Enhanced antimicrobial activity of photocatalytic titanium oxide upon formation of composites with polyaniline via an eco-friendly and facile microwave synthesis approach.

This study proposes inexpensive antimicrobial polyaniline-titanium oxide (PANI-TiO 2) samples prepared through eco-friendly enhanced microwave (MW) synthesis with 93 W applied over 10 min in aqueous 1.25 M hydrochloric acid media (HCl) using potassium iodate (KIO 3) as oxidising agent, an approach suitable for industrial scale up production of PANI polymers at room temperature. The PANI-TiO 2 samples are produced in the presence of 5–20 wt% of TiO 2 in the initial reaction mixture along with aniline monomer by both the enhanced MW method and a classical chemical synthesis (CS) method at room temperature. The nanocomposites showed lower conductivity than pure PANI, slightly higher conductivity was observed in the MW prepared PANI-TiO 2 in comparison to CS prepared PANI-TiO 2. This result can be correlated with the observation that the optical absorbance of MW PANI-TiO 2 samples were notable higher than for CS PANI-TiO 2 , which may be due to the presence of a greater amount of polarons present in the samples prepared by the enhanced MW method. MW PANI-TiO 2 samples were equally active against both Gram-negative E. coli and Gram-positive S. aureus bacteria, in contrast to the CS PANI-TiO 2 samples, which could be due to presence of short-chain fragments in the CS samples as confirmed by Fourier-transform infrared (FTIR) spectroscopy. The incorporation of PANI particles in TiO 2 showed enhanced antimicrobial activity compared to pure TiO 2 , with greater antifungal activity. Our study indicates that a facile, low-cost, and green enhanced MW method can be used for preparation of the advanced antimicrobial PANI-TiO 2 nanocomposites for biomedical applications. [Display omitted] [ABSTRACT FROM AUTHOR]