Highly efficient removal of amine via ion bonds based on renewable graphene templated poly-acids generated via reversible addition-fragmentation chain transfer polymerizations

Abstract

As the only alkaline gas in the atmosphere, ammonia (NH3) is a promoter of atmospheric haze generation. It is also one of the main indoor air pollutants, and has an irritating and corrosive effect on the upper respiratory tract of the human body. Here, we report the synthesis of polymer composites with reduced graphene oxide (rGO) as template for the efficient removal of ammonia via ion bonds under ambient conditions. rGO has an ultra-large specific surface area for immobilizing pyrene-terminated poly-acids (PyPAA and PyPSSA) to obtain polymer/rGO composites (PyPAA/rGO and PyPSSA/rGO) which are cross-linked by calcium alginate (CA) to form a three-dimensional highly porous spherical aerogel (polymer/rGO/CA) platelet. Reversible addition-fragmentation chain transfer (RAFT) polymerization is used to synthesize two poly-acids with acidic groups, which can react with NH3 to form ammonium salts via ionic bonding, resulting in the chemical removal of NH3 without the generation of any other by-products. Impressively, 100 mg of PyPAA/rGO and PyPSSA/rGO composites could remove 18.7 mg and 12 mg of NH3, respectively. The current methodology to prepare poly-acids/rGO composites provides a means for efficient removal of NH3 pollutant.