ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Nutrient nanohybrids based on sodium alginate and carboxymethyl cellulose provide enhanced slow release of magnesium, zinc and copper

R. K. Maduwanthi, I. Munaweera, and W. P. T. D. Perera

Department of Chemistry, University of Sri Jayewardenepura, Nugegoda, Sri Lanka

E-mail: imalka@sjp.ac.lk

Received: 6 January 2024  Accepted: 9 June 2025

Abstract:

The concurrent use of slow release and nanotechnology principles in agriculture is paving the way for innovative approaches that can effectively address global food scarcity. This study focuses on the development of a nanohybrid formulation that efficiently releases important nutrients, including magnesium, zinc and copper over an extended time period. The nanomaterial feature was achieved by including the Mg, Zn and Cu nutrients in their nano-oxide states. Nanoparticles (NPs) were incorporated into a matrix of sodium alginate and carboxymethyl cellulose to provide the slow-release characteristic. The nano-oxides were subjected to sonication with a composite and then cross-linked with Ca²⁺ ions to produce the nanohybrids. The oxides were analyzed using powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning electron microscopy (SEM). Furthermore, the creation of Ca²⁺ cross-links was established, which assisted in the analysis using FTIR spectroscopy. Flame atomic absorption spectroscopy (FAAS) was employed to examine the nutrient composition and the gradual release characteristics of the nutrients. The elements Mg, Zn and Cu exhibited cumulative release percentages of 22.73%, 11.23% and 3.03%, respectively, for periods of 6, 11 and 6 days in water at pH of 7.2. The release kinetics analysis revealed that Mg, Zn and Cu follow diffusion-driven release, aligning with the Higuchi and Korsmeyer–Peppas models. The mung bean plant trial demonstrated a significant increase in yield compared to plants treated just with NPK, as confirmed by statistical analysis using ANOVA.

Graphical abstract

Keywords: Nutrient nanohybrids; Nanometal oxides; Plant nutrients; Slow-release fertilizer; Release kinetics

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04185-3

Chemical Papers 79 (9) 6227–6245 (2025)