Triphenylene-modified chitosan: novel high efficient sorbent for cationic and anionic dyes
The first example of triphenylene-modified chitosan 4 was prepared by reacting chitosan with triphenylene aldehyde derivative 3. Its structure and morphology was characterized by elemental analysis, 1H NMR, FTIR, XRD, SEM and AFM image. The triphenylene units in Tp-chitosan 4 appended on the skeleton of chitosan and possessed orderly layered structure. Adsorption experiments of Tp-chitosan 4 indicated that it possessed excellent adsorption capacities for both cationic and anionic dyes [Orange G sodium salt, Brilliant ponceau 5R, Victoria blue B (VB), Crystal violet (CV), Neutral red (NR) and Methylene blue]. The highest adsorption capacities for CV, VB and NR were 5.612, 5.353 and 5.375 mmol/g, respectively. Adsorption kinetics and isotherms analysis showed that the adsorption processes obeyed pseudo second-order model and the Langmuir isotherm equation. The adsorption processes were exothermic and spontaneous. The best pH values for adsorption were pH = 6–8.
KeywordsChitosan Triphenylene Adsorption Dye
Financial support from the National Natural Science Foundation of China (No: 20402002), Fujian Natural Science Foundation of China (No. 2011J01031), Project of Fujian provincial department of education(JA11044) and Program for Excellent young researchers in University of Fujian Province (JA10056) were greatly acknowledged.