Recycling resources is essential to mitigate greenhouse gas emissions that cause climate change. In this thesis, cellulose nanofibers (CNFs) are isolated from dairy packages by utilizing ionic liquid (IL) and aqueous counter-collision (ACC) methods, and applied for preparing films. The IL separates the laminated plastic and pulp of dairy packages. After this, ACC treatment isolates CNFs from the dairy package pulp. The isolated CNF suspension is used to fabricate the CNF film through the drop-casting method, and a triboelectric nanogenerator is fabricated with the recycled CNF film to verify its energy-harvesting performance. The mechanical properties and light transmittance of recycled CNF film are lower than those of conventional CNF film made from hardwood pulp. Still, its thermal stability, hydrophobicity, and energy-harvesting performance are better. The FTIR spectroscopy, XRD analysis, XPS analysis, and morphology observation explain these phenomena.
A bio-based vanillin epoxy resin is coated on the CNF film to enhance its surface properties further. The vanillin epoxy (VE) resin is prepared by mixing VE and hardener 4,4'-diamino diphenylmethane for coating. The CNF film is fabricated utilizing the drop-casting method from the hardwood CNFs. After the fabrication of the CNF film, the VE is coated on it using the dipping method. The coating thickness is around 5~10 μm. The interaction of VE with CNF film and the curing of the coated CNF film are characterized by FTIR spectroscopy. In addition, mechanical properties, morphologies, thermal analysis, and wettability behavior are studied. A triboelectric nanogenerator is fabricated with the VE resin-coated CNF film, and its energy harvesting performance is also evaluated. The CNF films can be applied to environmentally friendly food packaging, UV-shielding, and energy harvesters.