Air/water interfacial formation of freestanding, stimuli-responsive, self-healing catecholamine Janus-faced microfilms.

A catecholamine freestanding film is discovered to be spontaneously formed at the air-water interface, and the film has unique properties of robust surface adhesiveness, self-healing, and stimuli-responsive properties. The interfacial film-producing procedure is a simple single step containing polyamines and catechol(amine)s. It is found that oxygen-rich regions existing at an air-water interface greatly accelerate the catecholamine crosslinking reaction.