Controlling the nanocellulose morphology by preparation conditions

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Polymer Science

Background:

• Nanocellulose (NC) is a key building block for advanced biomaterials.
• The morphology of NC significantly impacts the properties of engineered functional materials.
• Controlling NC morphology is crucial for developing novel applications.

Purpose of the Study:

• To investigate the relationship between sulfuric acid hydrolysis conditions and the resulting NC morphology.
• To achieve controlled morphological regulation of NC.
• To understand the formation mechanisms of different NC structures.

Main Methods:

• Sulfuric acid hydrolysis of microcrystalline cellulose under varying conditions (acid concentration, temperature, time).
• Characterization of obtained nanocellulose products (W-CNC, CNS, N-CNC) including size distribution and crystallographic form.
• Evaporation-induced self-assembly to form chiral nematic structures.

Main Results:

• Three distinct NC morphologies were produced: wide-size-distribution CNC (W-CNC), cellulose nanospheres (CNS), and narrow-size-distribution CNC (N-CNC).
• W-CNC and N-CNC exhibited cellulose I crystallographic form, while CNS showed a coexistence of cellulose I and II.
• W-CNC and N-CNC formed chiral nematic structures, reflecting specific wavelengths, unlike CNS.

Conclusions:

• Sulfuric acid hydrolysis conditions precisely control nanocellulose morphology.
• The formation of cellulose I/II coexistence in CNS was elucidated.
• This work provides a foundation for tailoring NC morphology for specific biomaterial applications.