Surface grafting of polyamidoamine dendrimer onto polyacrylonitrile nanofibers for removal of anionic dyes

In this paper, PAN nanofibers were functionalized by Diethylenetriamine (DETA), and the surface of nanofibers was then modified by PAMAM dendrimer. Results indicated that PAMAM molecules are crosslinked to DETA through the formation of imine groups by glutaraldehyde. SEM images of functionalized and surface grafted PAN nanofibers showed a rough surface and deposition of a dense layer on the nanofibers surface due to successful surface grafting of PAMAM, respectively. The surface average roughness of nanofibers increased from 42.4 to 46.4 and 68.6-81.9 nm for PAN-DETA and PAMAM grafted PANDETA compared to untreated PAN nanofiber, respectively. Direct red 80 (DR80) and direct red 23 (DR23) were used as model compounds to investigate the dye removal ability of the prepared nanofibers. It was found that adsorption of both dyes follows the Langmuir isotherm. In addition, adsorption kinetics of both dyes was found to conform to pseudo-second order kinetics.