Deconstruction of pineapple peel cellulose based on Fe2+ assisted cold plasma pretreatment for cellulose nanofibrils preparation

Abstract

An effective method based on Fe2+ assisted cold plasma (CP) to pretreat pineapple peel cellulose for the preparation of cellulose nanofibrils (CNF) was proposed in this study. The mechanism underlying Fe2+ assisted CP pretreatment based on the structural changes of cellulose was investigated. Results showed that the cellulose preabsorbed Fe2+, followed by 60 min of CP treatment, and then was nanofibrillated into CNF via ultrasonication. Fe2+ assisted CP treatment exhibited strong capacity to significantly decrease the degree of polymerization of cellulose and to enhance electrostatic repulsion of fibrils. Furthermore, the roughness and breakage were observed on the surface of pretreated cellulose. The content of inter-molecular hydrogen bonds and average crystallite size (Dhkl) also decreased significantly. The current results provided useful fundamental insights into Fe2+ assisted CP and cellulose interaction, which should be beneficial to developing new pretreatment methods for disintegrating cellulose into CNF.