Organic Sorbents for Air Purification: A New Application for Recyclable Hyper-Cross-Linked Polystyrene

Sorption-based air purification is typically performed using inorganic sorbents such as activated carbon. Organic polymeric sorbents with a microporous or nanoporous structure could be a promising alternative. We investigated the effectiveness of four hyper-cross-linked polystyrenic sorbents against formaldehyde and compared it to the effectiveness of three activated-carbon-based preparations. One of the polystyrenic sorbents (MN270) was nanostructured, and it reduced formaldehyde concentration by over 95% (from 0.463 +/- 0.037 mg/m(3) to 0.020 +/- 0.002 mg/m(3)) in short-duration tests. In the long-duration tests (500 min), MN270's performance was comparable to that of the pure coconut shell activated carbon. MN270 was found to be nanostructured (10-200 nm pores), which was associated with its superior sorptive properties and the comparatively high Brunauer-Emmett-Teller (BET) result of 1370.49 +/- 19.19 m(2)/g, which was higher than the best-performing activated carbon sorbent (941.76 +/- 18.10 m(2)/g). The novel application of the hyper-cross-linked polystyrenic sorbents for air purification provides a feasible and potentially more sustainable alternative to inorganic sorbents, thanks to their recyclability and manufacturability from biomass.

Automated summary

The study looked into the effectiveness of hyper-cross-linked polystyrenic sorbents, with the nanostructured MN270 showing a reduction of formaldehyde concentration by over 95% in short-term tests, comparable to the performance of activated carbon. The nanostructure and high specific surface area of MN270 played a key role in its superior sorptive properties.