Original scientific paper

https://doi.org/10.5562/cca1791

Adsorption of Tetramethylthiourea in the Presence of Cationic Detergent at Interface Electrode / Aqueous Perchlorate Solutions

Małgorzata Klin ; Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq.3, 20-031 Lublin, Poland
Jolanta Nieszporek ; Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq.3, 20-031 Lublin, Poland
Dorota Sieńko ; Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq.3, 20-031 Lublin, Poland
Dorota Gugała-Fekner ; Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq.3, 20-031 Lublin, Poland
Jadwiga Saba ; Department of Analytical Chemistry and Instrumental Analysis, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq.3, 20-031 Lublin, Poland

Abstract

The mixed adsorption layers of tetramethylthiourea and a cationic detergent formed at electrode
surface in NaClO₄ (1 mol dm–3) are described. The systems were characterized by the measurement of differential
capacity, zero charge potential, and surface tension at this potential. The data were analyzed to
obtain the surface pressure and relative surface excess of tetramethylthoiurea as a function of electrode
charge at bulk concentration of studied compounds. It was stated that the adsorbing tetramethylthoiurea
molecule pushed out the water molecule instead of the detergent molecule from the electrode surface.
The constants of the Frumkin and corrected Flory-Huggins isotherm point to a decreased TMTU adsorption
energy in the cationic detergents presence and stronger repulsive interaction. Electrostatic parameters
of the inner layer were assigned. In the range of more negative potentials, mixed adsorption
layers were described by investigating the kinetics of the Zn2+ ions electroreduction as a piloting ion.
(doi: 10.5562/cca1791)

Keywords

adsorption; cationic detergent; mixed adsorption layer; mercury electrode; tetramethylthiourea

Hrčak ID:

75055

URI

https://hrcak.srce.hr/75055

Publication date:

20.12.2011.

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