Isolation and characterization of cellulose nanofibers from bamboo using microwave liquefaction combined with chemical treatment and ultrasonication
Cellulose nanofibers were successfully isolated from bamboo using microwave liquefaction combinedwith chemical treatment and ultrasonic nanofibrillation processes. The microwave liquefaction couldeliminate almost all the lignin in bamboo, resulting in high cellulose content residues within 7 min, andthe cellulose enriched residues could be readily purified by subsequent chemical treatments with lowerchemical charging and quickly. The results of wet chemistry analyses, SEM images, and FTIR and X-rayspectra indicated the combination of microwave liquefaction and chemical treatment was significantlyefficient in removing non-cellulosic compounds. Ultrasonication was used to separate the nanofibrilsfrom the purified residues to extract nanofibers. The TEM images confirmed the presence of elementaryfibrils, nano-sized fibril bundles, and aggregated fibril bundles. As evidenced by the TGA analysis, cellu-lose nanofibers isolated by this novel technique had high thermal stability indicating that the isolatednanofibers could possibly be applied as reinforcing elements in biomaterials.