Nondestructive removal of superhydrophobic coatings by an electric switch.

Huang, Shuangyan; Yue, Qilin; Lv, Jiahao; Wang, Yanan; Yang, Hailei; He, Qisheng; Zhang, Jianwen; Wei, Yong et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Extensive efforts have been made to enhance the durability of superhydrophobic coatings by adhesives, yet it raises a challenge to nondestructively remove the failed coatings. Here, we propose a nondestructively removable superhydrophobic (NRS) coating by an electrical switch, inspired by the nondestructive ecdysis of snakes. To achieve this, we sequentially spray i-layer and e-layer using electro-responsively epoxy-based ionic adhesive and superhydrophobic CNT coating, respectively. Its adhesion energy to stainless steel sheets significantly declines from 2.46 kJ m<sup>-2</sup> to 0.01 kJ m<sup>-2</sup> (about 99.6% of removal efficiency), through the disordered-ordered switching of free ions, only applying 90 V DC voltage for 3 min. This enables it to be nondestructively removed from the substrates even after 10 recoating cycles. This work offers a common strategy to sustainably protect the metal substrates and facilitates their recycling, showing great potential in green manufacturing and surface protection for large-scale equipment.