mz9b00459_si_003.mp4 (1.17 MB)
Light-Switchable Polymer Adhesive Based on Photoinduced Reversible Solid-to-Liquid Transitions
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posted on 2019-07-22, 12:34 authored by Ying Zhou, Mingsen Chen, Qingfu Ban, Zhenlin Zhang, Shaomin Shuang, Kaloian Koynov, Hans-Jürgen Butt, Jie Kong, Si WuThe
development of switchable adhesives for reversible bonding
and debonding can overcome the problems associated with conventional
adhesives in separating, recycling, and repairing glued surfaces.
Here, a photoresponsive azobenzene-containing polymer (azopolymer)
is developed for photocontrolled adhesion. The azopolymer P1 (poly(6-(4-(p-tolyldiazenyl)phenoxy)hexyl acrylate)) exhibits photoinduced
reversible solid-to-liquid transitions due to trans–cis photoisomerization.
Trans P1 is a solid that glues two substrates with a stiffness comparable
to that of conventional adhesives. UV light induces trans-to-cis isomerization,
liquefies P1, weakens the adhesion, and facilitates the separation
of glued substrates. Conversely, visible light induces cis-to-trans
isomerization, solidifies P1, and enhances the adhesion. P1 enables
photocontrolled reversible adhesion for various substrates with different
wettability, chemical compositions, and surface roughness. P1 can
also be implemented in both dry and wet environments. Light can control
the adhesion process with high spatiotemporal resolution when using
P1 as a switchable adhesive. Photoinduced reversible solid-to-liquid
transitions represent a strategy for materials recycling and automated
production processes that require reversible bonding and debonding.