| Photonic crystal pigments have become a research hotspot in recent years,because of the advantages of environmentally friendly and more durable to bleaching.The photonic pigment particles prepared by confined self-assembly have poor mechanical performances due to the lack of strong interaction between the self-assembly components,and the structure of pigments can be easily damaged and thus lose structural color under a compression force.This restricts its large-scale application.In order to improve the mechanical performances of photonic pigments and the stability of its structure,we adopted the method of linear homopolymers(PS/PDMS)and bottlebrush copolymers(PS-b-PDMS)cooperative self-assembly under confinement.According to the similar compatible principle,the PS/PDMS homopolymer will selectively enter the corresponding microphase,resulting in the increase of lamellar thickness and structure size,which leads to the red shift of structure color.By changing the weight percentage of the homopolymer,the structural color of the microspheres can be adjusted from blue to green and from red to infrared,and the maximum reflection wavelength increases linearly with the increase of the weight percentage of the homopolymer.Therefore,the color of the photonic crystal microspheres can be adjusted accurately.Under ultraviolet light,PDMS domain will cross-link,so that a nanoscale “onion-like” structure of alternating glassy-rubbery microdomains can be constructed in the microspheres,showing good structural stability and elasticity.The structure color changes reversibly with the deformation of microsphere,and has sensitive mechanochromic property.The deformation recovery time is less than 1 s.Continuously loading-unloading micro compression test indicates that no obvious damage can be identified after 250 cycles,indicating the good structural stability and elasticity of the pigments.This work provides a simple and convenient method for the preparation of photonic pigments with strong mechanical properties,which has potential application value in display sensing,inkjet printing,etc. |
