Isolation and Characteristics of Cellulose and Nanocellulose from Lotus Leaf Stalk Agro-wastes

Abstract

Valorization of lotus leaf stalks (LLS) produced as an abundantly available agro-waste was achieved through the extraction of value-added nanocellulose. Nanofibrillated cellulose (NFC) was successfully prepared from LLS by using chemical pretreatment combined with high-intensity ultrasonication. The morphological characteristics of the chemically purified LLS cellulose microfibrils were characterized by optical microscopy and MorFi fiber analysis. Fourier transform infrared (FTIR) spectroscopy indicated the extensive removal of non-cellulosic components after chemical pretreatment. The transmission electron microscopy (TEM) results revealed agglomeration of the developed individual NFC, with a width of 20 ± 5 nm and length on a micron scale, into a network-like feature. X-ray diffraction results showed that the resulting NFC had a cellulose I crystal structure with a high crystallinity (70%). The NFC started to degrade at around 217 °C, and the peak rate of degradation occurred at 344 °C. Nanofibrils obtained from LLS have great potential as reinforcement agents in nanocomposites.

Keywords

• Nanocellulose
• Lotus leaf stalk
• Ultrasonication
• Morphological characteristics
• Thermal degradation