Ionic liquids and lignin interaction: An overview

In this review, highlights are focused on the most emerging bonding interactions, including hydrogen bonding, ion-dipole, van der Waals interactions, between various types of ionic liquids (ILs) and lignin/derived-lignin model compounds, which have been potentially reviewed in anticipation of their applications. ILs eventually formed the ionic inter- and/or intra-hydrogen bonding, covalent, π - π stacking, either lignin assisted to deconstruct the recalcitrant structure of plant biomass into a lower molar mass fractions, or pure form of polysaccharide. The impact of biomass sources in standing of recovered lignin molar mass, is discussed. Wide-ranging transformation of lignin hydroxyl groups to oxidation, esterification, methylation, depolymerization, dissolution, etc. in presence of ILs, has also been discussed in this review. Thereafter, the biomedical prospects of lignin along with the current situation and future development trend of ILs with lignin, are proposed due to its unique properties, including sustainability, biodegradability, and biocompatibility.