Exploring acid hydrolysis conditions and extended mechanical processing for producing cellulose nanocrystal and nanofibrils from pineapple leaf fibers.

This study investigates the potential of pineapple leaf fiber (PALF), as a renewable source, to produce cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC), addressing a gap in the literature regarding optimal conditions for CNC extraction from PALF. Chemical analysis revealed a high α-cellulose content (78.14 %), making PALF suitable for nanocellulose production. MorFi analysis confirmed successful CNF production. Various hydrolysis conditions were explored to obtain CNC and some of them showed promising results. Characterization using FTIR, XRD, AFM, and TGA confirmed successful nanocellulose production. The CNCs exhibited a crystallinity index of 78.5 % and nanoscale dimensions (647-1105 nm, depending on the process), while CNF showed lengths of approximately 256 nm. TGA demonstrated that CNCs had lower thermal stability compared to cellulose and CNF due to reduced molecular weight and sulfate groups. CNC1 and CNC2, produced under optimized conditions (55 % acid concentration, 45 °C, 30 min), demonstrated superior properties, including high crystallinity and desirable nano-dimensions. This study highlights the novelty of using PALF for CNC production with tailored characteristics, paving the way for its application in biocomposites, drug delivery, and tissue engineering. PALF's availability and favorable composition make it a promising candidate for sustainable nanocellulose materials.