Nanobiotechnologies and chemical technologies 

Formation of a nanoporous coating on urea granules
Yanovska G.O.1, Vakal S.V.2, Vakal V.S.2, Artyukhov A.E.1, Shkola V.Y.1, Zelenskiy A.N.2
1 Sumy State University, Rymskogo-Korsakova str., 2, Sumy, 40007, Ukraine. e-mail: yanovskaanna@gmail.com
2 Scientific-Research Institute of Mineral Fertilizers and Pigments of the Sumy State University, 12, Kharkovskaya Str., Sumy, 40012, Ukraine

Reducing the agrogenic load on the environment requires, on the one hand, a reduction in the doses of applied fertilizers and plant protection products, and, on the other hand, to obtain sustainable and consistently high crop yields, the use of significant amounts of agrochemicals is required. One of the options for resolving this contradiction is the development of organo-mineral complexes of prolonged action, as components of which it is advisable to use natural minerals and compounds. This approach stimulates the efforts of researchers to use the composition of the coating with special properties, such as porosity, to retain moisture in the soil and the content of nutrients. The nutritional properties of the previously studied phosphate-glauconite concentrates are proposed to be enhanced by such a sorbent as diatomite, which is a sedimentary rock. A distinctive feature of this component is its porous structure and high content of silicon compounds, which have biogeochemical activity and improve nitrogen and phosphorus metabolism in plant tissues. Finely ground diatomite also finds independent use as a natural bioinsecticide. Microscopic studies of the presented samples of finely dispersed diatomite and encapsulated urea show that the diatomite powder is mainly particles no larger than 20 microns. At the same time, pores no larger than 600 nm are present on individual particles. Spectral analysis of the sample shows that the main element is silicon. The study of the surface of the phosphate-containing coating made it possible to determine that the inclusion of finely dispersed diatomite in the coating composition forms a denser porous structure. The presence of porous diatomite particles throughout the entire thickness of the encapsulated layer makes it possible to create a developed porous surface not only for the prolonging effect of the nitrogen core of the granule but also for the accumulation of soil moisture. 

Acknowledgment: Grant number 0120U102003 “Process of formation of the novel ecologically safe fertilizers with prolonged action based on the phosphorite deposits raw materials“.