Application of 4-VP-g-PET fibers and its N-oxide derivative as an adsorbent for removal of cationic dye

Poly(ethylene terephthalate) fibers (PET) were grafted with 4-vinyl pyridine (4-VP) by a chemical grafting technique, and an N-oxide derivative was synthesized (N-oxide-4-VP-g-PET). The removal of methylene blue (MB) from the aqueous solutions by this material was investigated. The removal and desorption capacities for MB dye were studied under various conditions.4-VP-g-PET fibers exhibited a very low removal rate when compared to the basic dye; however, N-oxide-4-VP-g-PET fibers showed more increased removal results. 2.5% of the MB dyes removal was observed with 4-VP-g-PET fibers, while 100% of MB dyes removal was found with N-oxide-4-VP-g-PET fibers using 10ppm of MB solution. Removal capacity of N-oxide-4-VP-g-PET fibers increased with increasing pH values. The maximum removal capacity of MB dye on the N-oxide-4-VP-g-PET fibers was found to be 35.1mgg(-1) at 250ppm. Results showed that removal capacity of 4-VP-g-PET fibers was significantly improved by N-oxide functionalization. Almost all adsorbed dyes were eluted by acetic acid in methyl alcohol. Ten removal-desorption cycles indicated that the reactive fibers were favorable for use again without the notable change in removal capacity. The information gained from these studies showed that the N-oxide-4-VP-g-PET fibers demonstrated potential as an effective adsorbent for the extremely effective removal of cationic dyes from aqueous media.