Lignin Nanoparticle Nucleation and Growth on Cellulose and Chitin Nanofibers

Abstract

Cellulose (CNF) and chitin (ChNF) nanofibers are known to form materials that are both tough and strong. In this study, we hypothesize that the inertness of networks associated to CNF and ChNF makes them ideal templates for heterogenous reaction engineering and to install functionalities by in-situ formation of nanoarchitectures. We expand nanoparticles templating on polysaccharide colloids by introducing a new and facile process that leads to the growth of organic nanoparticles on CNF and ChNF suspended in water. The process based on solvent shifting supported on solid interfaces is demonstrated by direct observation and exploits the photocatalytic effect of lignin nanostructures. Importantly, the dynamics of nanoparticles nucleation and growth is correlated to the surface chemistry of the templates. Electrostatic repulsion between the deprotonated lignin molecules and the slightly negative CNF support led to limited adsorption and, therefore, was effective in producing free (non-bound) lignin nanoparticles (28±7 nm) by precipitation. In contrast, the stronger interfacial interactions between the positively charged ChNF and lignin molecules led to instantaneous and extensive lignin adsorption, followed by nucleation and growth into relatively larger nanosphere (46±17 nm). The latter were homogeneously distributed and strongly coupled to the ChNF support.Overall, we introduce lignin nanoparticle nucleation and growth on renewable nanofibers as an effective route toward in situ synthesis of highly functional fibrils and derived cohesive films that offer great potential in packaging and other areas.

Multifunctional lignin-based nanocomposites and nanohybrids

“…170 An interesting development is the use of chitin nanofibers to nucleate and grow lignin nanoparticles. 189 In this vein, other interesting applications is that of chitosan-lignin composites for emulsion stabilization and encapsulation of active payload. Nguyen et al used high pressure homogenization to prepare corn oil nanoemulsions encapsulating deltamethrin.…”

Plant‐Based Structures as an Opportunity to Engineer Optical Functions in Next‐Generation Light Management

“…[ 132 ] Regarding optical properties, improved compatibility between the biobased matrix and NP additive leads to better dispersion of the additive in the matrix, promoting the formation of transparent materials with high UV blocking capacity. [ 128,132–134 ]…”

“…In the case of CNF, the anionic lignin NPs were observed in the vicinity of the CNF, but not anchored to the CNF surfaces due to electrostatic repulsion, whereas the lignin NPs adhered to the surface of cationic nano-chitin. [132] Regarding optical properties, improved compatibility between the biobased matrix and NP additive leads to better dispersion of the additive in the matrix, promoting the formation of transparent materials with high UV blocking capacity. [128,[132][133][134] While lignin can be an effective UV absorber, the color of this material (brown-black color) can be undesirable or even detrimental to device efficiency because it reduces transparency in the visible range.…”

“…[132] Regarding optical properties, improved compatibility between the biobased matrix and NP additive leads to better dispersion of the additive in the matrix, promoting the formation of transparent materials with high UV blocking capacity. [128,[132][133][134] While lignin can be an effective UV absorber, the color of this material (brown-black color) can be undesirable or even detrimental to device efficiency because it reduces transparency in the visible range. This coloration depends on the number of unsaturated bonds in the lignin [135] and can be manipulated by different methodologies of extraction or modification, e.g., to obtain colorless lignin.…”

“…In situ nucleation and growth of lignin nanoparticles in the presence of c) cellulose and d) chitin nanofibers. Reproduced with permission [132]. Copyright 2020, American Chemical Society.…”