Sodium alginate/chitosan/glyphosate superabsorbent bio‐foam as a release system for herbicide

Abstract This work presents a prepare method of a bio‐foam constituted by sodium alginate, chitosan (CH), and glyphosate to form a material to be applied in controlled release of herbicide. It was investigated the influence of mixture pH on the bio‐foam physicochemical properties. Kinetic studies of glyphosate adsorption and release were performed. The interactions between the polysaccharides and the herbicide were also investigated. The bio‐foams were evaluated for their mechanical and morphological properties. All samples presented swelling degree above 1000%. The bio‐foam prepared at pH 6 presented a higher compression resistance and provided the higher herbicide adsorption. The bio‐foam was able to control the release of glyphosate. The release kinetics reached equilibrium state after 30 days, during which cumulative release was approximately 90%. Confocal microscopy images showed the preferential interaction of glyphosate with the CH molecules in bio‐foam. This work presents a new perspective for polysaccharide systems, enabling new high‐performance agricultural applications.