Preparation of homogeneous lignin nanoparticles by efficient extraction of lignin and modification of its molecular structure using a functional deep eutectic solvent containing γ-valerolactone

A lignin-extractive green reaction medium consisting of choline chloride, 5-sulfosalicylic acid, and γ-valerolactone was designed. Polyphenolic lignin was obtained. The green advancement of DES processing has been enhanced.