Isolation of Chitin Nano-whiskers Directly from Crustacean Biomass Waste in a Single Step with Acidic Ionic Liquids

We report on a first method for in situ formation of individual chitin nanowhiskers (ChNWs) straight from crustacean biomass. The method that utilizes the 1-butyl-3-methylimidazolium hydrogen sulfate ionic liquid ([C4mim][HSO4]) allows liberating ChNWs with simultaneous removal of the protein–mineral matrix, without the need of prior isolation and purification of chitin polymer. The process reduces the amount of required chemicals and decreases the volume of process waste while avoiding the necessity of handling boiling acidic solution used in the traditional preparation of ChNWs. The resulting chitin nanowhiskers from biomass exhibit a high aspect ratio of 75 and a crystallinity index of 92%, are fully acetylated, and of high thermal stability with a decomposition temperature of 347.9 °C.