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

Abstract

As a new and green type of nanomaterials, lignin nanoparticles (LNPs) have been considered as high-value renewable materials for application in many fields. However, the industrialization of LNPs faces many challenges, such as high manufacturing costs and small-scale production. Here, a simple but rapid and reversible approach for the fabrication of LNPs was provided via switching pH environments. The LNPs were regularly shaped in the acetonitrile/water system, and their size appeared to be very homogeneous. The alternation of forming and dissolving of LNPs could be repeated many times simply by alternately adding acid and alkaline solutions. There was little difference in the molecular structures between the original and regenerated LNPs. In addition, the consumption of solvents for LNPs production was only 200 mL g À 1 , reduced by more than 10 times compared with conventional solvent exchange methods. The concentration of LNPs in the solution also improved to 5.0 g L À 1 . This study not only provides a new, simple, and effective strategy for the fabrication of LNPs but also paves the way towards their real green production and application.

Comparative investigation of the structural characteristics of tobacco stalk lignin during the DES and alkaline deconstruction toward sustainable materials

“…In this study, the micromorphology of the lignin fractions was investigated by scanning electron microscope (SEM), and the SEM images of sub-micron lignin spheres are presented in Figure 3 . It can be observed that BLs presented some regular micro-nanoparticles with different sizes, suggesting that lignin was well self-assembled during the recovery process from black liquor ( Xu et al, 2022 ). Then, the recovered DES lignin also exhibited a micro-nanoparticle shape, in which the L EG and L Gly showed a relatively regular and large micro-nanoparticle shape.…”

Nanoscale Composite Lignin Colloids with Tunable Visible Colors Used for Anti-UV Cosmetics

“…Lignin is a natural polyphenolic antioxidant and a broad-spectrum sunscreen . Lignin contains a large number of chromophore structures such as benzene rings, carbonyl groups, and phenolic hydroxyl groups and has a high absorbance at 280–300 nm, which provides an excellent UV protection .…”

“…Lignin is a natural polyphenolic antioxidant and a broadspectrum sunscreen. 6 Lignin contains a large number of chromophore structures such as benzene rings, carbonyl groups, and phenolic hydroxyl groups and has a high absorbance at 280−300 nm, which provides an excellent UV protection. 7 The development of lignin nanoparticles in the past decade has not only cleverly avoided the nonhomogeneity of lignin but also endowed it with a variety of nanomaterial properties.…”

Preparation of Lignin-Based Nanoparticles with Excellent Acidic Tolerance as Stabilizer for Pickering Emulsion

“…Compared to colloidally unstable and interpenetrating micro- and larger-sized lignin particles, the lignin nanoparticles (LNPs) display enhanced adsorption ability at the oil–water interface of the emulsions, which are beneficial to the formation of stable and homogeneous Pickering emulsions [ 24 ]. Up to now, various methods have been explored to prepare LNPs, e.g., acidic precipitation [ 25 ], solvent exchange [ 26 ], solvent–antisolvent [ 27 ], ultrasonication polymerization [ 28 ], biological treatment [ 29 ], etc. The solvent–antisolvent technology is the most commonly used method due to its easy implementation process and the generated LNPs with controllable sizes.…”