Structural modification of aminoclay for catalytic applications

Efficient catalytic activity of novel fluorescent polyimide embedded Ag and V2O5 nanoparticles towards the removal of hazardous pollutants

A novel fluorescent polyimide (PI) made up of perylenetetracarboxylic dianhydride (PTCDAH) and p-phenylenediamine (PPDA) was prepared with or without Ag and V₂O₅ nanoparticles at 160 °C for 5 h under N₂ atmosphere with vigorous stirring. The influence of nanomaterials on the rate of polymerization (R_p) was determined. The synthesized PI and PI nanocomposites were characterized to analyse their chemical functionality (FT-IR), surface morphology (FE-SEM) and thermal properties (DSC and TGA). The catalytic reduction of Cr (VI), p-nitrophenol (NP) and rhodamine6G (R6G) dye was analysed using the prepared PI and PI nanocomposites as a catalyst. It was found that the R_p of PI nanocomposites was higher than pristine PI system. The PI/Ag nanocomposite system exhibited higher degradation temperature (T_d) and apparent rate constant (k_app) values towards the reduction of R6G dye.

Evaluation of physicochemical properties and catalytic activity of poly(PMDAH-co-ODA/PPDA) nanocomposites towards the removal of toxic pollutants

Synthesis of Polyimides (PIs) between pyromellitic dianhydride (PMDAH) and oxydianiline (ODA) or p-phenylenediamine (PPDA) in the presence and absence of V₂O₅ and Ag nanoparticles (NPs) were carried out under N₂ atmosphere at 160 °C for 5 h with vigorous stirring in N-methylpyrrolidone (NMP) solvent. The prepared PI and its nanocomposites were analyzed by FT-IR spectroscopy, ¹H NMR spectroscopy, FE-SEM, SEM, DSC and TGA like analytical instruments. The FE-SEM showed various surface morphologies for different PI nanocomposites. The particle size of the prepared nanoparticles was calculated as less than 60 nm for Ag and 15 nm for V₂O₅ nanoparticles by HR-TEM. The PI nanocomposites embedded with Ag nanoparticles (P2 and P5) showed a higher thermal stability than the pristine PIs (P1 and P4) and PI/V₂O₅ nanocomposites (P3 and P6). Further, the possible application of metal (Ag) and metal oxide (V₂O₅) NPs embedded PI nanocomposites was assessed on the catalytic reduction of highly toxic Cr(VI), Rhodamine 6G (R6G) dye and p-nitrophenol (NiP) pollutants with the help of a reducing agent (NaBH₄). The apparent rate constant (k_app) values were calculated to assess the catalytic efficiency of the prepared PI and its nanocomposites. The PI/Ag nanocomposite (P2) system showed an efficient catalytic reduction than the other systems.