Bio-based coating from eggshell calcium carbonate and natural polymers for water and oxygen barrier applications

Overview

This solution transforms eggshell waste into a high-value, bio-based coating that addresses two industrial challenges simultaneously: reducing food waste sent to landfills and replacing synthetic barrier coatings with biodegradable alternatives. By extracting calcium carbonate (CaCO3) from eggshells and blending it with chitosan and natural oils, the formulation produces a composite coating that delivers water and oxygen barrier performance suitable for protective surface applications.

The technology leverages the hydrophobic character that CaCO3 imparts to chitosan, while natural oils serve as carriers that enhance adhesion to substrates and contribute antimicrobial properties. The result is a fully biodegradable and compostable coating that adds significant value to agricultural and food-processing residues, reducing environmental contamination while delivering functional performance comparable to conventional synthetic coatings.

Technical specifications

Key features:

• Calcium carbonate extracted from eggshell residues serves as the primary hydrophobic filler
• Chitosan, a natural polymer, forms the structural matrix with enhanced biodegradable and compostable properties
• Natural oils integrated as carriers improve adhesion to substrate surfaces and provide antimicrobial performance
• Water contact angle measurement used to validate hydrophobic barrier properties
• Physicochemical and microscopy characterization techniques confirm formulation integrity and performance

Performance benefits:

• Water and oxygen barrier functionality for coating applications
• Biodegradable and compostable end-of-life profile
• Antimicrobial surface properties from natural oil integration
• Strong adhesion to real material substrates

Technology readiness level

The technology is currently at an early-to-mid development stage. The research team has established the formulation concept and identified the characterization methods needed to validate performance, including water contact angle testing, physicochemical analysis, microscopy evaluation, and laboratory-scale biodegradability and compostability assessment. The first formulation stage is projected to be completed within 12 months, with proof-of-concept demonstrations on real materials and full biodegradability validation expected within approximately two years from project initiation.