Project No.: 19013
Project Name: Bioactive glass and glass-ceramics for plant nutrition
Duration: 2008. - 2010.

Financier: The Ministry of Science and Technological Development of Serbia
Implementer: ITNMS
Leader: Dr. Mihajlo B. Tosic, scientific advisor ITNMS

Subject:

The aim of this project is the introduction of new materials for the food plants based on bioactive glass, which creates prerequisites for the production of economically viable high-quality healthy food for the domestic market, which would be sufficiently competitive on foreign markets.

By bioactive glasses macro and microelements are entering in the soil necessary for plant nutrition. These materials show new features: the chemical activity in biofluides-bioactivity and adjustment conditions of biofluides-biocompatibility. Biological activity of glass is estimated on the basis of their solubility in solution that occur around the roots of plants in the extraction of useful elements from the soil. Dissolution of glass is a complex process that depends on several factors: the composition of glass, solution pH, temperature, time effect of the solution and others. Under the influence of this solutions the glasses are selectively dissolving. For example, in the case of acidic solution, hydrogen ions disrupt the oxygen network connections glass forming on the surface of glass layer of silica gel as a new product process non-congruent dissolution, which binds a substantial part of the dissolved cation modifier. Then follows a gradual dissolution of the modifier cation from the layer silica gel. The vegetation period of plants, components that are extracted from bioglass are intensively consuming and their level in the vicinity of glass slices declines and therefore increases the driving force of dissolution and dissolution process is intensified. Conversely, after the end of vegetation period , consumption of selected components is reduced and their concentration around the glass of slices increases, and the driving force of dissolution decreases and therefore the process of dissolving the bioglass in the soil slows down. This shows that the process of dissolution of these glasses is very complex and takes place in several steps: decomposition of the spatial structure of glass, separating the structural elements from glass, they combining and forming the new compounds according to their preferences and further dissolution of newly formed compounds. Therefore, provides ample opportunities about choosing the chemical composition of the glass which affects to the mechanisms and kinetics of these processes, achieve their controlled solubility and thus programmed content necessary elements in the soil according to the vegetation cycle of plants. Experiments showed that the dissolution of 90% bioglass with specific composition and granulas size 4-5 mm, depending on other factors, you need between 1 and 3.5 years. This provides the opportunity to use these materials, without their necessarity to add them each year to the soil, which is another significant advantage of them because it reduces the amount of material that enters the soil and therefore the cost of growing the culture and level of contamination. The broad area of changes in their composition bioglasses obtaining the opportunity to optimize the composition from the aspect of the culture of plants, soil characteristics and climate.

The previous study also showed that bioglass have a positive impact on the process of nitrogenisation in the soil which is crucial for the development of flora and cultivated culture. It is believed that such an action is conditioned by forming clusters of micronutrients on the surface of granules of bioglasses. In this way, it increases the number of forms of free living bacteria that link nitrogen in the soil, microorganisms that break down cellulose and others who provide production nitrate and ammonijac nitrogen in a form that is acceptable to the plant and increase the content of humus in the soil. Bioglass belong to the class of low toxic substances which are not dangerous to health and life. They do not have irritating effects on skin and eyes and do not accumulate in the human body.

Collaborators on project:

1. Mr Vladimir D. Živanović, istraživač saradnik ITNMS
2. Dr Snežana R. Grujić, docent TMF
3. Dr Nataša G. Đorđević, naučni saradnik ITNMS
4. Mr Mirko S. Grubišić, istraživač saradnik ITNMS
5. Mr Deana B. Živanović, istraživač saradnik ITNMS
6. Dipl. hem. Snežana N. Zildžović, stručni saradnik