Chitosan/polyamide nanofibers prepared by Forcespinning® technology: A new adsorbent to remove anionic dyes from aqueous solutions

Chitosan/polyamide nanofibers (CP nanofibers) were prepared by a new Forcespinning (R) technology, and used as alternative adsorbent to remove Reactive Black 5 (RB5) and Ponceau 4R (P4R) dyes from aqueous solutions. The results demonstrated that under the best operational conditions (30 G1/2 needles, spinneret rotation of 12000 rpm for 10 min and chitosan polyamide ratio of 1.00/1.50), chitosan/polyamide nanofibers were produced at a rate of 3 g h(-1). CP nanofibers presented a semi-crystalline structure, with several functional groups and diameter from 100 to 500 nm. The adsorption of RB5 and P4R on the CP nanofibers was favored at pH of 1.0. Pseudo-second order (RB5) and Elovich (P4R) models were the more adequate to represent the kinetic data. The equilibrium data followed the Langmuir model, being the maximum adsorption capacities of 456.9 mg g(-1) for RB5 and 502.4 mg g(-1) for P4R. The adsorption was spontaneous, favorable and endothermic. Desorption and reuse was possible for four times, maintaining the same adsorption capacity. In brief, it can be concluded that the Forcespinning (R) technology is an alternative to obtain chitosan/polyamide nanofibers with suitable characteristics. These nanofibers in turn, can be successfully applied to remove dyes from aqueous media. (C) 2017 Elsevier Ltd. All rights reserved.