•Fouling resistance and interface cleaning of CN-PVDF membrane was investigated.
Membrane distillation (MD), boasting high interception efficiency and low operational pressures, emerges as an innovative membrane technology. However, the occurrence of membrane fouling due to interaction between natural organic matter (NOM) and inorganic ions during the MD process curtails water purification efficiency, thereby constraining its potential applications. To address this quandary, this study integrates sulfate radical-based advanced oxidation processes (SR-AOPs) into MD technology to bolster membrane fouling control. A straightforward hydrothermal method coupled with vacuum filtration was employed to synthesize a Co3O4/Nitrogen-modified carbon quantum dots (NCDs)/PVDF (CN-PVDF) membrane for the first time, which was utilized in the MD treatment of simulated humic acid (HA) wastewater. Under visible light irradiation (1.9 kW/m2), CN-PVDF membrane activation of peroxymonosulfate (PMS) effectively altered the chemical attributes of the MD feed solution and reduced organic matter concentration. Moreover, it dismantled the carboxyl sites on HA that interact with Ca2+, consequently attenuating the formation of organic–inorganic complex pollutants. The XDLVO analysis showcased that photo-Fenton oxidation led to a diminishment in pollutant hydrophobicity, correlating with a 17.59 kT reduction in pollutant-membrane adsorption and a 7.47 kT amplification in adhesion barriers. This strategy transformed the initial two-stage fouling mode into a singular one, which significantly decreased the flux decline and the fouling layer thickness. Furthermore, the CN-PVDF membrane demonstrated self-cleaning capabilities via photo-Fenton. This study advances an innovative approach to bolster the fouling resistance of MD membranes and provides substantial theoretical support for the integration of SR-AOPs and MD technologies.
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•PDMS micro- and nano-particles were prepared by heat and ultrasonic treatment.•The prepared sample exhibits superior mechanical robustness to high speed water jet.•The fabricated ...sample could suffer tape peeling test and continuously sand impact.•The fabricated sample shows excellent performance in anti-icing and self-cleaning.
Transparent and conformal superhydrophobic coating with mechanochemical robustness is of great importance for various applications, such as waterproof, self-cleaning, and anti-icing for windows of cars and buildings. However, it remains a daunting challenge to endow the functional surface with programmable wettability. Herein, we propose a hierarchical coating consisting of polydimethylsiloxane (PDMS) nanoparticles (NPs) and PDMS microparticles (MPs) functional NPs through a combination of thermal treatment and spray treatment. The evaporation of PDMS under heat treatment is firstly applied to form a uniform nanoarchitectures, followed by spraying a mixed P25-PDMS dispersion to construct a protective coating with enhanced surface roughness. This resulted coating is conformal and possess reversible wettability on various substrates. In virtue of the light-response property of P25, the reversible wettability between superhydrophobicity and hydrophobicity can be achieved by repetitive UV-light irradiation and dark environment storage. Besides, the coating can maintain superhydrophobicity with high transmittance (76% optical transmittance) after immersion in acid/base solution for 24 h and continuously sand impingement. Furthermore, the coating exhibits mechanochemical robustness against high speed water jet and Elcometer 99 tape peeling test for 30 cycles due to the high adhesion between the robust coating and the glass. For practical application, the coating was demonstrated to have excellent performance in anti-icing, photocatalytic degradation of pollutants and self-cleaning.
