Lignins are the most important aromatic renewable natural resource today, serving as a sustainable, environmentally acceptable alternative feedstock to fossil‐derived chemicals and polymers in a vast scope of value‐added applications. Lignin is a biopolymeric molecule that, together with cellulose, is a fundamental component of higher vascular plants structural cell walls. It can be extracted from by‐products of the pulp and paper industries, agricultural waste and residues, and biorefinery products. Lignin properties may vary depending on source and extraction method with carbon and aromatic as the main compositions in lignin structure. These rich compositions make lignin more valuable, allowing for the creation of high‐value‐added green composites. However, the complex structure of lignin creates low reactivity to interact with crosslinker, and hence chemical modification is substantial to overcome this problem. This review aimed to present and discuss lignin structure, variation of lignin chemical properties regarding its source and extraction process, recent advances in chemical modification of lignin to enhance its reactivity, and potential applications of modified lignin for manufacturing value‐added biocomposites with enhanced properties and lower environmental impact, such as food handling/packaging, seed coating, automotive devices, 3D printing, rubber industry, and wood adhesives.

The present study investigates the aqueous stability of polyethylene glycol and oleic acid-based anionic surfactants through the dynamic light scattering (DLS) and zeta potential methods, for application in enhanced oil recovery (EOR). Polyethylene glycol dioleate sulfonate (PDOS) surfactant solutions were prepared in concentrations of 0.05, 0.1, 0.3, 0.5, and 1 wt% in deionized water. Aqueous stability of PDOS was assessed by measuring the droplet size over five days, using nano particle analyzer HORIBA SZ-100 at 25 o C. Results show that good aqueous stability of PDOS was achieved at concentrations of 0.1 to 1 wt%, but with the droplet size becoming unstable at the lowest concentration of 0.05 wt%. The polydispersity indices were classified into polydisperse distribution type recorded as 0.3 to 0.5 at concentrations of 0.05 and 0.1 wt% and 0.2 at concentrations of 0.3 to 1 wt%. The critical micelle concentration (CMC) of PDOS was 0.3% and the interfacial tension of PDOS surfactant above the CMC was around 10-3 dyn/cm. The zeta potential of PDOS surfactant without the addition of salt in concentrations of 0.05, 0.1, 0.3, 0.5, and 1 wt% was highly stable up to-96.8,-90.5,-89.6,-82.3, and-64.4 mV, respectively. With the addition of salt they were moderately stable at a concentration of 1 wt%. The conductivity increased with increasing concentration. The zeta potential of PDOS with the addition of salt was moderately stable in a concentration of 1%. Although PDOS with concentration of 0.05% showed a high value of zeta potential with the addition of salt, there is no guarantee that the PDOS surfactant solution will be stable for five days.

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