Preparation of polymer microspheres with reactive epoxy group and amino groups as stabilizers for gold nanocolloids with recoverable catalysis

Narrow disperse poly(divinylbenzene-co-glycidyl methacrylate) (P(DVB-co-GMA)) microspheres with reactive epoxy group were prepared by distillation precipitation copolymerization of divinylbenzene (DVB) and glycidyl methacrylate (GMA) with benzoyl peroxide (BPO) as initiator in neat acetonitrile. The epoxy group was modified with ethylenediamine (EDA) for transferring to amino group, which was used as a stabilizer for the gold metallic nanocolloids during the in situ reduction of gold chloride trihydrate (HAuCl4) with sodium borohydride (NaBH4) as a reductant. The catalytic properties of the microsphere-stabilized gold nanocolloids (P(DVB-co-GMA)-NH2@Au) were investigated by the reduction of aqueous 4-nitrophenol (4-NP) to 4-aminophenol (4-AnP) with NaBH4 as reductant. The resultant microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), elemental analysis (EA), Zeta potential, X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP) mission spectrum, and ultraviolet-visible spectroscopy.