Molecular dynamics simulation study on the effect of crosslinker concentration on polymer aerogel properties and its CO2 adsorption

Abstract. Polyacrylamide-based aerogels represent a promising adsorbent for CO2 capture due to their unique structural properties. However, optimizing these materials for enhanced CO2 adsorption requires a comprehensive understanding of the relationship between crosslinker concentration and aerogel characteristics. The molecular simulation approach takes less time and resources to study the real adsorption performance of the polymer aerogel. Therefore, in this study, Grand Canonical Monte Carlo (GCMC) simulations investigated the crosslinker concentration (i.e. 1 and 7wt.%) impact on critical properties of polymer aerogels relevant to carbon capture. By examining the structural changes induced by differing crosslinker concentrations, we elucidate the relationship involved between molecular architecture and CO2 adsorption performance. The computational results reveal that the polymer aerogel with 7wt% MBA has a higher degree of crosslinking compared to 1 wt.%. MBA. As a result, the glass transition temperature of polymer aerogel was increased from 385.5 to 495K. Furthermore, it was observed that the increase in crosslinker content significantly decreases the free volume and CO2 adsorption of the polymer aerogel. The results of this research will help to understand the role of crosslinkers in designing the next-generation polyacrylamide-based aerogel for mitigating greenhouse gas emissions molecular simulation.