Effect of Sodium Humate on the Swelling Characteristics and Agricultural Application of Superabsorbent Hydrogels of Poly (acrylic acid/sodium alginate/sodium humate)

By : Shipra Agnihotri, Reena Singha

Page No: 663-680

Abstract
A series of superabsorbent hydrogel (SAHs) based on poly Acrylic Acid (AAc), Sodium Alginate (NaAlg) and Sodium Humate (SH) (AAc/NaAlg/SH) was prepared by free radical solution copolymerization. Hydrogel having sodium humate 9.09 wt% showed maximum water absorbency of 906 g of water per gram of superabsorbent hydrogel. The application of the synthesized superabsorbent hydrogel was investigated in agriculture as soil conditioner for water retention in sandy soil. The study revealed that the synthesized superabsorbent hydrogels could act as an effective water saving material for agricultural applications. Swelling behavior (such as swelling ratio, initial swelling rate constant, swelling exponent, diffusion coefficient and penetration velocity etc.) for all the synthesized superabsorbent hydrogels having various (6.9 to 11 wt %) concentration of SH was studied. Swelling exponent was found in range of (0.712 to 0.802); thus suggesting non fickian diffusion mechanism. The effect of synthesized SAHS on growth of seeds of corn and white gourd are reported.

Authors :
Shipra Agnihotri and Reena Singha : Department of Plastic Technology H. B. Technical University, Kanpur, U. P. -208002, India