摘要 |
<p>The present invention discloses new types of poly(amidoamine) (PAMAM) dendrimer-cross-linked polyimide membranes and methods for making and using these membranes. The membranes are prepared by cross-linking of asymmetric aromatic polyimide membranes using a PAMAM dendrimer as the cross-linking agent. The PAMAM-cross-linked polyimide membranes showed significantly improved selectivities for CO2/CH4 compared to a comparable uncrosslinked polyimide membrane. For example, PAMAM 0.0 dendrimer-cross-linked asymmetric flat sheet poly(3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride-3,3′,5,5′-tetramethyl-4,4′-methylene dianiline) (DSDA-TMMDA) polyimide membrane showed CO2 permeance of 135.2 A.U. and CO2/CH4 selectivity of 20.3. However, the un-cross-linked DSDA-TMMDA asymmetric flat sheet membrane showed much lower CO2/CH4 selectivity (16.5) and higher CO2 permeance (230.8 GPU).</p> |