Developing tailored lignin-based nanomaterials for environmental friendly applications within integrated biorefinery concept

Abstract

Lignin is a three-dimensional amorphous structure composed of phenylpropane units derived from oxidative coupling reactions involving p-coumaryl, coniferyl and sinapyl alcohols. Its aromatic nature variety of available functional groups for derivatization, and its ability to participate in radical-mediated cross-linking reactions make it attractive to obtain tailored materials from, matching various specific applications. The expansion of biorefinery activities to produce renewable fuels and chemicals from lignocellulosic biomass can considerably increase the amount of available lignin, currently underused to generate heat and electricity, as an ingredient in adhesives, or additive in cement. Thus, it is crucial to develop strategies that explore lignins to their full potential and generate additional revenue for biorefineries while improving the economic feasibility of the whole process. Despite the numerous value-added applications, the complex and heterogeneous chemical structure, low solubility and reactivity have been considered as important factors that impar lignin utilization Among the different biological and chemical approaches that can be exploited, lignin-based nanomaterials are considered a promising field of application. In this context, the aim of this study is design defined modifications on biorefinery lignins in order to generate novel lignin-based nanomaterials e.g. lignin nanoparticles with distinct functionalities that can improve the interaction with enzymes, aid in bioactive compounds entrapment, or be delivery vehicles for small molecules and stabilizers agents. Different lignin-rich streams obtained from sugarcane straw processing for biofuel production will be explored. The main goal is modifying the functionality of biorefinery lignins with respect to their surface functional groups, zeta-potential, size and hydrophobicity. Then, to systematically characterize these novel nanomaterials by using different techniques and to investigate the relationship between performance of the resulting nanomaterials and their interaction with target molecules.