New insight into the temperature effect on adsorption of cationic guar gum on halloysite – properties of the obtain systems

Abstract

The manuscript presents the new insight into temperature effect on the adsorption and adsorption kinetics of cationic guar gum (CGG) on the halloysite surface (NH). The polymer/clay mineral hybrid materials and stability of the CGG/NH suspensions were analyzed using the following methods: UV-Vis, FT-IR, XRD, SEM-EDX, nitrogen adsorption/desorption, CHN and electrokinetic potential measurements. According to the results the increase of temperature increases both the adsorption of CGG on NH and stability of the CGG/NH suspensions. Thus CGG can effectively stabilize the NH suspensions at higher temperatures. The textural properties of the obtained hybrid materials were also strongly influenced by temperature. It was also observed that the CGG adsorption on NH is spontaneous, endothermic and thermodynamically privileged (ΔGo15 C=-12.90kJ/mol; ΔGo25 C=-14.03kJ/mol; ΔGo35 C=-16.34kJ/mol; ΔHo15 C-30 C=37.15kJ/mol; ΔSo15 C-35 C=0.17kJ/mol). The mechanism of this process can be regarded as a physisorption. The adsorption kinetics was adjusted to the multi-exponential equation. The presented results have a great application potential in wastewater or water treatment processes.