Title
Optimization of acid hydrolysis process parameters for obtaining crystalline nanocellulose: higher crystallinity and lower aspect ratio
Authors
MURTAZA HAIDER SYED, KHODIJAH AL QUBRO, NORHAYATI ABDULLAH and MIOR AHMAD KHUSHAIRI MOHD ZAHARI

Received September 4, 2025
Published Volume 60 Issue 3-4 March-April
Keywords crystalline nanocellulose, microcrystalline cellulose, acid hydrolysis, crystallinity

Abstract
Cellulose is the most abundant renewable biopolymer on Earth. Due to its special properties, it is widely used and studied. Nano-sized cellulose, and specifically cellulose nanocrystals (CNCs), have great potential for biomedical applications. Although many studies have been published on obtaining CNCs from various sources and by different methods, to the authors’ knowledge, the current literature focuses mainly on the yield % of CNCs, lacking optimization for obtaining higher crystallinity. Considering that crystallinity and aspect ratio are extremely important in biomedical applications, the present study optimized four major parameters: acid type, acid percentage, duration of acid treatment, and temperature of the acid hydrolysis process. The developed CNCs were characterized using FTIR and XRD. Crystallinity index was measured for each parameter in order to find the optimum parameters for maximum crystallinity. Finally, TEM analysis was used to determine the aspect ratio of the CNC obtained under optimized conditions. Thus, the study obtained CNCs with higher crystallinity and a low aspect ratio (12.07). The findings can be used for industrial and lab applications to obtain CNCs for biomedical applications.