Organic–Inorganic Hybrid Luminescent Hydrogel Glued by a Cationic Polymeric Binder

Abstract

Luminescent hydrogels have shown great potential in many fields, such as lighting, display, imaging, and sensing, because of their unique optical properties, biocompatibility, and easy processing. Organic-inorganic hybrid self-assembly can not only enhance the hydrogels' mechanical strength, but also retain their self-healing ability. Herein, a luminescent supramolecular hydrogel is reported, which is formed via self-assembly of the negatively charged Laponite nanosheets and cationic lanthanide coordination polymer. The corresponding results reveal that the multiple binding interaction between Laponite and the polymeric binder is vital for improving the mechanical performance of the obtained luminescent supramolecular hydrogel.

Lanthanide-Containing Hybrid Hydrogels with High Mechanical/Luminescent Anisotropic Parameters

“…A broad band of excitation spectra in the range of 240−320 nm was observed, indicating that the energy transfer from 2,6-pyridinedicarboxylic acid to Ln 3+ is effective (Figure S13). 45,49,53,54 The Eu 3+ -containing hydrogel showed five emission peaks at 590, 595, 615, 650, and 695 nm, attributed to the transitions of 5 D 0 → 7 F J (J = 0, 1, 2, 3, and 4); the 5 D 0 → 7 F 2 peak at 615 nm is predominant and responsible for the red luminescence (Figure 4A). 44,46,49,53,55−59 Similarly, four shard peaks at 492, 542, 582, and 621 nm were observed in the Tb 3+ -containing hydrogel, ascribed to the transitions of 5 D 4 → 7 F J (J = 6, 5, 4, and 3, respectively).…”

“…They consist of layered tetrahedral silica oxide and octahedral alumina oxide, with a formula of Al 2 Si 2 O 5 (OH) 4 · n H 2 O. , HNTs exhibit a length of 1–15 μm with an external diameter of 50–100 nm and inner diameter of 10–50 nm, respectively, with two different types of hydroxyl groups on the inner (Al-OH) and outer surfaces (Si-OH), endowing abundant negative charge on the outer surface. On the other hand, HNTs do not quench chromophore fluorescence as carbon nanotubes do. , Therefore, HNTs are regarded as a promising 1D nanofiller for the construction of anisotropic hydrogels due to the above-mentioned structural features as well as good biocompatibility, low toxicity, and resource advantages. , We have been working to construct lanthanide (Ln)-containing luminescent hydrogels, especially tough hybrid luminescent hydrogels, through the co-assembly of the Ln complex and clay. − Compared with mechanical anisotropy, research on hydrogels with luminescent anisotropy is still in its infancy. Hydrogels with luminescent anisotropy show great potential applications in OLEDs, field emission devices, and optical memories.…”