透明光子晶体薄膜的力致变色调控及防伪应用

Mechanochromic modulation and anti-counterfeiting application of transparent photonic crystal film

利用SiO_(2)胶体粒子构筑三维蛋白石光子晶体阵列,并将其嵌入聚二甲基硅氧烷(PDMS)弹性体内,制备了一种具有力致变色性能的透明光子晶体薄膜。采用SEM、光纤光谱仪、拉力试验机、数码相机对光子晶体薄膜的结构、光学性能进行了表征,并研究了其在防伪中的应用。结果表明,施加拉力时,该透明光子晶体薄膜显现结构色,其最大反射波长随拉伸量的增加可发生持续蓝移,撤销拉力可逆回复至初始状态,且即使经历100次循环拉伸,光子晶体薄膜仍保持最大稳定的光学性能。将光子晶体薄膜进行图案化设计,通过施加或撤销拉力可使隐藏于其中的图案快速显现或消失,表明制备的光子晶体薄膜在防伪领域具有广阔的应用前景。

A transparent photonic crystal film with tunable mechanochromic properties was prepared by embedding 3D opal photonic crystals,constructed by self-assembly of SiO_(2) colloidal arrays,in elastomeric polydimethylsiloxane(PDMS).The structure and optical properties were characterized by SEM,fiber optical spectrometer,tensile testing machine and digital camera,followed by investigation on its anti-counterfeiting application.The results showed that the transparent photonic crystal film exhibited an obvious structural color rendering with tensile stress,whose maximum reflectance wavelength could display a continuous blue shift with tensile strain enhancement.Moreover,the photonic crystal film could return to its initial state upon stress release.This optical property was still stable and well maintained even after 100 cycles of stress applying and releasing.Corresponding pattern design of photonic crystal film based on this optical property could make the hidden pattern appear or disappear quickly by applying or withdrawing the tension,which could lead to broad application potential in the field of anti-counterfeiting.