Self‐assembly of a renewable lignin biopolymer in nanoparticles with multiple morphologies

Abstract

Lignin is considered one of the main biorenewable polymers from natural resources. Each year, a large amount of lignin is generated as a waste byproduct of the pulping process in the paper industry. However, it is seldom treated as a value-added material because of its undefined structure, the diverse methods of isolation and processing, and the origin of the material; these greatly hinder its application. Therefore, it is of great significance to explore new potential applications of this readily available yet underappreciated natural product. In this study, we developed a preparation method of lignin-based microstructures or nanostructures via self-assembly. We created various self-assembled nanostructures, including nanocubes, nanorods, nano-octahedrons, nanobranches, and other morphologies, by choosing different types of simple inorganic acids at various pHs. Some of these nanostructures have never been reported. These structures were fully characterized with scanning electron microscopy, ultraviolet-visible spectroscopy, and dynamic light scattering. All of them were uniform and stable. They displayed little or no cytotoxicity to cells in vitro at concentrations up to 1024 μg/mL. We hope the results of this study provide some insight for the future development of new applications of lignin-based materials.

Green and Scalable Preparation of Colloidal Suspension of Lignin Nanoparticles and Its Application in Eco-friendly Sunscreen Formulations

“…This result was probably due to the effect of the colloidal aggregation state on the UV absorbance capacity. 43 …”

Green and Sustainable Self-Assembly Nanocomposite from Gentamicin Sulfate/Lignosulfonate with Efficient Antibacterial and Wound-Healing Activity

“…After incubation for another 24 h, the medium was replaced by 20 μL of fresh medium containing MTT (5 mg/mL) and incubated for 4 h. Then, 150 μL of DMSO was added and incubated for 10 min. The absorbance was determined by monitoring the optical densities at 570 nm via a microplate reader . The cell viability was calculated according to eq . where OD sample and OD blank are the absorbance of sample groups at different concentrations and blank cell groups, respectively.…”

“…In addition, spheroidal and irregular disklike shapes of the LS nanocomposite have been observed in some studies. , Related research has speculated that the structures of LS complexes could be controlled by electrostatic repulsion . In our previous research, we found that the LS nanocomposite with a variety of morphologies, including nanospheres, nanocubes, nanorods, nano-octahedrons, and nanobranches, can be synthesized in different anion solutions and under different environmental pH values . Surprisingly, LS led to the formation of uniform nanospheres when SO 4 2– was added to adjust the pH to 7.…”

“…22 In our previous research, we found that the LS nanocomposite with a variety of morphologies, including nanospheres, nanocubes, nanorods, nano-octahedrons, and nanobranches, can be synthesized in different anion solutions and under different environmental pH values. 27 Surprisingly, LS led to the formation of uniform nanospheres when SO 4 2− was added to adjust the pH to 7. These results prompted us to hypothesize that LS can be combined with drugs containing SO 4 2− to form a uniform nanocomposite.…”

The research on multi‐responsive azobenzene block copolymer and its self‐assembly behavior

“…Various design concept, synthetic method, and structure construction have been realized. The study on both the structure and the property of the self‐assembly amphiphilic polymers has made significant progress . Amphiphilic polymers can achieve a variety of forms, ranging from micelles to vesicles .…”