Advances Toward Sustainable Lignin-based Gel for Energy Storage and Smart Sensing

Polymers obtained from biomass are promising alternatives to petro-based polymers owing to their low cost,biocompatibility,and biodegradability.Lignin,a complex aromatic polymer containing several functional hydrophilic and active groups including hydroxyls,carbonyls,and methoxyls,is the second most abundant biopolymer in plants.In particular,sustainable lignin-based gels are emerging as an appealing material platform for developing energy-and sensing-related applications owing to their attractive and tailorable physiochemical properties.This study describes the preparation strategies of lignin-based gels according to previously reported methods,with significant attention on the diverse performance of lignin-derived gel materials.Additionally,a detailed review of lignin-based gels utilized as an important resource in diverse fields is provided.Finally,a future vision on challenges and their possible solutions is presented.