Structural, dielectric, thermal, antioxidant activity, and antibacterial efficiency of electrospun PVA/PVP/TiO2-GO nanocomposites
Journal of Molecular Liquids, cilt.448, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 448
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.molliq.2026.129360
- Dergi Adı: Journal of Molecular Liquids
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Dielectric and antimicrobial properties, Electrospinning, Graphene oxide, PVA-PVP nanocomposite fibers, Thermal stability, TiO2 nanowires
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
Electrospun nanofiber composites based on PVA/PVP incorporating TiO2 nanowires and graphene oxide (GO) were fabricated, and the effects of GO loadings (0.5%, 1%, and 2%) on their structural, surface/interface, thermal, dielectric, and biological properties were systematically investigated. FTIR analysis confirmed hydrogen bonding and coordination interactions between GO/TiO₂ and polymer chains, while XRD verified the anatase phase of TiO₂ and revealed changes in polymer crystallinity. SEM images showed a marked reduction in average fiber diameter, from 396 to 122 nm, with increasing GO, and improved morphological uniformity. Surface characterization by contact angle and surface free energy analyses revealed a gradual increase in hydrophobicity, with the water contact angle rising from 38.9° for the PVA–PVP/TiO2 nanocomposite to 43.1° for the sample containing 2 wt% GO, accompanied by a reduction in surface free energy from 60.25 to 58.97 mN/m. These changes indicate the formation of more stable, low-energy interfaces, which are highly desirable for durable coating applications. Thermal analysis revealed enhanced stability, with the temperature corresponding to 50% weight loss (T₅₀) increasing from 315 to 342 °C, and the glass transition temperature rising from 118 to 131 °C at a 2 wt% GO loading. Dielectric measurements revealed an increase in dielectric constant (from 1.9 to 2.7 at 1 kHz) and AC conductivity (up to 7.5 × 10−6 S/cm at 1 MHz), confirming the role of GO in enhancing charge transport. Biological assays further demonstrated improved antioxidant activity through enhanced DPPH radical scavenging and increased antibacterial efficiency, particularly against Gram-negative strains. Overall, the incorporation of GO led to systematic improvements in the structural uniformity, dielectric response, thermal stability, antioxidant activity, and antibacterial efficiency of the PVA–PVP/TiO2 nanocomposites. These results demonstrate that controlled GO loading is an effective strategy for tailoring the functional properties of electrospun polymer-based nanocomposites.