Extraction and analysis of cellulose nanocrystals from cotton balls by acid hydrolysis

Abstract

Cellulose is one of the most widely used natural polymers developed in eco-friendly methods, which has been used in various industrial processes and products since ancient times. The sources of cellulose materials are plant and wood fibers. Cellulosic materials are converted into cellulose nanocrystals (CNCs) using mechanical or chemical methods. In this study, the CNCs were obtained from cotton balls by acid hydrolysis method using sulfuric acid. The sulfuric acid hydrolysis method was performed with 64% (w/w) sulfuric acid and combined using a liquor ratio of 1:20 with cotton balls while being subjected to vigorous stirring at 50°C for 60 minutes. The cellulose nanocrystals were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FTIR) spectroscopy analysis and X-ray Diffraction (XRD) techniques. The extracted cellulose nanocrystals had needle-shaped particles with a 6.35 nm average diameter and a length of 108.8 nm on average. The functional groups of the extracted cellulose nanocrystals were shown to have been evaluated through analysis of the FTIR spectra. Therefore, it was confirmed that the cellulose nanocrystals were successfully extracted from cotton balls using sulfuric acid hydrolysis. The distinctive crystalline cellulose phase of artificial cellulose nanocrystals was recognized using the XRD spectrum.