A forward osmosis hydrogel draw agent that responds to both heat and CO2

CO2-Responsive Branched Polymers for Forward Osmosis Applications: The Effect of Branching on Draw Solute Properties

“…As part of an ongoing project on CO 2 -switchable draw agents for FO, − we recently reported on design and evaluation of nitrogen-rich CO 2 -responsive polymeric draw solutes that reversibly change their osmotic pressure upon addition or removal of CO 2 . In the presence of CO 2 , polymers with tertiary amine groups (linear poly­( N -methylethylenimine) (l-PMEI), branched poly­( N -methylethylenimine) (b-PMEI), and poly­( N , N -dimethylallylamine) (PDMAAm)) form tertiary ammonium bicarbonate salts and exhibit high osmotic pressure (e.g., π CO2 ≈ 60 bar for 35 wt % PDMAAm solution).…”

Carbon Dioxide Switchable Polymers – Recent Developments and Emerging Applications

“…decided to explore the effects of making two important changes to how we were making and using PDMAAm. [ 42 ] Instead of synthesizing linear or branched polymer, we decided to make hydrogels. As importantly, we decided to also exploit the thermoresponsiveness of PDMAAm in addition to its CO 2 ‐responsiveness.…”

“…While we were further studying poly(N,N-dimethylallylamine) (PDMAAm), which was the most promising of the forward osmosis draw solute candidates, Ellis et al decided to explore the effects of making two important changes to how we were making and using PDMAAm. [42] Instead of synthesizing linear or branched polymer, we decided to make hydrogels. As importantly, we decided to also exploit the thermoresponsiveness of PDMAAm in addition to its CO 2 -responsiveness.…”

Thermo-sensitive hydrogels for forward osmosis with NIR light-induced freshwater recovery

“…1 Subsequently, a large amount of work on thermo-sensitive hydrogels for desalination, especially in the field of forward osmosis (FO), has been reported. 2,[19][20][21][22][23][24][25][26][27][28] These works can be broadly classified into two categories: the first is different hydrogel compositions, such as the poly(ionic liquid) hydrogels (PTVBP-C6-5/5) developed by Liu et al 24 and the electroresponsive hyaluronic acid/poly(vinyl alcohol) (HA/PVA) hydrogels prepared by Zhang et al 31 The second category is composite/hybrid hydrogels, such as reduced graphene oxide (rGo) composite hydrogels prepared by Wang et al 22 for water recovery under sunlight and sewage sludge ash (SSA) composite hydrogels prepared by Pan et al 18 for significantly improving the swelling rate of hydrogels. The incorporated components endow the hydrogel with various composite functions.…”