Low temperature splinting activity and catalytic behavior of nano Ag doped sulphamicacid bridged diblock copolymer

Modification of wool fibre's structural properties as a cheap adsorbent for the elimination of Cr6+ and Rhodamine6g dye from aqueous solution

Wool, a naturally occurring biopolymer made up of amino acids, is employed as an adsorbent for both modified and unmodified forms of the dyes rhodamine6G (R6G) and Cr6+. The two-step procedure of (i) ring opening polymerization (ROP) and (ii) condensation reaction was used to modify the structure of wool fibre. Both the ROP and the condensation provide steric free chain expanding groups as well as adsorption-improving groups. The FT-IR spectrum, which showed peaks about 1725 and 1630 cm-1 corresponding to the CO and CN stretchings, respectively, confirmed the structural modification. By detecting a slight hump at 8.5 ppm, 1H NMR was able to validate the later functional group. DSC, TGA, FE-SEM, EDX, and water contact angle (WCA) were also used to characterize it. With the aid of a UV-visible spectrophotometer, the quantitative adsorption of both Cr6+ and R6G by modified and unmodified Wool fibre was monitored. For the adsorption of Cr6+ and R6G, the pseudo first order and pseudo second order kinetics were used. The multilayer coating of adsorbate onto adsorbent was confirmed by the Langmuir adsorption isotherm. Thermodynamic parameters were calculated and compared to values found in the literature.

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.