The state of water adsorbed by the surface of amber particles and its composite system with nanosilic, according to NMR spectroscopy

The state of water in the hydrated amber powder and the amber/SiO2 composite system at a ratio of 1:9 was studied by low-temperature 1H NMR spectroscopy. It is shown that amber gasification in the composition of the composite is completed at a temperature of T = 550 °C, which is almost 100 °C lower than that for the initial amber. The likely cause is a decrease in the size of amber particles when it is immobilized on the surface of nanosilica. It is found that for the amber/SiO2 system with increasing water concentration from 100 to 280 mg/g, the contribution from water clusters whose radius does not exceed 1.5 nm increases. It is shown that in the presence of strong acids at the boundary with a hydrophobic environment, part of the water bound to the surface of the amber/SiO2 composite passes into a weakly associated state, which may serve as one of the signs of increasing the bioavailability of substances desorbed from the composite.