Synthesis and characterization of essential oil based antibacterial polymeric films

In our daily lives, bacteria with which we constantly come into contact survive under various conditions in different environments. These bacteria can be highly prevalent in diverse areas such as hospital materials, biomaterials, and food packaging. While some bacteria are beneficial, others possess infectious properties. Bacteria causing infections have become a clinical concern, prompting a shift towards natural alternatives due to the toxicity and carcinogenic effects of various chemicals used for prevention. Among these natural options, essential oils have been known for centuries but have recently gained significance through scientific research. Scientific studies have reported that essential oils can exhibit antimicrobial, antiviral, and antioxidant properties when used alone. When loaded onto polymer films, they find application in vastly different areas and maintain their antimicrobial activities. The aim of this thesis is to synthesize essential oil-based polymeric films using solvent casting technique by incorporating essential oils derived from herbal thyme and woody clove into polystyrene (PS), polycarbonate (PC), poly(lactic acid) (PLA), and poly(methyl methacrylate) (PMMA) polymers and to investigate the antibacterial activities of the obtained polymeric films. The surface properties of essential oil-based polymeric films were examined using optical microscopy, scanning electron microscopy (SEM), water contact angle, and surface free energy (SFE) analyses. Fourier-transform infrared spectroscopy (FTIR) analyses were utilized to elucidate the chemical structures of the essential oil-based polymeric films. The antibacterial activities of the polymeric films were tested against Escherichia coli (E. coli), a gram-negative bacterium, and Staphylococcus aureus (S. aureus), a gram-positive bacterium, using the agar disk diffusion method.