A compatible crosslinker for enhancement of CO₂ capture of poly(amidoamine) dendrimer-containing polymeric membranes

Poly(amidoamine) (PAMAM) dendrimers are physically immobilized in a crosslinked poly(ethylene glycol) (PEG) upon photopolymerization of PEG dimethacrylates (PEGDMAs) in the presence of the dendrimers in ethanol. The dendrimer-containing polymeric membranes exhibit excellent CO₂ separation properties over smaller H₂. However, immiscibility of PEG matrix and the dendrimer results in the formation of a bicontinuous phase-separated structure on a couple of microns scale, which inhibits to reduce the membrane thickness for enhancement of the CO₂ permeability. A compatible crosslinker, 4GMAP, is developed from the dendrimer and glycidyl methacrylate. Incorporation of the compatible crosslinker in the photopolymerization suppresses the macrophase separation between PAMAM dendrimer and PEG matrix and allows preparation of polymeric membranes as thin as 10μm with high CO₂ selectivity. The 4GMAP incorporation also endows pressure tolerance by increasing crosslinking density of the resulting polymeric membranes. The CO₂ permeance is elevated from 9.94×10^-13 to 1.68×10^-11m³(STP)m^-2s^-1Pa^-1, by reducing the membrane thickness from 640 to 9.5μm with 10 of CO₂ selectivity at 313K and 0.56MPa of CO₂ partial pressure.