Hydrogel particles for CO₂ capture

Capturing CO₂ from various sources, such as postcombustion exhaust gases and the atmosphere, is essential for a sustainable human society. Effective CO₂ separation materials such as adsorbents and membranes are of utmost importance in efficient CO₂ capture. This short review is focused on CO₂ separation materials consisting of hydrogel particles. The first chapter introduces stimuli-responsive micro- and nanogel particles that reversibly absorb CO₂ in response to thermal stimuli. The development of temperature-responsive hydrogel films comprising gel particles for reversible CO₂ capture is introduced. The importance of choosing amines with optimal pK_a values for efficient CO₂ capture from various sources is explained in detail. The assembly of CO₂ separation membranes consisting of amine-containing hydrogel particles is introduced in the final chapter. The paper highlights the promise of separation materials consisting of hydrogel particles for efficient CO₂ capture from postcombustion gases and air and the prospects for further advances in this area.