Khokhryakov A. Neutron Investigations of the Liquid System Water- Fullerene C60 Structure

The thesis concerns the research of physical properties of liquid systems water-fullerene C60 according to small angle neutron scattering data. The main attention is paid to the internal structure of aggregates in the system and their stabilization mechanism. Structural parameters were calculated on basis of the neutron data and a number of aggregates’ structure models were offered. The part of an additional component besides fullerene molecules in the aggregate structure is small (3-5% for possible impurity substances). Due to mathematical treatment of experimental data aggregate size distribution and additional information about their structure are obtained. The most corresponding aggregate structure model is chosen. It’s been shown that major part (70 – 90 %) of the aggregates has radius lower than 15 nm. It’s confirmed that water is located on the surface of the aggregates and plays role of stabilizer of the liquid system. Investigations of system coagulation approve aggregates’ structure stability. Neutron experiment during system coagulation doesn’t reflect growth of the aggregate size. This is explained by presence of strong water shell which doesn’t allow aggregates to approach close enough to each other. It is shown in the thesis that the liquid system water-fullerene C60 can interact with biological systems only indirectly via layers of water (not less than 5 nm). This fact should be taken into consideration in investigations of fullerene C60 biological activity.