Extraction and Characterization of Micro-fibrillated Cellulose from Rice Husk Waste for Biomedical Purposes

Abstract

This study aimed to report the extraction of micro-fibrillated cellulose (MFC) from rice husk (RH) through a series of processes including alkalization, bleaching, chemical hydrolysis, and mechanical treatment. The chemical structure, morphology, and crystallinity were assessed using Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), and X-ray diffraction (XRD). The results showed that alkalization was more effective in removing unwanted substances such as silica, hemicellulose, and lignin compared to bleaching. Chemical or mechanical treatment was more targeted towards removing the amorphous phase while fibrillating MFC. Further mechanical treatment significantly enhanced the crystallinity index (CI) of MFC, reaching 87.47%, while chemical treatment remained at 78.54%. The mechanical treatment led to a larger void size due to rigorous fibrillation, resulting in increased water retention during extraction compared to chemically treated MFC with a negatively charged surface. Crystal extraction through mechanical treatment disrupted the hydrogen bond, transforming cellulose crystal from triclinic Iα to monoclinic Iβ. The comprehensive evaluation of MFC extracted from RH showed its potential for biomedical application.