Cellulose nanocrystals extracted from rice husk using the formic/peroxyformic acid process: isolation and structural...

Area of Science:

• Materials Science
• Biomass Utilization
• Nanotechnology

Background:

• Cellulose, a renewable resource from biomass, has diverse applications.
• Rice husk (RH) is an abundant agricultural waste product.
• Developing efficient methods for extracting cellulose nanomaterials from biomass is crucial for sustainable material development.

Purpose of the Study:

• To isolate cellulose nanocrystals (CNC) from rice husk (RH) using formic/peroxyformic acid.
• To characterize the chemical, microstructural, and thermal properties of the derived CNC.
• To evaluate the potential of RH-derived CNC as a reinforcing material in nanocomposites.

Main Methods:

• Isolation of CNC from RH using formic/peroxyformic acid at atmospheric pressure.
• Acid hydrolysis of cellulose using 64% H2SO4 for 30 minutes at 45 °C.
• Characterization using transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and crystallinity analysis.

Main Results:

• Effective removal of lignin and hemicelluloses from RH.
• Achieved CNC crystallinity of 67.16%.
• TEM analysis revealed CNC dimensions: 19 ± 3.3 nm diameter, 195 ± 24 nm length, and aspect ratio of 10.2 ± 6.8.

Conclusions:

• The formic/peroxyformic acid method is effective for producing high-purity CNC from rice husk.
• Rice husk-derived CNC exhibits favorable characteristics for material applications.
• This study highlights the potential of valorizing agricultural waste (RH) into valuable nanomaterials for nanocomposites.