Physico-Chemical nanomaterials science

The influence of fucoidan on stability of the TiO2 suspensions

Matusiak J.1, Grządka E.1, Bastrzyk A.2
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
2 Department of Process Engineering and Technology of Polymer and Carbon Materials, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wrocław, Poland

Stability of colloidal systems is very important scientific objective because of the wide range of applications of such systems in science and industry. However, the colloidal systems composed of solid phase dispersed in a liquid medium are rather unstable. To avoid it, the addition of different substances is used to prevent the destabilization of such systems. Nowadays, among others, macromolecular compounds are used as stabilizers. However, the use of synthetic polymers in areas such as pharmaceutical, cosmetic and food industry is limited due to the adverse effect on human health. Therefore, it is important to find natural substitutes for synthetic stabilizers. The main objective of this work is to investigate stabilizing properties of the natural polysaccharide – fucoidan – for titanium(IV) oxide suspensions. Fucoidan was chosen because of its bioactive properties and proven positive impact on human health. Moreover, those two substrates can be successfully used in new cosmetic and pharmaceutical formulations. The comprehensive research was carried out including the adsorption (UV-Vis) and stability (turbidimetry) studies. 
The obtained results indicate that the addition of fucoidan influences the stability of TiO2 suspensions. Conducted adsorption measurements show that the polymer adsorbs on the solid surface and that pH have the influence on this process. The increase of stability is caused by higher repulsion between the TiO2 particles covered with fucoidan in comparison to bare ones (electrosteric stabilization). The conducted studies shine a light on the new possible use of fucoidan in colloidal systems, for example in different emulsions, creams and ointments.
The authors would like to acknowledge the National Science Centre, Poland for funding this project (Project ID 2017/27/N/ST4/02259).