title: Nanocasting technique to prepare lotus-leaf-like superhydrophobic electroactive polyimide as advanced anticorrosive coatings.
abstract: Nanocasting technique was used to obtain a biomimetic superhydrophobic electroactive polyimide (SEPI) surface structure from a natural Xanthosoma sagittifolium leaf. An electroactive polyimide (EPI) was first synthesized through thermal imidization. An impression of the superhydrophobic Xanthosoma sagittifolium leaf was then nanocasted onto the surface of the EPI so that the resulting EPI was superhydrophobic and would prevent corrosion. Polydimethylsiloxane (PDMS) was then used as a negative template to transfer the impression of the superhydrophobic surface of the biomimetic EPI onto a cold-rolled steel (CRS) electrode. The superhydrophobic electroactive material could be used as advanced coatings that protect metals against corrosion. The morphology of the surface of the as-synthesized SEPI coating was investigated using scanning electron microscopy (SEM). The surface showed numerous micromastoids, each decorated with many nanowrinkles. The water contact angle (CA) for the SEPI coating was 155°, which was significantly larger than that for the EPI coating (i.e., CA = 87°). The significant increase in the contact angle indicated that the biomimetic morphology effectively repelled water. Potentiodynamic and electrochemical impedance spectroscopic measurements indicated that the SEPI coating offered better protection against corrosion than the EPI coating did.
authors: Department of Chemistry and Center for Nanotechnology, Chung-Yuan Christian University-CYCU, Chung Li, Taiwan 32023, Republic of China.
authors: Kung-Chin
authors: KC
authors: Chang
authors: Hsin-I
authors: HI
authors: Lu
authors: Chih-Wei
authors: CW
authors: Peng
authors: Mei-Chun
authors: MC
authors: Lai
authors: Sheng-Chieh
authors: SC
authors: Hsu
authors: Min-Hsiang
authors: MH
authors: Hsu
authors: Yuan-Kai
authors: YK
authors: Tsai
authors: Chi-Hao
authors: CH
authors: Chang
authors: Wei-I
authors: WI
authors: Hung
authors: Yen
authors: Y
authors: Wei
authors: Jui-Ming
authors: JM
authors: Yeh