Shape of Humic Acid (a Natural Polymer) from Viscosity Studies

An attempt has been made to work out the shape (folded, or linear) of a natural polymer, namely humic acid from viscosity studies. The underlying principle is application of an extension of additivity of the B coefficient of Jones and Dole's equation to mixtures and large molecules, containing a number of functional groups. A semi-quantitative model has been proposed to correlate the findings to the surface area of the polymer chain exposed to water by using the concept of changes in microviscosity of the solvent brought about by the polymer.