Properties of poly(1-naphthylamine)/Fe 3O 4 composites and arsenic adsorption capacity in wastewater

The research results of poly(1-naphthylamine)/Fe 3O 4 (PNA/Fe 3O 4) nanocomposites synthesized by a chemical method for As(III) wastewater treatment are presented in this paper. XRD patterns and TEM images showed that the Fe 3O 4 grain size varied from 13 to 20 nm. The results of Raman spectral analysis showed that PNA participated in part of the PNA/Fe 3O 4 composite samples. The grain size of PNA/Fe 3O 4 composite samples is about 25--30 nm measured by SEM. The results of vibrating sample magnetometer measurements at room temperature showed that the saturation magnetic moment of PNA/Fe 3O 4 samples decreased from 63.13 to 43.43 emu/g, while the PNA concentration increased from 5% to 15%. The nitrogen adsorption--desorption isotherm of samples at 77 K at a relative pressure P/ P 0 of about 1 was studied in order to investigate the surface and porous structure of nanoparticles by the BET method. Although the saturation magnetic moments of samples decreased with the polymer concentration increase, the arsenic adsorption capacity of the PNA/Fe 3O 4 sample with the PNA concentration of 5% is better than that of Fe 3O 4 in a solution with pH= 7. In the solution with pH>14, the arsenic adsorption of magnetic nanoparticles is insignificant.