Background/Objectives: Autopolymerizing poly (methyl methacrylate) (PMMA) resin is widely used in provisional restorations; however, its inadequate mechanical properties represent a significant limitation. This study aimed to develop electrospun fibers with chemically reduced graphene oxide (rGO) and to evaluate the effect of fiber reinforcement on the mechanical and physical properties of a commercially available PMMA resin. Methods: Electrospinning was employed to produce nanofibers containing 0.02 wt% and 0.05 wt% rGO within a PMMA matrix. Fiber characterization was performed using SEM-EDS, XRD, TGA/DTG, and FTIR. Following characterization, the fibers were blended into PMMA resin at 1%, 2.5%, and 5% (by weight). The resulting fiber-reinforced composites were tested for flexural strength, elastic modulus, surface roughness, and Vickers microhardness. Results: The addition of 1% and 2.5% PMMA/rGO-0.02 fibers and 1% PMMA/rGO-0.05 fibers significantly improved the flexural strength of PMMA compared with the control group (p < 0.05). A statistically significant increase in elastic modulus was observed only in the group containing 1% PMMA/rGO-0.02 fibers (p < 0.05). However, there were no significant differences in surface roughness or microhardness between the control and experimental groups (p > 0.05). Conclusions: Incorporating electrospun PMMA-rGO fibers into PMMA resin enhances flexural properties at low concentrations without altering surface characteristics. These findings suggest that such fiber-reinforced systems hold promises for improving the mechanical performance and functional longevity of provisional dental restorations under clinical conditions.

The electrochemical behavior of (2E,5E)-2,5-dibenzylidenecyclopentanone (P1) and (2E,5E)-2,5-bis(4-nitrobenzylidene)cyclopentanone (P2) known as bis-chalcone derivatives was studied by cyclic voltammetry (CV) using an indium tin oxide (ITO) as the working electrode. Repeated cyclic voltammograms measurements exhibited excellent long-term redox stability for bis-chalcone derivatives. The oxidation peak for in the anodic region for the 1st cycle of the P1 appeared at -0.20 V, while the oxidation peak of P2 was observed at -0.47 V. On the other hand, the existence of the electron attracting NO2 group at p-position on the benzene ring in the structure of P2 caused an increase in the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy gap. The surface morphology and structural features of P1 and P2 films coated onto ITO glass substrates were investigated by using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). SEM micrographs demonstrated that the P1 and P2 were homogeneously distributed over the ITO surface. After CV measurement, it was observed that the grain size of P2 increased with increasing ITO surface roughness. Moreover, the EDS results confirmed the presence of P1 and P2 on the ITO surface.

Electrospun fibers are widely used in various applications such as tissue engineering, wound healing, drug delivery, materials science, chemical industry, energy storage, and sensor thanks to their combination of unique properties such as large surface area, high mechanical stability, high porosity, and great electrical conductivity. In addition, conducting polymers (CPs) used in fiber structures offer an extraordinary range of materials due to their diverse properties such as electrical and optical properties, the possibility of both chemical and electrochemical synthesis, and ease of processing. Among CPs, polythiophene (PTh) is highly important due to its unique redox electrical behavior, ease of synthesis, and application in many fields. In this study, 10 wt% polyacrylonitrile (PAN) fibers (P1), 10 wt% PAN/1 wt% PTh fibers (P2), and 10 wt% PAN/3 wt% PTh fibers (P3) were produced using an electrospinning technique. The structures, the morphologies and the electroactivities of the electrospun fibers were characterized by Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Thermogravimetric analysis (TGA), and Cyclic voltammetry (CV). FTIR, SEM-EDX and TGA results supported the presence of PTh in PAN fibers. The electrochemical behaviors of indium-tin-oxide (ITO) glasses coated with the P1, P2, and P3 fibers in phosphate buffer solution (PBS) at various concentrations were assessed by CV. These electrospun fibers containing PTh were used for phosphate anion sensing. For all fiber samples, the oxidation potential increased with a decreasing concentration of phosphate buffer solution. The obtained results indicated that the thermal stability and electrical conductivity of the fibers were affected by PTh. This study shows that PAN fibers containing PTh as anionic sensors can be used as new recognition models.

Bu çalışmada, kitosan (Ch)/poli(metil metakrilat) (PMMA) (K1), kütlece % 0.3 ibuprofen (Ibu) içeren Ch/PMMA (K2) ve kütlece % 0.6 Ibu içeren Ch/PMMA (K3) elektrospun fiberleri elektro-eğirme tekniği ile ilk kez elde edilmiştir. K2 ve K3 fiber yüzeylerinden ibuprofenin denetimli salımı kuvars kristal mikrobalans (QCM) sistemi ile incelenmiştir. QCM sonuçları, ultraviyole-görünür bölge (UV-Vis) absorpsiyon spektroskopisinin sonuçları ile karşılaştırılmıştır. Biyo-uyumlu fiberlerin morfolojik özellikleri taramalı elektron mikroskobu-enerji dağılım spektroskopisi (SEM-EDS) ile karakterize edilmiştir. İlaç salımına ait kinetik sonuçlardan en iyi ilaç salım mekanizmasının kütlece % 0.3 Ibu içeren Ch/PMMA çözeltisinden elde edilmiş olan K2 fiber yapısına ait olduğu ve bunun en ideal ilaç konsantrasyonu olduğu belirlenmiştir.

The aim of this study was to produce poly(methyl methacrylate) (PMMA)/zirconium oxide (ZrO2) electrospun composite fibers and to investigate the effect of ZrO2 addition on the properties of PMMA/ZrO2 fibers. A series of fibers with 10 and 15 wt% of PMMA containing different amounts of ZrO2 nanoparticles (1, 2.5 and 5 wt%) were produced at an optimal electric field potential. The chemical structure and surface morphology of the fibers were analyzed using SEM-EDS, XRD, and FTIR. The effect of ZrO2 nanoparticles addition on the thermal properties of the fibers was studied with TGA and DTG. The morphological observations showed that 2.5 and 5 wt% ZrO2 (PMMA-10/ZrO2-2.5 and PMMA-10/ZrO2-5) nanoparticles could be well-dispersed into 10 wt% PMMA polymer matrix due to the polymer chain interaction. The formation of fibers showed improvement with the increase in the amount of ZrO2 compared to PMMA-10 fibers. A quartz crystal microbalance (QCM) sensor was utilized to evaluate the behavior of materials coated with PMMA-10, PMMA-10/ZrO2-2.5, and PMMA-10/ZrO2-5 fibers at pH 7.0. The results indicated that the QCM electrode coated with PMMA-10/ZrO2-5 fibers performed better than PMMA-10/ZrO2-2.5 fibers.