Microfibrillated cellulose coatings as new release systems for active packaging.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Microfibrillated cellulose (MFC) is a sustainable biomaterial with unique nanoporous properties.
• Controlled release systems are crucial for various high-value applications, including food packaging.
• Existing paper-based materials often lack the capacity for sustained molecule release.

Purpose of the Study:

• To investigate the potential of microfibrillated cellulose (MFC) coated paper as a novel platform for controlled molecule release.
• To evaluate the release kinetics of caffeine as a model molecule from MFC-coated paper.
• To compare different methods of incorporating molecules into MFC-coated paper for optimized release profiles.

Main Methods:

• Coating paper substrates with microfibrillated cellulose (MFC) to form a nanoporous network.
• Conducting controlled release studies using caffeine as a model molecule in aqueous solutions.
• Implementing both continuous and intermittent (10-minute interval) diffusion experiments.
• Analyzing the impact of MFC coating and molecule incorporation methods on release duration and rate.

Main Results:

• MFC-coated paper significantly extended the release period of caffeine compared to uncoated paper (29 vs. 16 washings).
• Continuous diffusion rates were similar with or without MFC coating.
• Incorporating caffeine within the MFC mixture resulted in the slowest and most prolonged release, completing 9 hours after other samples.
• Two distinct methods for introducing molecules into MFC-coated paper were compared, with one offering more controlled and gradual release.

Conclusions:

• A nanoporous network of microfibrillated cellulose (MFC) on paper provides a novel and effective system for controlled molecule release.
• The method of incorporating molecules into the MFC matrix critically influences the release kinetics, enabling tunable release profiles.
• This MFC-based approach holds significant promise for advanced applications, particularly in the food-packaging sector, and can be extended to active species.