Ice-templated cellulose nanofiber structures as reinforcement material in composites

A method for using nanocellulose as reinforcement material in composites was developed in this doctoral thesis work. The method utilizes a special physical phenomenon based on unidirectional freezing of water. Foam-like and thread-like nanocellulose structures can thus be prepared that may be used similarly to traditional reinforcement fibers.

Composites are used in many of our everyday objects and appliances. They are usually composed of two separate materials – one that acts as a glue-like binder and another that brings strength and stiffness to the whole. Composites are especially useful in applications demanding lightness and good performance.

Plant-based nanocellulose is a promising replacement for the non-renewable reinforcement materials such as glass and carbon fibers. The mechanical properties are competitive, but the absence of a working fabrication process has long been an issue. The results of the thesis are an important contribution towards finding a practical solution to the problem.