Associative Behavior of Lignosulphonates in Moderately Concentrated Water, Water–Salt, and Water–Alcoholic Media

Abstract

Industrial derivatives of lignin lignosulfonates are produced during sulfite delignification of wood. They are characterized by a wide molecular weight distribution, polyfunctionality, and lack of crystallinity. The presence of hydrophobic and hydrophilic domains in the lignosulfonate macromolecular system determines the amphiphilic and polyelectrolyte properties of this biopolymer. As a polyelectrolyte, lignosulfonates (LSs) show complex conformational and phase behavior, which can be controlled by a wide range of external factors (ionic strength, medium acidity, solvent polarity, etc.). Herein, we present the results of a study of the associative behavior of three lignosulfonate samples with different molecular weight distributions (Mw 9250−46 300) and structural and cationic (Na + , Ca 2+ ) composition. The effects of the concentration of LS (0.2−200.0 g/dm 3 ), temperature (293−353 K), ionic strength of the medium (KCl, 0.08−0.80 mol), and ethanol additives (0.6−73.0 vol %) on the bulk and surface properties of lignosulfonates have been revealed. It was assumed that the LS association in solutions is a consequence of the processes of counterionic condensation with the formation of ionic pairs and multiplets. The binding of counterions is facilitated by an increase in the ionic strength of the medium and ethyl alcohol additives.

Sulfite Lignin Nanoparticles and Nanovesicles as Biologically Active Crop Growth Stimulants

“…Many of the above data were confirmed and supplemented by us in our work . Using various physicochemical methods (conductometry, viscometry, potentiometry, photometry, and tensiometry), the aggregation of a number of LS was studied.…”

“…Many of the above data were confirmed and supplemented by us in our work. 34 Using various physicochemical methods (conductometry, viscometry, potentiometry, photometry, and tensiometry), the aggregation of a number of LS was studied. It has been shown that an increase in molecular weight, LS concentration, temperature, the presence of an indifferent electrolyte (KCl), and ethyl alcohol lead to a change in the intensity of electrostatic, hydrophobic, and van der Waals interactions and hydrogen bonds.…”

Sodium Benzenesulfonate-Assisted Preparation of Lignosulfonate-Based Spherical Micelles: Insights from Mesoscopic Simulations

“…The molecular weight distribution of SL is wide, ,, so coarse-grained models of SL with different molecular weights (Table S1) had also gained attention in the work. Therefore, the effect of molecular weight of SL on the SL aggregates in ethanol was also investigated by DPD simulations.…”

“…On the other hand, a typical STEM image from experimental methods (Figure S1) showed that the independent SL molecules really led to SL aggregates with various micro sizes and irregular structures (Figure f). Various SLs indeed have complex conformations . Moreover, based on the DPD results, it was considered that the occurrence of SL aggregates with various sizes was related to the various molecular weights of SL.…”

“…Various SLs indeed have complex conformations. 27 Moreover, based on the DPD results, it was considered that the occurrence of SL aggregates with various sizes was related to the various molecular weights of SL. As a result, DPD simulations and STEM analysis showed that the independent SL molecules with various molecular weights only resulted in the formation of lignosulfonate-based aggregates with irregular and unordered structures.…”