On the Potential of Using Dual-Function Hydrogels for Brackish Water Desalination

Abstract

Although current desalination technologies are mature enough and advanced, the shortage of freshwater is still considered as one of the most pressing global issues. Therefore, there is a strong incentive to explore and investigate new potential methods with low energy consumption. We have previously reported that reversible thermally induced sorption/desorption process using polymeric hydrogels hold promise for water desalination with further development. In order to develop a more effective hydrogels architecture, polyelectrolyte moieties were introduced in this work as pendent chains and a thermally responsive polymer as network backbone using reversible addition-fragmentation chain transfer (RAFT) polymerisation. The ability of the comb-type polymeric hydrogels to desalinate water was evaluated. These hydrogels were proved to absorb water with low salinity from brine solution of 2 g L −1 NaCl and release the absorbed water at relatively low temperature conditions of 50 • C. The fraction of the grafted polyacrylic acid and the comb-chain length were varied to understand their influence on the swelling/deswelling behaviour for these hydrogels. The ionic fraction in the hydrogels and the resulting hydrophilic/hydrophobic balance are crucial for the proposed desalination process. In contrast, the comb-chain length impacted the swelling behaviour of hydrogels but showed relatively little influence on the dewatering process.

CO2-Responsive Superabsorbent Hydrogels Capable of >90% Dewatering When Immersed in Water

“…However, the proportion of H 2 O within M 20 DA 80 FD is higher than M 20 DA 80 FD, and this ought to have had a larger bearing on the T g . 57 Thus, we chose to perform DSC on the water-swollen hydrogels as well since this has been shown to elucidate the predominant type of water within a hydrogel network.…”

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

“…An example is the disappearance of the lower critical solution temperature (LCST) behavior of PNIPAM when copolymerized with monomers with high ionic contents. [ 23,41,43,44 ]…”

Characterization and Topical Study of Aloe Vera Hydrogel on Wound-Healing Process

“…where W s and W d stand for the weight of the hydrated and dry samples, respectively [56,57]. Fourier transform infrared spectra were acquired using an Alpha-T FTIR system (Bruker, Billerica, MA, USA) to examine chemical functional groups in dried hydrogel samples in the wavenumber range from 4000 to 400 cm −1 .…”