Polymer-based membranes and sorbents play a critical role in CO2 removal/sequestration, either from point source emissions or direct air capture. We are developing advanced measurement methods that assess the structure-processing-performance properties of polymer-based membranes and sorbents under application-relevant conditions. Specially, we are studying the effect of polymer chemistry, morphology, and dynamics on the molecular-level binding and/or transport of CO2 into and across the polymer material. Materials of interest include mixed-matrix membranes, facilitated transport membranes, and solid-polymer sorbents. Relevant measurement platforms include vibrational (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, quartz crystal microbalance (QCM), inverse gas chromatography (IGC), x-ray and neutron scattering (SAXS, SANS, QENS), and nanocalorimetry.