Formation of Uniform Colloidal Spheres Based on Lignosulfonate, a Renewable Biomass Resource Recovered from Pulping Spent Liquor

Abstract

Effects of mass ratios on the sodium lignosulfoante (NaLS) and cetyltrimethylammonium bromide (CTAB) mixing system were first investigated by zeta potential and surface tension measurements. Uniform colloidal spheres from the NaLS/CTAB complex were then fabricated via electrostatic and hydrophobic self-assembly and characterized by DLS, TEM, contact angle, elemental analysis, XPS, and FTIR measurements. Results showed the stoichiometric mass ratio (SMR) of the NaLS/CTAB system was 1:2.82, where the hydrophobicity was strongest and preparing colloidal spheres was feasible. Colloidal spheres were formed through gradual aggregation of NaLS/CTAB molecules at SMR, which was induced by continuously adding water into NaLS/CTAB/EtOH solutions. NaLS/CTAB molecules started to form spheres at a critical water content of 58 vol %, and the formation process was completed at a water content of 84 vol % when the initial concentration of NaLS/CTAB in EtOH was 1.0 mg mL −1 . The sizes of NaLS/CTAB colloidal spheres could be well controlled by adjusting water-adding rates. This preparation of lignosulfonate-based nanoparticles is very simple, safe, and low-cost, and these obtained nanoparticles have advantages of biodegradability and ultraviolet resistance. This study provides a green and valuable approach to value-added applications of lignosulfonate biomass recovered from pulping spent liquor and is of great significance for both economic and environmental benefits.

Assembly of lignin-based colloidal particles: effects of cationic surfactants, molecular weight, and solvent on morphology

“…This result is consistent with the data reported in the literature regarding changes in the benzene ring environment due to p-p aggregation. 23 This FTIR analysis further proves the decomposition of LS/STAB during the assembly process. Moreover, this provides a theoretical basis for the selection of cationic surfactants to form LS colloidal spheres.…”

“…According to the formation mechanism of LS/CTAB colloidal spheres, colloidal spheres are formed by the aggregation of individual clusters. 23 Further, small molecular surfactants can promote the disaggregation of lignin. 35 Therefore, we speculate that LS/CTAB with 5000-10 000 Da of LS only formed 50 nm particles owing to the fact that lowermolecular-weight LS and CTAB promote the disaggregation of LS/CTAB microspheres.…”

“…Accordingly, LS/CTAB colloidal spheres were prepared by self-assembly without necessitating any chemical modication. 23 For example, Li et al achieved the free conversion of the aggregation and disaggregation of LS/CTAB particles by adjusting the hydrophilic and hydrophobic surroundings of the system; further, LS/CTAB particles were used to wrap the photosensitive pesticide Avermectin (AVM) to improve the anti-photodegradation properties of AVM@LS/ CTAB. 24 In addition, Qiao et al reported that LS was rst modied by CTAB to increase its hydrophobicity; then, they transformed LS/CTAB colloidal particles from spherical to vesicular morphology by adjusting the dose of tetraethyl orthosilicate, which was applied toward the encapsulation of doxorubicin.…”

Friction and Wear of MoO3/Graphene Oxide Modified Glass Fiber Reinforced Epoxy Nanocomposites

“…Moreover, the Raman spectrum of the MoO 3 ‐GO nanocomposites also shows three sharp characteristic bands attributed to MoO 3 . The Raman bands at 989 and 820 cm −1 are attributed to the asymmetrical and symmetrical stretching vibrations of the terminal MoO bonds and the band at 662 cm −1 can be assigned to the asymmetrical stretching vibration of OMoO bonds . The bands appeared in the range of 100–400 cm −1 can be assigned to various bending modes of a‐MoO 3 crystal …”

Green self-assembly synthesis of porous lignin-derived carbon quasi-nanosheets for high-performance supercapacitors

“…It can be classified into water-insoluble alkali lignin and enzymatic lignin, along with water-soluble lignosulfonate and the sulfonated product of alkali lignin. Unfortunately, only ca.10% of industrial lignin is effectively utilized as dispersants or water reducers, and the rest is regarded as waste or burned as low-grade fuel [21]. Converting carbon-rich lignin into highvalued carbon materials would be a feasible way to address this issue, and it achieves the purpose of "waste into wealth".…”