Aalto University design sustainable method to produce strong and flexible cellulosic films

In Finland, the Bioproduct Chemistry team at Aalto University have designed a sustainable method to produce strong and flexible cellulosic films that incredibly maintain their strength even when wet.

The material is made through an innovative combination of wood-based and biodegradable polymers without any chemical modification, harnessing the maximum benefit of each component. For the co-authors in this study, sustainability is a significant motivator in understanding the chemistry of how these materials could work together and developing materials of tomorrow with the functionality we expect today.

From a materials design perspective, gaining the benefit of both hydrophilic cellulose and hydrophobic polymers at the same time without any chemical treatment of raw materials is mystifying. But what if we could engineer their interface with a third component, having favorable interactions with both cellulose and soft polymers such as polycaprolactone (PCL)? To achieve this goal, the team demonstrated that lignin nanoparticles with their well-defined morphology and active surface sites can interact with both cellulose, in this case cellulose nanofibrils, and PCL and act as a compatibilizer between hydrophilic cellulose and hydrophobic PCL. Although it looks complex, the solution is simple.