Design of acrylic acid/nanoclay grafted polysaccharide hydrogels as superabsorbent for controlled release of chlorpyrifos

In the present study, acrylic-bonded starch nanocomposite hydrogels were synthesized in the presence of montmorillonite nanoclay. N , N ′-methylenebisacrylamide was used as a crosslinker and ammonium persulfate was used as an initiator. The hydrogel performance was investigated as superabsorbent for water absorption under different synthesis conditions such as acrylic acid to starch ratio, crosslinker, initiator, and nanoclay amounts, and pH. Synthetic nanocomposites were characterized and approved using FTIR, XRD, FESEM-EDX, and DTA techniques. Under optimal conditions (acrylic acid to the starch ratio: 7 to 1, potassium persulfate: 0.04 g, methylenebisacrylamide: 0.002 g, nanoclay: 1 g, and pH = 7), the swelling ratio of synthetic hydrogel reached up to 400 times of the gel strength of the matrix. This superabsorbent was then investigated as a carrier for the controlled release of chlorpyrifos after in situ loading in different concentrations. The hydrogel with 1.0 M chlorpyrifos content showed a release percentage of 85% after 14 days. This proposed nanocomposite with excellent water absorbency , controlled release of chlorpyrifos, the economical and environment-friendly structure can be useful in agricultural applications. • Acrylic-bonded starch nanocomposite hydrogels were synthesized. • These hydrogels were synthesized in the presence of montmorillonite nanoclay. • The hydrogel performance was investigated as a superabsorbent for water absorption. • This superabsorbent was investigated for the controlled release of chlorpyrifos.