Tuesday april the 8th at 11am :
Hydrogels - three‑dimensional polymer networks containing 90 wt% water - combine a tissue‑like composition with good tunability, underpinning technologies from contact lenses and super‑absorbents to soft‑tissue repair scaffolds. Yet their inherently high water content compromises mechanical strength and durability, limiting broader applications. In 2003, a breakthrough pioneered by Prof. Jian Ping Gong introduced double‑network hydrogels, in which a brittle, tightly crosslinked “first network” dissipates energy under load while a ductile, loosely crosslinked “second network” maintains structural integrity. This architecture enhances load‑bearing capacity by up to two orders of magnitude compared to single‑network analogues. In this seminar, I will demonstrate how the double‑network concept can be extended beyond conventional chemistries by promoting physical interactions in the primary network, with a chemically crosslinked secondary network. Through two case studies, we reveal how this hybrid strategy dramatically improves mechanical robustness and toughness in materials derived from readily available polymers. Structural analyses will highlight the interplay between network topology, interactions between both networks and resulting mechanical properties. Our findings illustrate a versatile platform for designing next‑generation materials with tailored mechanical properties.