Herein we report a topographical study of the supramolecular organization of enzymatically polymerized lignin model compound - dehydrogenative polymer (DHP) of coniferyl alcohol - on cellulose substrate, using the Environmental Scanning Electron Microscopic (ESEM) technique. A comparison of deposits obtained by bulk polymerization in solution and direct polymerization in the presence of cellulose substrate shows distinct differences in supramolecular organization. DHP polymerized in solution expresses a 3-D structure with short-range ordered motifs, while the polymer formed in the presence of cellulose substrate arranges in a single layer compact structure consisting of several domains. Such structures could be described as a two-dimensional hexagonal close packed lattice(HCPL), with the dimension of unit cell in 1 μm range. The domains have a quite regular structure with few lattice defect forming a good example of two-dimensional colloidal crystal. The growth of DHP globules and their assembly into a supramolecular structures are interpreted in terms of cooperative electrostatic interaction of polymer precursors, with a framework of cellulose OH groups and interfacial interactions (hydrophilic/hydrophobic) in the course of the structure growth. The results strongly suggest that the carbohydrate matrix in plant cells can serve as a templates for lignin structure formation in the plant cell wall.
- Environmental scanning electron microscopy (ESEM)
- Supramolecular structures
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Polymers and Plastics
- Materials Chemistry