Construction And Performance Of Photonic Elastomers Based On Supramolecular Polymer

Photonic elastomers are a type of emerging functional nanocomposites,which can be obtained by the combination of the polymeric matrix and colloidal photonic crystal.Photonic elastomers exhibit structural colors by modulating the movement of photons.Compared with traditional colloidal photonic crystals,photonic elastomers have stable optical,mechanical,and mechanochromic properties,and therefore show important applications in anti-counterfeiting,visualized sensors,and color coating.Co-assembly is an emerging effective strategy for constructing photonic elastomers,through which polymers and colloidal nanoparticles are assembled to obtain high-performance photonic elastomers through solvent evaporation.The co-assembly method is beneficial to the large-area preparation of photonic elastomers.However,it is still facing some problems in their practical applications,such as simplex structure,poor color quality,narrow-spectrum responsiveness,and slow/poor damage healing.In this dissertation,supramolecular photonic elastomers were obtained by the co-assembly of supramolecular polymers with reversible dynamic bonds and functional colloidal nanoparticles,and their optical and mechanical properties can be readily regulated by intermolecular interactions,crosslinking kinetics,functional colloidal nanoparticles,and so on.The main research contents of this dissertation are as follows:1.Photonic elastomer with tunable photonic structures was constructed by regulating the assembly of colloidal nanoparticles via the supramolecular crosslinking network,in which the supramolecular crosslinking network was generated from the colloidal nanoparticle and the polymer.Meanwhile,the assembling process of the colloidal nanoparticles within the supramolecular matrix was monitored and revealed.Through optimizing the interaction between polymer and colloidal nanoparticles and adjusting the crosslinking kinetics,photonic elastomers with varied structures from short-range to long-range order were obtained.Besides,we show that photonic elastomers with varied structures exhibit different optical and mechanical properties.2.Polyborosiloxane with multiple weak interactions and high mobility was synthesized and co-assembled with Si O₂ colloidal nanoparticles to obtain photonic elastomer with rapidly self-healing properties.The arrangement of colloidal nanoparticles within photonic elastomer and the thus-resulted structural color,which were regulated by the crosslinking kinetics induced by rapid solvent evaporation,were investigated.The as-prepared photonic elastomers exhibited self-healing properties towards superficial scratches or cuts at room temperature due to the highly dynamic and reversible crosslinked network.Besides,large-area photonic elastomer film was prepared by a simple spray-coating process.3.A water-soluble and recyclable supramolecular polymer based on quadruple hydrogen bond was synthesized by copolymerization of monomers containing ureidopyrimidinone and poly（ethylene glycol）,which was then co-assembled with Si O₂colloidal nanoparticles to obtain the environment-friendly photonic elastomer.The as-prepared photonic elastomer exhibited adjustable optical and mechanical properties by varying amounts of polymer.More importantly,through the hot-press remolding and redissolving-casting process,photonic elastomers showed excellent recycling properties.4.Carbon-coated Fe₃O₄ nanoparticles with a high refractive index and broad light absorption were employed for the construction of supramolecular photonic elastomers with high-quality colors and broad-spectrum responsiveness by co-assembly with amino-terminated poly（dimethylsiloxane）polymer through supramolecular interactions.Through preparing photonic elastomers with different two-phase refractive index differences,the influence of high refractive index difference on the optical properties of photonic elastomers was discussed.Furthermore,by adjusting the content of colloidal nanoparticles,the mechanochromic properties of photonic elastomers were studied.At the same time,colloidal nanoparticles with photothermal capability can accelerate the healing of the damaged photonic elastomers by effectively absorbing light and converting it into heat under light irradiation.