Figure 2.

Surface charge and stability of LNPs. (a) ζ-potentials of LNPs as a function of pH. (b) Particle diameters of LNPs at the native pH 4.9 (dashed horizontal lines) and after 4 h holding at room temperature of dispersions adjusted to pH 2–4 (dilute HCl) and pH 5–10 (dilute NaOH). (c) Volume (V) and intensity (I) distributions of particle sizes of LNPs produced at a dilution rate 0.06 v v^–1 min^–1 (black solid line) and by rapid pouring of water to lignin solution (dilution rate >300 v v^–1 min^–1, red dashed line). (d) UV–vis mass extinction coefficients of soluble lignin, and LNPs produced at slow and high dilution rates.