Study of thin films of kraft lignin and two DHPs by means of single-molecule force spectroscopy (SMFS)

Abstract

This is a published version of a paper published in Holzforschung.Citation for the published paper: Norgren, M., Notley, S. (2012 AbstractThe adhesion of single and associated lignin chains to a substrate has been studied by means of single-molecule force spectroscopy (SMFS). Softwood kraft lignin (KL) and two lignin polymer models (dehydrogenation polymers, DHPs) based on coniferyl alcohol (DHP c.alc. ) and coniferaldehyde (DHP c.ald. ) were in focus. The desorption force from the " silicon nitride SMFS tip " for the KL was signifi cantly greater than that of the DHPs. The higher desorption force was interpreted as being due to the interaction of carboxyl groups through hydrogen bonding with the tip as well as to the less compact polymeric layer at the interface. The distribution of the extended chain lengths was determined, and self-association of lignin chains was observed. For both KL and the DHP c.ald. , chains were extended signifi cantly beyond the limit that would be expected for polymers with the corresponding degree of polymerization. The α -carbon on the DHP c.alc. has a strong intramolecular hydrogen bonding interaction with the adjacent aryl ether, which inhibits the possibility of the ether to participate in intermolecular hydrogen bonding with nearby lignin chains. Thus, the selfassociation for KL and DHP c.ald. was found to be dominated by intermolecular hydrogen bonding with carboxylic groups and aryl ether functionalities.

Plant biomechanics and resilience to environmental changes are controlled by specific lignin chemistries in each vascular cell type and morphotype

“…As G CHO and G CHOH residues are mostly interlinked with β– O –4 ether linkages in planta ( Yamamoto et al, 2020 ), we designed β– O –4 interlinked homomeric heptamers of G CHO and G CHOH (with or without αC–OH) according to previous characterization studies ( Grabber et al, 1998 ; Jourdes et al, 2007 ; Holmgren et al, 2009 ; Dima et al, 2015 ). Such lignin oligomers composed of only G CHO , G CHOH, or S CHOH have been chemically synthesized in vitro ( Ito et al, 2002 ; Önnerud et al, 2002 ; Holmgren et al, 2009 ; Tobimatsu et al, 2010 ; Notley and Norgren, 2012 ; Koshiba et al, 2013 ; Blaschek et al, 2020a ). Molecular dynamic simulations showed that oligomers of G CHO , which maintain an unsaturation in β– O –4 linkages ( Grabber et al, 1998 ; Jourdes et al, 2007 ; Holmgren et al, 2009 ), greatly reduce the rotation of the α C– β C torsions but not the rotation around β C–O or C 6 –O– α C compared to G CHOH with or without αC–OH ( Supplemental Figure S11, A and B ).…”

Well-Defined Lignin Model Films from Colloidal Lignin Particles

“…One of the important steps in the preparation of model film is the coating step. Langmuir–Blodgett deposition ,, and spin coating ,,,,, are among the methods preferred by many groups. However, the existing lignin model films have solely been prepared by dissolving lignin in different volatile solvents, such as tetrahydrofuran (THF), ,, 1,4-dioxane, , and ammonium hydroxide, ,,, resulting in lignin model films that may adequately describe the surface chemistry of lignin dried from a solvent but exhibiting dissimilar functional group orientation and accessibility as compared to CLPs.…”

Interaction of Single-Stranded DNA with Curved Carbon Nanotube Is Much Stronger Than with Flat Graphite

“…Single molecule force spectroscopy (SMFS) has emerged as a powerful tool for the study of the mechanical behavior of individual molecules. It has been used to characterize elasticity, − DNA binding modes, − cell adhesion, − protein unfolding, − and colloidal forces . It can also be used to measure the force required to remove an adsorbed molecule from a surface, − ,− which can be useful for label-free biosensing .…”