Next-Generation Fertilizers: A TiO₂-Chitosan Composite Superabsorbent as a Sustained Release N-Fertilizer

Area of Science:

• Materials Science
• Polymer Chemistry
• Agricultural Science

Background:

• Chitosan, a biodegradable polymer, is explored for agricultural applications.
• Titanium dioxide (TiO2) nanoparticles offer unique properties for material enhancement.
• Developing controlled-release fertilizers is crucial for efficient nutrient delivery and reduced environmental impact.

Purpose of the Study:

• To synthesize a sustained-release fertilizer using a TiO2-chitosan composite superabsorbent.
• To characterize the synthesized material and evaluate its swelling and urea loading capabilities.
• To investigate the fertilizer release kinetics and its effect on seed germination.

Main Methods:

• Synthesis of TiO2-chitosan composite superabsorbent via Schiff base condensation.
• Material characterization using FTIR, XRD, SEM-EDX, XPS, TGA-DSC, and rheology.
• Swelling behavior, urea loading capacity, release kinetics (Korsmeyer-Peppas model), and seed germination tests (Brassica oleracea).

Main Results:

• The synthesized hydrogel exhibited excellent swelling (706.6%) and high urea loading capacity (90% at acidic pH).
• Controlled urea release was observed, fitting the Fickian diffusion model (R²=0.89, n=0.27 at pH 4).
• Urea-loaded hydrogel significantly enhanced seed germination (274.69% germination index) compared to pure urea.

Conclusions:

• The TiO2-chitosan composite superabsorbent effectively delivers sustained-release fertilizer, particularly in acidic conditions.
• The material shows potential for agricultural use, improving nutrient availability and promoting plant growth.
• This study highlights a promising approach for developing eco-friendly and efficient fertilizer systems.