A Photopatternable Conjugated Polymer with Thermal‐Annealing‐Promoted Interchain Stacking for Highly Stable Anti‐Counterfeiting Materials

Abstract

Photoresponsive polymers can be conveniently used to fabricate anti‐counterfeiting materials through photopatterning. However, an unsolved problem is that ambient light and heat can damage anti‐counterfeiting patterns on photoresponsive polymers. Herein, photo‐ and thermostable anti‐counterfeiting materials are developed by photopatterning and thermal annealing of a photoresponsive conjugated polymer (MC‐Azo). MC‐Azo contains alternating azobenzene and fluorene units in the polymer backbone. To prepare an anti‐counterfeiting material, an MC‐Azo film is irradiated with polarized blue light through a photomask, and then thermally annealed under the pressure of a photonic stamp. This strategy generates a highly secure anti‐counterfeiting material with dual patterns, which is stable to sunlight and heat over 200 °C. A key for the stability is that thermal annealing promotes interchain stacking, which converts photoresponsive MC‐Azo to a photostable material. Another key for the stability is that the conjugated structure endows MC‐Azo with desirable thermal properties. This study shows that the design of photopatternable conjugated polymers with thermal‐annealing‐promoted interchain stacking provides a new strategy for the development of highly stable and secure anti‐counterfeiting materials.

Dual host–guest interaction-mediated photoswitchable fluorescent supramolecular polymers for anti-counterfeiting and encryption

“…Information encryption and anti-counterfeiting play an important role in daily life, such as information security, and avoiding the loss caused by imitation. 7,48–52 We first investigated the potential application in information encryption based on the binary codes of the standard 8-bit ASCII characters. SPS-5 containing NC-DSA-CN and SPS-4 containing NC-DSA-CN and CDSP were selected as encryption units to create information lattices (Fig.…”

Decoding the future: opportunities and challenges in next-generation optical data storage [Invited]

“…For instance, a photoresponsive conjugated polymer, which contains alternating azobenzene and fluorene units, exhibits high thermal stability at 370°C [Fig. 5(c)] [60] . Furthermore, the photoinduced anisotropy of liquid-crystal materials containing azobenzene moieties demonstrates reverse relaxation characteristics, enhancing their ability for long-term high-density data storage [61][62][63][64][65][66][67] .…”

Dynamic Fluorescence Materials Based on Naphthalimide-Functionalized Silica Aerogels and Applications in Advanced Information Encryption

“…Therefore, in the field of production, manufacturing, and sales, the application of the anticounterfeiting technology is becoming more and more obvious. − Common anticounterfeiting technologies include laser-based authentication, QR code verification, nanotechnology-based security features, chemical anticounterfeiting measures, fluorescent anticounterfeiting, and so on. Among these, fluorescent anticounterfeiting materials are widely explored because of their remarkable visibility, multilayer protection, and user-friendliness, which provide powerful anticounterfeiting measures for commodities and documents. − However, most fluorescent anticounterfeiting materials are based on their static features or signals, which greatly limits the encryption of advanced information. , In view of this, materials that can be switched to multiple states under external stimuli as needed would be promising candidates. These fluorescent patterns show dynamic color change with time after being exposed to external stimuli and show a vivid display of encrypted information, so they have a higher security level because of the increase in anticounterfeiting dimension. − …”