Biodegradable Nanocomposite Microcapsules for Controlled Release of Urea

Area of Science:

• Materials Science
• Polymer Science
• Agricultural Science

Background:

• Urea is a vital nitrogen fertilizer, but its overuse poses environmental risks.
• Controlled release of urea is crucial for efficient nutrient delivery and environmental protection.
• Biodegradable polymers offer a sustainable approach to fertilizer encapsulation.

Purpose of the Study:

• To encapsulate urea using poly(3-hydroxybutyrate) (PHB) and its nanocomposites (PHB/MMT, PHB/OMMT).
• To investigate the physicochemical properties and biodegradation of the prepared microcapsules.
• To evaluate the potential of these microcapsules for controlled urea release in soils.

Main Methods:

• Microcapsules were prepared using an emulsion method.
• Physicochemical characterization involved X-ray diffractometry (XRD), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM).
• Soil biodegradation tests were conducted to assess degradation rates.

Main Results:

• Increased poly(vinylacetate) (PVA) content enhanced microcapsule crystallinity.
• XRD, TGA, and SEM confirmed the presence of urea within the microcapsules.
• PHB/OMMT microcapsules exhibited higher degradation rates in sandy soils compared to neat PHB and other composites.

Conclusions:

• PHB-based microcapsules, particularly PHB/OMMT, are promising for controlled urea release.
• The PHB/OMMT formulation demonstrated superior performance in terms of biodegradation in sandy soil environments.
• These findings support the development of advanced, eco-friendly fertilizer technologies.