Xiaoxiang Wen,Xuegang Lu,Jianing Li,Chaoping Wei,Hongji Qin,Yuting Liu,Sen Yang
In nature, many organisms (e.g., chameleons) protect themselves by changing their colors in response to environmental changes. Inspired by these organisms, we present a multi-responsive, flexible, and structurally colored hydrogel film with a one-dimensional (1D) ordered periodic groove structure. The groove structure endows the film with bright, highly angle-dependent structural colors, which can be reversibly tuned by stretching and releasing. In addition, because of the thermosensitive properties of the hydrogel, the film can be switched between colored state and opaque white state with temperature. In addition, the optical state of the film is sensitive to solvent and can be reversibly changed between colored state and transparent state with soaking and evaporation of the solvent. This reversible, multi-responsive, flexible, and structurally colored hydrogel film has great potential to be used in the fields of color display, sensors, anti-counterfeiting, and so on because of its flexible and diverse tuning methods, excellent optical performance, and convenient preparation process.
Zeolitic imidazolate framework-8 (ZIF-8) nanocrystalline layers were grown on carboxylate-terminated sol–gel films patterned with surface-relief microstructures. The coverage of ZIF-8 nanocrystals was significantly affected by the surface morphology, like the size and interspace of microstructures. Its vertically aligning ability to a typical nematic liquid crystal (LC) E7 was verified and its applications as a hybrid aligned nematic (HAN) LC cell-based voltage-dependent light modulator and a switchable diffraction grating were demonstrated.
Xianrui Meng,Shunfei Qiang,Jiaqi Li,Jeong Jin Kim,Manman Zhang,Chiyu Wang,Zifan Ye,Yuhui Cao,Wenkai Zhang,Gil Ju Lee
Electrospun nanofiber-based physical unclonable functions (PUFs) offer ideal security features, positioning them as highly promising for document and packaging authentication as well as data encryption. Additionally, electrospun nanofiber membranes serve as versatile substrates for integrating functional components and nanoparticles, offering significant potential for photonic integration and enhanced optical security. In this study, we integrate plasmon-enhanced upconversion luminescence with hierarchical diffraction gratings on electrospun nanofiber membranes to create a multi-level, high-security PUF system. A novel approach is used to co-assemble silver nanocubes and upconverting nanoparticles at the oil–water interface, followed by microcontact printing to efficiently transfer the Ag/UCNP gratings onto electrospun nanofiber membranes. This hybrid structure exhibits a disorder–order–disorder pattern across multiple length scales: disordered Ag/UCNPs at the nanoscale, short-range ordered grating units at the microscale, and long-range randomness introduced by the electrospun nanofiber network at the macroscale. These structural features contribute to three distinct optical anti-counterfeiting mechanisms: plasmon-enhanced upconversion luminescence emission, achieving a fivefold increase in green luminescence intensity under 980 nm laser excitation; angle-dependent rainbow holography, generated by the ordered grating units; and physically unclonable patterns, which enable cryptographic key generation with a vast key space of 1063. The integration of multi-responsive nanoparticles with electrospun nanofiber membranes opens new possibilities for lightweight, compact, and secure optical devices, providing a robust platform for next-generation authentication and encryption technologies.
危险品化学品经营许可证（带存储）