Natural Rubber Latex Foam with ZnO Photocatalysts for Antibacterial Applications

Photocatalysts are promising materials that can easily convert solar energy for use in oxidation and reduction activities. ZnO photocatalysts with different shapes and sizes were incorporated in natural rubber latex foam (NRLF). The structures of ZnO powders were investigated by X-ray diffraction (XRD). ZnO powders were added as the primary gelling agent by replacing the commercial ZnO particles. In contrast, the control sample of the NRLF was made without adding any ZnO particles. The morphological appearances of NRLF with ZnO materials were evaluated by optical microscopy (OM) and scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). To investigate the mechanical properties, a uniaxial compression test was performed using a low-force electromechanical universal testing machine (UTM). The antibacterial activities of the modified NRLF with ZnO samples were evaluated qualitatively by antibacterial susceptibility tests against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) bacteria. It was found that XRD peaks of all ZnO samples matched perfectly with the hexagonal wurzite ZnO (the Joint Committee on Powder Diffraction Standards (JCPDS), International Centre for Diffraction Data, card number 01-089-1397). The average pore size given by OM image analysis is approximately 200-250 micrometers. The pores were proven by SEM and EDS. After carrying out the bacteria experiment, NRLF with ZnO photocatalysts was found to have antibacterial properties. The influence of shapes and sizes of ZnO photocatalysts was studied and will be reported.