Recent Advances in Superhydrophobic and Icephobic Surfaces

A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Surface Characterization, Deposition and Modification".

Deadline for manuscript submissions: closed (31 August 2023) | Viewed by 16940

Special Issue Editor


E-Mail Website
Guest Editor
Anti-icing Materials (AIM) Lab, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
Interests: superhydrophobic surfaces; superoleophilic surfaces; icephobic surfaces

Special Issue Information

Dear Colleagues,

I invite you to submit your recent research work to the Special Issue titled “Recent Advances in Superhydrophobic and Icephobic Surfaces”. Bio-inspired by nature, superhydrophobic surfaces have been utilized in various applications, including self-cleaning, anti-icing, anti-fouling, anti-fogging, anti-corrosion, oil/water separation, sensors, and energy storage devices. The long-term use and maintenance of superhydrophobicity in harsh environments are still big challenges in practical applications, which we would like to solve by rationally designing mechanically durable superhydrophobic surfaces. Due to their excellent water repellency, superhydrophobic surfaces can be applied in the field of anti-icing applications. However, superhydrophobic surfaces can lose their icephobicity due to many factors (i.e., condensation, the interlocking effect between the ice and interface, the sustainability of low surface energy); thus, we welcome discussions regarding the similarities, distinctions, and correlations between superhydrophobic and icephobic surfaces.

Although ice accumulation on exposed surfaces is an unavoidable problem as time elapses and temperatures lower sufficiently, to suppress such an issue, various types of icephobic surfaces have been developed, including superhydrophobic surfaces (SHSs), aqueous lubricating layers, organic lubricating layers, organogels, polyelectrolyte brush layers, electrolyte-based hydrogels, multi-crack initiator-promoted surfaces, etc. Generally, the two important issues for designing icephobic surfaces are the low ice adhesion strength and mechanical durability after icing/de-icing cycles. Moreover, very recently, active de-icing approaches (magnetic responsive, electro-thermal, and photo-thermal stimuli) have also been introduced to combine with passive icephobic surfaces for the realization of rapid and reliable de-icing. In short, the aim of this Special Issue is to summarize recent experimental and computational advances in both superhydrophobic and icephobic surfaces, as we hope for it to open new pathways for further research in both superhydrophobic and icephobic surfaces.

In particular, the topics of interest include, but are not limited to:

  • Design and preparation of superhydrophobic and icephobic surfaces;
  • Various applications of superhydrophobic surfaces;
  • The sustainability and durability of superhydrophobicity;
  • Correlations between superhydrophobicity and icephobicity;
  • Icing delay time on icephobic surfaces;
  • Low ice adhesion strength surfaces;
  • Durable icephobic surfaces;
  • Anti-icing mechanisms;
  • Active de-icing approaches (electro-thermal or photo-thermal stimuli);
  • Multi-scale simulations on superhydrophobic and icephobic surfaces.

Prof. Dr. Zhiwei He
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Coatings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • self-cleaning
  • repellency
  • anti-icing
  • icing delay time
  • ice adhesion strength

Published Papers (11 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

12 pages, 9413 KiB  
Article
Superhydrophobic and Thermally Conductive Coating for Restraining Corona Loss and Audible Noise of High-Voltage Transmission Lines
by Li Li, Junhuang Xu, Yifan Wang, Wei Meng, Shengping Fan and Hongqiang Li
Coatings 2023, 13(9), 1530; https://doi.org/10.3390/coatings13091530 - 31 Aug 2023
Viewed by 734
Abstract
In recent years, the number of high-voltage transmission lines has sharply increased with the rapid development of modern industry. However, a corona discharge phenomenon often occurs on the exposed high-voltage transmission lines, leading to energy loss and noise pollution. Herein, we have proposed [...] Read more.
In recent years, the number of high-voltage transmission lines has sharply increased with the rapid development of modern industry. However, a corona discharge phenomenon often occurs on the exposed high-voltage transmission lines, leading to energy loss and noise pollution. Herein, we have proposed a facile spraying method to prepare a superhydrophobic and thermally conductive coating to restrain the corona discharge phenomenon of high-voltage transmission lines, with vinyl silicone oil and hydrogen silicone oil as the main materials and modified boron nitride (BN) as a thermal conductive filler. The obtained composite coating exhibited superhydrophobicity, with a high water contact angle of 162°. In addition, the coating also showed a good self-cleaning capability, non-adhesion capability, mechanical stability, and chemical stability. Owing to the construction of the thermally conductive pathways with BN, the thermal conductivity of the coating reached 1.05 W/m·K, which was beneficial to quickly dissipating the heat generated by the current heating effect. Moreover, the corona losses of the positive and negative electrodes under simulated rainy conditions were decreased by 7.43% and 8.05%, respectively. The findings of our work have provided a new strategy to effectively restrain the corona discharge phenomenon of transmission lines, showing great application potential in the field of high-voltage power networks. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

16 pages, 5128 KiB  
Article
Study on Anti-Icing Performance of Biogas-Residue Nano-Carbon Coating for Wind-Turbine Blade
by Fang Feng, Ruixue Wang, Wei Yuan and Yang Li
Coatings 2023, 13(5), 814; https://doi.org/10.3390/coatings13050814 - 22 Apr 2023
Cited by 4 | Viewed by 1092
Abstract
Icing is a common phenomenon in nature and has a serious impact on wind turbines. Anti-icing coatings have become a major focus of industrial applications and academic research. In this study, a hydrophobic nano-carbon coating was prepared from corn-straw-biogas residue. The characterization results [...] Read more.
Icing is a common phenomenon in nature and has a serious impact on wind turbines. Anti-icing coatings have become a major focus of industrial applications and academic research. In this study, a hydrophobic nano-carbon coating was prepared from corn-straw-biogas residue. The characterization results of the SEM, BET, FTIR, and XRD analyses showed that the hydrophobic nano-carbon has good pore structure and crystal structure. The hydrophobic and anti-icing effects of the carbon were confirmed by contact-angle measurements and anti-icing experiments. The ice thicknesses of the hydrophobic nano-carbon-coated aluminum-alloy blade (AAB) and bakelite blade (BB) were found to decrease by 1.20 mm and 1.10 mm, respectively, compared with those without coating; their weights decreased by 2.00 g and 1.31 g, respectively. The ratios of the icing areas before and after the hydrophobic nano-carbon coating of the AAB and BB were 8.15% and 9.65%, respectively. In brief, this method is a more effective technique for creating anti-icing coatings on wind-turbine blades and other outdoor apparatus. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

9 pages, 3347 KiB  
Article
Wind Tunnel Tests of Surface Icing Distribution on Aluminum Alloy and Carbon Fiber-Reinforced Polymer Blades for Wind Turbines
by Weirong Lin, Xuefeng Lin, Chuanxi Wang, Tong Wu, Zhe Meng, Anmin Cai, He Shen, Yan Li and Fang Feng
Coatings 2023, 13(5), 810; https://doi.org/10.3390/coatings13050810 - 22 Apr 2023
Cited by 1 | Viewed by 995
Abstract
In cold areas, wind turbines face ice risk. The ice accretion on the blade surface will reduce the output power of wind turbines. To explore the effect of blade material on icing distribution, the blades of aluminum and carbon fiber-reinforced polymer (CFRP) were [...] Read more.
In cold areas, wind turbines face ice risk. The ice accretion on the blade surface will reduce the output power of wind turbines. To explore the effect of blade material on icing distribution, the blades of aluminum and carbon fiber-reinforced polymer (CFRP) were made, and the icing wind tunnel tests were carried out. The icing test is conducted under three icing times (2 min, 4 min, and 6 min) and three ambient temperatures (−5 °C, −10 °C, and −15 °C). The experimental results show that the icing time and ambient temperature are key factors in icing distribution. When the icing time increases, the average thickness of ice on the blade surface increases, and the airfoil profile of the blade changes significantly. When the ambient temperature decreases, the average thickness of ice on the blade surface increases, and the ice type changes from glaze ice to rime ice. The effect of blade material on the icing distribution is significantly affected by ambient temperature. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

17 pages, 5833 KiB  
Article
An Experimental Study on Biochar/Polypyrrole Coating for Blade Anti-Icing of Wind Turbines
by Xiaoheng Li, Xiaojuan Li, Zhongqiu Mu, Yan Li and Fang Feng
Coatings 2023, 13(4), 759; https://doi.org/10.3390/coatings13040759 - 12 Apr 2023
Cited by 2 | Viewed by 1420
Abstract
Wind turbines operating in cold regions are prone to freezing in winter, which can affect their performance and safety. To resolve this situation, the development of blade anti-icing technology has attracted widespread attention. In this study, a type of biochar/polypyrrole coating was obtained [...] Read more.
Wind turbines operating in cold regions are prone to freezing in winter, which can affect their performance and safety. To resolve this situation, the development of blade anti-icing technology has attracted widespread attention. In this study, a type of biochar/polypyrrole coating was obtained through synthesis on the surface of biochar. After characterization, it was found that the porous structure, irregular dents, and bumps on the surface of biochar/polypyrrole material contributed to the formation of a nanoscale roughness structure with a typical super-hydrophobic nanostructure. Additionally, it had a sufficient surface area. The wetting characteristics of the coating were analyzed with the assistance of a contact angle measurement instrument. The contact angle of the coating was determined as 151°, which indicates the excellent hydrophobic properties of the coating. Icing wind tunnel tests were carried out to evaluate the anti-icing effect of biochar coating and biochar/polypyrrole coating at different ambient temperatures and wind speeds. Compared with uncoated leaves, the icing area of biochar/polypyrrole coating was reduced. Additionally, the anti-icing effect of biochar/polypyrrole coating was most significant. This study provides a practical reference for the research of anti-icing coating on wind turbine blades. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

15 pages, 9503 KiB  
Article
A Wind Tunnel Test of the Anti-Icing Properties of MoS2/ZnO Hydrophobic Nano-Coatings for Wind Turbine Blades
by Bo Liu, Zhiyuan Liu, Yan Li and Fang Feng
Coatings 2023, 13(4), 686; https://doi.org/10.3390/coatings13040686 - 27 Mar 2023
Cited by 3 | Viewed by 1351
Abstract
Wind turbines operating in cold regions are prone to blade icing, which seriously affects their aerodynamic characteristics and safety performance. Coatings are one of the effective solutions to the icing problem on wind turbine blades. In this study, MoS2/ZnO/PDMS superhydrophobic nano-anti-icing [...] Read more.
Wind turbines operating in cold regions are prone to blade icing, which seriously affects their aerodynamic characteristics and safety performance. Coatings are one of the effective solutions to the icing problem on wind turbine blades. In this study, MoS2/ZnO/PDMS superhydrophobic nano-anti-icing coatings were prepared using the hydrothermal method and the liquid phase method. SEM revealed that the MoS2/ZnO coating was a typical superhydrophobic nanostructure with an ultra-thin sheet-like morphology of clusters and a hilly nano-rough structure, with contact angles (CA) of 152.1° and 4.7° with water droplets and the sliding angle (SA), respectively. The MoS2/ZnO/PDMS coating had an adhesion strength to ice of 78 kPa, which was 60.2% lower than an uncoated surface. The icing effects of the NACA0018 airfoil blade model with or without MoS2/ZnO coatings were studied at different ambient temperatures and wind speeds using the icing wind tunnel test. The results showed that, compared to uncoated blades, the level of icing was lower on the blade airfoil surface that was coated with MoS2/ZnO. At 10 m/s and −10 °C, the icing thickness and icing area of the leading edge of the blade airfoil were 13.7% and 28.3% lower, respectively. This study provides a valuable reference for the development of anti-icing coatings for wind turbine blades. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

16 pages, 11118 KiB  
Article
Preparation and Characterization of Stable Superhydrophobic Copper Foams Suitable for Treatment of Oily Wastewater
by Aikaterini Baxevani, Fani Stergioudi, Nikolaos Patsatzis, Lamprini Malletzidou, George Vourlias and Stefanos Skolianos
Coatings 2023, 13(2), 355; https://doi.org/10.3390/coatings13020355 - 03 Feb 2023
Cited by 2 | Viewed by 1465
Abstract
A simple two-stage chemical solution process is reported, to deposit a superhydrophobic film on copper foams with a view to be employed in oil absorption or filtration procedures. The first stage includes the growth of a silver layer to increase micro roughness and [...] Read more.
A simple two-stage chemical solution process is reported, to deposit a superhydrophobic film on copper foams with a view to be employed in oil absorption or filtration procedures. The first stage includes the growth of a silver layer to increase micro roughness and the second one evolves the modification of the film using stearic acid. The whole process is time-saving, cost effective and versatile. UV-Vis spectroscopy was employed to determine optimum deposition durations and detect potential film detachments during the synthesis process. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to examine the film structure and elemental analysis. Surface functional groups were detected by Fourier transform infrared (FTIR) spectroscopy. An adherent superhydrophobic silver coating was achieved under optimum deposition durations. A leaf-like structural morphology appeared from silver deposition and spherical, microflower morphologies stemmed from the stearic acid deposition. The influence of process conditions on wettability and the obtained silver film morphology and topography were clarified. Thermal stability at several temperatures along with chemical stability for acidic and alkaline environments were examined. Oil absorption capacity and separation efficiency were also evaluated for the optimum superhydrophobic copper foams. The results showed that the produced superhydrophobic copper foams can potentially be used to oil/water separation applications. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

11 pages, 3960 KiB  
Article
Numerical Investigation of the Effect of Symmetry on Evaporation Triggered Elastocapillary Top-Gathering of High Aspect Ratio Micropillars
by Farshad Barghi Golezani, Rama Kishore Annavarapu and Hossein Sojoudi
Coatings 2023, 13(2), 292; https://doi.org/10.3390/coatings13020292 - 28 Jan 2023
Cited by 8 | Viewed by 1630
Abstract
High-aspect-ratio (HAR) micropillar arrays offer a wide range of applications in micro-contact printing, switchable transparent optical windows, superhydrophobic surfaces, mechanical sensors, and actuators, due to their properties such as large surface area and excellent mechanical compliance. However, owing to their high aspect ratio, [...] Read more.
High-aspect-ratio (HAR) micropillar arrays offer a wide range of applications in micro-contact printing, switchable transparent optical windows, superhydrophobic surfaces, mechanical sensors, and actuators, due to their properties such as large surface area and excellent mechanical compliance. However, owing to their high aspect ratio, these microstructures are prone to lateral deflection by elastocapillary forces in liquid environments, which is known as top-gathering, limiting their manufacturing processes and applications. Here, the impact of symmetry on evaporation triggered top-gathering of micropillars was studied numerically. The initiation of the micropillar deflection due to capillary forces under varying force distributions was simulated using a COMSOL Multiphysics simulation package. The simulation was carried out for the configurations of two, four, and an array of micropillars. For the four micropillar configuration, a new equation was suggested for calculating the micropillar deflection due to elastocapillary forces, using force distributions around the micropillars. The suggested equation was verified by comparison with the experimental observations. The effect of droplet evaporation on deflection/top-gathering of micropillars was also investigated. It was found that initiation of deflection is due to asymmetry at the rim of the droplet, generating domino-like deflection of the other micropillars. This study provides a new equation/criterion for estimating deflection of the micropillars, suggesting array designs that are resistant to such deflections when interacting with liquids. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

12 pages, 19688 KiB  
Article
An Experimental Study on Adhesion Strength of Offshore Atmospheric Icing on a Wind Turbine Blade Airfoil
by Zhongqiu Mu, Yan Li, Wenfeng Guo, He Shen and Kotaro Tagawa
Coatings 2023, 13(1), 164; https://doi.org/10.3390/coatings13010164 - 11 Jan 2023
Cited by 6 | Viewed by 1463
Abstract
When wind turbines work in a cold and humid environment, especially offshore condition, ice accretion on the blade surfaces has a negative effect on the aerodynamic performance. In order to remove the ice from the wind turbine blade, the adhesive characteristics of atmospheric [...] Read more.
When wind turbines work in a cold and humid environment, especially offshore condition, ice accretion on the blade surfaces has a negative effect on the aerodynamic performance. In order to remove the ice from the wind turbine blade, the adhesive characteristics of atmospheric icing on the blade surface should be mastered under various conditions. The objective of this study is to evaluate the effects of offshore atmospheric conditions, including wind speeds, ambient temperatures and, especially, the salt contents on ice adhesion strength for wind turbine blades. The experiments were conducted on a NACA0018 blade airfoil under conditions including an ambient temperature of −3 °C~−15 °C, wind speed of 6 m/s~15 m/s and salt content of 1~20 mg/m3. The results showed that salt content was the most important factor affecting the ice adhesion strength, followed by ambient temperature and wind speed. The interactive effect of wind speed and salt content, ambient temperature and salt content were extremely significant. The research can provide a reference for the anti-icing for offshore wind turbines. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

10 pages, 3540 KiB  
Article
Splitting an Impacting Droplet by a Superhydrophobic Wire
by Dong Song, Changsheng Xu, Baowei Song, Guang Pan, Haibao Hu and Chang-Hwan Choi
Coatings 2022, 12(12), 1866; https://doi.org/10.3390/coatings12121866 - 30 Nov 2022
Cited by 3 | Viewed by 1420
Abstract
Splitting a droplet into several segments is of great significance in many applications such as the detection of tiny liquid samples, whereas the surface tension tends to hold liquid to remain as one drop, causing difficulty in separating the droplet into pieces. In [...] Read more.
Splitting a droplet into several segments is of great significance in many applications such as the detection of tiny liquid samples, whereas the surface tension tends to hold liquid to remain as one drop, causing difficulty in separating the droplet into pieces. In this work, a method is proposed to split an impacting droplet with a relatively high velocity or Weber number into two halves by a superhydrophobic wire. The effects of the wire wettability and the impact velocity of the droplet on the splitting phenomena and the efficacy to an anti-icing application are investigated. Compared to a hydrophilic wire, a superhydrophobic wire splits an impacting droplet at a relatively high speed of the Weber number greater than 3.1 and inhibits ice accretion at the temperature as low as −20 °C. The results suggest that a superhydrophobic wire can be utilized in the droplet manipulation and anti-icing applications such as power lines in high latitude areas. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

15 pages, 5431 KiB  
Article
The Synergistic Effect of Terminal and Pendant Fluoroalkyl Segments on Properties of Polyurethane Latex and Its Film
by Fuquan Deng, Shuangyi Qin, Na Liu and Wei Xu
Coatings 2022, 12(9), 1271; https://doi.org/10.3390/coatings12091271 - 31 Aug 2022
Cited by 2 | Viewed by 1258
Abstract
The hydrophobic modification effect and an appropriate cost of waterborne polyurethane are regularly pursued targets of researchers. To further enhance the hydrophobic modification effect of the terminal fluoroalkyl group and control the cost, a fluorine-containing pendant group diol (DEFA) was first synthesized by [...] Read more.
The hydrophobic modification effect and an appropriate cost of waterborne polyurethane are regularly pursued targets of researchers. To further enhance the hydrophobic modification effect of the terminal fluoroalkyl group and control the cost, a fluorine-containing pendant group diol (DEFA) was first synthesized by the Michael addition reaction of diethanolamine (DEOA) and dodecafluoroheptyl methacrylate (G04). Next, a series of modified polyurethane latexes (TPFPU) by the terminal fluoroalkyl segments (perfluorohexyl ethanol, S104) and the pendant fluoroalkyl segments (DEFA) were synthesized by varying the DEFA dosage. Structure and performance properties of the resultants were characterized by IR, 1H NMR, TEM, TGA, DSC, XRD, XPS, SEM, AFM and contact angle measurements. Results confirmed that the product could be successfully prepared using the present method. With the increase in DEFA dosage, the average particle size increased gradually. Thermal stability was enhanced and small regional crystals were probably produced. XPS and AFM results demonstrated that the degree of microphase separation and film roughness were increased with the increase in DEFA amount. Hydrophobicity of the TPFPU’s film was also increased with the increase in DEFA dosage, and it could be guaranteed when the mass content of S104 and DEFA was larger than 17.0 wt% in total mass of raw materials, which demonstrates that the terminal and pendant fluoroalkyl groups have the favorable synergistic effect on the properties of polyurethane. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

Review

Jump to: Research

34 pages, 7676 KiB  
Review
Superhydrophobic Wood Surfaces: Recent Developments and Future Perspectives
by Xianming Gao, Mingkun Wang and Zhiwei He
Coatings 2023, 13(5), 877; https://doi.org/10.3390/coatings13050877 - 07 May 2023
Cited by 2 | Viewed by 2661
Abstract
Wood is a renewable material that has been widely utilized as indoor and outdoor construction and decoration material in our daily life. Although wood has many advantages (i.e., light weight, high strength, low price and easy machinability), it has some drawbacks that influence [...] Read more.
Wood is a renewable material that has been widely utilized as indoor and outdoor construction and decoration material in our daily life. Although wood has many advantages (i.e., light weight, high strength, low price and easy machinability), it has some drawbacks that influence dimensional stability, cracking and decay resistance in real practical applications. To mitigate these issues, superhydrophobic surfaces have been introduced to wood substrates, creating superhydrophobic wood surfaces (SHWSs) that can improve stability, water resistance, ultraviolet radiation resistance and flame retardancy. Herein, the recent developments and future perspectives of SHWSs are reviewed. Firstly, the preparation methods of SHWSs are summarized and discussed in terms of immersion, spray-coating, hydrothermal synthesis, dip-coating, deposition, sol-gel process and other methods, respectively. Due to the characteristics of the above preparation methods and the special properties of wood substrates, multiple methods are suggested to be combined to prepare SHWSs rather than each individual method. Secondly, the versatile practical applications of SHWSs are introduced, including anti-fungi/anti-bacteria, oil/water separation, fire-resistance, anti-ultraviolet irradiation, electromagnetic interference shielding, photocatalytic performance, and anti-icing. When discussing these practical applications, the advantages of SHWSs and the reason why SHWSs can be used in such applications are also mentioned. Finally, we provide with perspectives and outlooks for the future developments and applications of SHWSs, expecting to extend the utilization of SHWSs in our daily life and industry. Full article
(This article belongs to the Special Issue Recent Advances in Superhydrophobic and Icephobic Surfaces)
Show Figures

Figure 1

Back to TopTop