Cation−π Interactions as a Mechanism in Technical Lignin Adsorption to Cationic Surfaces

Abstract

The assembly of dissolved technical lignins in aqueous and organic medium has been studied at the solid-liquid interface. Adsorption of alkali lignin onto gold coated crystals treated with a cationic polymer was determined using a quartz crystal microbalance with dissipation monitoring. Complete coverage of the cationic surface with alkali lignin occurred at low solution concentration, revealing a high affinity coefficient under both alkali and neutral conditions. With additional adsorption studies from organosolv lignin in organic solvent and spectroscopic analysis of mixtures of cationic polymer and alkali lignin, a noncovalent interaction between lignin's aromatic rings and the cation of the quaternary ammonium group was shown to exist. The work underscores how polyphenolic biopolymers can strongly interact with cations through noncovalent interactions to control molecular architecture.

Anionic wood nanofibers produced from unbleached mechanical pulp by highly efficient chemical modification

“…41 In addition to being used to produce self-standing films, surface-functionalized AWNFs could be suitable as flocculants in water purification 42 or the removal of toxic heavy metals 43 and organic dye molecules from water. 44 The presence of lignin can also provide some enhanced properties, such as π-π 45 or cation-π 46 interaction between lignin-containing nanocellulose and harmful chemicals (e.g., organic dyes), which could improve water purification efficiency. The use of non-bleached pulp instead of bleached cellulose fibers reduce the environmental burden of the production of wood-based nanomaterials.…”

Direct Preparation of Hollow Nanospheres with Kraft Lignin: A Facile Strategy for Effective Utilization of Biomass Waste

“…The FTIR spectra for the KL and the hollow KL nanospheres are shown in for hollow KL nanospheres, a positive movement of 2.1 cm -1 in peak shift. Because the two samples' chemical compositions were identical, the peak shift can only be attributed to the lignin's aromatic groups being in different aggregating environments (Pillai and Renneckar 2009). The lower wave numbers provided direct evidence that hollow KL nanospheres have stronger π-π interactions among the aromatic groups than KL.…”

Nano-lignin filled natural rubber composites: Preparation and characterization

“…interactions, widely reported between benzene rings and polycations [41,42], which can result in charge-transfer from the aromatic rings in lignin to PDADMAC. For the driving forces of adsorption of PDADMAC onto lignin, Pillai and Renneckar [43] considered that cation-! interactions as driving forces contribute to the adsorption besides ion-ion interactions.…”