Susan Rempe, Sandia National Laboratories
Ultra-Thin and Robust Liquid Membrane for CO2 Capture from Gas Mixture
Written by Chetna Madan
The dire effects of ever-increasing CO2 in the atmosphere can be sensed by the unpredictable climate change taking over the planet. The attempts of sequestering CO2 require high energy inputs and costs. An effective approach as developed at Sandia National Laboratories could be using nature-inspired, ultra-thin, and robust enzyme functionalized membranes with pore size selectivity that permits only CO2 molecules separation. The membrane functionalized with metalloenzyme carbonic anhydrase (CA) is comprised of 18-nm thick arrays of 8-nm diameter hydrophilic pores stabilizing water by capillary action. The benefit of functionalizing with CA comes from the catalyzed conversion of CO2 and water into carbonic acid, thus facilitating the capture and release of CO2. The mixed pore chemistry of the membrane is designed strategically to have super hydrophilic surface on the catalytic side while a superhydrophobic surface on the other. With the optimized diffusion constraints and CA concentration within the nanopore array, the super-thin membrane was able to achieve 10 times better CO2 capture as compared to other methods.