Physico-Chemical nanomaterials science

Comparison of the adsorption and the electrokinetic properties of the fucoidan/CaCl2/TiO2 and fucoidan/CaCl2/Al2O3 systems

Matusiak J.1, Grządka E.1
1Department of Radiochemistry and Environmental Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University in Lublin. Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland. 
E-mail: jakub.matusiak@poczta.umcs.lublin.pl
Adsorption of macromolecular compounds plays a significant role in the science and industry. Because many factors influence this process, it is important to carry out a comprehensive study regarding the adsorption of polymers on solid surfaces. Among others, the type and the concentration of the used electrolyte is a factor influencing the adsorption and electrokinetic properties of the studied systems. The polymer used in the presented studies is a fucoidan, natural polysaccharide extracted from Fucus serratus. Because of the anionic nature of this compound, the presence of divalent ions such as Ca2+ can strongly influence the adsorption and the electrokinetic properties of the fucoidan/oxide systems.
The aim of this study is to investigate the adsorption and the electrokinetic properties of the fucoidan/CaCl2/TiO2 and fucoidan/CaCl2/Al2O3 systems. Investigation of the adsorption was carried out using a colorimetric Dubois method [1], whereas the electrokinetic properties were studied in terms of electrophoretic mobility recalculated to the zeta potential. The obtained results show that in the presence of divalent Ca2+ ions, the adsorption of fucoidan increases in both studied systems in comparison to the systems containing monovalent Na+ ions. It was also observed that the polymer concentration influences the zeta potential of the studied systems. However, the observed results show that the presence of Ca2+ ions strongly influences the properties of the electrical double layers of TiO2 and Al2O3. 
The authors would like to acknowledge the National Science Centre, Poland for funding this project (Project ID 2017/27/N/ST4/02259).

1.	DuBois M., Gilles K. A., Hamilton J. K., Rebers P. A., Smith F. Colorimetric Method for Determination of Sugars and Related Substances. Anal. Chem.-1956.-28.-P. 350-356.