Fabrication And Driving Behavior Research Of PNIPAM-based Composite Hydrogel

Polymer hydrogel actuators are smart stimulus-responsive hydrogels that may reversibly deform when triggering various external stimuli.The conversion of external energy such as pH,light,heat,magnetic fields,and ionic strength into the practicality of hydrogel actuators in a wide range of fields requires the establishment of stable and reliable fast response and fast recovery performance.Several solutions have been proposed,such as using nanocomposites to provide porous and specific structures in hydrogels to improve response speed and deformation efficiency.Starting from the design of the main shaft structure,a hydrogel telescope with high response speed and high recovery speed was designed.The research contents of this thesis mainly include the following parts:1.Preparation of MMT-PNIPAM composite hydrogel and construction of hydrogel actuators.The driving direction of hydrogels is controlled through MMT content adjustment,and the structural diversity is used to increase the driving diversity of actuators.T When the MMT content is 0.2g,the response speed of the actuator can reach 36°/s,and the response amplitude can reach 289°.The hydrogel can be controlled and driven by structural design,such as being transformed into the letters "Z","S","T" "U".2.In order to solve the problem of slow recovery after hydrogel driven deformation,we are based on MMT-PNIPAM composite hydrogel,MMT is hydrolyzed with 3-aminopropyltriethoxysilane to make its surface positively electrified,and the heterogeneous charges attract each other to make the hydrophilic graphene oxide nanosheets fastened.Firmly bonded to the MMT surface.Due to the supporting effect of the graphene oxide nanosheets,MMT@GO will not block the water transport channel due to too close accumulation,and the hydrophilic graphene oxide nanosheets provide water during the hydrogel reswelling process.In the passage,in 20? water,MMT@GO-PNIPAM composite hydrogel can absorb water and re-swell faster,and the recovery speed can reach 59.5°/min.