2015-Macromolecules:Simultaneous Enhancement of Stiffness and Toughness in Hybrid Double Network Hydrogels via the First, Physically-Linked Network
作者：Qiang Chen*, Dandan Wei and Jie Zheng*, et al.
關(guān)鍵字：Double Network Hydrogels, Agar, Hybrid
論文來源：期刊
具體來源：Macromolecules
發(fā)表時間：2015年
Combining both chemical and physical crosslinks in a double-network
hydrogel (DN gel) has emerged as a promising design strategy to obtain highly
mechanically strong hydrogels. Unlike chemically crosslinked DN gels, little is known about the fracture
process and toughening mechanisms of hybrid chemically-physically linked DN
gels. In this work, we engineered tough hybrid DN gels of agar/polyacrylamide
(Agar/PAAm) by combining two
types of cross-linked polymer networks: a physically-linked, first agar network
and a chemical-linked, second PAAm network. The resulting Agar/PAAm exhibited
high stiffness of 313 kPa and high toughness of 1089 J/m2. We then specifically
examined the effect of the first agar network on the
mechanical properties of hybrid Agar/PAAm gels. We found that by controlling
agar concentrations above a critical value, the physically-linked agar network
can simultaneously enhance both stiffness and toughness of Agar/PAAm DN gels,
as evidenced by a linear relationship of elastic modulus and tearing energies
of the gels as the increase of agar concentration. This toughening behavior is
different from that of chemically-linked DN gels. Complement to
chemically-linked DN gels, this work provides a different view for the design
of new stiff and tough hydrogels using hybrid physical and chemical networks.
