Daftar Isi: Electrochemical and Viscous Properties of Synthetic Humic Acids

Daftar Isi:

Synthetic humic acids have been prepared from each of catechol, hydroqninone, resorcinol, vanillin, glucose and gallic acid with or without glycine as the source of nitrogen by simple air oxidation in 0·5N sodium hydroxide solution at 32° in the presence of different catalytic surfaces, e.g., clay, sand and silt fractions of soil. After about one month of air oxidation, the humus formed was separated with 0·5N sodium carbonate solution by centrifugation from which humic acids were precipitated with hydrochloric acid at \(p\)H 2-3. They were purified by repeating the processes of dissolution and precipitation and finally by dialysis and electrodialysis. Conductometric, potentiometric and viscosity studies of the solutions of the synthetic humic acids reveal their polyelectrolytic nature. Features of titration curves, mainly the conduotometric ones, of humic acids with or without nitrogen in their molecules were compared amongst themselves and with those of the monomers, from which the nature of the functional groups could be suggested. The similarity of the behaviour of the synthetic humic acids with their natural counterparts was clearly noticeable, suggesting a similar mechanism of formation of the latter.