In the first chapter, we discuss various techniques and strategies used to synthesize lignin-derived functional materials. The transformation of lignin during pyrolysis and hydrothermal carbonization is also reported. Furthermore, current applications and surface properties of lignin-based carbonaceous materials in the fields of catalysis, bio-absorption removal of pollutants, and supercapacitors are summarized. The second chapter focuses on using electromembrane extraction with high performance liquid chromatography (HPLC) for preconcentration and determination of ampicillin residues in cow milk. In the third chapter, step growth polymerization or polycondensation has been used as an efficient pathway to synthesize polymers with high thermal stability. The resulting materials have different industrial applications. For instance, they can be used as coatings or films in industries, where the materials should be stable in very high temperature (above 500 °C).