Introduction/Objective: Antimicrobial cotton textiles are important for medical, protective, hygienic, and functional applications. This study aimed to develop a durable, costeffective two-step method for modifying cotton textiles with copper-containing nanoparticles while preserving mechanical strength and air permeability. Methods: Bleached cotton fabric was first treated using a TEOS-based sol-gel process to form a silica-containing coating. Copper-containing nanoparticles were then synthesized by glucosemediated reduction of CuSO₁ in an acidic aqueous medium and deposited onto the preformed coating. Nanoparticle morphology was evaluated by scanning electron microscopy (SEM). Modified textiles were characterized by SEM and FTIR spectroscopy and evaluated for tensile strength, air permeability, microbiological degradation resistance, antibacterial activity against Staphylococcus aureus, and antifungal activity against Aspergillus niger and Penicillium brevicompactum. Washing durability was assessed after five cycles. Results: The optimal synthesis conditions were 0.07 mol/L CuSO₁ and 0.03 mol/L glucose, producing predominantly spherical or quasi-spherical particles with apparent sizes of 44-106 nm. The modified fabrics showed pronounced antibacterial and antifungal activity, with maximum microbial suppression at 0.07 mol/L CuSO₁. Microbiological degradation resistance reached 98%, while breaking strength increased by up to 37%. Air permeability was maintained. After five washing cycles, microbiological performance decreased by only approximately 2%. FTIR confirmed formation of a silica-containing cellulose composite. Discussion: The TEOS-derived silica network provided a stable matrix for copper-containing nanoparticles, contributing to their retention, mechanical reinforcement, and washing durability while preserving breathability. Conclusion: The developed cotton textiles combine antimicrobial and antifungal activity, enhanced strength, preserved air permeability, high microbiological resistance, and washing durability. The simple two-step approach is promising for medical, protective, hygienic, and other functional textile applications.
Introduction: Magnetic nanofluids (MNFs) have attracted considerable attention as smart heat transfer fluids because their thermal conductivity can be actively tuned using an external magnetic field. However, existing correlations fail to accurately predict thermal conductivity over the entire range of magnetic field strengths, particularly beyond the critical magnetic field (CMF), where excessive nanoparticle aggregation leads to a gradual decline in thermal conductivity. This study aims to develop a semi-empirical correlation for predicting the magnetic-field-dependent thermal conductivity of the NiFeⁿO₁/water-based MNF system. Methods: NiFeⁿO₁/water-based MNFs containing nanoparticle concentrations of 0.5, 1, and 2 vol.% were prepared and stabilized with tetramethylammonium hydroxide. Their thermal conductivity was measured using the transient hot-wire method under various magnetic field strengths. Results: The thermal conductivity increased with increasing magnetic field strength up to the CMF, reaching a maximum enhancement ratio of 1.45 compared to the zero-field condition at 2 vol.%, after which it gradually decreased because of field-induced nanoparticle aggregation. Discussion: A power-exponential correlation was developed and validated against the measured data. The proposed correlation accurately reproduced the thermal conductivity over the entire investigated magnetic field range, yielding a low chi-squared value (χ² = 3.04 × 10⁸⁰) and a coefficient of determination of R² = 0.998. Conclusion: The proposed correlation provides a practical tool for predicting the thermal conductivity of NiFeⁿO₁/water-based MNFs under external magnetic fields. The model has potential applications in the design and optimization of magnetically assisted thermal management systems, including electronic cooling, solar thermal collectors, and magnetically controlled heat exchangers.
Coatings are the most common method for protecting metals from corrosion. The use of nano-sized coating materials can enhance the strength and decrease the porosity level of the developed coatings. The nano-coatings have shown improved mechanical properties, corrosion resistance, and wear resistance in recent studies. As a result, the use of nano-sized coatings can provide the benefit to the Industrial machinery components for longer operational periods. This review article covers the corrosion behavior of nano-structured coatings in the initial section followed by the role of artificial intelligence in predicting the corrosion rate of nanostructured coatings.
Introduction: Silver nanoparticles (AgNPs) have been widely recognized as effective antimicrobial agents for combating bacterial resistance. Methods: In this study, wastewater from Rosa canina oil distillation was utilized as a catalyst in the eco-friendly synthesis of AgNPs. As this waste has the potential to become enriched, ion-exchange column chromatography was used to prepare a polyphenol-enriched fraction from the wastewater. After evaluating the antioxidant activities (DPPH, FRAP, ORAC, NO scavenging, and comet assay) of fractions, the most potent antioxidant fraction was selected for the green synthesis of AgNPs. The AgNPs were synthesized using both chemical and green methods and optimized using Design-Expert® software based on particle size, polydispersity index (PDI), and zeta potential. Results: The optimized chemical (C-Ag-9) and green (G-Ag-1) synthesized nanoparticles displayed particle sizes of 84 and 52 nm, polydispersity indices (PDIs) of 1.9 and 1.4, and zeta potentials of -42.5 and -81 mV, respectively. The SEM-EDX analysis revealed weight percentages of 91.8% and 1.89% for the chemical (C-Ag-9) and green (G-Ag-1) synthesized AgNPs, respectively. The antibacterial activities of selected AgNPs were evaluated by determining inhibition zones on Pseudomonas aeruginosa media. When comparing two antibiotics, cefotaxime and chloramphenicol, as positive controls, G-Ag-1 results were significantly higher (p<0.0001) than C-Ag-9. Additionally, their ability to inhibit biofilm formation in Pseudomonas aeruginosa is significant when compared to ciprofloxacin. Discussion: These findings demonstrate that Rosa canina distillation wastewater constitutes a sustainable and valuable source of bioactive compounds for the green synthesis of AgNPs with enhanced antimicrobial efficacy. Conclusion: This wastewater can serve as an effective reducing agent. It would be a competitive alternative to chemical methods. These findings reveal the potential of valorized waste for the eco-friendly production of nanomaterials with promising antimicrobial and biomedical applications.
Introduction: Antimicrobial-resistant bacterial infections remain a significant public health concern, creating a need for new strategies to address this global problem. This study aimed to evaluate the antimicrobial activity of biogenic silver nanoparticles (Bio- AgNPs) synthesized using cell-free supernatant from the previously characterized probiotic Enterococcus durans strain against resistant bacterial strains. Methods: The antibacterial activity of Bio-AgNPs against vancomycin-resistant Enterococcus faecium (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) was evaluated based on bacterial growth (minimum inhibitory concentration [MIC] using resazurin staining), viability (minimum bactericidal concentration [MBC] using CFU/mL), and time-kill assays (CFU/mL). Antibiofilm activity was evaluated using crystal violet staining to assess biofilm biomass and the XTT assay to assess metabolic activity. The viability of sessile biofilmforming cells was determined by CFU/mL. Bacterial membrane permeability was assessed using propidium iodide (PI) staining. Results: Bio-AgNPs exhibited inhibitory activity, with MIC values of 1.5 μg/mL for VRE E. faecium and 3.1 μg/mL for MRSA S. aureus. The MBC of Bio-AgNPs was twice the MIC for both strains. Bio-AgNPs demonstrated bactericidal activity, with a significant reduction in the number of surviving cells at concentrations equal to or greater than 0.15 μg/mL for E. faecium and 0.7 μg/mL for S. aureus. The time-kill assay showed a marked reduction in viable cells following exposure to Bio-AgNPs at 1× MIC after 12 h. Reductions of up to 53% in biofilm biomass and 92% in metabolic activity were observed. Bio-AgNPs also significantly reduced the number of viable sessile cells within biofilms. Discussion: Bio-AgNPs synthesized using cell-free supernatant from E. durans exhibited bactericidal activity against the MRSA and VRE strains evaluated, with low MIC and MBC values and a concentration-dependent effect on bacterial growth and survival. Fluorescence microscopy with PI suggested compromised bacterial membrane integrity following Bio- AgNP treatment, indicating that membrane disruption may contribute to their antibacterial activity. Bio-AgNPs also reduced biofilm biomass, metabolic activity, and the number of viable sessile cells. These findings support further investigation of Bio-AgNPs as biogenic antimicrobial candidates. Conclusion: These findings demonstrate that Bio-AgNPs synthesized using cell-free supernatant from E. durans exhibited bactericidal and antibiofilm activity against the resistant strains evaluated in vitro, supporting their potential as biogenic antimicrobial candidates for further investigation.
