A comparative study of lignocellulosic nanofibrils isolated from celery using oxalic acid hydrolysis followed by sonication and mechanical fibrillation

• DOI: 10.1007/s10570-019-02454-5
• Publication Date: 2019-04-26T05:04:21Z
• Authors: Jing Luo; Kaixuan Huang; Yong Xu; Yimin Fan
• Keywords: Oxalic Acid; Sonication; Thermal Stability; Aqueous suspension; Degradation

Two lignocellulosic nanofibrils (LCNF) were produced from celery using oxalic acid hydrolysis and sonication (OS) or refining by a SuperMassColloider grinder treatment (MT). Physicochemical properties, such as morphological properties, crystallinity, thermal stability, zeta potential and transmittance for the obtained nanofibrils were evaluated. Compared to refining in SuperMassColloider grinder, OS treatment contributed greater separation of nanofibril bundles by introducing negative carboxyl groups. In detail, mechanical fibrillation resulted in the LCNF with longer length and thicker diameter. OS treatment produced LCNF with smaller height of 5.5 nm and higher aspect ratio than the one obtained by MT treatment, and endowed high crystallinity and thermal stability due to its preferential degradation of amorphous carbohydrates and lignin. Furthermore, OS-LCNF with carboxyl group contributed more stable aqueous suspension with surface charge of − 32.9 mV, better than MT-LCNF sample with entangled network structure. The comparative study can gain insight into the use of celery as a potential source for nanocellulose production.