Cellulose Nanocrystals as Advanced Barrier Coatings for Food Packaging

Purdue University researchers say they have developed a large-scale manufacturing process that may change the way some grocery store foods are packaged. The Perdue team, led by Jeffrey Youngblood, a professor in Purdue's School of Materials Engineering, created a new manufacturing process using cellulose nanocrystals (CNCs) as advanced barrier coatings for food packaging. CNCs are an alternative renewable raw material derived from abundant resources such as wood and plants. They have properties including nontoxicity, biodegradability, high specific strength, high thermal conductivity and optical transparency, all of which make them excellent components for advanced food packaging.

The Purdue manufacturing technique also is scalable since it is a roll-to-roll manufacturing process using waterborne polymer systems. CNCs are highly crystalline and easily dispersed in water, so manufacturers can control the structure to eliminate free volume and end up with only the properties that are needed for the barrier material. The  unique process uses the power of natural nanotechnology and allows a much higher density and packing coating that reduces diffusion pathways and drastically improves oxygen, carbon dioxide and water vapor permeability. The Purdue technology also offers food packaging manufacturers excellent optical, thermal and mechanical properties to ensure that food remains as fresh as possible when it is delivered to the grocery store for consumers.