Effect of modified zinc oxide nanoparticles on enhancement of mechanical, thermal and antibacterial properties of disinfectant natural rubber latex foams

Natural rubber latex foams (NRLF) filled with unmodified zinc oxide (ZnO) and modified ZnO nanoparticles (ZnOnp) through the chemical coating on the calcium carbonate (CaCO3) are manufactured. This aimed to develop the mechanical, thermal, antibacterial properties of the NRLF for creating new innovative products and turn the NRLF to be the disinfectant NRLF. Various specific properties were considered, particularly the structure of modified ZnOnp and the antimicrobial activity of foams. It was found that the use of ZnOnp-coated CaCO3 at a ratio of 90:10 (ZnOnp-Ca10) indicated the highest of reinforcement efficiency, crosslink density based on the observed Mooney-Rivlin, and thermal stability. This related to the smaller particles, surface contacting area to the rubber chains, and shorter band gap in the activated states relative to the ZnO and unmodified ZnOnp. This NRLF had also the highest % inhibition of bacterial activity within 1 h by killing 94.01% of gram-native E.Coli bacteria. Relating the indication of the inhibition zone, NRLF filled with ZnOnp-Ca10 also showed strong effi- ciency for prohibiting the E.Coli and gram-positive S.Aureus bacteria. This affirmed the achievement of the disinfectant NRLF by using less ZnO purity in the foam which can support the preparation of other end rubber foam products.