Copper (II) ions extraction by poly(N-vinylcaprolactam-mathacrylic acid) microgels for in situ reduction formation of copper nanoparticles to reduce pollutants

It is very important to eliminate organic dyes and most of the toxic transition metal ions from water because they are hazardous substances for livings. Many systems are reported to eliminate organic pollutants or transition metal ions solely from water. A new systematic way has been developed for effectively removal of both metal ions and organic pollutants (nitroarenes and toxic dyes). For this purpose, a spherical poly(N-vinylcaprolactam-co-methacrylic acid) P(NVC-MAAc) microgel system was developed by free radical precipitation polymerization (FRPP) method. The XRD, FTIR, SEM, DLS, and TEM techniques were used for characterization of P(NVC-MAAc) system and then used that system as an adsorbent for removal of copper (II) ions from water under a variety of conditions, including different P(NVC-MAAc) concentrations, pH, copper (II) ions contents, and agitation times. Various adsorption isotherms were applied to evaluate the best fitted adsorption isotherms for extraction of copper (II) ions with P(NVC-MAAc) microgel system. Furthermore, the kinetics of copper (II) ion adsorption on P (NVC-MAAc) were investigated using the pseudo-1st order (P1O), intra-particle diffusion model (InPDM), pseudo-2nd order (P2O), and Elovich model (EM). The loaded copper (II) ions in P(NVC-MAAc) microgel were then in-situ reduced to generate copper nanoparticles (NPs). The resulted [Cu-P(NVC-AAc)] hybrid microgels were used as catalyst to reduce toxic pollutants from water such as 4-nitrophenol (4NiP), 4-nitroaniline (4NiA), chromium (VI) ions (ChVI), rhodamine-B (RhB), methyl orange (MeO), and eyosin-Y (EyY). The values of apparent rate constant (kapp) for 4NiP, 4NiA, ChVI, RhB, MeO and EyY were found 0.725 min-1, 0.587 min-1, 0.097 min-1, 0.821 min-1, 0.860 min-1, and 0.833 min-1 respectively. As a result, a broad range of new organic transformations can be efficiently catalyzed by the Cu-P(NVC-MAAc) system.