Fusion of capsules to produce liquid-filled monoliths for carbon capture

Abstract

Solid–liquid composites (SLCs) combine the properties of solids and liquids, enhancing functionalities and expanding potential applications. Traditional methods for creating SLCs often face challenges such as low mass transfer efficiency, difficulty in controlling separation behavior, and substantial waste production. Herein, we report a new approach to solve these challenges by using disulfide-based responsive polymeric capsule shells to make liquid-filled monoliths for carbon capture. The capsules are prepared through interfacial polymerization and contain either non-polar poly(α-olefin)₄₃₂ or highly polar 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([HMIM][TFSI]) at 74–82 wt%. Upon gentle heating, the dynamic disulfide bonds of the isolated capsules undergo bond exchange, leading to the fusion of capsule shells into free-standing monoliths that retain >89 wt% of their liquid core and remain stable for at least two weeks. These monoliths demonstrate CO₂ absorption rates and capacities comparable to their capsule counterparts; further, in response to radiofrequency (RF), they reach the CO₂ desorption temperature in only ∼31 s. This innovative system addresses the limitations of conventional SLC fabrication techniques, offering a versatile and practical approach to fusing polymer capsule shells for applications across separation, energy storage, and carbon capture applications.