Fig. 6
From: Advances in self-healing supramolecular soft materials and nanocomposites
(reproduced with permission from: Ref. [58], ©2018 AAAS)
H-bonding approach of thiourea and urea moieties: a thiourea units which form nonlinear zigzag arrays adopting cis/trans and strained trans/trans conformations (I), whereas urea groups form linear arrays of H-bonding adopting only a trans/trans conformation (II); b proposed mechanism for transformations of H-bonded thiourea pairs. The triethylene glycol spacer that connects the thiourea units optimally modulates the exchange of H-bonded thiourea pairs; consequently, the highly crosslinked non-covalently, can heal by only compression without heating