Silver Nanoparticles Engineered Polystyrene‐Poly(N‐isopropylmethacrylamide‐acrylic acid) Core Shell Hybrid Polymer Microgels for Catalytic Reduction of Congo Red

Abstract

Polystyrene‐poly(N‐isopropylmethacrylamide‐acrylic acid) [pSty‐p(NIpmam‐AC)] core shell microgels loaded with silver nanoparticles (NPs) as a recyclable catalyst for rapid reduction of Congo Red (CR) dye in aqueous medium is reported for the first time. Catalytic activity of Ag‐pSty‐p(NIpmam‐AC) core shell composite microgels is measured by adopting the reduction of CR as a benchmark reaction. Restriction of Ag NPs in single layered p(NIpmam‐AC) shell of Ag‐pSty‐p(NIpmam‐AC) core shell composite microgels enhances the diffusion of reactants to access the Ag NPs, surface during reaction with respect to previously reported core shell and homogenous composite microgels, and thus enhances the rate of CR reduction. The solid nonresponsive pSty core induces easy recyclability in core shell composite microgel catalysts. The effect of different reaction parameters such as amount of catalyst, concentration of NaBH4 and CR on the reaction completion time for CR reduction, as well as on the value of apparent rate constant (kapp), is also studied by keeping all other parameters constant, separately. Reduction efficiency of Ag‐pSty‐p(NIpmam‐AC) catalyst is also measured under different reaction conditions for the reduction of CR. A slight decrease in the percentage activity of Ag‐pSty‐p(NIpmam‐AC) catalyst is observed for up to four cycles for CR reduction. The reported Ag‐pSty‐p(NIpmam‐AC) composite microgel catalysts can be used to degrade other pollutants.

Zinc oxide supported silver nanoparticles as a heterogeneous catalyst for production of biodiesel from palm oil

“…Begum et al reported that immobilization of Nobel NPs to various supports (graphine oxide, porous silica, and alumina) have encountered the following disadvantages such as preparation methods required long time and nucleation sites of inorganic sheets suffers oxidation. Thus, to overcome this, they prepared microgel fabricated noble NPs to use in several chemical reaction . Ghosh et al observed that NPs doped or supported with another metal boosted the catalytic efficiency to great extent due to synergistic effect .…”

Recent advances in stimuli-responsive core-shell microgel particles: synthesis, characterisation, and applications

“…Hence, it would be desirable to have an efficient procedure to decompose this dye. The work by Naseem et al reveals an enhanced reduction efficiency of Congo Red by this particular core-shell microgel dispersion type [104].…”

Hydrogel: Diversity of Structures and Applications in Food Science

“…[354][355][356] Many studies have examined hydrogels with core-shell structures. For example, Farooqi et al [357] synthesized polystyrene-poly (N-isopropylmethacrylamide-acrylic acid) core-shell microgels loaded with silver nanoparticles (NPs), which were used as a recyclable catalyst for the rapid reduction of Congo Red dye. The same research group [358] also used a precipitation polymerization method to fabricate nearly mono-dispersed spherical core-shell polymer microgels consisting of an un-responsive polystyrene (PSt) core and a temperature-and pH-responsive poly(N-isopropylmethacrylamide-acrylic acid).…”