Flexible Nanocellulose - Nanoparticle Composites: Structures and Properties GARUSINGHEUTHPALA MANAVI 2018 Nanocellulose is biodegradable and renewable and has many attractive properties of technological interest. Therefore, nanocellulose can be converted into thin films, which is used in wide range of applications. However, the property range achievable with nanocellulose by itself still has limitations. This thesis focuses on the production of nanocellulose-inorganic nanoparticle composites to combine the advantage associated with both individual components together to extend the range of properties achievable. In the first part, methods are developed to overcome the problems in composite production, characterization and optimization. Then the thesis focuses on engineering composites that can be used for high end applications.