# Preparation and Characterization of Antibacterial Polyvinyl Alcohol Films Containing Syzygium aromaticum Essential Oil

## TL;DR

This study creates antibacterial PVA films using clove essential oil, which shows increased effectiveness against Klebsiella pneumoniae as the oil concentration increases.

## Contribution

The novel use of Syzygium aromaticum essential oil as a plasticizer and antibacterial agent in PVA films is demonstrated.

## Key findings

- SAEO acts as an effective plasticizer, increasing polymer chain mobility and lowering the glass transition temperature.
- Antibacterial efficacy of the films increases with higher concentrations of clove essential oil.
- Molecular docking suggests interactions between clove oil components and K. pneumoniae virulence proteins.

## Abstract

The resistance of pathogenic bacteria to antimicrobial agents is currently one of the most significant health challenges. Polymers and nano-polymer composites with antimicrobial properties are widely used, particularly in hospitals, biocompatible implants, and the medical device industry. Syzygium aromaticum (clove) contains several bioactive compounds, including potent antioxidants and antimicrobials, which confer antioxidant, antibacterial, and antiseptic properties. For this purpose, polyvinyl alcohol (PVA) films were produced at three different concentrations using a direct integration method and doped with clove essential oil. The spectral, structural, and thermal properties of the produced films were analyzed, and their antibacterial activity against Klebsiella pneumoniae was tested. Fourier Transform Infrared Spectroscopy (FTIR) results confirm that the structural integrity of the PVA matrix is preserved and that the essential oil is physically trapped within the polymer network. Overall, the Differential Scanning Calorimetry (DSC) results confirm that Syzygium aromaticum essential oil (SAEO) acts as an effective plasticizer in PVA films, significantly modifying the glass transition behavior and enhancing polymer chain mobility in a concentration-dependent manner. The Dynamic Mechanical Analysis (DMA) results, supported by DSC analysis, clearly demonstrate that SAEO acts as an effective plasticizing agent in PVA films by increasing molecular mobility, lowering the glass transition temperature (Tg), and promoting thermally induced deformation. The concentration-dependent increase in the diameter of the inhibition zone of essential-oil-added films showed that their antibacterial efficacy increased as the S. aromaticum essential oil content increased (0.5%, 0.75%, and 1.0%). Additionally, molecular docking was performed to examine interactions between selected virulence proteins of K. pneumoniae and the main components of clove essential oil. As a result, S. aromaticum essential oil conferred antibacterial properties to the polyvinyl alcohol films without significantly altering their transparency and thermal properties.