Facile preparation of robust microgrooves based photonic crystals film for anti-counterfeiting.

Photonic crystals structural colors have many advantages (e.g., environmentally friendly, nonfading, etc.), showing great potential application in some emerging fields of display, detection and anti-counterfeiting. Unfortunately, they are easily damaged because of the poor mechanical robustness origined from the weak interfacial adhesion between film substrate and nanoparticles. Although some photonic crystals show good mechanical robustness, they are often suffered from complex methods. Therefore, it is still a huge challenge to prepare photonic crystals with good mechanical robustness via facile methods. Herein, an efficient and facile strategy to prepare polycarbonate (PC)/silica nanoparticles (SNPs) photonic crystals film based on microgrooves is proposed. That is, with the help of micromilling and vacuum-assisted hot-pressor, microgrooves were prepared onto PC film surface, and SNPs can be spontaneously deposited into the as-prepared microgrooves via capillary force. Such PC/SNPs photonic crystals film exhibits excellent mechanical robustness, vivid structural color, and color can change with the viewing angle. Interestingly, such films with quick response (QR) code pattern can store information and can be used as anti-counterfeiting labels. This work proposes a facile strategy to prepare microgrooves based photonic crystals film with good mechanical robustness, which can further expand its applications in anti-counterfeiting. Via micromilling and vacuum-assisted hot-pressor, PC/SNPs photonic crystals film was successfully prepared. Moreover, some complex photonic crystals patterns with vivid structural colors can also be prepared by this method. More interestingly, the as-prepared PC/SNPs photonic crystals film with QR code pattern has background-dependence and can be used as anti-counterfeiting labels. [Display omitted] • Microgrooves based PC/SNPs photonic crystals film with vivid and angle-dependent structural color was prepared. • Such PC/SNPs photonic crystals film exhibits excellent mechanical robustness thanks to the microgrooves. • Various photonic crystals patterns based on microgrooves can also be prepared and the quick response (QR) code pattern can be used as anti-counterfeiting labels. [ABSTRACT FROM AUTHOR]