Yazar "Kara, Ali" seçeneğine göre listele

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  • Küçük Resim Yok
    Öğe
    Activation of Polypropylene (PP) Fiber Surface with 1-Vinyl-1,2,4-triazole and Vinyl Acetate: Synthesis, Characterization, and Application in Cementitious Systems
    (Mdpi, 2025) Kaya, Yahya; Balci, Petek; Ozen, Suleyman; Mardani, Ali; Kara, Ali
    Recently, the potential of recycled materials to improve the performance of concrete and other building materials has become an important research topic. It is known that various methods are applied to improve the tensile strength and energy absorption capacity of cementitious systems. One of the most common of these methods is the addition of fibers to the mixture. In this study, the effects of surface-modified polypropylene (PP) fibers obtained from recycled masks on the mechanical properties of mortar mixtures were investigated. In order to improve the matrix-fiber interface performance, 6 mm and 12 mm long recycled PP fibers were chemically coated within the scope of surface modification using 1-Vinyl-1,2,4-Triazole and Vinyl Acetate. With this modification made on the surface of PP fibers, we aimed to increase the surface roughness of the fibers and improve their adhesion to the matrix. Thus, we aimed to increase the mechanical properties of mortar mixtures as a result of the fibers performing more effectively in the concrete matrix. FTIR AND SEM-EDS analyses confirmed the success of the modification and the applicability of 1-Vinyl-1,2,4-Triazole and Vinyl Acetate to the fiber surface and showed that the fibers were successfully modified. It is seen that the fibers modified with Vinyl Acetate exhibit superior performance in terms of both the workability and strength performance of cementitious systems compared to the fibers modified with 1-Vinyl-1,2,4-Triazole. This study provides a significant contribution to sustainable construction materials by revealing the potential of using recycled materials in cementitious systems.
  • Küçük Resim Yok
    Öğe
    Manyetik ve fotokatalitik polimer tanecikleri ile atık suların renksizleştirilmesi ve yeniden kullanım denemeleri
    (İdris Karagöz, 2025) Turan, Şeyma Yalçın; Kara, Ali; Uygun, Gizem Bayaçlı; Özyurt, İrem
    Tekstil endüstrisi, yüksek istihdam potansiyeli ve sürekli yenilik ve gelişim fırsatlarıyla birçok ülke için kritik bir sektördür. Ancak, bu sektör aynı zamanda su tüketimi açısından da en büyük tüketicilerden biridir. Bu çalışmada, tekstil endüstrisinde oluşan renkli atık suyun renksizleştirilmesi için manyetik ve fotokatalitik özelliklere sahip polimer tanecikler sentezlendi ve atık su arıtma deneyleri gerçekleştirildi. Polimer tanecikler, süspansiyon polimerizasyon yöntemiyle sentezlendi ve SEM , FTIR, BET ve ESR ile karakterize edildi. Bu tanecikler, Karesi polyester şirketinden alınan atık suyun renksizleştirilmesinde adsorpsiyon ve heterojen fotokataliz yöntemleri bir arada kullanıldı. Deneyler üç döngü boyunca tekrarlandı. İşlemlerin ardından, renksizleştirilmiş sularla boyama deneyleri yapıldı. Sonuçlar, %99,68'e kadar uzanan giderim verimliliklerini gösterdi. Bu, polimer taneciklerin su arıtımı için etkili, çevre dostu ve yenilikçi bir yöntem olarak kullanılabileceğini göstermektedir.
  • Küçük Resim Yok
    Öğe
    Modification of Polypropylene Fibers with Sodium Silicate: Enhancement of Pozzolanic Properties in Cement-Based Systems
    (Mdpi, 2025) Kaya, Yahya; Balci, Petek; Ozen, Suleyman; Mardani, Ali; Kara, Ali
    This study investigates the effect of sodium-silicate-based chemical surface modification of polypropylene (PP) fibers on the mechanical and fresh-state properties of cementitious composites. The proposed method introduces silanol and siloxane groups onto the PP surface through a radical-assisted chlorination route, aiming to enhance fiber-matrix interfacial bonding. Modified fibers increased the polycarboxylate ether (PCE) demand by 100% compared to the control mixture, while unmodified PP fibers caused a 58% increase at equivalent workability. The incorporation of PP fibers resulted in limited changes in compressive strength (1-7%), whereas silicate-modified fibers led to notable late-age flexural strength gains of 10% (28 days) and 17% (56 days). Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Fourier Transform Infrared Spectroscopy (FTIR) analyses confirmed successful surface functionalization, while the heterogeneous silicate deposition still contributed positively to interfacial transition zone (ITZ) performance. Overall, sodium-silicate-modified PP fibers improve flexural behavior and interfacial bonding in cement-based systems, offering a promising approach for enhanced mechanical performance and sustainability.