Robust and Reversible Thermal/Electro-Responsive Supramolecular Polymeric Adhesives via Synergistic Hydrogen-Bonds and Ionic Junctions.

Adhesive conducting elastomers are rising materials towards cutting-edge applications in wearable and implantable soft electronics. Yet, engineering the conductive adhesives with robust and tunable interfacial bonding strength is still in its infancy stage. We herein identify a structurally novel supramolecular polymer scaffold, characterized by synergistic coexistence of hydrogen-bonding (H-bonding) interactions and electrostatic ionic junctions, endowing the robust and tunable elastic conducting adhesives with remarkable thermal/electro-responsive performance. H-bonding association and electrostatic interaction play orthogonal yet synergistic roles in the strong supramolecular adhesive formation, serving as the leveraging forces for opposing both cohesion and adhesion energy. To do so, six-arm star-shaped random copolymers P1, and P2 are strategically designed, bearing H-bonding PDAP (poly(diaminopyridine acrylamide)) and PThy (poly(thymine)) segments, which can form hetero-complementary DAP/Thy H-bonding association, along with ionic conductive poly(ionic liquid)s segment: PMBT, (poly(1-[2-methacryloylethyl]-3-methylimidazolium bis(trifluoromethane)-sulfonamide)). DAP/Thy H-bonding association, along with electrostatic ionic interaction, can yield dual supramolecular forces crosslinked polymeric networks with robust cohesion energy. Moreover, coexistence of poly(ionic liquid)s can impact and interfere the configuration of H-bonding association, liberate more free DAP and Thy motifs to form H-bonds towards substrate, affording strong surface adhesion in a synergistic manner. This work demonstrates a significant forward step towards potential adhesives devoted to hybrid electronic devices.