Preparation and characterisation of cellulose nanocrystals thin films utilising layer-by-layer deposition

Cellulose nanocrystals (CNC) with 3–4 nm in diameter and 100–300 nm long were obtained by sulphuric acid hydrolysis from cellulose pulp. CNC were deposited by layer-by-layer (LBL) assembly with cationic polyelectrolyte, poly(allylamine hydrochloride) (PAH) and poly(diallyldimethylammonium chloride) (PDDA), to prepare thin films. PDDA is a fully charged polyelectrolyte while PAH is partially charged and its charge density is dependent on pH value. We compared the LBL assembly behaviour of CNC with weak and strong polyelectrolyte.