3 results
Search Results
Now showing 1 - 3 of 3
- The demand for multifunctional nanocomposites with superior electrical, dielectric, and antimicrobial properties has driven the development of polymer-graphene hybrid materials. This study investigates polyvinylpyrrolidone (PVP)-graphene nanocomposites with varying graphene concentrations (1–20 wt%) synthesized via the solution casting method, focusing on their electrical, dielectric, and antimicrobial properties. Structural and morphological characterizations confirm successful graphene incorporation and dispersion within the polymer matrix. Impedance spectroscopy reveals significant enhancements in electrical and dielectric properties, with a percolation threshold observed at 10 wt% graphene loading. The optimized composition, i.e., PVP-10 wt% graphene nanocomposite, demonstrates a significant enhancement in AC electrical conductivity (~ 3.70 × 10− 6 S/m at 1kHz) compared to pure PVP (~ 3.40 × 10− 7 S/m 1 KHz) exhibiting an enhancement of >10 times, facilitated by the development of a conductive network within the PVP matrix. Dielectric analysis reveals frequency-dependent behavior for both the real and imaginary parts of the electrical modulus, with variations observed based on graphene content. Furthermore, electromagnetic interference (EMI) shielding effectiveness (SE) was about 20 dB (frequency range: 1 kHz – 8 MHz) for PVP-10 wt% graphene nanocomposite, demonstrating the potential for shielding applications. The nanocomposites also exhibit enhanced antimicrobial efficacy against E. coli and S. aureus, with inhibition zones increasing with graphene content. These findings highlight the potential of PVPgraphene nanocomposites as multifunctional materials for electronics, biomedical coatings, and EMI shielding. The study provides crucial insights into the structure-property relationships, enabling the rational design of polymer-graphene composites for next-generation applications.
- 1
- 4
- 0
- Metal oxide nanoparticles (MONPs) have been increasingly reported to possess diverse industrial and biomedical applications. Herein, we synthesized secondary (CuO, Fe2O3 (FeO), ZnO), ternary (ZnO/CuO-FeOx) and quaternary (ZnO-CuO-FeOx) co-assembled core-shelled MONPs by (co-) precipitation technique, characterized the synthesized MONPs and consequently investigated their antibacterial capacity. The UV-Vis absorption spectra of the prepared MONPs presented experimental band gaps; ZnO of 3.36 eV; ZnO-FeOx (x ¼ 0.1; x ¼ 0.5) with 3.38 eV and 3.37 eV; and ZnO-FeOx-CuOx (x ¼ 0.1; x ¼ 0.5) of 3.36 eV and 3.36 eV band gaps respectively. Thermogravimetric analysis revealed the stability of the prepared MONPs, by the presented total mass lost (%):ZnOFeO0.5 (1.34) > ZnOFeO0.1 (1.93) > ZnOFeO0.1CuO0.1 (2.12) > ZnOFeO0.5CuO0.5 (2.34) >CuOFeO0.1 (3.78) > CuOFeO0.5 (4.25) > Fe2O3 (4.44) > CuO (6.37) > ZnO (8.69). The XRD peak positions of the secondary MONPs prepared presented hexagonal structures for ZnO, monoclinic structures for CuO and rhombohedral structures for Fe2O3 without identified impurity peaks. Finally, the co-assembled MONPs prepared showed that they possessed varied efficiency for protection from different bacterial strains, with Staphylococcus.pneumonia growth being the most inhibited, with MONPs treatments CuO > ZnOFeO0.5CuO0.5 > CuOFeO0.5 > ZnOFeO0.1CuO0.1 >Fe2O3 > ZnOFeO0.5 > ZnO.
- 1
- 21
- 0
- 2021| ElsevierFabrication of polymer-based nanocomposites for numerous biomedical applications represents a predominant form of therapeutics for combating microbial and bacterial infections. Herein, we firstly synthesized metal oxide nanoparticles (MONPs) by previously reported precipitation methods. Hydrogel nanocomposites were then prepared by free radical polymerization of a combination of the synthesized MONPs, polyvinylpyrrolidone (PVP) and acrylamide. The hydrogel nanocomposites were characterized by FTIR, XRD and investigated for potential antibacterial protection. FTIR spectra of the prepared hydrogel nanocomposites revealed significant characteristic peaks of the distinctive MONPs within the polymer matrix. XRD micrographs revealed slight shifting of peak positions in nanocomposites; the change in peak intensity, coupled with the observed slight shift in the diffraction peaks of both CuO and ZnO nanoparticles confirmed the successful incorporation of the MONPs into the polymer matrix. The presence of the MONPs, in combination with PVP, displayed a synergistic antibacterial activity, with increasing concentration of the MONPs. The treatment against S.pneumoniae, revealed a zone of inhibition phenomenon which showed zones of PVP-5 > PVP-8 > PVP-6 > PVP-9 > PVP-7. PVP-1, PVP-2, PVP-3, PVP-4 did not show any significant zone of inhibition on treatment due to the quantity of MONPs present. The findings show that the hydrogel nanocomposites are potential topical wound dressing materials for the management of bacterial infections.
- 1
- 20
- 0