Characterization of Carboxylated Cellulose Nanocrytals Isolated through Catalyst-Assisted H₂O₂ Oxidation in a...

Area of Science:

• Materials Science
• Nanotechnology
• Green Chemistry

Background:

• Cellulose nanocrystals (CNCs) isolation and modification typically involve multiple steps and harsh chemicals.
• Developing sustainable and efficient methods for CNC production is crucial for their wider application.

Purpose of the Study:

• To develop a green and facile one-pot method for isolating carboxylated cellulose nanocrystals (CNCs) from native cellulose.
• To characterize the properties and morphology of the produced carboxylated CNCs.

Main Methods:

• A one-pot reaction using hydrogen peroxide as an oxidant and copper(II) sulfate as a catalyst in an acidic medium under mild thermal conditions.
• Characterization techniques included conductometric titration, Fourier transform infrared spectroscopy, atomic force microscopy, optical polarized microscopy, transmission electron microscopy, dynamic laser scattering, solid carbon-13 nuclear magnetic resonance, and X-ray spectroscopy.

Main Results:

• The method successfully produced carboxylated CNCs with a charge content of approximately 1.0 mmol g⁻¹.
• Morphological analysis confirmed rod-shaped CNCs with an average size of 263 nm in length and 23 nm in width.
• Dynamic laser scattering indicated electrostatic stability of the carboxylated CNC suspensions in the presence of salt.

Conclusions:

• The developed one-pot method is an economical and ecological alternative for producing carboxylated CNCs.
• The carboxylated CNCs exhibit desirable properties for potential applications in various fields.
• This green approach facilitates the sustainable production of functionalized nanomaterials.