Preparation and characterization of new cellulose nanocrystals from marine biomass Posidoniaoceanica

•Cellulose and holocellulose were extracted from Posidonia oceanica leaves and balls.•Cellulose nanocrystals were extracted from these materials.•High aspect ratio Cellulose nanocrystals were obtained.

In the recent decades, the rational management of agricultural residues and industrial byproducts presented an interesting approach. In this context, the valorization of Posidoniaoceanica leaves and balls, a widely available marine residue in Tunisia, was carried out. This biomass was found to be an interesting source of cellulose. Thus, the cleaned and ground raw material was delignified and bleached. The extraction with alkali solution (yield 60% of cellulose) followed by bleaching gave 45% of pure cellulose. The resulting extracted cellulose was characterized by various techniques. Then, different nanocrystal suspensions were prepared from the P. oceanica cellulose and holocellulose and characterized by different methods such as TEM and nano-sizer, which gave their morphological parameters (length and size). The obtained nanocrystals were compared with those usually prepared from wood and annual plants, and it was shown that promising nanomaterials can be prepared.