Synergetic catalytic effect of α-cyclodextrin on silver nanoparticles loaded in thermosensitive hydrogel

Abstract

Thermosensitive poly(NIPAAm-co-AMPS) hydrogels were prepared by copolymerization of N-isopropyl acrylamide (NIPAAm) and 2-acrylamido-2-methyl 1-propansulfonic acid (AMPS) by employing N,N′- methylenebis(acrylamide) (BIS) as cross-linker. Uniformly distributed silver nanoparticles (Ag-NP) were obtained within hydrogel networks as nanoreactors via in situ reduction of silver nitrate (AgNO3) using sodium borohydride (NaBH4) as reducing agent. The catalytic properties of Ag-NP-poly(NIPAAm-co-AMPS) hydrogels presented obvious temperature dependence upon the reduction of 4-nitrophenol (4-NP) in aqueous solution. Interestingly, the addition of α-cyclodextrin (α-CD) could further enhance the reduction rate and change the associated activation parameters. This advanced catalytic system with temperature dependence and α-CD synergetic effect presented promising applications in catalytic chemistry.