Concluding remarks: Faraday Discussion on Frontiers in physical chemistry in lignin valorization

The valorisation of lignin, the only high-volume, naturally occurring aromatic biopolymer, represents an essential frontier for the sustainable production of chemicals and materials. However, despite its tremendous potential, lignin still remains the "dark horse" of biorefining - harbouring great promise yet still insufficiently understood. This closing personal perspective summarizes the recent Faraday Discussion on 'Frontiers in physical chemistry for lignin valorisation', framing the multidisciplinary efforts required to transition this field into industrial viability. The meeting presented work across four critical domains: fundamental structural understanding, stabilization during extraction and processing, conversion of technical lignins, and strategies for compatibilisation with commercial applications. The discussion reinforced that future success hinges on achieving mastery over several interconnected domains: relating fundamental studies on structure, morphology and reactivity to industrially relevant processing and product development strategies. By leveraging in-depth analytical methods, exercising precise control over supramolecular interactions, understanding structure-reactivity aspects, and maintaining a holistic focus on techno-economics and circularity, we can harness the promise of this important renewable feedstock, establishing lignin's key role in future bio- and circular-economy strategies.