Electrowetting of Ionic Liquids on Superhydrophobic Silver Surfaces

Abstract

Abstract: Rough silver films were fabricated on glass substrates using silver mirror reaction, and the superhydrophobic surface was obtained by subsequent selfassembly with alkyl thiol. Electrowetting properties of various ionic liquids, including ［Emim］［BF4］, ［Bmim］［BF4］, ［Hmim］［BF4］, ［Hmim］［Br］, and ［Hmim］［OTf］, and aqueous KCl solution with different concentations on these superhydrophobic silver films was investigated, and the influence of factors such as the ion volume, the size of liquid droplet and the molecular structure of assembled layer on the electrowettablity was discussed. The results show that the electrowettability of ionic liquids is correlated with the ion volume and the charge delocalization, but is not influenced by the size of liquid droplet. In addition, it was found that the ionic liquids and KCl solution have similar electrowettablity as long as they have similar electrical conductivity.

Key words: electrowetting, superhydrophobic, ionic liquid, surface tension, alkyl thiol

CLC Number:

LI Wei, LI Mei, LU Qing-Hua. Electrowetting of Ionic Liquids on Superhydrophobic Silver Surfaces[J]. Journal of Shanghai Jiaotong University, 2011, 45(12): 1879-1884.

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