Visualization of artificial lignin supramolecular structures

Abstract

Summary:In this paper we are presenting the results of our environmental scanning electron microscopy (ESEM) investigation of the lignin model compound-enzymatically polymerized coniferyl alcohol, also known as dehydrogenate polymer (DHP). The goals of this study were to visualize the supramolecular organization of DHP polymer on various substrates, namely graphite, mica, and glass, and to explore the influence of substrate surface properties and associated collective phenomena on the lignin self-assembled supramolecular structure. Based on results obtained with ESEM, combined with previously published results based on scanning tunneling microscopy (STM) and electron spin resonance (ESR) technique, we looked at lignin structure ranging from a monomer on a fraction of nanometer scale to a large aggregate on a fraction of millimeter scale, therefore using six orders of magnitude range of size. Herein, we are presenting evidence that there are at least four different levels of the supramolecular structure of lignin, and that its supramolecular organization is well dependent on the substrate surface characteristics, such as hydrophobicity, delocalized orbitals, and surface-free energy.

Growing of Artificial Lignin on Cellulose Ferulate Thin Films

“… 29 The first two steps are based on the formation of covalent bonds, whereas the formation of supramolecular structures (step 3 and 4) is caused by hydrogen bonding and van der Waals interactions. 30 …”

“…Applying advanced microscopic techniques, an aggregation of these supermodules into globules and finally self-assembling into a colloidal crystal structure was found . The first two steps are based on the formation of covalent bonds, whereas the formation of supramolecular structures (step 3 and 4) is caused by hydrogen bonding and van der Waals interactions …”

“…29 The first two steps are based on the formation of covalent bonds, whereas the formation of supramolecular structures (step 3 and 4) is caused by hydrogen bonding and van der Waals interactions. 30 In our study, we assume a covalent attachment of modules or supermodules to ferulate anchor groups on top of the films.…”

Nano-lignin filled natural rubber composites: Preparation and characterization

“…It can be attributed that the attractive forces including hydrophobic interactions, hydrogen bonding interactions [28] and !-! interactions [36][37][38][39] surpass the electrostatic repulsive forces. Conceivably, the lignin particles will aggregate and form agglomerates in rubber matrix, when the NRL and lignin is co-precipitated by adding acid.…”

Nanochitin and Nanolignin: Activity and Effectiveness

“…product of lignocellulosic biomass, obtained from the paper industry for around 50%. Lignin, constituting from 20% to 30% of the Earth Plant biomass, is a polymer formed by the polymerization of 3 different phenyl propanoid units: conipheryl, pcoumaryl coumaryl-and sinapsyl alcohol linked together by different linkages to form a macromolecule, organized by a fibrillar structure (fig 9) [52,53]. This structure is composed by a great number of monomers named phenylpropanols, molecules having 6 carbon atoms organized as a ring and rich of side chains bound by hydrogen bonds.…”