Study On Preparation And Properties Of Two-component Hydrogels Based On Ferrocene And β-cyclodextrins Host-Guest Interaction

Stimuli-responsive hydrogels can reversibly change their dimensions or shapes in response to the external stimuli such as temperature, pH, light, and biological signal, and have found potential applications in the areas of hydrogel actuators, molecular devices, optical materials, biomedical, and so on. In this thesis, various two-component self- assembly hydrogels (bi-gel) were synthesized, which were based on (3-cyclodextrin (β-CD) hydrogels, the synthesized hydrogels showed temperature, glucose, or optical- and thermal-sensitivity as host hydrogels and ferrocene-based hydrogels as guest hydrogels. The bi-gel showed excellent sensitivity to temperature, glucose, or near-infrared (NIR) radiations, respectively and their potential applications were also investigated.(1) Three host hydrogels, PNIPAM-CD with different β-CD contents, and a ferrocene-based polyacrylamide guest hydrogel (PAM-Fc) were synthesized, and the monomers were characterized with 1H-NMR and MS. The host and guest hydrogels structures were confirmed by FT-IR spectroscopy. The bi-gels with different β-CD contents were prepared through the host-guest interactions. The response of assembly and disassembly was induced through redox stimulation for the ferrocene components, and the temperature response of bi-gel was investigated. It was found that the bi-gel bended at a temperature higher than the lower critical solution temperature (LCST) of the pure host hydrogel. With the same components, the hydrogels bended quickly with the increase of temperature; the bending of hydrogels was slowed down with the increase of content of β-CD at the same temperature. The application of the bi-gel as temperature control switches was proposed.(2) Host hydrogel AAPBA-CD with three different contents of crosslinking agent and 3-acrylamidophenylboronic acid (AAPBA) were synthesized, and the monomer was characterized with 1H-NMR. The host hydrogels structures were confirmed by FT-IR spectroscopy. Six bi-gels with different contents of crosslinking agent or AAPBA were prepared through host-guest interactions. The response of assembly and disassembly of the bi-gels based on host hydrogel (AAPBA-CD) and guest hydrogel (PAM-Fc) was induced through redox stimulation for the ferrocene components, and their response to pH and glucose was also investigated. The variation in pH value or concentration of glucose resulted in bending of the bi-gel because of the change in water-solubility of AAPBA-CD hydrogel. At the same concentration of glucose, the bending of the bi-gel was slowed down with the increase in content of crosslinking agent, however, the bending speed was increased with increasing the content of AAPBA. At the same pH value, the bending of the bi-gel became fast with the increase in the concentration of glucose. The potential application of the bi-gel was also discussed.(3) Three host hydrogels, PNIPAM-CD/GO with different contents of graphene oxide (GO) were synthesized and verified by FT-IR, XRD and TEM. The color of the hydrogel prepared by radical polymerization was increased with the increase in the content of GO. The resulting host hydrogels ware optical- and thermal-sensitive because of the introduction of GO. Three bi-gels with different GO contents were prepared through the host-guest interactions between PNIPAM-CD/GO and PAM-Fc. The response of assembly and disassembly was induced through redox stimulation of the ferrocene components. The assembly property and bending behavior of bi-gel were investigated. It was found that GO did not significantly affect the LCST and bending behavior of the prepared hydrogels. The photothermal behavior of the bi-gel was investigated and it was found that with exposured to NIR laser irradiation, the temperature increased, and the volume of PNIPAM-CD/GO hydrogel changed obviously, which resulted in bending of the bi-gels and such hydrogels could be used as in optical switch and artificial muscle.(4) Three host hydrogels, PNIPAM-CD/Fe3O4 with different contents of Fe3O4 were synthesized and verified by FT-IR, XRD. The resulting host hydrogels were optical- and thermal-sensitive because of the introduction of Fe3O4. Three bi-gels with different Fe3O4 contents were prepared through the host-guest interactions between PNIPAM-CD/Fe3O4 and PAM-Fc. The response of assembly and disassembly was induced through redox stimulation for the ferrocene components. The assembly property and bending behavior of bi-gel were investigated. It was found that Fe3O4 did not significantly affect the LCST of the prepared hydrogels. The photothermal behavior of the bi-gel was investigated and it was found that with exposured to NIR laser radiations, the temperature increased, and the volume of PNIPAM-CD/Fe3O4 hydrogel changed obviously, which resulted in bending of the bi-gel. Through the exploration of the magnet-control performance and potential application of bi-gel, it was found that the bi-gel had good application prospect in the magnet-control transportation and photo switches.(5) Three host hydrogels, PNIPAM-CD/GO/Fe3O4 with different contents of GO/Fe3O4 were synthesized and verified by FT-IR, XRD. The resulting host hydrogels were optical- and thermal-sensitive because of the introduction of GO/Fe3O4. Three bi-gels with different GO/Fe3O4 contents were prepared through the host-guest interactions between PNIPAM-CD/GO/Fe3O4 and PAM-Fc. The response of assembly and disassembly was induced through redox stimulation for the ferrocene components. The assembly property and bending behavior of bi-gel were investigated. It was found that GO/Fe3O4 did not significantly affect the LCST and bending behavior of the prepared hydrogels. The photothermal behavior of the bi-gel was investigated and it was found that with the exposured to NIR laser radiations, the temperature increased and the volume of PNIPAM-CD/GO/Fe3O4 hydrogel changed obviously, which finally resulted in bending of the bi-gel. Through the exploration of the magnet-control performance and potential application of bi-gel, it was found that the bi-gel had good application prospect in the magnet-control transportation and photo switches.