"Nanocomposites and nanomaterials"

Advances in the synthesis and sorption application of amino-functionalized mesoporous materials
Stolyarchuk N.V.1, Tomina V.V.1, Vaclavikova M.2, Beganskiene A.3, Katelnikovas A.3, Kareiva A.3, Melnyk I.V.1,2 
1Chuiko Institute of Surface Chemistry of NAS of Ukraine. General Naumov street, 17, 03164 Kyiv, Ukraine.
E-mail: stonata@ukr.net
2 Institute of Geotechnics SAS. Watsonova street, 45, 04001 Kosice, Slovak Republic. 
3Vilnius University. Naugarduko street, 24, LT-03225 Vilnius, Lithuania.

The research deals with the production of functional silica materials with high sorption capacity in relation to the rare earth metals and unique luminescence properties. Lanthanides are capable of complexation with nitrogen-containing compounds. The advantage of such coordination compounds is that lanthanide ions are characterized by narrow-band luminescence in a wide spectral range. We synthesized functional silica nano and microparticles with amine-containing groups of different structure in the surface layer. The composition and ratio of components during the synthesis determines the features of the structure of the polysiloxane network, the nature of the surface, and the presence of different types of groups. It is known that the emission and excitation of optically active metal cations depends on coordinating ligands and symmetry of such structures. Therefore, the arrangement of surface groups will form different coordination spheres with target rare earth metal ions. In addition, the presence or absence of porosity facilitates the arrangement of groups on the surface of pores or particles, thus influencing the luminescence characteristics of such materials.
Thereby, extensive opportunities for the design of the surface allow synthesizing sorbents with high selectivity and sorption ability to rare earth metals. The sorption of lanthanides will provide materials with luminescent properties, expanding the scope of their application. 

The authors are grateful to the project VEGA 2/0156/19 and joint Ukrainian-Lithuanian r&d project (М/ 8 -2019).