Carbonization of cellulose cell wall evaluated with ultraviolet microscopy

Area of Science:

• Materials Science
• Biomass Conversion
• Chemical Engineering

Background:

• Cellulose is a primary component of plant cell walls.
• Understanding cellulose carbonization is crucial for biomass valorization.
• Previous studies have not investigated carbonization within cell wall interiors.

Purpose of the Study:

• To investigate cellulose carbonization within the interior of plant cell walls.
• To examine the effect of aromatic solvents on cellulose carbonization.
• To characterize the carbonized products using UV microscopy and spectroscopy.

Main Methods:

• Pyrolysis of cotton cellulose under nitrogen or in aromatic solvents at 280 °C.
• Cross-section examination of cell walls using ultraviolet (UV) microscopy.
• Analysis of UV spectra, model compounds, and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) data.

Main Results:

• UV absorption indicating carbonization was observed within cell walls after pyrolysis under nitrogen.
• Carbonized products showed homogeneous UV absorptivity, slightly lower than cell surfaces, with maximal absorption around 250 nm.
• Aromatic solvents reduced solid carbon yields and UV absorptivity, maintaining homogeneity.
• Furanic and polycyclic aromatic structures were identified in the carbonized products.

Conclusions:

• Cellulose carbonization occurs internally within cell walls, forming furanic and polycyclic aromatic structures.
• Aromatic solvents influence the carbonization process by decreasing product yield and altering UV absorptivity.
• The findings provide insights into the mechanism of cellulose carbonization within a complex biological matrix.