Fig. 2.

LNPs preparation methods. a Schematic of solvent shifting method; (A1) AFM height image of LNPs prepared by solvent shifting from Sipponen et al. [55]; (A2) TEM image of a CLP dispersion (scale bar 500 nm) from Lintinen et al. [63]. (A1) and (A2) reproduced by permission of The Royal Society of Chemistry. b Simplified experimental aerosol-flow reactor setup for the synthesis of lignin particles; (B1) SEM micrographs of solid lignin spheres synthesized by aerosol flow of OSL. b and (B1) Reprinted (adapted) with permission from Ago et al. [46]. Copyright © 2016, American Chemical Society. (B2) SEM image of wrinkled lignin particles with scale bars = 200 nm; From Kämäräinen et al. [70], reproduced by permission of The Royal Society of Chemistry. c TEM image of LNPs obtained by the acid precipitation of 0.56%wt Indulin AT in ethylene glycol and further dialysis in milli‐Q water with scale bars = 50 nm, reproduced with permission from Frangville et al. [50] © 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. d Sonicated wheat straw lignin morphological characterization by TEM, reproduced with permission from Gilca et al. [73] Copyright © 2014 Elsevier B.V. All rights reserved. e SEM images of the lignin mechanically sheared for 2 h, reproduced with permission from Nair et al. [74] © 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim