Synthesis, Characterisation and Antibacterial Properties of Silicone-Silver Thin Film for the Potential of Medical Device Applications

Highly Durable Antibacterial Textiles: Cross-Linked Protonated Polyaniline-Polyacrylic Acid with Prolonged Electrical Stability

This study addressed the limited antibacterial durability of textile materials, which has suppressed their applications in preventing infectious disease transmission. A class of highly durable antibacterial textiles was developed by incorporating protonated polyaniline (PANI) textile with poly(acrylic acid) (PAA) as the functional binder via cross-linking polymerization. The resulting PAA-PANI textile exhibits exceptional electrical conductivity, reaching 8.33 ± 0.04 × 10-3 S/cm when cross-linked with 30% PAA. Remarkably, this textile maintains its electrical stability at 10-3 S/cm even after 50 washing cycles, demonstrating unparalleled durability. Furthermore, the PANI-PAA textile showcases remarkable antibacterial efficacy, with 95.48% efficiency against Pseudomonas aeruginosa and 92.35% efficiency against Staphylococcus aureus bacteria, even after 50 washing cycles. Comparatively, the PAA-PANI textile outperforms its PANI counterpart by achieving an astounding 80% scavenging activity rate, whereas the latter only displayed a rate of 3.22%. This result suggests a solid integration of PAA-PANI into the textile, leading to sustainable antioxidant release. The successful cross-linking of PAA-PANI in textiles holds significant implications for various industries, offering a foundation for the development of wearable textiles with unprecedented antibacterial durability and electrical stability. This breakthrough opens new avenues for combating infectious diseases and enhancing the performance of wearable technologies.

Enhancing the Washing Durability and Electrical Longevity of Conductive Polyaniline-Grafted Polyester Fabrics

The demand for wearable electronics has driven the development of conductive fabrics, particularly those incorporating polyaniline (PANI) that is known for its high electrical conductivity, flexibility, and ease of fabrication. However, the limited stability and durability of the conductive fabric, especially during washing, present significant challenges. The drawbacks can be traced by weak physical attachment between the fabric and the conductive coating, leading to a decrease in conductivity over time. These drawbacks significantly impact the fabric's functionality and performance, highlighting the need for effective solutions to enhance its stability and durability. This study focuses on addressing these challenges by employing a thermochemical treatment. A hydrophilic surface of the polyester fabric is obtained after the treatment (hydrolysis), followed by grafting of PANI on it. The adhesion between PANI and the polyester fabrics was found to be enhanced, as proved by contact angle analysis. Furthermore, the PANI-hydrolyzed fabrics (treated) demonstrated stable conductivity (∼10-3 S cm-3) even after 10 washing cycles, showcasing their excellent durability. In comparison, the unhydrolyzed PANI fabric experienced a drop in conductivity by three orders of magnitude. X-ray photoelectron spectroscopy via N 1s core line spectra showed chemical shifts and quantified the level of doping through PANI's protonation level. We found that PANI-hydrolyzed fabrics preserved their dedoping level from 44.77 to 42.68%, indicating improved stability and extension of their electrical properties' lifetime after washing as compared to unhydrolyzed (untreated) fabrics, from 36.99 to 26.61%. This investigation demonstrates that the thermochemical approach can effectively enhance the durability of conductive PANI fabrics, enabling them to withstand the washing process while preserving their electrical endurance.

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.