Reversible absorption of CO2 triggered by phase transition of amine-containing micro- and nanogel particles

Yu Hoshino; Kazushi Imamura; Mengchen Yue; Gen Inoue; Yoshiko Miura

doi:10.1021/ja3080192

Reversible absorption of CO2 triggered by phase transition of amine-containing micro- and nanogel particles

J Am Chem Soc. 2012 Nov 7;134(44):18177-80. doi: 10.1021/ja3080192. Epub 2012 Oct 29.

Authors

Yu Hoshino¹, Kazushi Imamura, Mengchen Yue, Gen Inoue, Yoshiko Miura

Affiliation

¹ Department of Chemical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. yhoshino@chem-eng.kyushu-u.ac.jp

PMID: 23092398
DOI: 10.1021/ja3080192

Abstract

Herein we report that an aqueous solution of temperature-responsive micro- and nanogel particles (GPs) consisting of N-isopropylacrylamide (NIPAm) and N-[3-(dimethylamino)propyl]methacrylamide (DMAPM) reversibly absorbs and desorbs CO(2) via a phase transition induced by cooling and heating cycles (30-75 °C). Below the phase-transition temperature, most of the amines in the swollen GPs are capable of forming ion pairs with absorbed bicarbonate ions. However, above the phase-transition temperature, shrinkage of the GPs lowers the pK(a) and the number of amine groups exposed to water, thereby resulting in almost complete desorption of CO(2). The GPs can reversibly absorb more than the DMAPM monomer and polymer without NIPAm, which indicates the importance of the temperature-responsive phase transition of polymers in determining the degree of absorption. The results show the potential of temperature-responsive polymer solutions as absorbents to sequester CO(2) at a low energy cost.