Dual Functionalization of Hexagonal Boron Nitride Nanosheets Using Pyrene-Tethered Poly(4-vinylpyridine) for Stable Dispersion and Facile Device Incorporation

Owing to its favorable solution processability, the development of a stable dispersion of two-dimensional (2D) boron nitride (BN) has received significant attention for cutting-edge optic/electronic applications. Herein, we report an efficient method to disperse BN nanosheets (BNNSs) in polar solvents via dual noncovalent interactions using pyrene-tethered poly(4-vinylpyridine) (P4VP-Py). As a dispersion agent, P4VP-Py enables bifunctionalization with BNNS through ??????? and Lewis acid???base interactions arising from the pyrene and pyridine moiety, respectively, resulting in highly stable BNNS dispersions in different polar solvents. The blend of P4VP-Py-functionalized BNNS with the pristine P4VP matrix resulted in increased thermal conductivity and dielectric constant combined with superior thermal stability by forming a compatible interface between the P4VP-Py matrix and the BNNS adjacent to the P4VP-Py. We demonstrated that dual noncovalent functionalization of BNNSs based on molecular design presents a strategy to achieve high dispersion of 2D materials into various media, ranging from polar solvents to solid matrices, for the expansion of advanced optic/electronic applications using BNNSs

Dual-light emitting 3D encryption with printable fluorescent-phosphorescent metal-organic frameworks

Abstract Optical encryption technologies based on room-temperature light-emitting materials are of considerable interest. Herein, we present three-dimensional (3D) printable dual-light-emitting materials for high-performance optical pattern encryption. These are based on fluorescent perovskite nanocrystals (NCs) embedded in metal-organic frameworks (MOFs) designed for phosphorescent host-guest interactions. Notably, perovskite-containing MOFs emit a highly efficient blue phosphorescence, and perovskite NCs embedded in the MOFs emit characteristic green or red fluorescence under ultraviolet (UV) irradiation. Such dual-light-emitting MOFs with independent fluorescence and phosphorescence emissions are employed in pochoir pattern encryption, wherein actual information with transient phosphorescence is efficiently concealed behind fake information with fluorescence under UV exposure. Moreover, a 3D cubic skeleton is developed with the dual-light-emitting MOF powder dispersed in 3D-printable polymer filaments for 3D dual-pattern encryption. This article outlines a universal principle for developing MOF-based room-temperature multi-light-emitting materials and a strategy for multidimensional information encryption with enhanced capacity and security

Eight Inch Wafer-Scale Flexible Polarization-Dependent Color Filters with Ag–TiO₂ Composite Nanowires

In this study, 8 in. wafer-scale flexible polarization-dependent color filters with Ag–TiO₂ composite nanowires have been fabricated using nanoimprint and E-beam evaporation. The filters change their color via a simple rotation of the polarizer. In addition, the color of the filter can be controlled by altering the thickness of the Ag and TiO₂ nanowires deposited on the polymer patterns. Polarization-dependent color filters were realized by selective inhibition of transmission using the plasmonic resonance at the insulator/metal/insulator nanostructure interface, which occurs at particular wavelengths for the transverse magnetic polarizations. Special colors, including purple, blue, green, yellow, and pink, could be obtained with high transmission beyond 65% by varying the thickness of the deposited Ag and TiO₂ nanowires on the periodic polymer pattern under transverse magnetic polarization. In addition, a continuous color change was achieved by varying the polarization angle. Last, numerical simulations were implemented in comparison with the experimental results, and the mechanism was explained. We believe that this simple and cost-effective method can be applied to processes such as anticounterfeiting and holographic imaging as well as to color displays

Eight Inch Wafer-Scale Flexible Polarization-Dependent Color Filters with Ag–TiO₂ Composite Nanowires

In this study, 8 in. wafer-scale flexible polarization-dependent color filters with Ag–TiO₂ composite nanowires have been fabricated using nanoimprint and E-beam evaporation. The filters change their color via a simple rotation of the polarizer. In addition, the color of the filter can be controlled by altering the thickness of the Ag and TiO₂ nanowires deposited on the polymer patterns. Polarization-dependent color filters were realized by selective inhibition of transmission using the plasmonic resonance at the insulator/metal/insulator nanostructure interface, which occurs at particular wavelengths for the transverse magnetic polarizations. Special colors, including purple, blue, green, yellow, and pink, could be obtained with high transmission beyond 65% by varying the thickness of the deposited Ag and TiO₂ nanowires on the periodic polymer pattern under transverse magnetic polarization. In addition, a continuous color change was achieved by varying the polarization angle. Last, numerical simulations were implemented in comparison with the experimental results, and the mechanism was explained. We believe that this simple and cost-effective method can be applied to processes such as anticounterfeiting and holographic imaging as well as to color displays