Fabrication of Smart Hydrogel Based on Functionally Modified Colocasia esculenta as Potential Nutrient Carrier and Soil Conditioner

Circular economy has renewed its focus; a novel eco-friendly semi-interpenetrating network (semi-IPN) device was prepared from functionally modified natural backbone ( Colocasia esculenta ) for controlled release of fertilizers. The method encompasses the usage of natural non-toxic materials with addition of fortifying nutrients. Naturally procured starch moieties converted into acetylated starch, coded as Acy CE. This was further cross-linked with polyacrylamide (PAAm) in the presence of N, N'-methylene bisacrylamide and ammonium persulfate as a crosslinker-initiater system. The chemical, physical, and thermal properties of the synthesized semi-IPN coded as Acy CE-cl-PAAm were also presented through various characterization techniques. The Acy CE-cl-PAAm was assessed for its fertilizer release mechanism in water media studied on three pH values. The release kinetics of all the fertilizers followed Korsmeyer-Peppas Model (Fickian diffusion), unveiling its excellent potential as controlled agrochemical release device. The macromolecular relaxation of the given network matrix was found to be comparable to the diffusion rate of urea indicated by Fickian ( n = 0.4) diffusion mechanism. The initial diffusion coefficients of D I = 8.03*10 −7 , D I = 7.9*10 −7 , D I = 9.8*10 −7 , D I = 1.7 * 10 −7 were found to be greater than the lateral diffusion co-efficients of D L = 1.4*10 −7 , D L = 1.3*10 −7 , D L = 3.9*10 −7 , D L = 3.9*10 −7 in the case of urea, ammonium sulfate, potassium nitrate, and bio-fertilizer, released at pH = 7.0, respectively. Also, it was found to get degraded up to 76% by weight with 1.1% rate of degradation per day within 70 days in vermi-compost method. The results indicated that this is an effective approach for controlled agrochemical release with great potential applications in sustained agriculture. Highlights • Biodegradable hydrogel was synthesized from acetylated derivative of Colocasia esculenta (CE) based backbone under the influence of microwave irradiations. • The synthesized device showed highest swelling of 1375%. • Hence, used for comparative analysis of urea, ammonium sulfate, potassium nitrate, and biofertilizer-controlled release in water media. • The semi-IPN was found eco-friendly and biodegradable in nature. Graphical Abstract