バイオミメティックなアプローチによるソフトマテリアルの濡れ性と摩擦特性の制御

Abstract

Since surfaces and interfaces of soft materials (“soft interface”) play an important role in various technological applications, precise control of soft interfaces would greatly promote the innovation of future science and technology. This study investigated the design of soft interfaces by biomimetic approach such as nano-texturing of polymer thin films, and high-density polymer brush immobilization to achieve the control of wettability and tribological characteristics. The anisotropic wetting which can preset on the desert beetle surface was designed by micropatterned fluoroalkylsilane monolayer surfaces consisting of a hydrophilic/hydrophobic area. The lotus leaf like nano-texture was fabricated on the fluoropolymer film surface by nanoimprinting technique to reveal lotus effect with an water and oil repellency based on the Cassie mode wetting. Super hydrophilic surface was fabricated on the silicon wafer by surface grafting of zwitter-type polyelectrolyte bearing phosphorylcholine groups which exist as a hydrophilic group in biomembrane. A water droplet on the polyelectrolyte brush surface showed a very low contact angle, and the air bubble and hydrocarbon liquid were hardly attached to the brush surface in the hydrated state. The phosphobetaine-type polyelectrolyte brush showed a low friction coefficient in humid air and aqueous solution because the hydrated brush formed a boundary layer for water lubrications.