Acetone/Water Cosolvent Approach to Lignin Nanoparticles with Controllable Size and Their Applications for Pickering Emulsions

Abstract

In this study, we showed that lignin nanoparticles (LNPs) with controllable size could be prepared using the acetone/water cosolvent (A/W) approach. The solubility of lignin in A/W of varied constitution (10:0 to 0:10 v/v) was determined, and A/W containing 7:3 (v/v) acetone to water was identified as the optimum solvent. A positive correlation between LNP size and lignin concentration was observed, with the smallest LNPs (28.5 ± 5.4 nm) obtained at 5.00 g/L of lignin, while serious aggregation occurred at lignin concentrations above 100 g/L. The rotary evaporation procedure used to remove acetone had no noticeable effect on the size of LNPs. The obtained LNPs were utilized as emulsifiers to stabilize oil-in-water Pickering emulsions of various oils. The results indicated that the high efficiency of LNPs in stabilizing Pickering emulsions was due to their irreversible adsorption at the oil–water interface of the droplets. Overall, a straightforward way for the controllable preparation of LNPs and their use as Pickering emulsifiers was demonstrated.

Physicochemical properties of insoluble dietary fiber from pomelo ( Citrus grandis ) peel modified by ball milling

“…The morphology and optical micrographs were illustrated in Figure 6a. After 120 days storage, the emulsions prepared with 0.01%, 0.03%, 0.05%, 0.10% of PP‐IDF‐BM2h or 1:9, 1:19, 1:29 of O/W ratio exhibited excellent stability against creaming which was superior to the published results (Li, Shen, et al., 2021). This admirable stability profited from the thick interfacial layer and pectin‐lignocellulose network in PP‐IDF (Qi et al., 2021).…”

Lignin Nanoparticles as Highly Efficient, Recyclable Emulsifiers for Enhanced Oil Recovery

“…23,24 In our work, LNPs were prepared in enzymatically hydrolyzed lignin powders by the acetone/water co-solvent method and characterized. 38 Oil-in-water Pickering emulsions were received by dispersing LNPs in mineralized water as the aqueous phase and kerosene as the oily phase. The emulsion could be stabilized at 60 °C for at least 6 months.…”

“…However, it is mainly utilized as sacrificial agent, in combination with more expensive petroleum sulfonate surfactants. , Currently, there are also a number of inorganic nanoparticles employed as emulsifiers in EOR applications, such as SiO 2 nanoparticles. These, however, often require more complex grafting modifications to make them amphiphilic, or should be used in combination with surfactants giving a higher total concentration. − Lignin nanoparticles (LNPs) are excellent emulsifiers, as well as Pickering emulsion stabilizers, which have been proved by previous research. − If successful, preparation of LNPs as bio-emulsifiers for EOR would provide a new platform for high value-added applications of lignin. More importantly, due to the alkali solubility properties of lignin, , it is expected that the stable emulsion produced from LNPs can be demulsified to facilitate the separation of oil and water and recover the emulsifier.…”

A Rapid and Reversible pH Control Process for the Formation and Dissociation of Lignin Nanoparticles

“…However, the high consumption of solvents and the low concentration of product significantly increased the costs of the production and limited the application of LNPs. Although spray drying and a few cosolvent approaches can prepare LNPs with higher concentrations, [5b,14] the uniformity, stability, and regenerability of LNPs also limited their large‐scale applications. Several strategies have been investigated to enhance the stability of LNPs [15] .…”