Adsorption of Dyes on the Surface of Polymer Nanocomposites Modified With Methylamine and copper(II) Chloride

J Colloid Interface Sci. 2017 Oct 15;504:549-560. doi: 10.1016/j.jcis.2017.06.008.

Abstract

Polymer nanocomposite was prepared by the conventional sol-gel method using formaldehyde and resorcinol. The surface of the nanocomposite was functionalized with methylamine. Some of the samples were additionally impregnated with copper(II) chloride. All the materials obtained were characterized by FT-IR spectroscopy, low-temperature nitrogen sorption, thermal and elemental analysis. The samples modified with amine groups had lower surface areas and smaller pore volumes than the pure nanocomposite. The modification with methylamine and copper(II) chloride led to increased content of both acidic and basic oxygen functional groups. All materials were tested for the removal of rhodamine B and sunset yellow FCF from the liquid phase. The sorption capacities of the samples studied towards rhodamine B (140-208mg/g) were higher than their maximum capacities towards sunset yellow FCF (58-105mg/g). The most effective adsorbent of the dyes was the material modified with amine groups and copper(II) chloride. Thermodynamic study showed that the adsorption of the dyes was a spontaneous and endothermic process. The character of adsorption of sunset yellow FCF and rhodamine B on the composite materials studied could be described by the Langmuir type isotherm.

Keywords: Nanocomposites; Rhodamine B; Sol-gel methods; Sunset yellow FCF; Surface treatments; Thermal properties.