Thesis Type: Postgraduate
Institution Of The Thesis: Gazi University, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2022
Thesis Language: Turkish
Student: Nurcihan ÇANGA OYMAK
Supervisor: Nursel Dilsiz
Abstract:
Within the scope of the thesis study, it was aimed to synthesize chitosan (CH) and polycaprolactone (PCL) biopolymers and graphene oxide (GO), silane modified graphene oxide (fGO) and titanium dioxide (TiO2) nanofillers with different contents for usage in the field of food packaging. The experimental study was carried out in three stages. In the first stage of the study, graphene oxide was synthesized from graphite by the modified Hummer's method. In the second step, silane modified graphene oxide was obtained from graphene oxide by silanation method. In the final stage, PCL film, PCL/GO, PCL/fGO, PCL/GO/TiO2, PCL/fGO/TiO2 nanocomposite films and chitosan film, CH/GO, CH/GO/TiO2, CH/fGO, CH/fGO/TiO2 nanocomposite films were prepared by solution casting method. The properties of the synthesized nanocomposite films were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction method (XRD), surface wettability characterization, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), water absorption values and appearance analysis. While the addition of graphene oxide increased the water absorption value of the PCL film to the maximum value of 19.47%. The addition of TiO2 nanoparticles decreased the water absorption value of the films. Photographs of strawberries coated with PCL film and nanocomposite films at the end of the 21st day show that strawberries coated with PCL/fGO/TiO2 have the best appearance. Mold formation was not observed in bread covered with chitosan film and nanocomposite films for 50 days. As a result of the study, it was concluded that the use of the synthesized nanocomposite materials in the field of food packaging would be advantageous.
Key Words : Food packaging, bionanocomposite, polycaprolactone, chitosan,
graphene oxide, silane modified graphene oxide, titanium dioxide.