The general interest in carbon nanomaterials is related to the wide possibilities of their functionalization for a variety of practical, including biomedical, applications. This class of substances includes ultra-fine nanodiamonds of detonation synthesis, which are formed as a result of the explosion of oxygen-unbalanced explosives in an inert medium (Ōsawa, Pure Appl Chem 80:1365–1379, 2008) . Recently, a number of methods for obtaining liquid systems with detonation nanodiamonds have been developed. Their large specific surface area and a non-uniform charge distribution over particle surface leads to the clusterization of these particles, which, nevertheless, in many cases, does not break the stability of the system. Despite the fact that there are many theoretical and experimental works on the study of liquid systems with nanodiamonds, the problem of the relationship between the structure and stability of such systems in a wide range of concentrations remains insufficiently studied today. The particle interaction and the structure of such liquid nanosystems are the subjects which are of current interest in modern molecular physics (Shenderova and McGuire, Biointerphases 10:030802, 2015; Bulavin and Chalyi, Modern problems of molecular physics, 2018) [2, 3]. The corresponding studies constitute the basis for improving the synthesis technology of highly stable nanodiamond suspensions with predefined properties and for the creation of new liquid systems, better in general meaning. In recent decades, nuclear physics methods are becoming widespread in the research of nanosystems. Among these methods, small-angle scattering of thermal neutrons takes in important place (Feigin and Svergun, Structure analysis by small-angle X-ray and neutron scattering, 1987) . The high penetrating power of this radiation, as well as the application of the neutron contrast variation technique, allow one to effectively investigate a supramolecular level of 1–1000 nm in multicomponent objects, including liquid systems with nanodiamonds.