Self‐Healable Metallogels for Selective Dye Adsorption

Abstract

The low molecular weight gelator, disodium L-(3,5-di-tert-butyl-2-hydroxy-benzyl)amino aspartic acid (Na 2 HL), has been used to prepare three metal-organic hydrogels (metallogel) with the metal ions Ni 2 + (MOG 1), Co 2 + (MOG 2), and VO 2 + (MOG 3). The gels have been prepared by mixing the aqueous solutions (0.5 mL) of the Na 2 HL(0.01 to 0.05 mmol) and M(CH 3 COO) 2 ⋅4H 2 O {M=Ni or Co} or VO(SO) 4 ⋅H 2 O (0.01 to 0.05 mmol). The gels have been characterized by IR spectroscopic studies, MALDI TOF spectrometry and various microscopic studies. All the gels are multi-responsive in nature to different external stimuli, and among them, MOG 1 and MOG-2 show the self-healable property indicating a strong metal-ligand interaction and hydrogen bonding interactions in the gel network. The thixotropic behavior and viscoelastic nature of the self-healable metallogels have been confirmed by time dependent stepstrain experiment at room temperature. It was observed that MOG 1 shows rapid and more efficient selective dye adsorption of cationic dyes, rhodamine B (RhB) {61.7 mg g À 1 }, and malachite green (MG) {15.3 mg g À 1 } from mixtures of cationic, anionic dyes, and neutral dyes. MOG 2 also selectively adsorb cationic dyes from the mixture of dyes. The gel, MOG 3, selectively degrades fluorescein (FL) dye.

Exploration of Variable Solvent Directed Self-Healable Supramolecular M(II)-Metallogels (M = Co, Ni, Zn) of Azelaic Acid: Investigating Temperature-Dependent Ion Conductivity and Antibacterial Efficiency

“…However, the achievement of self-healing metallogel is still challenging due to the complicated intrinsic mechanisms leading to a metallogelation process, and most of the potential metallogels are discovered by serendipity. , Metal–ligand coordination interaction existing between the gelator molecule and metal ions is one of the premiere driving forces leading to metallogelation . The presence of some typical functional groups within a molecule including carboxylic groups, , hydroxyl groups, phosphate groups, and compounds with oxygen, nitrogen, and sulfur donor sites is an essentially crucial feature of a low molecular weight gelator (LMWG). − Additionally, some of the gels based on LMWG exhibit marvelous phase-selective properties that can selectively trap organic solvents from aqueous–organic solvent mixtures . Such gels can be of practical utility in oil spill remedy, phase partition, water treatment, , and in the catalytic reactions of organic compounds …”

“…49−51 Additionally, some of the gels based on LMWG exhibit marvelous phase-selective properties that can selectively trap organic solvents from aqueous−organic solvent mixtures. 52 Such gels can be of practical utility in oil spill remedy, 53 phase partition, 54 water treatment, 53,55 and in the catalytic reactions of organic compounds. 35 Azelaic acid has been judicially chosen as a low molecular weight organic gelator to fabricate the metallogels with different metal sources in diverse solvent medium.…”