Development and fabrication of PAMAM-based composite membrane module with a gutter layer of Chitosan/PAA polymer double network for CO₂ separation

To improve the CO₂ separation performance of a poly(amidoamine) (PAMAM) dendrimer composite membrane, a gutter layer of chitosan(CTS)/polyacrylic acid(PAA) polymer double network (DN) and its fabrication are proposed. In our previous studies, PAMAM-based composite membrane module with a gutter layer of cross-linked CTS showed high CO₂ separation properties from CO₂/N₂ mixed gases. In this study, CTS/PAA polymer DN was used to prepare the gutter layer instead of CTS to enhance CO₂ permeance and pressure durability of PAMAM-based composite membrane. A PAMAM dendrimer composite membrane module with a gutter layer of CTS/PAA polymer DN, which was prepared with a coating solution of CTS/PAA (CTS/PAA=1/2 molar ratio), showed a high permeance of 8.8 × 10^-11 m³ (STP) m^-2 s^-1 Pa^-1 with a high CO₂ separation factor of 104 at 40 °C, pressure 550 kPa with a feed gas mixture CO₂/N₂=5/95 (vol./vol.). (paper)