1 research outputs found
Thermoresponsive Magnetic Nanoparticles for Seawater Desalination
Thermoresponsive
magnetic nanoparticles (MNPs) as a class of smart materials that respond
to a change in temperature may by used as a draw solute to extract
water from brackish or seawater by forward osmosis (FO). A distinct
advantage is the efficient regeneration of the draw solute and the
recovery of water via heat-facilitated magnetic separation. However,
the osmotic pressure attained by this type of draw solution is too
low to counteract that of seawater. In this work, we have designed
a FO draw solution based on multifunctional Fe<sub>3</sub>O<sub>4</sub> nanoparticles grafted with copolymer poly(sodium styrene-4-sulfonate)-<i>co</i>-poly(<i>N</i>-isopropylacrylamide) (PSSS-PNIPAM).
The resulting regenerable draw solution shows high osmotic pressure
for seawater desalination. This is enabled by three essential functional
components integrated within the nanostructure: (i) a Fe<sub>3</sub>O<sub>4</sub> core that allows magnetic separation of the nanoparticles
from the solvent, (ii) a thermoresponsive polymer, PNIPAM, that enables
reversible clustering of the particles for further improved magnetic
capturing at a temperature above its low critical solution temperature
(LCST), and (iii) a polyelectrolyte, PSSS, that provides an osmotic
pressure that is well above that of seawater