High-Efficiency Sorbent for Dyes Based on Cellulose Resin Crosslinked with Perylene Tetracarboxylic Diimides

The novel cellulose resin crosslinked with perylene tetracarboxylic diimides 3 was synthesized and its structure was characterized by elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electronmicroscopy (SEM), etc. Dyes adsorption experiments of polymer 3 suggested that it exhibited excellent adsorption capacities for tested four cationic and anionic dyes [Orange G sodium salt (OG), Brilliant ponceau 5R (BP), Methylene blue (MB), and Crystal violet (CV)]. The adsorption capacities for OG, BP, MB, CV were as high as 1.04, 1.21, 1.14, and 0.96 mmol/g, respectively. The adsorption processes obeyed the pseudo second-order model and followed the Langmuir isotherm equation. The adsorption processes were exothermic and spontaneous. The pH = 2 similar to 12 made slight influences on adsorption capacities of polymer 3 for dyes. It was supposed that the adsorption mechanism was not only the electrostatic forces and hydrogen bond but also the pi-pi stacking interaction playing an important role in the adsorption processes.