Self-Healable Lanthanoid-Based Metallogels: Dye Removal and Crystallization in the Confined Gel State

Abstract

The self-healing property of metallogels resembles the innate self-healing of plant and animal biomaterials, making metallogels potential candidates for detailed studies. Tetrazoles with diverse coordination abilities and extensive H-bond formation capabilities may be able to be used as ligands to generate metallogels. In this report, four metallogels (M1G6Cl, M2G6Cl, M1G6NO 3 , and M3G6NO 3 ) based on different lanthanoids and functionalized with di­(1H-tetrazole-5-yl)­methane (H 2 G6) are designed and fabricated. All the metallogels are well characterized by different spectroscopic methods. The mechanical strengths of the metallogels are determined by rheology, and FE-SEM images reveal diverse needle-like morphologies of the metallogels after the formation of ordered self-assembled networks. All the metallogels are found to be photoluminescent in nature, with quantum yields falling in the range 0.75–0.12. The emissive nature of the gels is utilized to perform invisible photopatterning experiments, which show the potential of these metallogels to be used in confidential image or writing applications. Furthermore, the crystallization of the M3G6NO 3 metallogel in a confined gel space provides a pathway of elucidating its structure, which can be used to help predict the kinds of noncovalent interactions involved in the ordered self-assembly process. The self-healing nature of the M1G6Cl metallogels makes them the most interesting among all the gels and is further explored by the rhodamine dye-doped approach. Moreover, the low molecular weight, self-healable M1G6Cl metallogels act as unique soft materials for water purification by absorbing 98% Rhodamine B dye from water in 24 h.

Preparation of Tris-Tetrazole-Based Metallogels and Stabilization of Silver Nanoparticles: Studies on Reduction Catalysis and Self-Healing Property

“…Plant and animal biomaterials show an intrinsic natural self-healing property. Metallogels are found to be potential candidates, which can mimic such kinds of properties . Tetrazole, with four electronegative N-atoms in the ring, is one of the probable candidates that might show an inherited self-healing property as it tends to form coordinate covalent bonds with metal centers and is also open for extensive hydrogen bonding .…”

“…Introduction of metal ions in a gel network influences several properties including gel strength and morphology. A metal-containing gel can also show additional qualities such as optical properties, magnetic properties, sensing, catalysis, , conductivity, self-healing properties, , etc. Apart from that, as per literature reports, metallogels can show the tendency to stabilize nanoparticles of the same metals in the gel matrix to obtain different nanocomposites, which are generally formed by different covalent and noncovalent interactions between supramolecular soft materials and multidimensional nanomaterials.…”

Self-healing Materials: A Review of Recent Developments

“…The material can be stretched to 21 times its initial length of a loading rate of 100 mm Min without cracking, and can lift 2250 without cracking, 6,400 times its own weight, these excellent properties make the material's range of optical and mechanical applications significantly improved. At the same time, Novina Malviya [77] and others had found that lanthanide ions (Ln 3+ ) could be used as self-healing materials, and metal coordination bonds were formed between lanthanide ions (Ln 3+ ) and the complexes, which make the self-healing materials have unique properties such as luminescence. We had studied the luminescent properties of the material for the following reasons: The unique luminescent properties of lanthanide ions (Ln 3+ ), the high coordination number of Ln 3+ , and the dynamic properties of Ln 3+ Ligands.…”

Self-Assembly of Lanthanide-Based Metallogel Nanoplates into Microcubic Blocks as Self-Calibrating Luminescent Methanol Sensors

“…Therefore, it is imperative to procure a rapid, less-consumed, and easy-to-use method to identify and respond to methanol or its vapor. Optical sensors have attracted extensive attention owing to technical simplicity, high sensitivity, and efficiency. , A variety of materials for fluorescence sensors have been developed, including inorganic nanomaterials, quantum dots, organic molecules, and luminescent metal–organic hybrid materials (LMOHs). − Among them, LMOHs constituted by bridging central metal ions or metal clusters with organic ligands have the characteristics of both inorganic and organic materials which have been widely applied in sensor, optics, and bioimaging fields on account of flexible synthesis strategies, good porosity, large specific surface area, appropriate biocompatibility, non-aggregating quenching, and excellent photoluminescence (PL) properties. − Luminescent supramolecular metallogels, as an emerging class of LMOHs, are gradually being favored by researchers due to the characteristics of both gels and LMOHs. , Remarkably, the gel characteristics endow a qualitative breakthrough in the viscosity, flexibility, ductility, and self-repair of the metallogel. − Therefore, luminescent supramolecular metallogels have great potential in assembling optical devices, designing optical probes, and constructing fluorescent sensors.…”