Self-cleaning Coatings Research Articles

Soiling, Adhesion, and Surface Characterization of Concentrated Solar Power Reflectors: Insights and Challenges in the MENA Region

Desert environments are prime locations for concentrated solar power (CSP) applications due to abundant direct normal irradiance. Despite this advantage, the accumulation and adhesion of dust on CSP mirror surfaces present significant challenges to plant efficiency. This paper comprehensively explores soiling phenomena and dust adhesion mechanisms, complemented by advanced measurement techniques tailored for CSP reflector mirrors. By elucidating the factors influencing dust accumulation and delving into the thermodynamics of self-cleaning coatings, alongside an analysis of various mirror materials, this study aims to enrich our understanding of soiling in CSP systems. This study aims to provide valuable insights that will help develop strategies to reduce dust-related efficiency losses in CSP plants, ultimately supporting the development of more reliable and sustainable solar energy solutions for the MENA region.

Self-cleaning and anti-corrosion superhydrophobic coatings of PA-TiO2@SiO2 copolymerized hetero compound

Inspired by leaf lotus effect, superhydrophobic surfaces have developed rapidly in recent years. In this paper, anatase nano TiO2 with particles size of about 70 nm was successfully loaded on the surface of SiO2 by sol-gel method. SiO2 and TiO2 were chemically bonded by Ti-O-Si and constructed a certain micro- and nano-composite structure. After superhydrophobic composite PA-TiO2@SiO2 was obtained by copolymerizing with acrylate and other monomers. The coating was prepared by drop coating plus spraying coating on glass substrates with water contact angles >160° and excellent self-cleaning properties, which could maintain the performance of the superhydrophobic coating by immersion in acidic solutions or water for 2 days. Meanwhile, the coating on the surface of the glass plate at −20 °C significantly delayed the freezing time of the ice. The rough structure of the surface and the presence of fluorine-containing hydrophobic groups gave the superhydrophobic coating an advantage over acrylate polymers in reducing the corrosion rate of steel surfaces.

Highly transparent, self-cleaning, and UV-shielding composite coating: When eco-friendly waterborne omniphobic surface cooperates with quantum dots

Solar energy is an inexhaustible carbon-free source, and solar cells are invaluable enablers for achieving carbon neutrality; however, the surface contamination on the glass of solar cells poses a formidable obstacle to maintaining a high power conversion efficiency. Existing self-cleaning coatings for combating surface contamination generally lack the highly comprehensive properties required for applications in real-world conditions. Herein, eco-friendly, highly transparent, waterborne omniphobic Si2.5WPA/AmZnO@SiO2 coatings were developed by the ingenious design of polydimethylsiloxane-grafted waterborne polyacrylate (SixWPA) and (3-aminopropyl)triethoxysilane-modified-SiO2 encapsulated ZnO quantum dots (AmZnO@SiO2). The enriched PDMS flexible chains on the coating surface overcame the energy barriers for moving liquids, and the AmZnO@SiO2 inside absorbed and scattered UV rays, which synergistically endowed the coating with self-cleaning and UV-shielding properties. Importantly, after the self-cleaning procedure, the light transmission of dust-contaminated glass and short-circuit current density of corresponding solar cells could be restored to 99.78 % and 97.77 % of initial metrics, respectively. Furthermore, the commonly ignored self-cleaning mechanism was investigated and proposed: the coating weakened the adhesion of dust particles and utilized the drag force generated during liquid slip to achieve self-cleaning. The coating also showed good UV/humidity/thermal stability and mechanical strength, providing a design blueprint for outdoor optical device protection.

Mechanically robust and self-cleaning antireflective coatings for photovoltaic modules

As the conversion efficiency of solar cells approaches its theoretical upper limit, the importance of photon management in enhancing photovoltaic modules performance becomes paramount. One promising approach involves the application of antireflective coatings to the surface of the photovoltaic glass to improve its transmittance. However, balancing mechanical durability, self-cleaning characteristics, and optical performance for photovoltaic applications remains challenging. This study focuses on synthesizing a composite coating through the sol-gel method, aiming to achieve high optical transmittance and superior mechanical properties. Hollow silica nanoparticles (HSN) are employed to achieve a reduced refractive index, while a composite sol of zirconium dioxide (ZrO2) and titania (TiO2) is utilized to enhance mechanical strength and hydrophilicity. The prepared composite coatings demonstrate notable improvements, with the photovoltaic transmittance (TPV) increasing from 88.31 % to 94.03 % in the 300–1100 nm wavelength range, with peak transmittance reaching 98.01 %. Additionally, the coatings exhibited a pencil hardness rating of 3H alongside exceptional abrasion resistance, affirming their potential for enduring practical deployment. When compared to uncoated glass, modules integrated with these composite coatings showed a significant increase in short-circuit current density (JSC) by 1.28 mA cm-2 and in photoelectric conversion efficiency (PCE) by 0.70 %. These results highlight the composite coatings' capacity to enhance the conversion efficiency of photovoltaic modules significantly. By attempting to prepare anti reflective coatings with high mechanical strength and self-cleaning properties, this study is expected to make a valuable contribution to the advancement of sustainable and durable solar cell technology.

Self-Cleaning Antibacterial Composite Coating of Fluorinated Acrylic Resin and Ag/SiO2 Nanoparticles with Quaternary Ammonium.

With improvements in living standards, the demand for antibacterial self-cleaning coatings has significantly increased. In this work, self-cleaning coatings with antibacterial properties were fabricated by spray-coating a composite of fluorinated acrylic resin and Ag/SiO2 nanoparticles with quaternary ammonium salts. The synergistic action of the quaternary ammonium salts and silver nanostructures caused the coating to show a dual antibacterial effect. The Ag/SiO2 nanoparticles roughened the coating's surface and, in combination with the fluorinated chains, provided the surface a superhydrophobic self-cleaning property with a contact angle of 156° and a sliding angle of less than 2°. Notably, the composite coating withstood 100 abrasion cycles without losing its superhydrophobicity and the contact angle is still exceeded 150° after 60 h of immersion solutions with different pH values, demonstrating outstanding wear resistance and acid/alkali stability. The incorporation of nanostructured antibacterial agents was effective in improving the roughness and antibacterial properties of the low-surface-energy resin, resulting in a self-cleaning antibacterial composite coating. This method may pave a new route for the design of functional coating materials with excellent overall performance.

Transparent superhydrophilic acrylic resin@GO-Fe3O4 coatings for glass surfaces with highly efficient visible-light-induced self-cleaning and anti-fogging properties

A transparent layer containing acrylic resin, graphene oxide and Fe3O4 have been studied based on its potential application including photocatalytically active and self-cleaning coatings. In this study, a transparent and superhydrophilic acrylic resin@graphene oxide-Fe3O4 (PA@GO-Fe3O4) composite coating has been successfully deposited on a glass substrate by dip coating technique to provide a thin film with a self-cleaning and photocatalytically active surface. The prepared samples were characterized by field emission scanning electron microscope (FE-SEM), atomic force microscope (AFM), fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy, UV–vis diffused transmittance (DTS) and water contact angle (WCA) measurements. The photocatalytic activity of the coated surfaces was investigated by the photocatalytic degradation of methylene blue (MB) under UV and visible light irradiation. The glass film of PA@GO-Fe3O4 (5 %) with an average roughness of 20.71 nm exhibited 76 % and 72 % MB photodegradation efficiency for 450 min under UV and visible light illuminations. The transparency of the glass coated film decreased to 76 % relative to that of the non-coated bare glass (92 %). The hydrophilicity of the glass coated film facilitated the formation of a thin water layer, which can increase self-cleaning property of glass coated film and augment the anti-fog effect. Therefore, the PA@GO-Fe3O4 composite coating exhibits significant superhydrophilicity, self-cleaning, and antifogging properties.

Transparent Superhydrophobic and Self-Cleaning Coating.

Surface roughness and low surface energy are key elements for the artificial preparation of biomimetic superhydrophobic materials. However, the presence of micro-/nanostructures and the corresponding increase in roughness can increase light scattering, thereby reducing the surface transparency. Therefore, designing and constructing superhydrophobic surfaces that combine superhydrophobicity with high transparency has been a continuous research focus for researchers and engineers. In this study, a transparent superhydrophobic coating was constructed on glass substrates using hydrophobic fumed silica (HF-SiO2) and waterborne polyurethane (WPU) as raw materials, combined with a simple spray-coating technique, resulting in a water contact angle (WCA) of 158.7 ± 1.5° and a sliding angle (SA) of 6.2 ± 1.8°. Characterization tests including SEM, EDS, LSCM, FTIR, and XPS revealed the presence of micron-scale protrusions and a nano-scale porous network composite structure on the surface. The presence of HF-SiO2 not only provided a certain roughness but also effectively reduced surface energy. More importantly, the coating exhibited excellent water-repellent properties, extremely low interfacial adhesion, self-cleaning ability, and high transparency, with the light transmittance of the coated glass substrate reaching 96.1% of that of the bare glass substrate. The series of functional characteristics demonstrated by the transparent superhydrophobic HF-SiO2@WPU coating designed and constructed in this study will play an important role in various applications such as underwater observation windows, building glass facades, automotive glass, and goggles.

Sol gel synthesis of TiO2@ZnO composites for self-cleaning and antimicrobial coating

Abstract In recent years, the development of advanced materials for applications in self-cleaning surfaces and antimicrobial coatings has received considerable attention due to its potential impact on environmental sustainability and public health. Among the emerging materials, metal oxide-based photocatalysts have shown promise in addressing these challenges. In this context, the present study focuses on the promise sol-gel synthesis and potential photocatalytic properties of TiO2@ZnO (x = 0.6 - 0.9) nano-scaled particles, with particular emphasis on their applications in self-cleaning and microbial coatings. The choice of TiO2@ZnO (x = 0.6 - 0.9) as the subject of investigation is driven by the advantageous properties of both titanium dioxide (TiO2) and zinc oxide (ZnO). TiO2 is known for its exceptional photocatalytic activity, while ZnO is known for its antimicrobial properties. By combining these two metal oxides in a controlled manner, we aim to harness their synergistic effects to create a multifunctional material with enhanced performance. A titanium (IV) isopropoxide and zinc acetate dihydrate have been used as precursors for the so-gel process. The synthesised powders were evaluated by X-ray diffraction analysis and Raman spectroscopy to determine the allotropy of TiO2 and possible lattice distortions. The optical band gap (Egap) was evaluated by molecular reflection UV-VIS spectroscopy. In addition, size and morphology were determined by scanning electron microscopy (SEM).

A self-cleaning coating on copper for inhibiting calcium carbonate crystallization and scaling

To address the technical bottleneck of synergistic damage caused by corrosion and scaling after damage to protective coatings on heat exchangers, petrochemical pipelines, and seawater desalination equipment, the surface scaling amount and calcium carbonate crystal morphology of anti-corrosion polymer coating (expressed as ZF,WCA = 95°) and self-cleaning coating (expressed as ZQ,WCA = 120°, WSA = 14°) are compared in a scaling system involving metal ions (Fe2+) generated by corrosion. The anti-scaling effect of the ZQ coating (34.6 %) with ions is 61.7 % higher than that of the ZF coating (21.4 %). As the concentration of Fe2+ increases, the aragonite on the ZQ coating transform from needle shaped crystals to cactus shaped crystals (expressed as C-CaCO3) with their whisker length about 20 μm. Furthermore, Cu2+ is introduced into the system by galvanic corrosion between steel and copper. The crystals on the ZQ coating are honeycomb shaped calcite, which transform to C-CaCO3 with shorter whisker length about 10 μm as the contacting area of steel/copper galvanic couple increases. The C-CaCO3 reduces the adhesive area of crystals on the surface of self-cleaning coatings with low surface energy, making it easier to be removed in dynamic scaling environment. Therefore, a self-cleaning coating on copper for inhibiting CaCO3 crystallization and scaling was prepared, hoping to provide a new method for the crystallization of multiple ions on the surface of self-cleaning coatings in the field of engineering scale prevention.

Excellent self-cleaning surface achieved through the synergistic effect of superhydrophilicity and photocatalysis of PVDF-TiO2-HAP coating

With the increasing demand for living environment, high-performance self-cleaning coatings have become an urgent need in the development of new building industry. Herein, a TiO2-HAP-PVDF self-cleaning coating was successfully developed using a facile precursor mixing method, where porous hydroxyapatite (HAP) was used to facilitate the adsorption of pollutants, TiO2 served as photocatalyst to decompose pollutants, and polyvinylidene fluoride (PVDF) served as adhesive to combine TiO2 with HAP. Owing to the synergistic effect of superhydrophilicity and photocatalysis, the TiO2-HAP-PVDF coating displays outstanding self-cleaning performance. Furthermore, the as-fabricated coating attached to aluminum veneer not only resists mechanical abrasion such as rainwater, sand flow and sandpaper, but also exhibits good stability in the extremely temperatures from -196 to 150 °C, as well as in strong acid and alkaline solutions, and even presents satisfactory performance after 8000 hours of outdoor service test. These merits open exciting possibilities for the industrial application of self-cleaning coating.

Robust and Durable Photonic Crystal with Liquid-Repellent Property for Self-Cleaning Coatings and Structural Colored Textiles.

Photonic crystal coatings with unique structural colors and self-cleaning properties have been providing an efficient way for substrate coloration. However, the enhancement of the robustness and durability of structural colored coatings to meet the requirements in diverse environments remains a challenging task. Here, to realize the application of photonic crystal films under various kinds of conditions, we present a poly(fluoroalkyl acrylate)-based colloidal photonic crystal (fCPC) coating. Fluorinated core-interlayer-shell (FCIS) colloidal particles of polystyrene (PS) core, poly(methyl methacrylate) (PMMA) interlayer, and poly(fluoroalkyl acrylate-ethyl acrylate-butyl acrylate) (P(FA-EA-BA)) shell copolymers have been first prepared by a stepwise emulsion polymerization. fCPCs with self-supporting property, reprocessing ability, friction resistance, as well as excellent wettability and liquid-repellent properties are successfully obtained via the bending-induced ordering technique (BIOT). When applied in antifouling applications, the fCPC film exhibits resistance against various oil and inorganic liquids. Furthermore, the fCPC coatings demonstrate their durability under outdoor conditions by maintaining stable color appearances during rainy and sunny conditions. Additionally, an electronic product adhered with the fCPC coatings is presented, which exhibits a surface that remains clean even after prolonged usage in comparison to the conventional CPC coating. Structural colored textiles with enhanced stability and functionalized liquid-repellent properties are achieved through a one-step process using FCIS particles. Therefore, the developed self-cleaning and comprehensive fCPC coatings capable of withstanding diverse conditions may open up new avenues for the advancement of structural coloration in decoration, vehicle, textile, and building.

The Droplet Creeping-Sliding Dynamic Wetting Mechanism on Bionic Self-Cleaning Surfaces.

The dynamic wetting behavior of droplets has been of wide concern due to the hazards of accretion/icing of supercooled droplets on engineering components/systems served in low temperature freezing rain environment; thus, it is urgent to establish the relationship between droplet depinning/removing behaviors and surface characteristics. In this article, the actual rotation conditions of moving components such as wind turbine blades are simulated. The self-cleaning hydrophobic coating surface(S1) and bionic superhydrophobic coating surface(S2) show outstanding droplet removal performance compared to hydrophilic bare steel surface(S0), and the average speed of the droplet removal is increased by 400-500%. The "creeping-sliding" behavior of droplets on self-cleaning coatings is investigated by the change of droplet displacement(ΔD). The effect of the energy storage caused by the droplet creeping process provides initial kinetic energy for the droplet removal. Combined with the experimental data and theoretical model, the critical depinning resistance is calculated. The difference of the wetting interface free energy(ΔEx) during the dynamic wetting process of the droplets on the bionic superhydrophobic self-cleaning surface is researched. And the influence mechanism of the droplet embedded depth(x) on the creeping/sliding behavior in the nanotexture is clarified. Thus, the mechanical criterion of droplet depinning is proposed (the error is about 10%). The results can provide a theoretical basis for the design principle of antifreezing rain coatings on moving components.

Design and preparation of durable intelligent haze removal and self-cleaning protective coatings

Conventional superhydrophobic coatings lose effectiveness over due to degradation from ultraviolet (UV) radiation, contaminants, and abrasion. Moreover, external cleaning methods are often needed to maintain self-cleaning performance in the presence of oils and organic contaminants. This study develops an organic-inorganic hybrid coating comprising polymethylhydrosiloxane (PMHS)-modified diatomaceous earth (DE) loaded with titanium dioxide (TiO2) on a room-temperature vulcanized rubber (RTV) substrate. The PMHS-DE-TiO2 coating achieves a synergistic effect, combining superhydrophobicity and photocatalysis. Notably, it exhibits a water contact angle (WCA) of 162.2°, a sliding angle (SA) of 5°, and achieves complete degradation of methylene blue (MB). It maintains hydrophobicity, integrity and functionality under UV radiation, prolonged abrasion, and acidic/alkaline salt solution immersion. The coating also degrades NO at 73.09 % maximum rate. Integration with a negative air ion generator further harnesses the timely superhydrophobic self-cleaning and photocatalysis to significantly enhance dust and fog removal efficiency beyond conventional commercial ion generators. Aligning with green low-carbon principles, this multifunctional coating provides an innovative solution for environmentally-friendly construction materials suitable for long-lasting exterior and interior usage. It resists pollution while mitigating airborne hazards, meeting growing demands for healthy buildings.

Silver and Copper Nanoparticle-Loaded Self-Assembled Pseudo-Peptide Thiourea-Based Organic-Inorganic Hybrid Gel with Antibacterial and Superhydrophobic Properties for Antifouling Surfaces.

The escalating threat of antimicrobial resistance has become a global health crisis. Therefore, there is a rising momentum in developing biomaterials with self-sanitizing capabilities and inherent antibacterial properties. Despite their promising antimicrobial properties, metal nanoparticles (MNPs) have several disadvantages, including increased toxicity as the particle size decreases, leading to oxidative stress and DNA damage that need consideration. One solution is surface functionalization with biocompatible organic ligands, which can improve nanoparticle dispersibility, reduce aggregation, and enable targeted delivery to microbial cells. The existing research predominantly concentrates on the advancement of peptide-based hydrogels for coating materials to prevent bacterial infection, with limited exploration of developing surface coatings using organogels. Herein, we have synthesized organogel-based coatings doped with MNPs that can offer superior hydrophobicity, oleophobicity, and high stability that are not easily achievable with hydrogels. The self-assembled gels displayed distinct morphologies, as revealed by scanning electron microscopy and atomic force microscopy. The cross-linked matrix helps in the controlled and sustained release of MNPs at the site of bacterial infection. The synthesized self-assembled gel@MNPs exhibited excellent antibacterial properties against harmful bacteria such as Escherichia coli and Staphylococcus aureus and reduced bacterial viability up to 95% within 4 h. Cytotoxicity testing against metazoan cells demonstrated that the gels doped with MNPs were nontoxic (IC50 > 100 μM) to mammalian cells. Furthermore, in this study, we coated the organogel@MNPs on cotton fabric and tested it against Gram +ve and Gram -ve bacteria. Additionally, the developed cotton fabric exhibited superhydrophobic properties and developed a barrier that limits the interaction between bacteria and the surface, making it difficult for bacteria to adhere and colonize, which holds potential as a valuable resource for self-cleaning coatings.

Towards the Development of One-Step Scalable Self-Cleaning and Stain-Resistant Coating on Cellulosic Wood

Towards the Development of One-Step Scalable Self-Cleaning and Stain-Resistant Coating on Cellulosic Wood

UV-durable self-cleaning coatings for autonomous driving

A key technology to ensure the safety and accuracy of autonomous driving for future transportation is the cleanliness of the sensor surfaces for accurate signal reading. This study focuses on hydrophobic coatings with self-cleaning performances and UV durability, their possible degradation mechanism of static water contact angle (sWCA), and the effect of the hydrophobic surface on camera image quality. The UV-durable hydrophobic coatings are applied by a spray process followed by a thermal curing. The UV-durable hydrophobic coatings are evaluated on a vision camera under lab-simulated weathering conditions such as rain, mud, fog, and bugs, on samples as-prepared and after various hours of Weather-Ometer® weathering. The results indicate that the sWCA degradation of the UV-durable hydrophobic coatings during accelerated weathering is corresponding to the loss of fluorine (F) atomic percentage in the coatings, and the vision camera imaging quality improves significantly with the UV-durable hydrophobic coatings in comparison to an uncoated surface. The self-cleaning performances of the UV-durable hydrophobic coatings, as measured by two metrics using signal-to-noise ratio and modulation transfer function 50 loss (MTF50loss), linearly correlate with sWCA of the coatings. The UV-durable hydrophobic coatings on the sensor surface will significantly benefit autonomous driving specifically for accurate signal reading under inclement weather.

Highly Stable Self-Cleaning Paints Based on Waste-Valorized PNC-Doped TiO2 Nanoparticles.

Adding photocatalytically active TiO2 nanoparticles (NPs) to polymeric paints is a feasible route toward self-cleaning coatings. While paint modification by TiO2-NPs may improve photoactivity, it may also cause polymer degradation and release of toxic volatile organic compounds. To counterbalance adverse effects, a synthesis method for nonmetal (P, N, and C)-doped TiO2-NPs is introduced, based purely on waste valorization. PNC-doped TiO2-NP characterization by vibrational and photoelectron spectroscopy, electron microscopy, diffraction, and thermal analysis suggests that TiO2-NPs were modified with phosphate (P=O), imine species (R=N-R), and carbon, which also hindered the anatase/rutile phase transformation, even upon 700 °C calcination. When added to water-based paints, PNC-doped TiO2-NPs achieved 96% removal of surface-adsorbed pollutants under natural sunlight or UV, paralleled by stability of the paint formulation, as confirmed by micro-Fourier transform infrared (FTIR) surface analysis. The origin of the photoinduced self-cleaning properties was rationalized by three-dimensional (3D) and synchronous photoluminescence spectroscopy, indicating that the dopants led to 7.3 times stronger inhibition of photoinduced e-/h+ recombination when compared to a benchmark P25 photocatalyst.

SiO2/WO3/ZnO based self-cleaning coatings for solar cells

The accumulation of pollution and any kinds of contamination on the glass cover of the solar cell affects the efficiency of the photovoltaic (PV) systems. The contamination on the glass cover can absorb and reflect a certain part of the sunlight irradiation, which can decrease the intensity of the light coming in through the glass cover. With the study, it was planned to develop self-cleaning coatings for the PV systems. It was aimed to prevent or reduce the contamination-induced efficiency loss of the existing PV systems. In the scope of the project, SiO2/WO3 and SiO2/WO3/ZnO composites were coated from their solutions on the glass substrates using a dip-coating technique. WO3 was selected as a photocatalyst semiconductor. Under the UV light irradiation, WO3 could absorb the photons of the UV light, generating the photoinduced charge carriers. The photoexcited charge carriers provide both the photoinduced hydrophilicity on the surface of the coating and the photocatalytic degradation of the organic contaminants accumulated on the surface of the coating, which allows water droplets to spread and flow on the surface of the cover glass to remove the contaminations. However, the recombination rate of the photoexcited charge carriers on the WO3 film was high. In order to suppress the recombination of the photoinduced charge carriers, WO3 was coupled with SiO2 and ZnO. Both of these semiconductors improved the photocatalytic activity of the WO3 film. Although SiO2 has superior features in terms of the light transmission, it was not very effective under UV light as a photocatalyst alone. The widely preferred photocatalyst ZnO was added into the composite film structure to enhance the photocatalytic activity. The self-cleaning mechanism of the film coatings on a solar cell was investigated through the photocatalytic dye removal efficiency on the as-prepared film samples. There was a slight decrease in the light transparency and the solar cell efficiency because of the WO3 content of the composite film. On the other hand, coupling the SiO2/WO3 film with ZnO enhanced the photocatalytic activity, and it suppressed the reduction effect of the WO3 phase on both the light transparency and the solar cell efficiency. The photocatalytic dye removal efficiency was increased to over 90% after 240 min of UVA light irradiation. In addition, the solar cell coated with the SiO2/WO3/ZnO film provided almost the same solar cell efficiency as the uncoated solar cell. The water contact angle measurement also exhibited the photocatalytic degradation of the model contamination on the glass cover of the solar cell under the UVA light irradiation.Graphical

Fabrication and characterization of durable superhydrophobic and superoleophobic surfaces on stainless steel mesh substrates

Introduction. This study explores the fabrication of durable superhydrophobic and superoleophobic surfaces on stainless steel mesh, inspired by natural structures like lotus leaves. Achieving superoleophobicity, especially with enhanced durability, is challenging due to the lower surface tension of oils. Methodology. This novel technique involves using Perfluorooctyltriethoxysilane (PFOTES) and silicon dioxide nanoparticles to create re-entrant structures, low surface energy, and high roughness. This cost-effective approach ensures simplicity without requiring expensive equipment. Results. The resulting surfaces exhibit remarkable superoleophobic properties, with hexadecane and soybean oil contact angles reaching 170° and 163.8°, respectively. Scanning electron microscopy confirms successful fabrication, and wear abrasion tests demonstrate mechanical durability, with contact angles remaining high even after cyclic loading and sandpaper abrasion. Conclusion. This study presents a pioneering, cost-effective method for fabricating durable superoleophobic surfaces on stainless steel mesh. These surfaces hold promise for applications in self-cleaning coatings and oil-repellent materials.

Impact of Titanium Dioxide Nanoparticles on Eudrilus eugeniae: A Toxicological Study

The increasing use of nanotechnology means that nanomaterials will inevitably enter the environment. Eco-toxicological data are therefore required so that adequate risk assessments can be carried out. Nanoparticles (NPs) exhibit greater reactivity as their sizes, less than 100nm size, are so small that their surface area is larger. The NPs can intrude into human body more easily and are more toxic than bulk material due to increased reactivity to cells in the body. Further, investigations on the ecotoxicology of NPs have also been conducted, aiming to assess NP’s harmful effects to the ecosystem. NPs of titanium dioxide (TiO2) are widely used in sun care products as well as in self-cleaning coatings. During the life cycle of these commercial products, NPs may be released into the environment and become a threat to ecosystems. Particularly, TiO2 NPs have been shown to have toxic effects and can inhibit the growth of essential soil microorganisms. This study focused on the toxicological and histopathological effects of TiO2 nanoparticles on Eudrilus eugenia, aiming to shed light on the potential hazards posed by nanoparticles to soil organisms. This study assessed the toxicity, biomass change, cocoon production and mortality rate of earthworms under various concentrations of titanium dioxide. The results showed that TiO2 nanoparticles could lead to sublethal effects on earthworm survival and reproduction and the nanoparticles were accumulated in earthworm tissues. The study emphasized the need to consider nanoparticle interactions with soil organisms.