Adjustment and detection of topology freezing transition temperature of vitrimers based on vitrimers doped with nanoparticles and photonic crystals

Topology freezing transition temperature (Tv) of vitrimers is an important indicator for their applications. Tvof vitrimers could be changed by using chemical methods. Herein, a physical method is proposed to adjust and detect Tv of vitrimers based on the upper vitrimers doped with SiO2nanoparticles and the lower photonic crystals (PCs) from SiO2 nanoparticles. When the photonic coatings are heated, the upper vitrimers are changed from viscoelastic-solid state to viscoelastic-liquid state, intensities of reflection peaks of PCs are increased because light would easily penetrate the coatings. Tv of vitrimers could be decided according to great changes of intensities. When photonic coatings are synthesized at 140 °C for 6 h under 2.6 MPa, the lower PCs are kept the same, as doping amounts of SiO2 nanoparticles of the upper vitrimers are increased, Tvof photonic coatings are decreased from 90 °C to 72.5 °C. They have potential applications in adjustment and detection of Tv of other vitrimers, anti-counterfeiting and displays.