You are welcome to attend Silu Chen's PhD defense, when they will discuss the use of pebax-based composite membranes for carbon capture.
Abstract
A great amount of anthropogenic CO2 emissions has caused the greenhouse effect which impacts the living environment of creatures on the planet.
Effective carbon capture technologies need to be developed to reduce CO2 emissions. Membrane separation technology can be applied in carbon capture due to its advantages in energy conservation and pollution prevention.
Poly(ether block amide)-based (PEBAX 1657) composite membranes were developed for carbon capture in separating CO2/N2, CO2/CH4, and CO2/H2 mixtures in this study.
Polyvinylamine/PEBAX (PVAm/PEBAX) blend membranes were prepared for carbon capture by a solution casting method. The presence of PVAm enhanced membrane hydrophilicity and gas solubility. To further increase CO2 permeability in the membranes, PEBAX/PVAm/diethanolamine (PEBAX/PVAm/DEA) composite membranes were fabricated on polysulfone substrate membranes. The structures of the composite membranes not only improved gas permeance due to reducing the thickness of the permselective layer but also provided great mechanical strength. DEA can increase membrane hydrophilicity. Water-swollen membranes showed great gas permeability, but the gas selectivity still needs to be improved. NH4F/PEBAX membranes were developed by a solution casting method.
The introduction of F- affected the permeabilities of N2, CH4, and H2 in the membranes more significantly than CO2 permeability due to the salting-out effect, resulting in an increase in gas selectivity. Mixed matrix membranes were fabricated by embedding amino-modified multi-walled carbon nanotubes
(MWCNTs) as a dispersed phase in a PEBAX polymer matrix. After acid treatment, MWCNTs were modified by polydopamine (PDA) through self-polymerization of dopamine (DA). The catechol groups can react with amine groups on branched polyethylenimine (PEI) by the Michael addition reaction and Schiff base reaction. The addition of MWCNT-PDA-PEI can facilitate CO2 transport and adjust membrane structures. The prepared PEBAX/MWCNT-PDA-PEI membrane showed higher gas permeability and selectivity than the pristine PEBAX membrane.
Supervisor: Professor Feng