KCS

In nature, insects have an exoskeleton, which are built through catecholamine chemistry. We studied new catecholamine film at liquid/air interface by mimicking the insect cuticle formation. When the catecholamine solution exposed to air, the microfilm was formed at liquid/air interface. The film shows the folding property and self-healing property. First, the film has Janus-face; the top of the film exposed to air is hydrophobic and flatten. On the other hand, the bottom of the film faced to liquid is hydrophilic and porous. The different structure and amphiphilicity of the both sides give the folding property according to dry-wet condition. In addition, the film can beself-healing at the damaged site when catecholamine solution re-exposed to the air at liquid/air interface. The self-healing can be repeated until all catecholamines in the solution are oxidized.