Adsorption behavior of crystal violet from aqueous solutions with chitosan–graphite oxide modified polyurethane as an adsorbent. Issue 17 (10th January 2015)

• Record Type: Journal Article
• Authors: Qin, Jiao; Qiu, Fengxian; Rong, Xinshan; Yan, Jie; Zhao, Hao; Yang, Dongya
• Is Part Of: Journal of applied polymer science. Volume 132:Issue 17(2015:Sep. 05)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2015-01-10
• Subjects: adsorption -- foams -- polyurethanes; Polymers -- Periodicals; Polymerization -- Periodicals; 668.9
• DOI: 10.1002/app.41828
• Languages: English
• ISSNs: 0021-8995

Abstract

ABSTRACT: A series of chitosan (Ch)–graphite oxide (GO)‐modified polyurethane foam (PUF) materials as adsorbents were synthesized by a foaming technique. The adsorbent was characterized through IR spectroscopy, scanning electron microscopy, and thermogravimetric analysis (TGA). Batch adsorption experiments of the cationic dye crystal violet (CV) were carried out as a function of the Ch–GO content (1.0–8.0 wt %), solution pH (2–10), dye concentration (100–300 mg/L), adsorbent dosage (10–60 mg/mL), and temperature (20–45°C). At a lower pH value, the surface of Ch–GO/PUF acquired positive charge by absorbing H + ions; this resulted in a decreasing adsorption of the cationic CV dye because of electrostatic repulsion. As the pH of the aqueous system increased, the numbers of negatively charged sites increased by absorbing OH − ions, and a significantly high electrostatic attraction existed between the negatively charged surface of Ch–GO/PUF and the cationic dye (CV) molecules. This led to maximum dye adsorption. The kinetics, thermodynamics, and equilibrium of CV adsorption onto Ch–GO/PUF were investigated. The equilibrium data for CV adsorption fit the Langmuir equation, with a maximum adsorption capacity of 64.935 mg/g. The adsorption kinetics process followed the pseudo‐second‐order kinetics model. Thermodynamic parameters analysis revealed that the adsorption of CV from an aqueous solution by a Ch–GO modified PUF material was a spontaneous and endothermic process. We concluded that Ch–GO/PUF is a promising adsorbent for the removal of CV from aqueous solutions. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015, 132, 41828. Abstract :