Supramolecular structure, humic substance

Piccolo, A. (2001). The supramolecular structure of humic substances. Soil Sci. 166, 810-832. 

Three different viewpoints on the humic substances structural conformation are actually reported in the literature. One suggests that HS are macromolecular and assume random coil conformations in solution (Swift, 1999) a second proposes that HS are molecular associations of relatively small molecules held together by weak interaction forces, thus forming a supramolecular structure (Piccolo and Conte, 1999) a third considers that HS are in solution as micelles or pseudomicellar structures (Wershaw, 1999). Viewpoints two and three could be broadly considered to be under the same umbrella (Clapp and Hayes, 1999). 

Piccolo A. The supramolecular structure of humic substances A novel understanding of humus chemistry and implications in soil science. Advances in Agronomy 2002 75 57-134. 

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