Multi-Functional Hydrogels Simultaneously Featuring Strong Fluorescence, Ultralong Phosphorescence, and Excellent Self-Healing Properties and Their Use for Advanced Anti-counterfeiting

Abstract

Herein, we present a class of multi-functional hydrogels, which simultaneously features strong fluorescence, ultralong room-temperature phosphorescence (RTP), and excellent self-healing properties. In particular, the as-prepared hydrogels could produce strong fluorescence with a photoluminescence quantum yield (PLQY) value of 22.4%, as well as ultralong RTP (lasts for ∼20 s with phosphorescence lifetime of ∼264 ms). In addition to the superior optical performance, the as-prepared hydrogels possess excellent self-healing property, with ∼91.5% self-healing efficiency at room temperature and an increased elasticity of ∼281%. Taking advantages of these unique merits, we further exploit such highperformance hydrogels for advanced anti-counterfeiting applications. Significantly, the hydrogel-based anti-counterfeiting tags are capable of realizing multi-color static information in the spatial scale and more than five kinds of dynamic information during 15 s of the phosphorescence decay process in the temporal scale.

Mimicking Color-Changing Organisms to Enable the Multicolors and Multifunctions of Smart Fluorescent Polymeric Hydrogels

“…Consequently, the on-demand encryption of multicolor fluorescent patterns was realized with increasing irradiation time, significantly raising the difficulty of data decryption. Along this line, a number of smart FPHs with diverse responsiveness and programmable fluorescence changes have been designed for multistage information encryption, greatly enriching the potential tool box against data forging. ,− …”

Aqueous Room‐Temperature Phosphorescence from Assembled Phosphors for Analytical Detection†

“…[12][13][14][15] For example, heavy atom effect [16][17][18] or introduction of heteroatoms (N, O, S) [19] could promote spin-orbit coupling (SOC) process; while crystallization, [20][21][22][23] polymerization, [24][25][26] H-aggregation [27][28] and host-guest interaction [15,[29][30][31][32] could limit molecular motion and suppress quenching from O 2 and H 2 O. Nowadays, RTP materials are attracting much attention in the fields of OLED, [33][34][35] information storage [36][37] and anti-counterfeiting. [38][39] It should be noted that most of the existing applications of RTP materials tend to be in the solid state, since phosphorescence is easily quenched by water molecules or solvent-assisted deactivation. Besides, the motions of molecules in the aqueous phase are more active than that in the solid state, which limits its efficiency and further applications of RTP for analytical detection.…”

“…[ 12‐15 ] For example, heavy atom effect [ 16‐18 ] or introduction of heteroatoms (N, O, S) [ 19 ] could promote spin‐orbit coupling (SOC) process; while crystallization, [ 20‐23 ] polymerization, [ 24‐26 ] H‐aggregation [ 27‐28 ] and host‐guest interaction [ 15,29‐32 ] could limit molecular motion and suppress quenching from O 2 and H 2 O. Nowadays, RTP materials are attracting much attention in the fields of OLED, [ 33‐35 ] information storage [ 36‐37 ] and anti‐counterfeiting. [ 38‐39 ]…”

Room‐Temperature Phosphorescent Tough Hydrogels Based on Ionically Crosslinked Nonaromatic Polymers

“…[39,40] On the other hand, the incorporation of phosphors into hydrogels can exacerbate the structural inhomogeneity of the gel network, and thus, most reported phosphorescent hydrogels are mechanically very weak. [41] It remains a challenge to prepare phosphorescent hydrogels with long lifetimes and strong mechanical properties, which could greatly broaden their potential applications. Recently, nontraditional luminogens (NTLs) without any aromatic structures have been reported.…”