•Preparation a hierarchically porous wood sponge (WS)•Enhancing heat generation for water evaporation by GF/PANI nanocomposite.•Self-cleaning photoabsorber with reduced thermal ...conductivity.•Achieving an impressive evaporation flux of 1.49 kg m−2h−1 under 1 sun.•Effectively purification of dye-contaminated seawater.
This research presents an innovative approach for developing a flexible wood sponge (WS) with a hierarchically porous structure. This unique structure is achieved through a sequential process involving balsa wood delignification, freeze-drying, and subsequent coating with graphene flake (GF)/polyaniline (PANI) nanocomposite. The resulting GF/PANI nanocomposite significantly reduces electron transfer resistivity, thereby enhancing heat generation for water evaporation. This results in self-cleaning photoabsorber, benefiting from GF’s salt-rejecting properties, PANI’s ionic network, and the WS’s porous structure. The photoabsorber demonstrates improved mechanical strength, reduced thermal conductivity, and a single water route design atop a drilled insulator foam, effectively minimizing heat loss during solar desalination. Under 1 sun (1 sun = 1 kW m−2) illumination, the photoabsorber achieves an impressive evaporation flux of 1.49 kg m−2h−1 and a high solar to thermal efficiency of 95.51 %. Importantly, continuous 10-cycle testing under 1 sun illumination reveals no salt deposition on the surface. Furthermore, the photoabsorber demonstrates promising applications in wastewater treatment, effectively purifying dye-contaminated seawater and desalinating both acidic and alkaline seawater. The investigation into the GF/PANI nanocomposite’s effect on steam generation, conducted through electrochemical impedance spectroscopy in a 0.5 M Na2SO4 electrolyte, reveals enhanced interfacial charge transfer, surpassing both PANI and GF due to reduced electrochemical resistance. Evaluation of desalinated seawater and purified wastewater demonstrates a significant decrease in major cation concentrations, meeting WHO and EPA drinking water standards. These findings underscore the potential of the GF/PANI nanocomposite in superior steam generation applications.
The insufficiency of available freshwater has surged as a major global concern in recent years, and the issue is raising ever more awareness. Meanwhile, the recent experimental synthesis of ...graphenylene has inspired researchers to pursue its applicative merits. The related properties regarding lithium-ion storage electrodes and gas separation membranes of graphenylene have been reported. However, the suitability of graphenylene as a desalination membrane has yet to be fully established. In the present study, with a view to delineating the action mechanism of graphenylene desalination membrane, we have dissected its structure and properties through first-principles and molecular dynamics. The results illustrate that graphenylene comprising dodecagonal, hexagonal, and tetragonal carbon rings contains 0.55 nm nanopores, which should permit outstanding desalination properties. In addition, the periodic pore distribution should support stress dispersion in service to preserve membrane integrity. The low water-molecule free-energy barrier, remarkable salt ion adsorption properties, and favorable anti-agglomeration ability endow graphenylene with desirable permeability and selectivity. Furthermore, we demonstrate that graphenylene is a 2D Dirac semi-metallic material. The interlinked electronic structure of which confers it with self-cleaning behavior, facilitating the restoration of water flux. The present research has elucidated the mechanism whereby effective desalination may be achieved on graphenylene membranes. Further, it has clarified the potential applicability of such membranes. They show good prospects for the advancement of seawater desalination technology.
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•A two-dimensional carbon based desalination membrane material with porous structure was discovered.•The action mechanism of seawater desalination and self-cleaning of this material in detail.•Graphenylene possesses a satisfactory electronic properties and desalination properties.
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•Superhydrophobic HTV silicone rubber by direct replication using compression molding.•Micro-nanostructured Al templates were produced using simple chemical etching.•Antistiction ...coating preserved both template and replicate patterns during demolding.•Self-cleaning samples easily removed introduced contaminants on the surface.
We describe a simple method for fabricating superhydrophobic high temperature vulcanized (HTV) silicone rubber surfaces by direct replication using a compression molding system. The resulting rubber samples possessed micro-nanostructures on the surface. This micro- and nano-scale roughness produced a water contact angle of >160° and a contact angle hysteresis of <3°. The roughness patterns on chemically etched aluminum surfaces, which served as templates, were successfully replicated on the rubber surfaces. An antistiction coating applied to the template surface ensured that the rubber was completely removed during demolding and that the replicated micro-nanostructures on the silicone surface were preserved. Surface roughness of the aluminum templates was optimized at HCl concentrations of 15 wt.%, with a lower roughness value observed at acid concentrations above and below this value. The developed HTV silicone rubber surfaces also demonstrated a freezing delay and a self-cleaning capacity.
The present paper reports the distribution of Epistylididae (Sessilida) epibiotic ciliates on the signal crayfish Pacifastacus leniusculus in relation to specialized structures of the host's ...exoskeleton for the first time. This species is known to maintain a relatively clean carapace, but it is sometimes overgrown by other organisms. Epibionts cover different parts of the signal crayfish body, mainly antennae, antennules, maxillipedes III and pereiopods with inner edges of chelae; however, some parts of the signal crayfish are not fouled. e.g. dorsal surfaces of the carapace and dorsal surfaces of chelae. Using scanning electron microscopy (SEM), topographies of different parts of the crayfish's exoskeleton were examined. Our investigations revealed that the epibiosis in the signal crayfish was determined by morphology of body surfaces. No epibionts were found on smooth surfaces with regular single setae (a known design that prevents fouling in aquatic environments). The dimpled surfaces with regular single micro‐papillae may be considered as a newly described example of self‐cleaning surfaces. Bio‐inspired surface patterning presents promising approaches to the design of novel functional surfaces that can prevent biofouling. The new self‐cleaning design may be used in further technological applications.
The present paper reports the distribution of Epistylididae (Sessilida) epibiotic ciliates on the signal crayfish Pacifastacus leniusculus in relation to specialized structures of the host's exoskeleton for the first time. Using scanning electron microscopy (SEM), topographies of different parts of the crayfish's exoskeleton were examined. Our investigations revealed that the epibiosis in the signal crayfish was determined by the morphology of body surfaces. No epibionts were found on smooth surfaces with regular single setae (a known design that prevents fouling in aquatic environments). Furthermore, dimpled surfaces with regular single micro‐papillae may be considered as a newly‐described example of self‐cleaning surfaces. Bio‐inspired surface patterning presents promising approaches to the design of novel functional surfaces that can prevent biofouling.
•SiO2-TiO2 nanoparticles were prepared via heterocoagulation method.•The properties of SiO2-TiO2 depend on the calcination temperature at the final stage.•SiO2-TiO2 enhances the mechanical ...characteristics and activated the self-cleaning properties of cement paste.•The use of SiO2-TiO2 with a specific surface of more than 300 m2·g−1 allows reducing the amount of additive.
SiO2-TiO2 mixed oxides have been used in this research to improve compressive strength and self-cleaning characteristics of cement. SiO2-TiO2 samples have been synthetized by the heterocoagulation method and characterized by a series of techniques, such as infrared spectra with Fourier transform, X-ray diffraction and thermogravimetric/derivative thermo-gravimetric analyses. Photocatalytic characteristics of the prepared specimens have been evaluated in methylene blue aqueous solution under ultraviolet ray irradiation. It has been found that the structural-adsorption, surface properties, and the photocatalytic activity of the SiO2-TiO2 depend on the final stage calcination temperature. The experimental results have shown that the material which was heated to 800 °C exhibited a high-specific surface area (307.1 m2·g−1) and highest photocatalytic activity. The physico-mechanical characteristics of the specimens were tested using a compressive strength study, thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM) to investigate characteristics of cement pastes containing SiO2-TiO2 and without them. It has been determined that the use of SiO2-TiO2 having a specific surface area of more than 300 m2·g−1 allows reducing the amount of additive in the production of cement paste with improved technical characteristics. Results achieved have shown the optimum amount of SiO2-TiO2 in the cement paste composition to be 0.1–0.5%. Besides, the discoloration test has been used to estimate the photocatalytic activity on the treated cement surface.
In response to the fact that oil removal materials were easily contaminated by viscous oil, materials with easy cleaning ability and long-term efficiency were developed for oil-water separation in ...this study. The ceramic coating was prepared on the surface of aluminum mesh by the micro-arc oxidation (MAO) method, and poly (vinyl alcohol) gel (PVA) was used to cover the MAO Al mesh. PVA@MAO Al mesh with subsea oil repellent function was prepared. As expected, PVA@MAO Al mesh exhibited good “hydrophilic” properties in the air and “oleophobic” properties underwater. The synthetic PVA@MAO Al mesh exhibited good self-cleaning properties, chemical stability, and abrasion resistance. Compared with the traditional oil-water separation method, this method has a simple preparation process, low cost, and excellent performance. These properties make PVA@MAO Al mesh ideal for oil-water separation. It has wide application prospects in oil spill cleanup, wastewater treatment, and water purification.
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•PVA@MAO Al mesh can be used for oil-water separation.•PVA@MAO mesh has good self-cleaning properties.•PVA@MAO Al mesh can effectively improve the corrosion resistance of the Al mesh.•It exhibits hydrophilic and submerged superoleophobic properties, easily reusable.
Porous aromatic frameworks (PAFs) composed of high‐density phenyl units are renowned for stable micro/meso‐porous architecture and highly hydrophobic surface, which make them ideal candidates for ...durable superhydrophobic applications, especially under harsh conditions. Herein, a carbazole‐based PAF solid is synthesized using carbazole and triphenylamine as the building units through the CC linking pattern. For the first time, the PAF powder is uniformly deposited on the fabric surface via a facile dip‐coating method, which thus shows superhydrophobicity with high water contact angle of 153.8° and oil contact angle of approximately 0°. Consequently, the PAF‐coated fabric displays an outstanding simple oil/water mixture and separation efficiency of over 96% and enables simple and time‐saving cyclic utilization at least 10 times. Due to the ultrahigh stability of PAF skeleton, the PAF‐based composite maintains high superhydrophobicity under extreme conditions including high temperature, high humidity, and strong acidic/alkaline solutions. These results delineate important research advances toward the implementation of PAF powder in superhydrophobic applications.
Porous aromatic frameworks featuring stable micro/meso‐porous architecture and highly hydrophobic surface make them ideal candidates for durable superhydrophobic applications. After coated with the fabric, the composite shows remarkable capability and durability for oil/water separation and self‐cleaning.
The use of more toxic reagents in the finishing of superhydrophobic cotton fabrics is one of the main factors that limit the application of the fabrics. Therefore, a green and sustainable method for ...preparing superhydrophobic cotton fabrics is urgently needed. In this study, a cotton fabric was etched with phytic acid (PA), which can be extracted from plants, effectively improving the surface roughness of the fabric. Subsequently, the treated fabric was coated with epoxidized soybean oil (ESO)-derived thermosets and then covered with stearic acid (STA). The finished cotton fabric exhibited excellent superhydrophobic properties, with a water contact angle of 156.3°. The superhydrophobic coatings of the finished cotton fabric endowed the fabric with excellent self-cleaning properties, irrespective of the liquid pollutant or solid dust. In addition, the inherent properties of the finished fabric were largely retained after the modification. Therefore, the finished cotton fabric with excellent self-cleaning properties has great potential for applications in the household and clothing fields.
•Green and sustainable method was used to prepare superhydrophobic fabric.•The surface roughness of fabric was improved by phytic acid etching.•The finished fabric exhibited excellent self-cleaning properties.•Inherent properties of fabric were largely retained after finishing.
Passive daytime radiative cooling technology without any electricity input offers great promise to mitigate carbon emissions and greenhouse effects. As a type of daytime radiative cooling emitters ...(DRCEs), daytime radiative cooling aerogel attracts a lot of attention and has great advantages in minimizing parasitic solar absorption and reducing environmental heat gain. However, designing daytime radiative cooling aerogel with amphiphobic surface properties is still challenging. Herein, a novel daytime radiative cooling aerogel based on eco-friendly bacterial cellulose (BC) as the skeleton, modified barium sulfate (BaSO4) as functional particles and fluoride coating as amphiphobic surface modifier was developed by simple freeze-drying and spraying. The optimal daytime radiative cooling aerogel, designated as M-BC/BaSO4-14 (M-BC/BaSO4-14 refers to the modified BC/BaSO4 aerogel), exhibited a high average reflectivity (95.6%) and excellent average emissivity (98.1%). The M-BC/BaSO4-14 achieved a mean temperature drop of 6.64°C and maximum temperature drop of 13.30°C on a cloudy day, and a mean temperature drop of 8.49°C and maximum temperature drop of 12.34°C on a clear day. It should be noted that the temperature drop referred to the temperature inside the measurement box (called the inner ambient temperature throughout this article) not the true ambient temperature. Meanwhile, the M-BC/BaSO4-14 aerogel exhibited favorable amphiphobic surface properties (water contact angle of about 151°, ethylene glycol contact angle of 141° and N-Hexadecane contact angle of 139°) and daytime radiative cooling performance before and after self-cleaning changed insignificantly. This work provides a viable strategy for the simultaneous improvement of the spectral properties and amphiphobic surface properties of the DRCEs.
•Aerogel with great cooling performance and favorable amphiphobic surface properties was developed.•M-BC/BaSO4-14 aerogel exhibited average reflectivity (95.6%) and excellent average emissivity (98.1%).•M-BC/BaSO4-14 aerogel exhibited excellent contact angles for water, ethylene glycol and N-Hexadecane, respectively.•Cooling performance of M-BC/BaSO4-14 aerogel before and after self-cleaning had insignificant changes.
Salt deposition and pollutant enrichment greatly hamper efficient and sustainable water production for a solar evaporator. Inspired by the desert beetle, a dual-region hydrophobic ...graphene/hydrophilic titanium dioxide (TiO2) aerogel (GTA) with internal hydrophilic–hydrophobic hybrid wettability structure is prepared via a facile freeze-drying and thermal reduction method. The evaporator shows adjustable wettability, optimized water content, and a low energy loss in the evaporation process. Simultaneously, the hybrid wetting structure in aerogel subjects salt to a dynamic crystallization–dissolution process to prevent salt deposition. The GTA solar evaporator achieves an evaporation rate of 1.52 kg·m–2·h–1 with a 91.02% efficiency under 1 sun irradiation. Furthermore, GTAs achieve a stable evaporation rate in high salinity brine (25 wt % NaCl) under 1 sun irradiation for 100 h, which could compete well with other most advanced photothermal evaporation materials. Moreover, the synergistic effect of graphene and TiO2 endows GTAs with excellent photocatalytic degradation and self-cleaning properties, which can effectively reduce the enrichment of contaminants on the evaporator. Therefore, GTA evaporators can efficiently and stably obtain clean water from seawater and wastewater, which provides a feasible strategy for the purification of complex wastewater.
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