Recoverable self-cleaning surface formed by nanostructured microcapsules encapsulating hydrophobic agent

Abstract

A recoverable self-cleaning surface is studied by coating the nanostructured core–shell microcapsules like a chestnut bur. The microcapsules encapsulate the hydrophobic agent so that when they are broken by mechanical damage, it is released and functions to recover the loss of the self-cleaning performance. The core–shell droplets encapsulating the hydrophobic agent are generated continuously by introducing immiscible fluids into a multi-coaxial microfluidic channel platform and cured by UV irradiation to be polymerized. The control of the size and shell thickness of the microcapsules, and the volume of the hydrophobic agent are examined. Also, the nanostructures on the surface of the microcapsules are obtained by the polyaniline process for additional increase in roughness. The critical breakage forces of the microcapsules are measured for increasing the shell thickness. Finally, the nanostructured microcapsule surface is fabricated on a glass substrate and the water contact angle is measured to determine the self-cleaning performance. Also, its recovery of the self-cleaning performance surface from the mechanical damage is demonstrated. The formation of the recoverable self-cleaning surface by coating enables to apply for a large scale and arbitrary curved surface.