Advanced functional surfaces through controlled damage and instabilities

Namdari, Navid; Mohammadian, Behrouz; Jafari, Parham; Mohammadi, Reza; Sojoudi, Hossein; Ghasemi, Hadi; Rizvi, Reza

doi:10.1039/c9mh01516g

Cited by 26 publications

(9 citation statements)

References 296 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[38,39] Yet, investigations into creating/tuning SH surfaces with mechano-dynamic properties through surface cracking, as emphasized here, remain relatively unexplored. [40] Numerous SH materials follow the Cassie-Baxter (CB) wetting state due to high surface roughness and extremely low surface wetting. [41,42] In this wetting state, the surface wettability is governed primarily by the solid-liquid contact fraction (f), according to the following equation which has been simplified to include the solid-liquid contact fraction: [29,43]…”

Section: Fabrication Of Mechanically Tunable Hierarchical Micro/nanostructurementioning

confidence: 99%

Mechanically Tunable Superhydrophobic Surfaces Enabled by the Rational Manipulation of Microcrack Networks in Nanoporous Films

Mazaltarim

Torres

Morin

2021

Adv Materials Inter

View full text Add to dashboard Cite

make fabrication difficult. In contrast, mechanically-adaptive superhydrophobic surfaces based on elastomeric materials with mechanically controlled wrinkles [8,9] and microstructure [10,11] offer simple, rapid control in compliant formats useful to, for example, droplet manipulation and water repellency. However, surface instabilities (i.e., microcracks) have limited the operational range of strain for these materials [12] and sophisticated fabrication procedures (e.g., ion etching and direct-write printing) have confined their application space. [13] We sought to develop a versatile process for the fabrication of soft, mechanically compliant, and tunable SH materials that was simple, scalable, and cost-effective. These mechano-adaptive materials would feature mechanically responsive wettability and droplet adhesion with characteristics that surpass the limitations of existing materials. To achieve this goal, we fabricated elastomer-supported, hierarchically structured surfaces comprised of nanoporous films with networks of mechanically tunable microcracks. Specifically, we oxidized silicone rubbers to generate a rigid silica interfacial layer which, through the application of tensile strain, could be fractured along surface instabilities to generate a network of microcracks. We then rendered this surface SH through a simple chemical etching procedure which introduced nanoporosity in the silica layer. Although the chemical oxidation (ultraviolet ozone, UVO) procedure introduced polar functionalities onto the surface, which would typically increase wettability, the hierarchical micro/nano-structuring afforded mechano-tunable superhydrophobic properties that were readily manipulated using small magnitudes of force easily accessible through inexpensive motors/controllers or even biomechanical input from a user.We believe the unique combination of mechano-induced surface microcracks, which have often been viewed as undesirable in adaptive systems owed to the difficulty in predicting surface instabilities, and chemical etching, an extensively exploited process to generate micro/nanotopography in superhydrophobic films, [14][15][16] provides an exciting, unexplored avenue in the field of adaptive SH materials with the potential to nucleate the design of materials with new functionalities and applications. Unlike existing procedures, combining the convenient processing of solution-phase etching and Adaptive materials with tunable superhydrophobic surfaces promise to impact a range of fluid handling technologies; however, adaptive superhydrophobic materials remain difficult to fabricate, control, and switch rapidly. Here, a versatile method for generating hierarchically structured and adaptive superhydrophobic silicone films for the rational control of surface wettability and droplet adhesion is reported. Specifically, mechanical tension is utilized to manipulate networks of microcracks in nanoporous layers supported on elastomeric silicone films, enabling dynamic modulation of superhydrophobicity and droplet adhesion. ...

show abstract

Section: Fabrication Of Mechanically Tunable Hierarchical Micro/nanostructurementioning

confidence: 99%

Mechanically Tunable Superhydrophobic Surfaces Enabled by the Rational Manipulation of Microcrack Networks in Nanoporous Films

Mazaltarim

Torres

Morin

2021

Adv Materials Inter

View full text Add to dashboard Cite

show abstract

“…Typically, surface chemistry and surface roughness play important roles in the surface wettability. According to the Cassie equation (Li et al, 2019 ; Zhang et al, 2019a ; Namdari et al, 2020 ): cos θ * = f s cos θ s - f a ; f s + f a =1, θ * and θ s are the apparent contact angle (CA) and intrinsic CA of the substrate. f s and f a are apparent area fractions of the substrate and air troughs.…”

Section: Mechanismmentioning

confidence: 99%

Bioinspired Surfaces With Switchable Wettability

et al. 2020

View full text Add to dashboard Cite

The surface wettability of plants exhibits many unique advantages, which enhances the environmental adaptability of plants. In view of the rapid development of responsive materials, smart surfaces have been explored extensively to regulate surface wettability through external stimuli. Herein, we summarized recent advancements in bioinspired surfaces with switchable wettability. Typical bioinspired surfaces with switchable wettability and their emerging applications have been reviewed. In the end, we have discussed the remaining challenges and provided perspective on future development.

show abstract

“…Superhydrophobic surfaces have shown excellent anti-wetting properties identified by high water contact angle (WCA) and very small WCA hysteresis (difference between advancing and receding WCA) [13]. Some of these surfaces typically have very low surface energy with micro-scale, nano-scale, and/or hierarchical features that enable entrapping a thin air layer between them and the droplet [14][15][16][17]. More recently, superhydrophobic surfaces have also shown some promise in delay of icing with potential applications in power lines, wind turbines, photovoltaic panels, and other infrastructures [18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Droplet Dynamics and Freezing Delay on Nanoporous Microstructured Surfaces at Condensing Environment

2021

Self Cite

View full text Add to dashboard Cite

Superhydrophobic surfaces have aroused great interest for being promising candidates in applications such as self-cleaning, anti-icing, and corrosion resistance. However, most of the superhydrophobic surfaces lose their anti-wettability in low surface temperature and high humidity. The loss of superhydrophobicity by condensed liquid is a very common practical incident, yet to be understood properly. Here we report the wettability of the superhydrophobic nanoporous surfaces in condensation and freezing environments. Various structured surfaces fabricated with carbon nanotubes (CNT) and coated by an ultrathin, conformal, and low surface energy layer of poly (1H,1H,2H,2H-perfluorodecylacrylate) (pPFDA) are exploited in humid conditions. Droplet impact dynamics, condensate characteristics, and freezing time delays are investigated on the CNT micropillars with various geometries along with the CNT forest and two commercially available anti-wetting coatings, NeverWet and WX2100. Nanoporous microstructured CNT pillars with the favorable topological configuration demonstrated complete droplet bouncing, significant freezing delays, and considerable durability during several icing/de-icing cycles. This study provides an understanding on the preferable geometry of the highly porous CNT micropillars for retaining hydrophobicity and preventing ice formation, which is of practical importance for the rational development of anti-wetting surfaces and their applications in low temperatures and humid conditions.

show abstract

Advanced functional surfaces through controlled damage and instabilities

Abstract: Functional surfaces are of paramount engineering importance for various applications. The purpose of this review is to present counter-intuitive methods of fabrication based upon damage or instabilities for creating value-added surface functions.

Cited by 26 publications

References 296 publications

Mechanically Tunable Superhydrophobic Surfaces Enabled by the Rational Manipulation of Microcrack Networks in Nanoporous Films

Mechanically Tunable Superhydrophobic Surfaces Enabled by the Rational Manipulation of Microcrack Networks in Nanoporous Films

Bioinspired Surfaces With Switchable Wettability

Droplet Dynamics and Freezing Delay on Nanoporous Microstructured Surfaces at Condensing Environment

Contact Info

Product

Resources

About