Functional Materials from Nanocellulosic Networks and Uses in Water Purification

Due to their nano-scaled dimensions and mechano-chemical versatility, nanocelluloses have generated interest in the production of various types of bioproducts. However, the full potential of these materials and their applications, which are strongly coupled to their structural features, is yet to be realized. In this thesis, two types of nanocelluloses, cellulose nanofibrils (CNF) and bacterial nanocellulose (BNC), are introduced to achieve different types of porous networks and functional materials. The performance of CNF and CNF-based materials is investigated in applications related to water purification. Composites incorporating cationic CNF and silver nanoparticles are studied for use in drinking water disinfection. Phosphorylated CNF is implemented for the removal of uranium from water via batch adsorption. With BNC, the opportunities provided by biological fabrication of nanofibrous materials are considered in the synthesis of 2D membranes as well as intricate 3D structures. The impact of physico-chemical modifications of the fibrous networks in the BNC membranes are investigated to give insights on their potential use in pressure-driven filtration. To produce 3D structures from BNC, a simple method is developed utilizing hydrophobic particles for stabilization of air-water interfaces. Utilizing this method, capsules were produced and applied as sensors and enzymatic reactors in aqueous media. This thesis provides insights and novel pathways for the production and application of porous nanocellulose-based structures. They are expected to contribute to the development of future functional materials, for instance in the field of water purificaton.