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Abstract Photonic crystals are extensively explored to replace inorganic pigments and organic dyes as coloring elements in printing, painting, sensing, and anti‐counterfeiting due to their brilliant structural colors, chemical stability, and environmental friendliness. However, most existing photonic‐crystal‐based pigments can only display monochromatic colors once made, and generating multicolors has to start with designing different building blocks. Here, a novel photonic pigment featuring highly tunable structural colors in the entire visible spectrum, made by the magnetic assembly of monodisperse nanorods into body‐centered‐tetragonal photonic crystals, is reported. Their prominent magnetic and crystal anisotropy makes it efficient to generate multicolors using one photonic pigment by magnetically controlling the crystal orientation. Further, the combination of angle‐dependent diffraction and magnetic orientation control enables the design of rotation‐asymmetric photonic films that display distinct patterns and encrypted information in response to rotation. The efficient multicolor generation through precise orientational control makes this novel photonic pigment promising in developing high‐performance structural‐colored materials and optical devices.
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This content will become publicly available on November 19, 2025
Utilizing 2D metal halide perovskite thin films as highly tuneable surfaces for orientation control of energetic materials
The development of high performing and stable energetic materials (EMs) is a focus for a variety of applications including explosives, propellants, and pyrotechnics. To enhance stability, energetic crystals are often interfaced with materials such as chemical binders, which can introduce a variety of physiochemical phenomena ultimately leading to unpredictable stability and performance within the composite. Therefore, a thorough understanding of how energetic crystals behave when interfaced with various chemical functionalities is crucial for designing safer, high performing energetic formulations. This work provides a fundamental insight into interactions between a high performing energetic material, CL-20 (hexanitrohexaazaisowurtzitane), and other materials' surfaces. Highly controlled, tunable 2D metal-halide perovskite (2D MHP) templates with tunable periodicity and chemistry were created and used as a template layer to influence nucleation and growth of CL-20 crystals. All MHP/CL-20 bilayer films exhibit small, nonuniform crystalline deposit morphology for the CL-20 crystals with β-CL-20 polymorphic structure. While most MHP films template the formation of β-CL-20 crystals with a (111) preferential orientation, PbPMA2Cl4/β-CL-20 films crystallize with a (020) preferential orientation. The results presented herein suggest interfacial energy minimization between the two bilayer components is the dominant driving force behind the CL-20 preferential orientations. This methodology can potentially be used for developing techniques for growing energetic crystals with desired morphology, packing density and crystallographic orientation.
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- Award ID(s):
- 2326713
- PAR ID:
- 10573394
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Reaction Chemistry & Engineering
- Volume:
- 9
- Issue:
- 12
- ISSN:
- 2058-9883
- Page Range / eLocation ID:
- 3248 to 3256
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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