Preparation And Controllable Adhesion Research Of Smart Polymer Film With Superhydrophobicity

In recent years,inspired by the special adhesion phenomena in nature,scientists have prepared a large number of intelligent adhesion surfaces.The adhesion effect with intelligent stimulus-response gives these surfaces unique advantages in capturing/releasing objects,and they have been widely used in many fields such as astronautics,navigation,and medicine.However,there are still some deficiencies in the intelligent adhesion surface,such as poor adhesion characteristic stability,adhesion responsiveness regulation that can only be applied to solid or liquid,etc.To solve the existing problems,this paper designed and prepared a series of superhydrophobic surfaces with controllable adhesion based on intelligent materials and surface array structure.Meanwhile,their applications in droplets control,solid capture,and transportation are also demonstrated.The main research contents are as follows:Superhydrophobic shape memory epoxy resin（SMP）microarray films were prepared by template method.Based on the shape memory property of SMP,construct a microstructural pattern（dot and line pattern）on the surface of the superhydrophobic SMP microarray film and realized the intelligent superhydrophobic SMP microstructural patterned preparation on the superhydrophobic surface.Based on the shape memory effect of the material,the reversible transitions between high adhesion state and low adhesion state and between isotropic adhesion state and anisotropic adhesion state were successfully realized by constructing and eliminating the microstructural pattern（dot and linear pattern）on the surface.The results of the mechanism study and experimental results show that the reversible deformation of the surface microstructure directly changes the solid/liquid contact state,thus endowing the surface with intelligent adhesion characteristics.In addition,we also carried out the application research of intelligent adhesion surface in droplet storage,directional transportation,and other aspects,which were further proved that the prepared intelligent microstructure patterned surface had significant advantages in the patterned functional stability and pollution resistance compared with the traditional hydrophilic/hydrophobic patterned surface.Superhydrophobic PU/SMP composite films were prepared by bonding superhydrophobic polyurethane（PU）microarray films on the shape memory epoxy resin film substrate.Based on the shape memory effect of the substrate s,the film could reversibly transform between the curved state and the unfolded state.At the same time,the film can control the distribution of the surface microarray structure.With the reversible transformation of surface microstructure distribution morphology,the surface and solids/water droplets show similar intelligent responsive adhesion characteristics,that is,the adhesion performance between the surface and the target object can be controlled reversibly between the high adhesion state and the low adhesion state.The results showed that high surface energy is good for controlling the adhesion between the surfaces and solid objects,while low surface energy is suitable for controlling the adhesion between the surfaces and water droplets.After optimal selection,it was found when the surface energy was between 36.5 and 52.1 m N·m^-1,the synergistic effect by combining the surface energy with microstructure deformation caused the change of contact area between the surface and the target endowed the surface unique adhesion characteristics.Electrically responsive controllable adhesion superhydrophobic PU/BGA composite films were prepared by combining BGA actuator（BGA）with superhydrophobic PU microarray film.By controlling the magnitude and direction of the applied electric field,the reversible adhesion between the composite film and solid/liquid was realized.Based on the prepared composite film,we further designed and prepared the intelligent gripper,and realized the in-situ capture/release of liquid and solid.The results show that the synergistic effect between the membrane deformation caused by BGA driving and the surface superhydrophobic microstructure gives the intelligent operator a unique capturing function.Finally,we further realized the in-situ capture/release of different shaped solids,acid droplets,and alkaline droplets.