Graphene oxide embedded P(AAm)/PANI cryogel polymer composites for sensor application against pesticide, nitro compound, and organic dyes

Abstract

Graphene oxide (GO) embedded superporous poly(acrylamide) (P(AAm)) cryogel composites (P(AAm)-GO) were prepared and used as conductive sensor materials. For this goal, the GOs flakes within superporous P(AAm) cryogels were reduced in-situ employing hydriodic acid (HI), hydrazine (N2H4), and sodium borohydride (NaBH4) as reducing agents. Amongst all reduced agents\ he highest conductivity was observed for HI reduced P(AAm)-GO (P(AAm)-rGO) with 1.7 × 10−6±9.7 × 10−8 S.cm−1. Then again, this P(AAm)-rGO was used for in-situ synthesis of conductive polymers, poly(aniline) (PANI), and poly(pyrrole) (PPy) by using oxidative polymerization technique. The SEM, FT-IR, TGA and conductivity measurements were done for the characterization of prepared cryogel composites. It was found that the conductivity of P(AAm)-rGO increased 70- and 1400-fold with the presence of PANI and PPy, respectively. Furthermore, potential sensor application of P(AAm)-rGO/conductive polymers were tested against herbicides such as paraquat, glyphosphate (G), and a phenolic compound, 4-nitrophenol (4-NP), and some dyes such as methylene blue (MB), methyl orange (MO). Conductivity of P(AAm)-rGO/PANI decreased 5.3 -fold upon reacting with 10 mL 50 ppm G solution. The sensitivity and effect of G amounts were also tested for P(AAm)-rGO/PANI cryogel composite.