Facile fabrication of super-hydrophobic nano-needle arrays via breath figures method

Abstract

Super-hydrophobic surfaces which have been fabricated by various methods such as photolithography, chemical treatment, self-assembly, and imprinting have gained enormous attention in recent years. Especially 2D arrays of nano-needles have been shown to have super-hydrophobicity due to their sharp surface roughness. These arrays can be easily generated by removing the top portion of the honeycomb films prepared by the breath figures method. The hydrophilic block of an amphiphilic polymer helps in the fabrication of the nano-needle arrays through the production of well-ordered honeycomb films and good adhesion of the film to a substrate. Anisotropic patterns with water wettability difference can be useful for patterning cells and other materials using their selective growth on the hydrophilic part of the pattern. However, there has not been a simple way to generate patterns with highly different wettability. Mechanical stamping of the nano-needle array with a polyurethane stamp might be the simplest way to fabricate patterns with wettability difference. In this study, super-hydrophobic nano-needle arrays were simply fabricated by removing the top portion of the honeycomb films. The maximum water contact angle obtained with the nano-needle array was 150°. By controlling the pore size and the density of the honeycomb films, the height, width, and density of nano-needle arrays were determined. Anisotropic patterns with different wettability were fabricated by simply pressing the nano-needle array at ambient temperature with polyurethane stamps which were flexible but tough. Mechanical stamping of nano-needle arrays with micron patterns produced hierarchical super-hydrophobic structures.PACS: 05.70.Np, 68.55.am, 68.55.jm

Molecular Architectonics‐Guided Fabrication of Superhydrophobic and Self‐Cleaning Materials

“…A number of reports in the literature demonstrated the fabrication of honeycomb‐structured superhydrophobic materials using BFT through drop‐casting of polymer solutions. [ 71–74 ] Recently, our group fabricated self‐cleaning superhydrophobic surface by BFT employing small functional molecule in contrast to traditional polymer. [ 42 ] In order to imprint micro or nanostructured films, BFT involving solution process is advantageous for large area applications over other techniques in terms of its simplicity, robustness, rapidity, and cost effectiveness.…”

Ordered Honeycomb‐Pattern Membrane†

“…Chemical structures of amphiphilic PS‐based polymers [ 72‐78 ] …”

Facile Fabrication of Superhydrophobic Surface from Fluorinated POSS Acrylate Copolymer via One-Step Breath Figure Method and Its Anti-Corrosion Property

“…Yabu et al [14] prepared fluorinated acrylate copolymer films with honeycomb porous structure using the BF method, and the superhydrophobic behaviour was achieved by surface peeling with a maximum contact angle of 170 • . Super-hydrophobic nano-needle arrays were simply fabricated by removing the top portion of the honeycomb films and the maximum water contact angle was 150 • [15]. The second one is implementing another surface texturing on the ordered honeycomb surfaces.…”