Surface Durability Research Articles

Application of micro and nano modifying additives in road construction materials

The need for stronger and more sustainable road infrastructure has stimulated research into innovative materials, including micro- and nano-additives, to improve the performance of asphalt and bitumen. This paper aims to summarize the advances in the application of these additives with a focus on improving mechanical, thermal, and environmental properties. The study provides a detailed review of traditional micro-additives such as elastomers and resins, as well as advanced nanomaterials including nano silica, nano clay, and carbon nanoparticles. Methods include analyzing experimental data from recent studies on bitumen modification with biopolymeric materials such as polylactic acid (PLA), which show an increase in molecular weight, softening point, and ductility. The main results show that the use of nano additives improves the durability of the road surface, increases its resistance to cracking, and increases the service life of the material under different climatic conditions. For example, roads modified with nano silica showed a 20-30% improvement in tensile strength and a 15% reduction in deformation. In addition, PLA bitumen modification increased the softening point by 10°C and improved the overall elasticity by 25%. These results emphasize the potential of micro- and nano-additives to create more durable, environmentally friendly, high-performance road materials.

Biomimetic 3D-Printed Armored Structures for Durable Superhydrophobic Surfaces: Integrating Macroprotection and Nanofunctionality

Biomimetic 3D-Printed Armored Structures for Durable Superhydrophobic Surfaces: Integrating Macroprotection and Nanofunctionality

Bionic Fluorine-Free Multifunctional Photothermal Surface for Anti/de/Driving-Icing and Droplet Manipulation.

Due to safety concerns associated with ice accumulation, there is a need to develop a durable surface with anti/de-icing properties. Inspired by Gecko skin and Nepenthes, a superhydrophobic photothermal surface (SH-PS) with micro-nano hierarchical structure based on carbon nanotube composites is prepared by one-step laser method. It can be switchable to a slippery photothermal surface (S-PS) by injecting silicone oil. S-PS can effectively delay icing at -20 °C/-30 °C, and maintain excellent dynamic anti-icing capabilities following 28 times supercooled droplet impact (-30 °C). Under near-infrared (NIR) irradiation, S-PS exhibits high-efficiency photothermal deicing and excellent ice droplet control capabilities. Furthermore, S-PS also exhibits remarkable droplet manipulation capabilities under NIR irradiation, even anti-gravity transport (8°) and programmable track manipulation. Notably, after 20m abrasion, the S-PS still maintains good performances of anti/de-icing and droplet manipulation after infusing lubricant. All these excellent performances can promote its application in a wider range of fields.

Dual-Coated Antireflective Film for Flexible and Robust Multi-Environmental Optoelectronic Applications.

Artificial antireflective nanostructured surfaces, inspired by moth eyes, effectively reduce optical losses at interfaces, offering significant advantages in enhancing optical performance in various optoelectronic applications, including solar cells, light-emitting diodes, and cameras. However, their limited flexibility and low surface hardness constrain their broader use. In this study, we introduce a universal antireflective film by integrating nanostructures on both sides of a thin polycarbonate film. One side was thinly coated with Al2O3 for its high hardness, enhancing surface durability while maintaining flexibility. The opposite side was coated with SiO2 to optimize antireflective properties, making the film suitable for diverse environments (i.e., air, water, and adhesives). This dual-coating strategy resulted in a mechanically robust and flexible antireflective film with superior optical properties in various conditions. We demonstrated the universal capabilities of our antireflective film via optical simulations and experiments with the fabricated film in different environments.

Superhydrophobic Modification of Atomic Layer Deposition Antireflection Aluminum Oxide Film: A Simple Evaporative Coating Technique.

The antireflective transmittance-enhancing films have important applications in solar cells and other applications due to their self-cleaning and high light transmittance. However, obtaining high transmittance, highly durable, and superhydrophobic surfaces in a simple and easily accessible way is still a challenge. A simple evaporative coating technique has been proposed that can be used to prepare antireflective superhydrophobic aluminum oxide films using 1H,1H,2H,2H-perfluoroalkyltriethoxysilanes. The results show that the contact angle of grass-like alumina increased from 99.5° to 155°. The surface energy of grass-like alumina decreased from 17.96 to 1.93 mN/m. The maximum value of light transmittance is close to 98%, and the average transmittance is above 95%. The films have excellent ultraviolet resistance and thermal stability along with relative mechanical and chemical stability. Meanwhile, this method has an excellent capacity for shape preservation. The relationships between the evaporation temperature and time and the light transmittance and hydrophobic angle of the films were also investigated together. This approach has the potential to be extended to large-scale industrial production.

Superhydrophobicity induced antibacterial adhesion and durability of laser bidirectionally-textured zirconia surfaces with different inclination angles

Femtosecond laser bidirectional texturing with different laser energy densities and inclination angles was performed on zirconia (ZrO2) surfaces. The laser bidirectional texturing models under different inclination angles were constructed to predict the water contact angles (WCAs), and the superhydrophobicity induced antibacterial adhesion mechanism was analyzed. The results revealed that under the combined effect of the optimal laser energy density (7.0 J/cm2) and inclination angle (90°), the laser-textured ZrO2 surface could obtain a micro-nano dual-scale structure composed of periodic regular micro-cones and nanoparticles. This structure not only promoted the adsorption of carbon-containing hydrophobic groups from the stearic acid and the air to form a superhydrophobic surface with excellent chemical/mechanical durability and anti-fouling/self-cleaning abilities, but also minimized the contact area with the bacterial suspension (solid/liquid contact area ratio of 6 %) to enhance antibacterial ability. The optimal stearic acid-modified laser-textured ZrO2 surface exhibited an extremely low adhesive force (Fadhesive=6.69 μN) to the bacterial suspension, and thus achieved the highest antibacterial ratio of 85.3 %. This study is expected to enrich the application of ZrO2 ceramics in the medical field.

Improving the surface durability of wind gears via shot peening and superfinishing

Gearbox power density plays a key role in wind energy competitiveness. As wind turbines have become increasingly larger, gear surface durability and flank fracture load carrying capacity have become key elements in gearbox sizing. While shot peening and superfinishing have been studied independently as potential techniques to improve surface durability, few reported studies have combined both of these processes to increase the gear flank load-carrying capacity. In this work, spot pitting tests were carried out to evaluate the expected load-carrying capacity increase for wind gears through this combination of finishing processes. The results are consistent with previous research's conclusions and highlight the need for further investigations to evaluate potential increased flank fracture risk related to the near-surface residual stress distribution.

Fluorine-free superhydrophobic Ni/Mn-TiO2 composite coatings on carbon steel via one-step electrodeposition for enhanced durability and corrosion resistance

The application of superhydrophobic coatings on carbon steel (CS) surface represents an effective strategy for mitigating corrosion in these materials. This study presents the preparation of superhydrophobic Ni/Mn-TiO2 composite (SNMT) coatings on CS substrates through a facile one-step electrodeposition technique. The formation mechanism of SNMT coatings was meticulously analyzed under varying conditions of nanoparticle types and concentration levels. The inclusion of TiO2 nanoparticles, with an optimal additive concentration of 1 g, facilitated the formation of numerous low surface energy, cauliflower-like microstructures on CS interface. Surprisingly, the results indicate that SNMT coatings maintained commendable superhydrophobicity even post-exposure to superficial damages such as tape peeling, sandpaper wear, and knife-scratch, as evidenced by a static contact angle (CA) exceeding 158° and a sliding angle (SA) below 2°. Furthermore, the corrosion inhibition efficacy of SNMT coatings was quantitatively assessed via dynamic potential polarization curves in a simulated seawater environment. The results demonstrated that SNMT coatings exhibited excellent corrosion inhibition performance in simulated seawater solution, with a protection efficiency (PE) reaching 96.5%. In conclusion, superhydrophobic surfaces can effectively inhibit the penetration of corrosive liquids. The durability and robustness of such superhydrophobic surfaces advocate for their potential widespread application in enhancing the longevity and reliability of CS in corrosive environments.

Mechanically durable plant-based composite surface towards enhanced antifouling properties

The biofouling adhering to underwater facilities has a negative impact on the environment, energy, and economic development. However, conventional anti-adhesion organic silicon and organic fluorine materials often have poor adhesion properties and mechanical stability when combined with substrates. This work presents a novel strategy for preparing composite antifouling coatings that low surface energy plant-based carnauba wax (CW) covering through rough substrates and chemically bond with flexible polydimethylsiloxane (PDMS) oligomers or polymers. The CW coating adheres strongly to the substrate owing to the mobility of the liquated CW, which flows into the micro-nano structure of the substrate and solidifies on the solid surface. The polymerization reaction of (PDMS) oligomers compounded the coating, thereby creating a composite coating with superior lubricating and antifouling properties. This distinctive bonding process imbued the coating with exceptional characteristics, including remarkable mechanical stability in destructive tests as well as an impressive ability to repel fouling, such as protein attachment, bacterial adhesion, diatom deposition, and biofilm formation. This work systematically investigated the impact of the composition and structure of composite materials on their mechanical stability and resistance to fouling, and developed high-performance antifouling coatings in the real world.

MODELING THE PLASTIC DEFORMATION STATE OF THE CONTACT SURFACE DURING FRICTION

The mechanics of contact destruction of compounds during friction under conditions of complex thermodynamic loading was researched. The possibility of a mathematical description of complex damage to friction units and wear intensity is shown, taking into account the peculiarities of the surface layer formation during contact. A method for calculating the surface strength and durability of tribo-compounds is presented. This allows us to relate the parameters of the stressed state of a point (friction coefficient, shape factor) with the thermomechanical parameters of the process. By assessing changes in the friction coefficient and shape parameters, it becomes possible to determine the yield stress and establish structural transformations corresponding to a given stress state.

Rapidly one-step fabrication of durable superhydrophobic graphene surface with high temperature resistance and self-clean

High temperature resistant and self-cleaning superhydrophobic flexible film has potential application value in lunar exploration. In this paper, a novel method of magnetic field-assisted ultrafast laser induced plasma was proposed to fabricate strongly superhydrophobic graphene on polyimide film with multi-level micro-nano structure. The longitudinal magnetic field contributed to constrain the induced plasma in the lateral direction so as to form a plasma plume with high temperature and high energy density. The multi-level micro-nano graphene structures with better ordering and superhydrophobicity were fabricated, which had a contact angle of 163.1° and a roll-off angle of 1.5°, as well as hydrophobic CC bond content of 72.82 %. The droplets can achieve obvious bouncing at different heights of 1 cm and 5 cm on surfaces at different angles of 0°, 5° and 10°. The contact angle was still greater than 160° after 25 days of aging treatment and heating at 300 °C for 40 min. The water droplets before and after the heating of the sample can push the dust off the surface, showing excellent high temperature resistance and self-cleaning performance.

Study of the Impact of Droplets on Superhydrophobic Surfaces

The potential applications of superhydrophobicity for self-cleaning, microfluidic systems, and so on, inspired by the “lotus leaf effect”, have recently attracted great attention from academia and industry. To date, however, neither experimental nor theoretical studies have reached the scalable application of superhydrophobic surfaces, and no simple methods have been developed to produce durable superhydrophobic surfaces. In this project, conical, cylindrical, and cube microstructures with different shapes and dimensions were prepared by 3D printing. Among these structures, the conical microstructures without further modification exhibited the best hydrophobic performance with a contact angle of 120°. However, the hydrophobic performance of the cube microstructures was significantly improved with the addition of an FAS coating to the surface, reaching 131°. This indicates that, with the help of the coating, the 3D printed materials with special features can be transformed into hydrophobic surfaces. The outcome of this project will be useful in promoting the efficient and low-cost preparation of superhydrophobic functional surfaces and their engineering applications.

Durable self-cleaning superhydrophobic cotton fabrics for wearable textiles

Cotton fabric is widely used in various industrial goods due to its ability to enhance aesthetic appeal, but preserving its shine and genuine appearance presents a significant challenge. In this work, a durable self-cleaning superhydrophobic surface suitable for wearable textiles was achieved on cotton fabrics by applying a composite coating of stearic acid-modified titanium oxide (TiO2) nanoparticles and polydimethylsiloxane (PDMS) through a simple dip/spray coating technique. The fabric surface displayed an exceptional water contact angle (WCA) of 165 ± 2° and a minimal slide angle (SA) of approximately 2°, demonstrating outstanding water repellency and sliding characteristics. The surface exhibited impressive self-cleaning abilities for both dust particles and muddy water. The coated cloth maintained its exceptional superhydrophobic properties even after being subjected to 40 abrasion cycles, 30 adhesive tape peels, nearly 60 min of ultrasound treatment, and 30 washing cycles. Additionally, the as-coated cotton showed excellent chemical stability, tensile strength, flexibility, air permeability and breathability. The model trials with a baby doll have proven the high possibility of commercializing self-cleaning clothing in this research.

Design and Characterization of Epoxy Resin Systems Based on Mixtures of Imidazolium-Based Ionic Liquids with Docusate and Dicyanamide Anions

This study focuses on the synthesis, characterization, and application of four ionic liquids (ILs), three of which are being reported for the first time, with unique thermal properties and diverse anion-cation combinations, specifically in the context of epoxy resin polymerization. 1-3-Didodecylimidazolium dicyanamide (dDDIM DCA), 1-3-Didodecylimidazolium docusate (dDDIM DOSS), 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA), and 1-ethyl-3-methylimidazolium docusate (EMIM DOSS) were used to prepare six different mixtures with the same cation and with varying concentrations of DCA components, which is the main factor of an efficient polymerization, while the other component is intended to modify the properties of the cured resin. Mixtures based on EMIM cation demonstrated increased enthalpy and lower onset polymerization temperatures, indicating more efficient curing processes. The hardness of cured epoxy resins can be adjusted by altering the curing temperature and IL composition, with EMIM DCA and EMIM DOSS mixtures displaying high Shore A hardness, suitable for durable surface applications. In contrast, mixtures with higher dDDIM DCA proportions offered a balance between rigidity and flexibility, ideal for applications requiring both mechanical strength and elasticity.

Construction of a superhydrophobic surface with long-term durability on 5052 Aluminium for corrosion protection

Superhydrophobic surfaces have been demonstrated to offer exceptional corrosion protection for metal surfaces. However, long-term stability issues have plagued superhydrophobic surfaces. In this study, a durable superhydrophobic surface on aluminum (SHC-Al) was created using etching combined with anodizing followed by polydimethylsiloxane (PDMS) modification. To optimize the multi-scale rough structures, the optimal anodizing conditions were explored in detail. The superhydrophobic surfaces were analyzed using Field emission scanning electron microscopy (FESEM), Confocal laser microscopy (CLSM), X-ray energy spectrometry (EDS), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), contact angle (CA) measurements, stability tests, and electrochemical analysis. The results reveal the successful preparation of a nest-like micro-nano composite structure on metal surface, and the contact and sliding angles of SHC-Al were measured at 157.6° and 6°, demonstrating the formation of excellent superhydrophobic surface. Electrochemical tests showed a corrosion current density of only 1.38 × 10–9 A∙cm-2 for SHC-Al, with a corrosion inhibition efficiency of 99.97 %, highlighting its outstanding anti-corrosion performance. Furthermore, stability tests demonstrated the SHC-Al surface had long-term durability. This study not only provides new evidence for the preparation of long-lasting superhydrophobic surfaces, but also provides a new solution for the practical application of superhydrophobic surfaces.

Femtosecond Bessel laser beam induced concentric rings on SiC for circular symmetry wide-viewing angle structural color

The laser-induced structural coloring technique holds significant potential for various applications due to its precision, controllability, and versatility across different materials. However, laser-induced structural colors face the problems of durability, homogeneity and indistinguishability, which are not conducive to their application as large-scale identifiable markers. In this paper, an innovative approach has been developed to achieve a circular-symmetric structural color display on durable SiC surfaces by fabricating periodic concentric ring structure arrays using the sidelobe light field of a femtosecond zero-order Bessel beam. The research involved a systematic study of the effects of laser power and pulse number on SiC, along with a detailed analysis of the micro-nanostructures evolving on the SiC surface after laser scanning. Additionally, an examination of the characteristics of circular-symmetric structural color displays and their wide viewing angles in periodic circular structures was conducted. Finally, a comparison was made between the structural color display effects of a concentric ring structure generated by a single pulse and the Laser-Induced Periodic Surface Structures (LIPSS) generated by three pulses. This comparison underscores the potential application of alternating between the high saturation color of the concentric ring structure and the low saturation dark light of the LIPSS for anti-counterfeit coding purposes. The findings of this research present promising opportunities for low-cost mass manufacturing in anti-counterfeit labeling and the advanced processing of photonic devices using SiC.

Unveiling the novel anti-corrosion and anti-bacterial biofilm forming characteristics of eco-safe MWCNT-AZ91E alloy for food-processing surfaces

This study explores the eco-friendly modification of AZ91E alloy with MWCNT casting to enhance surfaces crucial for food processing, storage, and transportation, with a specific focus on reducing bacterial biofilm formation and preventing corrosion. Incorporating nanomaterials like MWCNT into magnesium alloys offers promising prospects for improving the surfaces of equipment and structures used in food-related industries. The advanced mechanical properties observed in MWCNT-doped alloys can lead to the development of lightweight yet durable surfaces essential for maintaining hygiene standards and ensuring food safety during processing, storage, and transportation. Employing sophisticated systematic practices such as XRD, FTIR, and Vickers hardness testing allows for comprehensive evaluation of surface modifications and mechanical enhancements. Furthermore, the demonstrated corrosion resistance of MWCNT-doped magnesium alloys is crucial for protecting surfaces from degradation caused by exposure to corrosive environments commonly encountered in food processing facilities and transportation systems. Additionally, the remarkable antibacterial properties exhibited by MWCNT-doped alloys hold promise for mitigating bacterial biofilm formation on surfaces, thereby contributing to enhanced sanitation and hygiene practices in food-related industries. KEY WORDS: Multiwalled carbon nanotube, Magnesium alloys, Anticorrosion, Squeeze casting, Antibacterial, Biofouling Bull. Chem. Soc. Ethiop. 2024, 38(6), 1897-1914. DOI: https://dx.doi.org/10.4314/bcse.v38i6.30

A durable superhydrophobic surface with bud-particle structure prepared by one-step spray method

Superhydrophobic surfaces play an essential role in numerous applications such as anti-fouling, waterproofing, and drag reduction due to their water-repellent. However, for most fabrication methods, there are high requirements for the preparation process and conditions. Meanwhile, the superhydrophobic surfaces generally have the problem of insufficient durability. In this study, a one-step method to fabricate a stable superhydrophobic surface by spraying is proposed. A new bud-particle structure is obtained by modifying micron and nano Aluminium hydroxide(Al(OH)3) particles, which helps the coated surface to demonstrate excellent superhydrophobicity with the water contact angle ∼157.0° and rolling angle ∼2.0°, and it shows great repellency to water droplet impact. Due to the compatibility of Al(OH)3with the pretreatment substrate and the reinforcing effect of nanoparticles, the coating maintained the superhydrophobicity well in the sandpaper wear and the ultrasonic damage test, which reflects the outstanding robustness of the coating.Moreover,benefiting from the control of the wetting state by micronand nanoparticles doping,the coating showed an excellent underwater drag reduction effect in the rheometer experiment, with a drag reduction rate of ∼67.7 %. The one-step spraying method proposed is a simple and convenient way to create the surface with excellent superhydrophobicity and durability, which has great potential applications in improving metal surface oxidation resistance and underwater reducing drag.

Enhancing durability of superhydrophobic surfaces via nanoparticle-induced bipolar interface effects and micro-nano composite structures: A femtosecond laser and chemical modification approach

Superhydrophobic coatings are vital in energy, aerospace, and chemical engineering, while their complex preparation and limited durability hinder widespread application. Therefore, inspired by the unique structures of hydrophobic cotton surfaces and mosquito eyes in nature, a durable aluminum alloy superhydrophobic surface is developed using a combination of femtosecond laser and chemical modification methods. Initially, porous microneedle micro-nanostructures are ablated on the surface of the aluminum alloy via femtosecond laser technology. Then, epoxy resin modified with γ-aminopropyl triethoxysilane (KH550) forms a covalently bonded intermediate layer. Finally, biphasic silicon dioxide (BP-SiO2) nanoparticles modified by hexadecyltrimethoxysilane (HDTMS) are used to construct the top hydrophobic layer. The covalent interface interactions between the aluminum alloy substrate and the intermediate layer, as well as between the intermediate layer and the top layer, significantly enhance the durability of the superhydrophobic surface. The prepared F-M@KH-EP/BP-SiO2 coating exhibits outstanding superhydrophobic properties, with a water contact angle (CA) as high as 168.56° and a sliding angle (SA) as low as 1.52° More encouragingly, the composite coating maintains its excellent water resistance even when subjected to harsh mechanical durability damage, including sandpaper wear, tape stripping tests, water drop and sand impact tests. Moreover, the prepared coatings maintain distinguished non-wettability in harsh operating conditions such as corrosive liquid environments, ultraviolet radiation, ultrasonic vibration, etc. Additionally, the coating demonstrates remarkable self-cleaning properties. Superhydrophobic surface durability is significantly enhanced by combining nanoparticle-induced bipolar interface effect and micro-nano structures. These findings provide theoretical reference for the design and application of durable superhydrophobic coatings.

Effect of lubricant loading in slippery liquid-infused surface for persistent anti-icing performance

Due to the vast applications in biomedical materials and aerospace industry, smart slippery liquid-infused porous surfaces (SLIPSs) have attracted remarkable attention. However, there are still challenges in the fabrication of durable SLIPS. In this work, based on linear polyurea and silicone oil, a series of durable anti-icing surface were fabricated. Based on the long-lasting secretion of lubricant, the ice adhesion strength of 60-PUa was 2.7 ± 0.5 kPa and could remain below 10 kPa even after 30 icing-deicing cycles. And the icing delay time of 60-PUa could be extended up to 870 s at a temperature of −15 °C. The introduction of large numbers of reversible hydrogen bonds in the system and silicone oil made it possible to achieve high self-healing efficiency under natural conditions. The coating system not only improved the ice removal ability, but also had excellent water-sliding properties, the droplet could slide under its own weight on 60-PUa at a tilt angle of 4.7°. This work provides an easy way to fabricate multi-functional SLIPS with durability.