Fungal Chitin-Glucan: Renewable Nanofibrils for Water Treatment and Structural Materials

Abstract

Materials on the nanoscale, for instance carbon nanotubes or polymer nanofibers, both well-known for high strength and modulus, have become focal points of research in material science. In the quest for sustainable materials exhibiting those characteristics, nano-sized materials based on renewable resources would be a major leap forward. Natural nanofibrils are thus an attractive development to combine advantages of the nanoscale with renewable raw materials. Specifically, nanocellulose has attracted great attention in this regard, in particular nanocellulose sheets, i.e. nanopapers, have shown huge potential both in composite and water treatment applications. This is based on nanoscale fibrils having high specific surface areas resulting in remarkable mechanical properties, together with the possibility to establish specific chemical and surface properties enabled by a plethora of functional groups attachable. Even though chitin was identified prior to cellulose as load-bearing component in natural structures, research into nanocellulose has already seen a significant rise over the course of the past two decades, whereas chitin nanofibrils have slightly lagged behind this trend. However, extraction of chitin nanofibrils from fungi has initiated a new direction of research. Fungal chitin nanofibrils are natively already present in nanoscale and thus can be isolated with very little energy demand and effort compared to nanocellulose. These nanofibrils can be directly employed in water treatment but nanopapers utilizable in structural applications are also facilitated. Furthermore, utilization of mycelium, that is the vegetative part of fungi, could allow for an even more sustainable approach to attain renewable nanofibrils, as there is no competition with an edible food product present.