Bambang Piluharto 

Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember  

Dwi Indarti

Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Donatus Setyawan Purwo Handoko

Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Tinok Dwi Ananda 

Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

DOI: https://doi.org/10.19184/icl.v3i2.4325

ABSTRACT 

Urea exhibits high nitrogen content (∼46%), which is essential for plant growth. However, significant nitrogen losses occur through decomposition, leaching, denitrification, and volatilization. Employing controlled-release systems, such as chitosan membranes crosslinked with glutaraldehyde, can mitigate these losses and enhance fertilizer efficiency. Therefore, this study aimed to develop and characterize chitosan-glutaraldehyde membranes as controlled-release fertilizer systems for urea. Chitosan membranes were crosslinked with varying glutaraldehyde concentrations (0%, 0.4%, 0.9%, 1.3%, and 1.8%) and used to encapsulate urea. The membrane produced was characterized using FTIR and swelling degree assay. The potency of glutaraldehyde crosslinked chitosan as a urea coating agent was also studied spectrophotometrically using the Nessler reagent. FTIR analysis revealed low intensity of the C=N stretching vibration, indicating limited crosslinking reaction. Additionally, both swelling degree and urea release increased proportionally with increasing glutaraldehyde concentration. These findings suggest limited crosslinking reactions occurred between glutaraldehyde and chitosan within the studied concentration range. 

Keywords: urea, chitosan, glutaraldehyde, crosslinking.