WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Article Citation - WoS: 3Citation - Scopus: 2Design and Evaluation of Novel Poly (Vinyl Alcohol)-Based Electrospun Nanofibers Bearing Quaternized Zinc Phthalocyanine with Improved Antibacterial Efficiency(Elsevier Sci Ltd, 2025) Yavuz, Ozgur; Cakir, Neslihan Turhan; Alcay, Yusuf; Kadi, Ilayda Hizir; Kahveci, Muhammet U.; Yilmaz, Ismail; Altinkok, CagatayElectrospinning of macrocyclic compounds offers a versatile route to functional nanofibers for biomedical applications. However, the small molecular size and tendency to aggregate of such compounds often preclude their direct processing. Herein, we report the fabrication of poly(vinyl alcohol) (PVA) nanofibers uniformly embedded with a dimethylaminophenyl-functionalized, quaternized zinc phthalocyanine derivative (Q-DMAPZnPc) via a straightforward aqueous electrospinning process. Successful incorporation of Q-DMAPZnPc into the PVA matrix was confirmed by FT-IR and 1H NMR spectroscopies. SEM revealed bead-free fibers with average diameters decreasing from 152 +/- 20 nm to 110 +/- 23 nm as the Q-DMAPZnPc loading increased. Water contact angle, thermogravimetric, and differential scanning calorimetry analyses demonstrated that both hydrophilicity and thermal stability of the fibers improved with higher Q-DMAPZnPc content. The singlet oxygen quantum yield (Phi Delta) of the PVA-Q-DMAPZnPc (5 wt %) was measured as 0.35. Importantly, quaternization endowed the fibers with potent antibacterial activity: under visible-light irradiation, PVA-Q-DMAPZnPc mats achieved significant log-reduction against both Gram-negative (Escherichia coli, Salmonella typhimurium) and Gram-positive (Staphylococcus aureus, Bacillus cereus) pathogens, markedly outperforming neat PVA controls. These findings highlight the promise of Q-DMAPZnPc-loaded PVA nanofibers as light-activated antimicrobial platforms for next-generation therapeutic and protective materials.Article Citation - WoS: 7Citation - Scopus: 7Improving Mechanical Behavior of Adhesively Bonded Composite Joints by Incorporating Reduced Graphene Oxide Added Polyamide 6,6 Electrospun Nanofibers(Elsevier Sci Ltd, 2024) Yeke, Melisa; Barisik, Murat; Tanoglu, Metin; Ulas, M. Erdal; Nuhogu, Kaan; Esenoglu, Gozde; Iris, M. ErdemAdhesive joining of fiber-reinforced polymer (FRP) composites requires adequate interface tailoring and careful surface preparation to obtain a strong bond between components. This study aimed to improve the mechanical performance of adhesively bonded unidirectional carbon fiber-based (CFRP) composite parts by modifying joint surfaces with graphene-added electrospun Polyamide 6,6 (PA66) nanofibers. Reduced graphene oxide (rGO) was dispersed at 10 % wt/v PA66 solution at three different concentrations below rGO saturation limits. Bead-free nanofibers with homogenous graphene distribution were obtained on a prepreg by electrospinning. Addition of up to 2 % rGO yielded complete dispersion through the nanofiber network while the higher values created local agglomerations. Surface wetting experiments showed conversion of slightly hydrophobic surfaces to complete hydrophilic with electrospun nanofiber coating and the lowest contact angle was obtained at 2 % wt/v rGO addition (26.18 degrees +/- 2.03 degrees). Composite plates were produced in a hot press keeping the modified prepregs on top. Plates with different surface treatments joined by secondary bonding using 3 plies of FM 300 K film adhesive. Mechanical properties of adhesively bonded composites were tested by Single lap joint and Charpy impact tests. We achieved an 18 % increase in shear strength and 31 % increase in impact strength by adding 2 % wt/v ratio rGO into PA66 electrospun nanofiber.
