Samples of humic substances (HS) of black earth and compost and their chromatographic fractions (A, B, C + D) have been obtained by a combination of gel-chromatography and electrophoresis aimed to decrease their dimensions and to increase the electrophoretic mobility and studied by small-angle neutron and synchrotron X-ray scattering methods. It has been showed that the initial HS preparations and their fractions are polydisperse, the low-molecular mass fractions (B, C + D) being more polydisperse than the high-molecular mass fraction (A). It has been found that HS of black earth are enriched with low-molecular mass fractions as compared to the HS of compost. Analysis of particle conformation permitted us to conclude that HS macromolecules in A and B fractions of black earth have a branched coiled structure. At the same time, the conformation of macromolecules in the C + D fraction of black earth and in all compost fractions has a rod-like (elongated) structure. Investigation of the large-angle portion of scattering curves both of initial HS specimens and their fractions has showed that all the studied compounds belong to the class of mass fractals.
|Number of pages||12|
|Journal||Surface Investigation X-Ray, Synchrotron and Neutron Techniques|
|Publication status||Published - Jan 1 2000|
ASJC Scopus subject areas
- Surfaces, Coatings and Films