# Recyclable and eco-friendly xanthan gum-based hygroscopic hydrogel for atmospheric water harvesting

## TL;DR

This paper introduces a new eco-friendly hydrogel made from xanthan gum that efficiently captures and releases water from the air, offering a sustainable solution to water scarcity.

## Contribution

The novelty lies in the development of a recyclable, non-toxic, and cost-effective xanthan gum-based hydrogel for atmospheric water harvesting.

## Key findings

- The hydrogel achieved 50% of its maximum water uptake within 3 minutes.
- Water uptake increased with AA and CaCl2 but decreased with excess N-MBA.
- Over 94% of sorbed water was rapidly released, and the hydrogel showed excellent reusability.

## Abstract

Water scarcity is a pressing issue in several regions of the world. Nevertheless, atmospheric water vapor offers an abundant freshwater source that is constantly renewed through the hydrological cycle. Among water harvesting technologies, Sorption-based methods, which involve sorbents to capture water vapor and heat to release the sorbed water, have proven its effectiveness for collecting moisture. This study introduced a novel type of sorbent hydrogel made from natural, cost-effective, and non-toxic polysaccharide polymer. The hydrogel was prepared by grafting partially neutralized acrylic acid (AA) monomers onto Xanthan Gum (XG) using N, N′-methylene-bis-acrylamide (N-MBA) as a crosslinker and potassium persulfate as an initiator. Characterization was done using FTIR, SEM, TGA, and XRD. It was found that the swelled sample showed a higher value of water uptake which reached to about 50% of their maximum swelling capacity at the first 3 min. Moreover, the water uptake of the hydrogel increased as the amount of AA and CaCl2 increased up to a certain value and decreased beyond this value. While, increasing the concentration of N-MBA led to decreasing the water uptake. Finally, over 94% of the sorbed water being rapidly released. While, the hydrogel showed excellent reusability without noticeable fading.

The online version contains supplementary material available at 10.1038/s41598-025-23971-3.