Boosting CO2/N2 Separation from Cellulose Nanocrystal-Reinforced and Amine-Rich Facilitated Transport Membranes Comprising Deprotonated Amino Acid Salt and Ultrahigh-Molecular-Weight Polyvinylamine

Anultrathin amine-rich selective layer comprising thefixed-sitecarrier from polyvinylamine (PVAm) and the mobile carrier with anamino acid salt was successfully coated on top of the polysulfone(PSf) substrate for enhanced CO2-facilitated transport.PVAm with an ultrahigh molecular weight was synthesized via the inverseemulsion polymerization method, which allows the excellent dissipationof the reaction heat and reduces gel formation drastically. Severalbatches of PVAm with different hydrolysis degrees and molecular weightswere successfully synthesized. The mobile carriers of 2-(1-piperazinyl)ethylaminesalts of sarcosine (PZEA-Sar) were synthesized and introduced to strengthenthe facilitated transport contribution, while cellulose nanocrystals(CNCs) were incorporated into the polymer matrix to enhance the mechanicalstrength and also increase the free volume of the polymer matrix.The amine-rich composite membranes made from 0.5 wt % PVAm/PZEA-Sar-0.5wt % CNC with a high-molecular-weight PVAm of 4.4 MDa at a degreeof hydrolysis (DOH) of 78% demonstrate a significantly enhanced CO2 permeance of 160 GPU with a good CO2/N-2 selectivity of 48 at 35 & DEG;C and a feed pressure of 2 bar. Thedeveloped amine-rich facilitated transport membrane shows excellentpotential for industrial carbon capture.