Surface and structure characteristics, self-assembling, and solvent compatibility of holocellulose nanofibrils

Area of Science:

• Biomaterials Science
• Nanotechnology
• Sustainable Chemistry

Background:

• Cellulose nanofibrils (CNFs) are derived from pure cellulose, limiting their yield and amphiphilic properties.
• Agricultural waste like rice straw presents an underutilized source for nanomaterial production.

Purpose of the Study:

• To develop a streamlined process for producing holocellulose nanofibrils (HCNFs) from rice straw.
• To characterize the properties of HCNFs and compare them with CNFs derived from pure cellulose.
• To explore the potential applications of HCNFs due to their unique amphiphilic nature.

Main Methods:

• TEMPO oxidation and mechanical defibrillation of rice straw holocellulose.
• A two-step delignification process using toluene/ethanol extraction and acidified NaClO2.
• Characterization of HCNF dimensions, surface oxidation, charge, and surface affinity.

Main Results:

• HCNFs were produced with a higher yield (33.7%) compared to CNFs.
• HCNFs exhibited similar lateral dimensions but were longer, less surface oxidized, and less negatively charged than CNFs.
• HCNFs demonstrated increased affinity for hydrophobic surfaces while retaining attraction to hydrophilic surfaces, indicating amphiphilic behavior.
• The streamlined delignification process for holocellulose was more efficient than for pure cellulose.

Conclusions:

• Rice straw holocellulose is a viable precursor for producing high-yield HCNFs with unique amphiphilic characteristics.
• The simplified production process and amphiphilic nature of HCNFs offer advantages over traditional CNFs.
• HCNFs present unique properties suitable for novel applications requiring interaction with both hydrophobic and hydrophilic environments.