This review explores supramolecular gels as materials for environmental remediation. These soft materials are formed by self-assembling low-molecular-weight building blocks, which can be programmed with molecular-scale information by simple organic synthesis. The resulting gels often have nanoscale ‘solid-like’ networks which are sample-spanning within a ‘liquid-like’ solvent phase. There is intimate contact between the solvent and the gel nanostructure, which has a very high effective surface area as a result of its dimensions. As such, these materials have the ability to bring a solid-like phase into contact with liquids in an environmental setting. Such materials can therefore remediate unwanted pollutants from the environment including: immobilisation of oil spills, removal of dyes, extraction of heavy metals or toxic anions, and the detection or removal of chemical weapons. Controlling the interactions between the gel nanofibres and pollutants can lead to selective uptake and extraction. Furthermore, if suitably designed, such materials can be recyclable and environmentally benign, while the responsive and tunable nature of the self-assembled network offers significant advantages over other materials solutions to problems caused by pollution in an environmental setting.

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Applying low-molecular weight supramolecular gelators in an environmental setting – self-assembled gels as smart materials for pollutant removal

Photocatalytic mineralization of antibiotics using 60%WO3/BiOCl stacked to graphene sand composite and chitosan

Water contamination is one of the main problems of modern society, and scientific research is continuously involved in identifying solutions able to preserve this valuable source. In this context, we characterized novel ionogels formed by organic salts with different anions. In particular, they show self-strengthening behavior, a quite unusual property for supramolecular gels, and they also exhibit a good load-bearing capacity. These ionogels are able to remove cationic dyes from wastewater. Thanks to their properties, they can be used in different apparatuses like dialysis membranes and as loading in adsorption columns. In the latter case over 95% removal is achieved in less than 10 min. Interestingly, soft materials can be reused for at least 20 cycles, partially regenerated, and reused for further 15 cycles. Comparison with data previously reported in the literature shows that this is a prerogative of this system and this represents not only an improvement but also a warranty of low raw material produc...

Self-Sustaining Supramolecular Ionic Liquid Gels for Dye Adsorption

A novel multi-stimuli responsive gelator based on D-gluconic acetal and its potential applications

A critical review of the aniline transformation fate in azo dye wastewater treatment

Several effective PSGs have been developed from a series of glucose-based compounds for the removal of aniline and nitrobenzene from their biphasic mixtures with water via a simple shaking strategy at room temperature within 1 min. The morphologies of the gels formed in aniline and nitrobenzene in the absence or presence of a large amount of water have been examined by field emission scanning electron microscopy (FE-SEM). The dominant factors that drive gelation in the case of the gelator and aniline or nitrobenzene have been studied using FT-IR, concentration-dependent 1H NMR, and XRD. Additionally, the efficient purification of toxic dye solutions has been realized by using one of these gelators as the adsorbent in a gel column. And the corresponding xerogel can also be used for efficient dye removal. HPLC and UV/vis spectroscopy provide the quantification means for the estimation of the purification efficacy. The easy-to-implement performance and high removal efficiency of the organic pollutants from water indicate the potential and promising applicability of these organogelators in water purification.

Phase-selective gelators based on closed-chain glucose derivatives: their applications in the removal of dissolved aniline/nitrobenzene, and toxic dyes from contaminated water

Ning Gao

Papers

Phase-selective gelators based on closed-chain glucose derivatives: their applications in the removal of dissolved aniline/nitrobenzene, and toxic dyes from contaminated water