Stretchable And Functional Hydrogels Based On Noncovalent/Dynamic Covalent Bonds

Hydrogels based on noncovalent/dynamic covalent bonds are much different from the traditional chemically crosslinked hydrogels.The reversible and dynamic characters of noncovalent interactions/dynamic covalent bond often provide the corresponding hydrogels with multifuctionality and/or stimuli-responsive properties.Recently,more and more functional/stimuli-responsive hydrogels crosslinked by noncovalent or dynamic covalent bonds are reported.But most of them often show very weak mechanical properties.In this thesis,we aim to synthesis stretchable and functional hydrogels based on noncovalent/dynamical covalent bonds.The main contents of this thesis are described as follows:1.Stretchable and functional supramolecular hydrogels based on host-guest inclusion complexation interaction.?-cyclodextrin(?-CD)based linear copolymer(poly?-CD)was synthesized and used as the macromolecular host,hydrophilic flexible spacer modified ferrocene(Fc)monomer acted as the guest.The polymerizable Fc monomer was preloaded on poly?-CD to form a novel kind of 'macromolecular supramolecular cross-linker'(MSCL)due to the inclusion complexation interaction between ?-CD and Fc.For the first time,due to the polyp-CD's supramolecular imprinter effect,stretchable,stab-resistant and adhesive supramolecular hydrogels were prepared via simple free-radical copolymerization of MSCL and acrylamide.These results provide a new strategy for the construction of stretchable and functional supramolecular materials based on host-guest interaction.2.Stretchable and functional hydrogels based on metal-ligand coordination interaction.A novel kind of supramolecular cross-linker(SCL)was prepared using the metal-ligand coordination interaction between Tb3+ and polymerizable dopamine monomer(A-DP).Through simply free-radical copolymerization of SCL with Am in aqueous solution,a series of stretchable,adhesive and photo-luminescent hydrogels can be obtained.Further results showed that Tb3+ not only provide the hydrogels with photo-luminescent property,but also can prevent dopamine from being oxided because of the coordination interaction,and thus efficiently keeps the stretchable and adhesive property of the hydrogels.These results provide some new references for the preparation of new stretchable and functional materials via metal-ligand coordination interaction and for the protecting of dopamine from being oxided.3.Stretchable and functional supramolecular hydrogels based on dynamical covalent bond.By utilizing the dynamical covalent interaction between boric acid and polymerizable dihydroxy monomer,we first prepared a new kind of dynamic covalent cross-linker(DCL).After being simply copolymerized with Am in aqueous solution,hydrogels with extremely stretchable and excellent self-healing properties can be easily obtained.These results open a new avenue for the easy preparation and pontential applications of dynamic covalent bond based stretchable and self-healing materials.