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Abstract Photonic crystals (PCs) constructed from colloidal building blocks have attracted increasing attention because their brilliant structural colors may find broad applications in paints, sensors, displays, and security devices. However, producing high‐quality structural colors on flexible substrates such as textiles in an efficient and scalable manner remains a challenge. Here a robust and ultrafast approach to produce industrial‐scale colloidal PCs by the shear‐induced assembly of liquid colloidal crystals of polystyrene beads pre‐formed spontaneously over a critical volume fraction is demonstrated. The pre‐crystallization of colloidal crystals allows their efficient assembly into large‐scale PCs on flexible fabric substrates under shear force. Further, by programming the wettability of the fabric substrate with hydrophilic–hydrophobic regions, this shear‐based assembly strategy can conveniently generate pre‐designed patterns of complex structural colors. This assembly strategy brings structural coloration to flexible fabrics at a scale suitable for commercial applications; therefore, it holds the potential to revolutionize the coloration technology in the textile industry.
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Multicolor Photonic Pigments for Rotation‐Asymmetric Mechanochromic Devices
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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- PAR ID:
- 10446287
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 34
- Issue:
- 4
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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