Antibacterial Activity of Polyaniline Coated in the Patterned Film Depending on the Surface Morphology and Acidic Dopant

Novel Capturer-Catalyst Microreactor System with a Polypyrrole/Metal Nanoparticle Composite Incorporated in the Porous Honeycomb-Patterned Film

A composite of polypyrrole/metal nanoparticles (PPy/MNPs) was selectively incorporated into the pores of a honeycomb-patterned porous polycaprolactone polymer film to fabricate a novel capturer-catalyst microreactor system. This fabrication involved a modified breath figure method, where the polymer solution containing metal ions as an oxidizing agent was cast under humid conditions along with the pyrrole monomer through an interfacial reaction in a one-step in situ process. The higher hydrophilicity of the metal ions compared to the polymer solution led to their self-assembly around the pore surface, resulting in the selective incorporation of the PPy/MNP composite into the porous film. Copper (Cu), silver (Ag), and gold (Au) were used for the PPy/MNP fabrication. Various methods characterized the fabricated film. Strong catalytic degradations of methylene blue and methyl orange were obtained with PCL-PPy/MNPs. Recycling experiments showed no loss of activity even after five cycles of recycling. Comparative analysis of PCL-PPy, PCL-MNP, and PCL-PPy/MNP results indicated the synergistic action of PPy and MNPs in dye degradation. High-performance liquid chromatography and mass spectroscopy analyses confirmed dye degradation after treatment with a fabricated microreactor. PPy might have acted as a capturer of the dye molecule and MNPs as a catalyst, thereby enhancing the efficiency of dye degradation. Additionally, the PCL-PPy/Cu composite exhibited strong antimicrobial properties against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) with no cytotoxicity as measured by the MTT assay. Therefore, the fabricated microreactor film has promising applications in various fields.

Bismuth Vanadate Decked Polyaniline Polymeric Nanocomposites: The Robust Photocatalytic Destruction of Microbial and Chemical Toxicants

Functional materials have long been studied for a variety of environmental applications, resource rescue, and many other conceivable applications. The present study reports on the synthesis of bismuth vanadate (BiVO₄) integrated polyaniline (PANI) using the hydrothermal method. The topology of BiVO₄ decked PANI catalysts was investigated by SEM and TEM. XRD, EDX, FT-IR, and antibacterial testing were used to examine the physicochemical and antibacterial properties of the samples, respectively. Microscopic images revealed that BiVO₄@PANI are comprised of BiVO₄ hollow cages made up of nanobeads that are uniformly dispersed across PANI tubes. The PL results confirm that the composite has the lowest electron-hole recombination compared to others samples. BiVO₄@PANI composite photocatalysts demonstrated the maximum degradation efficiency compared to pure BiVO₄ and PANI for rhodamine B dye. The probable antimicrobial and photocatalytic mechanisms of the BiVO₄@PANI photocatalyst were proposed. The enhanced antibacterial and photocatalytic activity could be attributed to the high surface area and combined impact of PANI and BiVO₄, which promoted the migration efficiency of photo-generated electron holes. These findings open up ways for the potential use of BiVO₄@PANI in industries, environmental remediation, pharmaceutical and medical sectors. Nevertheless, biocompatibility for human tissues should be thoroughly examined to lead to future improvements in photocatalytic performance and increase antibacterial efficacy.

Antibacterial Performance of Protonated Polyaniline-Integrated Polyester Fabrics

During the last few years, there has been an increase in public awareness of antimicrobial fabrics, as well as an increase in commercial opportunities for their use in pharmaceutical and medical settings. The present study reports on the optimized fabrication of protonated polyaniline (PANI)-integrated polyester (PES) fabric. Para-toluene sulfonic acid (pTSA) was used to protonate the PANI fabric and thus grant it antibacterial performance. The results of a 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay showed high antioxidant activity of protonated PANI fabric at a scavenging efficiency of 84.83%. Moreover, the findings revealed remarkably sensitive antibacterial performance of PANI-integrated fabric against the following Gram-positive bacteria: methicillin-resistant Staphylococcus aureus (MRSA), S. epidermidis, and S. aureus; and also against the following Gram-negative bacteria: P. aeruginosa, E. coli, and S. typhi. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and energy dispersive X-ray fluorescence (EDXRF) were used to determine the changes in the structural and elemental compositions of PANI fabric upon treatment with bacterial strains. Electrochemical impedance spectroscopy (EIS) revealed that the electrical conductivity value of protonated PANI fabric decreased by one (1) order of magnitude against P. aeruginosa and S. aureus, from 3.35 ± 7.81 × 10-3 S cm-1 to 6.11 ± 7.81 × 10-4 S cm-1 and 4.63 ± 7.81 × 10-4 S cm-1, respectively. Scanning electron microscopy (SEM) analysis showed the disruption of bacterial membranes and their structures when exposed to protonated PANI fabric; meanwhile, thermogravimetric analysis (TGA) demonstrated that the fabric retained its thermal stability characteristics. These findings open up potential for the use of antimicrobial fabrics in the pharmaceutical and medical sectors.