Investigating the Structure-Size Relationship between Organosolv Lignin and Its Colloidal Particles.

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomass Valorization

Background:

• Lignin's complex and heterogeneous nature hinders understanding of its structural impact on nanoparticle fabrication.
• Controlling lignin structure is crucial for developing functional colloidal lignin particles (CLPs).

Purpose of the Study:

• To investigate the influence of diverse organosolv lignin structures on the size-tunable fabrication of colloidal lignin particles (CLPs).
• To establish correlations between lignin structural features and CLP size for tailored applications.

Main Methods:

• Extraction of organosolv lignins with varying β-aryl ether linkages, phenolic hydroxyl (OH) groups, and molecular weights.
• Fabrication of CLPs using different initial lignin concentrations.
• Dynamic Light Scattering (DLS) analysis to determine CLP size distribution.

Main Results:

• CLP size strongly correlated with both lignin structure and initial concentration, ranging from 200-750 nm.
• Lower lignin concentrations (1-2.5 mg/mL) produced smaller CLPs (200-400 nm), while higher concentrations (10-20 mg/mL) yielded larger CLPs (500-750 nm).
• Lignin with fewer β-O-4 linkages, lower molecular weight, and higher phenolic OH content resulted in smaller CLPs at low concentrations and larger CLPs at high concentrations.

Conclusions:

• The study elucidates the relationship between lignin structural characteristics and CLP size.
• Provides a foundation for fabricating size-tunable CLPs with specific properties for diverse applications.
• Highlights the importance of lignin heterogeneity in controlling nanoparticle formation.