Rational design of thermo-responsive adsorbents: demand-oriented active sites for the adsorption of dyes.

A smart adsorbent RA@MS is fabricated by incorporating a di-block copolymer through the combination of the thermo-responsive block poly(N-isopropylacrylamide) (R) and the active block poly{N-[3-(dimethylamino) propyl]methacrylamide} (A, tertiary amines as basic sites) into mesoporous silica. The di-block copolymer RA preserves the thermo-responsive nature, which makes the active sites reversibly exposed/blocked in light of temperature variation. The obtained adsorbent possessing thermo-responsive properties can thus realize both selective adsorption and efficient regeneration for temperature-swing adsorption (TSA) of dyes.