(623b) Ecofriendly Lignin Nanoparticles for Oil-Spill Remediation

Oil spill on the ocean and coastal waters has adverse impact on marine life and other related ecosystems. Oil-herding is one of the most promising methods of managing such large-scale oil-spills. In this herding process, a liquid solution of an amphiphile is added to the oil-slick, which confines the oil to a small pile. This oil pile can be further burnt leaving behind an oil-free surface. Currently used silicone-based oil herding agents are non-degradable and have toxic impact on the surrounding environment. Therefore, it is eminent to develop new dispersants and formulations of biocompatible amphiphiles with improved oil-herding properties and minimum environmental impact. Lignin is one such naturally derived biopolymer where its microbial decomposition in the environment transforms it into non-toxic low-molecular weight sub units. Here, we will introduce lignin nanoparticle dispersions as a new class of eco-friendly alternative for oil-spill remediation. Here, we will quantify the affinity of lignin nanoparticles to oil-water interface using the adsorption isotherms. The adsorption dynamics will be presented in terms of time-dependent dynamic interfacial tension measurements as function of lignin concentration and salinity. This dynamic measurement will allow estimating the interfacial pressure and kinetics of lignin binding to the interface, which is crucial for efficient oil-herding. We will also present the origin of long-term stability in terms of structuring of the lignin nanoparticles at oil-water interface by determining the interfacial-rheological properties. The fundamental principles presented here will lay a foundation for fabricating next generation of eco-friendly oil-herders using lignin materials and other biocompatible amphiphiles.