Statistical modeling of adsorption isotherm of potassium on aza[7]helicene-coated gold electrode attached to quartz crystal microbalance. Issue 15 (13th October 2019)

• Record Type: Journal Article
• Authors: Knani, Salah; Mabrouk, Nabil; Tounsi, Moncef; Ben Yahia, Mohamed
• Is Part Of: Separation science and technology. Volume 54:Issue 15(2019)
• Page Start: 2386
• Page End: 2396
• Publication Date: 2019-10-13
• Subjects: Dibromoaza[7]helicene -- adsorption isotherms -- QCM -- statistical physics -- thermodynamic functions; Separation (Technology) -- Periodicals; 660.284205
• DOI: 10.1080/01496395.2018.1546743
• Languages: English
• ISSNs: 0149-6395

Abstract

ABSTRACT: A chemically coated piezoelectric sensor has been used for the determination in liquid phase of the adsorption isotherm of potassium. A thin film of aza[7]helicene was attached to the surface of a gold electrode of a quartz crystal microbalance using spin coating method. Statistical physics formalism was applied to elucidate the adsorption mechanism of potassium onto coated electrode by aza[7]helicene. The simulation results showed that a monolayer adsorption occurs with the number of potassium per site about 1 and the adsorption energy is less than 30 kJ.mol −1, characteristic of physical adsorption. The statistical model was used to investigate three thermodynamic potentials such as the entropy, the free enthalpy, and the internal energy. It is found that the adsorption took place with releasing energy, such behavior confirms the exothermic character of the adsorption process.