Fast self-healing superhydrophobic surfaces enabled by biomimetic wax regeneration

While an increasing number of superhydrophobic surfaces have been developed in the past two decades due to their tremendous application potential, they generally suffer from low durability as their liquid repellency could be easily damaged by chemical or mechanical erosion. A promising route to address this issue is to design self-healable superhydrophobic surfaces that can restore the liquid repellency upon external damage. Although several types of self-healable superhydrophobic surfaces have been prepared by introducing healable polymers or migratable low-surface-energy materials, these surfaces are limited by the requisite of external energy input to drive the healing process or long self-healing time. Inspired by the self-healing mechanism of wax secretion in natural plant leaves, herein we report a unique self-healing superhydrophobic poly(dimethylsiloxane)/n-nonadecane wax composite surface that can spontaneously recover its superhydrophobicity after severe plasma etching via surface wax regeneration. Significantly, the prepared poly(dimethylsiloxane)/n-nonadecane composite surface exhibits a remarkably fast self-healing dynamics, which can spontaneously recover its superhydrophobicity upon damage in only 20 min without external stimuli. The healing time, to our best knowledge, is much shorter than that of previously reported self-healing superhydrophobic surfaces (generally from hours to days in the absence of external stimuli). The fast self-healing ability of the prepared surface is attributed to the relatively low melting point of n-nonadecane and the high mobility of poly(dimethylsiloxane) molecular chains, which ensure fast migration of n-nonadecane molecules in the poly(dimethylsiloxane) matrix. We believe that the present biomimetic strategy could motivate the development of high-performance self-healing superhydrophobic materials with quick healing dynamics.