Interaction of synthetic and lignin-based sulfonated polymers with hydrophilic, hydrophobic, and charged self-assembled monolayers.

There is a need to understand the role of polymer structure on its interaction with surfaces to produce effective functional surfaces. In this work, we produced two anionic polymers of lignin-3-sulfopropyl methacrylate (L-S) and poly(vinyl alcohol--vinyl acetate)-3-sulfopropyl methacrylate (PVA-S) with similar charge densities and molecular weights. On the gold-coated surface, we deposited self-assembled monolayers (SAM) bearing different terminal moieties namely, hydroxyl, carboxyl, methyl, and amine groups of alkanethiols.

Fabrication of amphoteric lignin and its hydrophilicity/oleophilicity at oil/water interface.

Amphoteric polymers have tremendous applications in colloidal systems. Despite the enormous availability of lignin, the generation of amphoteric lignin polymer has yet to be discovered. In this work, amphoteric lignin was synthesized in an industrially attractive aqueous system via integrating the advantages of grafting quaternary ammonium groups onto lignin and polymerizing lignin with sulfonate containing monomers.

Production of Flocculants, Adsorbents, and Dispersants from Lignin.

Currently, lignin is mainly produced in pulping processes, but it is considered as an under-utilized chemical since it is being mainly used as a fuel source. Lignin contains many hydroxyl groups that can participate in chemical reactions to produce value-added products. Flocculants, adsorbents, and dispersants have a wide range of applications in industry, but they are mainly oil-based chemicals and expensive.