Polymeric Hydrogels—A Promising Platform in Enhancing Water Security for a Sustainable Future

Abstract

anthropogenic activities that have led to saline intrusion and contamination of the existing freshwater sources, making the current approaches for water treatment even more difficult and costly. [2][3][4] This, in combination with the continuously rising global water demand, results in a rather pessimistic prediction that an additional 2000 billion m 3 of freshwater supply will be required by 2030 to meet the global demand, assuming no gains on the current state of water-production capacity and efficiency. [5,6] As the existing freshwater sources are being depleted, there is a growing need for utilization of a broader range of water sources beyond the conventional ones, that is, brackish water, seawater, wastewater, and atmospheric moisture. [7] On top of that, there is a call for a greater focus on enhancing water security, particularly for the poor and vulnerable populations, as water scarcity is more critical in these geographical regions due to the lack of access to conventional infrastructure and power sources to produce clean water. [1,8,9] This, in addition to the increasing intensity and frequency of climate-related disasters, present unique demands, such as simple and off-grid operations, for water technologies (WTs) that can be deployed to manage the constraints imposed by these circumstances. [10]

Robust and multifunctional natural polyphenolic composites for water remediation

“…129,130 Hydrogel, a 3D network capable of absorbing large amounts of water, has confirmed its potential as a multifunctional material platform to escort global water security, owing to the unique physicochemical characteristics, such as swellability, porosity, and hydrophilicity. 131 For example, hydrogel with large specific surface area could rapidly adsorb various pollutants and then realize recycle via the regeneration of active sites. 132 Superabsorbent hydrogel with bactericidal property could directly absorb microorganism-contaminated water and then extrude to produce the disinfected water.…”

Influence of Gel Stage from Cellulose Dissolution in NaOH-Water System on the Performances of Cellulose Allomorphs-Based Hydrogels

“…It has been observed that the transition process from CI to CII is accompanied by modifications of the intensities corresponding to different crystallographic planes. The diffraction peaks characteristic of CI are presented in Figure 4a and appear at Bragg angles (2θ) of 14.6°, 16.2°, and 22.5°, which are typical for the crystallographic planes, (110), (1)(2)(3)(4)(5)(6)(7)(8)(9)(10), and (200), respectively. In the case of the CII, three characteristic cellulose lattice planes were identified in the XRD diffraction pattern (Figure 4b), and these appear at 12.1° assigned to the (110) plane, at 20.1° for the (1-10) plane, and at 21.8° for (200) plane, respectively.…”

“…Using the natural polymers in the preparation of the hydrogels represents an attractive option over the most of the synthetic counterparts, due to the wide design possibilities of some specific compositions and properties, providing, besides the support function, key features such as biodegradability, biocompatibility, and low latent toxicity [ 8 , 9 ]. Moreover, hydrogels based on natural polymers can be employed either for the sustained and controlled (stimuli-responsive systems) delivery of active pharmaceutical principles (mainly drugs and proteins) to different cultures and tissues, or as scaffolds for tissue engineering [ 10 , 11 , 12 , 13 , 14 ].…”

Colorimetric Indicators Based on Anthocyanin Polymer Composites: A Review

“…Apart from the fibrous mats and the foams, hydrogels are also gaining growing interest in the field of porous colorimetric indicators. Hydrogels are a category of three-dimensional polymer networks consisting of macromolecular chains linked through chemical bonds, and their most important characteristic is that they can absorb and retain large quantities of water or aqueous fluids [ 206 ] maintaining their structural integrity, as shown in Figure 7 a [ 207 ]. Hydrogel based materials have been developed for various applications including food packaging [ 208 ], biomedical [ 209 ] and water technologies [ 207 , 210 , 211 , 212 ], and as carriers of bioactive compounds.…”

“…Hydrogels are a category of three-dimensional polymer networks consisting of macromolecular chains linked through chemical bonds, and their most important characteristic is that they can absorb and retain large quantities of water or aqueous fluids [ 206 ] maintaining their structural integrity, as shown in Figure 7 a [ 207 ]. Hydrogel based materials have been developed for various applications including food packaging [ 208 ], biomedical [ 209 ] and water technologies [ 207 , 210 , 211 , 212 ], and as carriers of bioactive compounds. The incorporation of anthocyanins [ 125 , 213 , 214 ] and other dyes [ 215 ] in hydrogels has been recently studied, thus the use of the hydrogel structure for the development of colorimetric indicators appears auspicious [ 69 ].…”