Polydopamine Based Photo-responsive Shape Memory Polymer And The Achievement Of Specific 3D Structures

Developing smart materials responsive to external stimuli is a hotspot of many scientific and technological fields.Photo-active shape memory polymer(SMP)attracts great attention due to its capability of converting light into mechanical response.However,most known SMPs are only thermal-responsive and the existing methods to achieve photo-responsive ability always face the problem of complex synthesis and filler dispersing precudure.Before used as certain devices,the smart materials must present designed 3D structures as well as desired surface function.Especially,it will be ideal if the 3D shape can be spontaneously achieved out of a flat 2D sheet without manual manipulation.However,such material is rare.By applying mussel-inspired polydopamine(PDA),a novel approach for photo-active shape memory was achieved.The PDA nanoparticles can act as photo-thermal fillers with good dispersion behavior in the polymeric material.The PDA coating can be applied as a tool to endow normal SMP with photo-active property.Besides,certain 3-D shape deformation from a planar SMP sheet can be achieved by designing corresponding surface pattern.Morever,the surface property of material can be optimized by secondary surface modification.The main achievements in this thesis are present as follows:(1)Photo-active SMP is prepared by incorporating PDA nano-particles with liquid crystalline vitrimer.The photo-thermal conversion ability of the resultant material is evaluated.Then the photo-active,photo-mouldable,photo-reparable properties are studied.Lastly light-controlled 3D deformation into dynamic and static structures is preliminarily investigated.(2)A novel post-synthesis approach is introduced to endow normal SMPs with photo-activity property by PDA coating.The photo-activity and mechanical properties of the resultant material are evaluated.The relevance between the shape of PDA pattern and the light-triggered 3D deformation of the material is deeply studied.Lastly,the surface functionalization of the photo-responsive SMPs by secondary modification is inverstigated.