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 pKa 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. In this short review, we focus on the development of CO2 separation materials consisting of hydrogel particles. The review starts with development of stimuli responsive micro- and nano-gel particles that reversibly absorb CO2 isn response. The next chapter focuses on the development of temperature-responsive hydrogel films consisting of gel particles that reversibly absorb CO2 and the importance of optimizing the pKa values of the amines in the particles. In the end, assembly of defect-free nano-meter-thick CO2 separation membranes consisting of the amine containing hydrogel particles are introduced.