Functional and versatile superhydrophobic coatings via stoichiometric silanization

Abstract

Superhydrophobic coatings have tremendous potential for applications in different fields and have been achieved commonly by increasing nanoscale roughness and lowering surface tension. Limited by the availability of either ideal nano-structural templates or simple fabrication procedures, the search of superhydrophobic coatings that are easy to manufacture and are robust in real-life applications remains challenging for both academia and industry. Herein, we report an unconventional protocol based on a single-step, stoichiometrically controlled reaction of long-chain organosilanes with water, which creates micro- to nano-scale hierarchical siloxane aggregates dispersible in industrial solvents (as the coating mixture). Excellent superhydrophobicity (ultrahigh water contact angle >170° and ultralow sliding angle <1°) has been attained on solid materials of various compositions and dimensions, by simply dipping into or spraying with the coating mixture. It has been demonstrated that these complete waterproof coatings hold excellent properties in terms of cost, scalability, robustness, and particularly the capability of encapsulating other functional materials (e.g. luminescent dyes).

Effect of Chemical Surface Texturing on the Superhydrophobic Behavior of Micro–Nano-Roughened AA6082 Surfaces

“…The major drawback of aluminum alloys is the corrosion sensitivity in several environmental conditions, limiting its applicability for structural and functional applications, inducing relevant waste and serious contamination [ 5 , 6 , 7 , 8 ]. To avoid this issue and extend their application fields, many researchers proposed the use of a corrosion inhibitor, organic and inorganic coating, chromate-based coating, and anodized layers or polymer duplex coatings [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. However, these methods require complex processes, expensive equipment, and usually toxic chemical agents [ 17 ].…”

Novel fabrication of hydrophobic/oleophilic human hair fiber for efficient oil/water separation through one-pot dip-coating synthesis route

“…When water does not impregnate the rough surface, the formation of air pockets between solid–liquid interface transpires, which further enhances the contact angle of the hierarchical surface, and then the contact angle of such a surface is given by the Cassie–Baxter equation 42 : where f is defined as the fraction of the solid surface contacting the different liquids. The reflections from air bubbles trapped under the water droplet validate the Cassie-Baxter wetting state 36 , 43 (Fig. S2 ).…”

“…The peaks at approximately 2926 and 2879 cm −1 may be attributed to the typical stretching vibration of –CH 2 in the PODS coating 35 . Moreover, the HHF-PODS has weak characteristic absorption peaks at 1115 cm and 1040 cm −1 , which are attributed to the Si–O–Si asymmetric stretching mode confirming the formation of long chain linear polysiloxane 36 . The peaks at 895 cm −1 were attributed to the incomplete polycondensation of ODS.…”

Facile Construction and Fabrication of a Superhydrophobic and Super Oleophilic Stainless Steel Mesh for Separation of Water and Oil

“…In particular, it needs to be mentioned that the growing of Fe 2 O 3 -NCs on SSM after immerging-burning treatment is beneficial to the coating of OTS on the surface of Fe 2 O 3 -NCs@SSM, which will enhance the superhydrophobic property of the material. Additionally, OTS can be used to grow a compact and self-assembled monolayer with low surface energy on the surface of Fe 2 O 3 -NCs@SSM, leading to an improvement in the hydrophobicity of the sample [ 37 , 38 ].…”