Fabrication of a Superhydrophobic Triphenylene Ether Derivative Film on an Al Plate

Abstract

In recent years, superhydrophobic surfaces have received much attention owing to their smart functions such as selfcleaning property, water repellent property, anticontamination, and anti-icing.1-3 In nature, many plants, animals, and insects exhibit superhydrophobicity, and this phenomenon motivates researchers to fabricate new superhydrophobic surfaces for practical applications.The most famous example of such a surface is the lotus leaf surface, which is composed of a nano/microscale rough structure and covered with a low-surface-energy material (i.e., wax).4 The self-cleaning property of lotus leaf can be attributed to superhydrophobicity. A superhydrophobic surface has a high water contact angle (> 150°) and a low sliding angle (< 10°). The nano/microscale rough structure minimizes the contact between a particle and the surface of lotus leaf. Thus, the contamination on lotus leaf can be easily removed with water droplets. Therefore, the surface of lotus leaf is always maintained clean. These results have shown that the surface wettability of biological systems can be attributed to the nano/microscale roughness of the surface and the properties of surface-coated materials. Based on these observations, many efforts have been devoted to fabricate artificial biomimetic surfaces with various materials. In general, a superhydrophobic surface is fabricated in two steps: (1) creation of nano/microscale roughness and (2) chemical treatment of the rough surface with a low-surfaceenergy material. The created rough nano/microstructures on the surface trap air between them, and the trapped air prevents the penetration of water.Various fabrication methods for nano/microscale hierarchical rough surfaces have been reported by mimicking natural surfaces, such as chemical etching, 5-7 sol-gel,lithography, 12-15 spray, 16-19 and self-assembly coating. 20-23To fabricate superhydrophobic metal surfaces, nano/microscale rough surfaces should be treated with low-surfaceenergy materials because clean metal surfaces are usually hydrophilic. Although numerous methods have been reported for the fabrication of hierarchical surfaces, low-surfaceenergy materials used for coating metal surfaces are limited. Fluorinated long alkylthiols 24,25 or long alkyl carboxylic acids 26-28 and fluorinated alkylsilanes 29,30 have been used as the low-surface-energy materials to modify hydrophilic metal surfaces by reacting with the surface hydroxyl groups to afford the corresponding superhydrophobic surfaces.In this paper, we report the fabrication of a superhydrophobic surface on Al alloy. The nano/microscale roughness of Al surface was created by chemical etching, and the surface energy was lowered by the UV curing of the Al plate with 2,3,6,7,10,11-hexakis(6-acryloyloxyhexyloxy)triphenylene (HAHTP). The acryloyl group of HAHTP induced photopolymerization. The effects of HAHTP concentration and immersion period on the superhydrophobicity of Al surface were evaluated. The superhydrophobic surface of modified Al plate was analyzed by scanning electr...

Fabrication of Superhydrophobic Silica Nanoparticles and Nanocomposite Coating on Glass Surfaces

“…The generation of rough surfaces and subsequent coating with a material having a low surface energy is a common process for fabricating artificial superhydrophobic surfaces. Various techniques have been recently used to generate such surfaces, with the common ones being lithography, plasma treatment, electrospinning, chemical vapor deposition, sol–gel process, and chemical etching . Silica nanoparticles are one of the most popular nanomaterials and produced by numerous companies.…”

Synthesis of Water-Soluble Cyclophane Hexamers Having a Triphenylene Core and Their Enhanced Guest-Binding Behavior

“…In addition to that, these linear and divergent-type cyclophane oligomers do not have a fluorescent moiety. − Hence, fluorescence sensing of the bind of guest molecules is somewhat inconvenient. In this report, we designed water-soluble triphenylene-based cyclophane hexamers that were constructed with six macrocycles having cationic and anionic moieties as side chains and fluorescent triphenylene-2,3,6,7,10,11-hexaol as a core ( 1 and 2 , respectively, Figure ). Six macrocycles located in the exterior of the cyclophane hexamers are considered to be equivalent for the guest-binding behavior, which is good for accurate analysis.…”