Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Synthesis of Pristine Chitosan Foams with Enhanced Pore Structure, Surface Area, and Mechanical Strength for Tissue Engineering Applications
    (Iop Publishing Ltd, 2025) Polat, M.; Cropper, Chelsea; Ozdamar, A. B.; Polat, H.
    With its excellent biocompatibility, biodegradability, and antimicrobial activity, chitosan is a promising scaffold material for hard-tissue engineering. Yet, pristine chitosan foams typically lack the strength and porosity required for such use. Here we present a simple emulsion-templating approach to fabricate pristine chitosan foams with optimized strength and porosity. Sodium dodecyl sulfate (SDS), a widely used biocompatible anionic surfactant, was employed at trace levels to aid polymerization. The foams display a dual-scale pore morphology. Cavities of 150-300 mu m are separated by around 50 mu m thick chitosan walls containing large interconnecting openings. The walls are further populated with meso- and macropores of 50-500 nm. This architecture should support cell attachment and growth, facilitate proliferation, and enhance nutrient transport and metabolic exchange. The structure yields high surface area (up to 10 m2 g-1). Mechanically, the thick-walled cavities impart both elastic recovery and high compressive resistance (255 kPa at 40% strain from foams polymerized with 4% chitosan). A preliminary drug-release study using vancomycin confirmed excellent loading and sustained release.
  • Article
    Performance of Sheet Pile Walls With Rubber-Modified Backfill
    (Springer, 2025) Ecemis, Nurhan; Kadekeshova, Kuralay; Khlaif, Ali Hamid
    This study investigates the behavior of clean sand and sand-rubber mixtures used as backfill materials behind sheet pile walls under vertical loads. Physical model experiments were conducted to assess lateral displacement and pressure for backfills containing 10% granulated rubber (2.5-5 mm) under both dry and saturated conditions, and across varying backfill inclination angles. To complement the experiments, discrete element method (DEM) simulations were performed to capture the micromechanical behavior of sand-rubber mixtures, enabling analysis of particle-scale interactions. Material stiffness and friction parameters were calibrated through direct shear tests to ensure computational efficiency and accurate representation. Comparative analyses were conducted between the DEM simulations and the physical sheet pile tests across various sand-rubber backfill configurations. The results suggest that sand-rubber mixtures offer a practical and sustainable alternative for backfill applications, improving both mechanical performance and pressure mitigation. Furthermore, force chain development and deformation patterns were thoroughly examined to understand the role of micro parameters; such as particle contact behavior, porosity, internal friction, and stiffness of the rubber-sand composite backfill in reducing active earth pressure against sheet pile walls.
  • Article
    Silver-Loaded Titania-Based Metal-Organic Frameworks as a Platform for Silver Ion Release for Antibacterial Applications
    (American Chemical Society, 2025) Mazare, Anca; Goldmann, Wolfgang Heinrich; Kocak, Esra; Osuagwu, Benedict; Qin, Shanshan; Cao, Ran; Schmuki, Patrik
    Conventional Ag-decorated TiO<inf>2</inf>coatings suffer from low adsorption capacity and burst release kinetics, limiting long-term antibacterial efficacy and risking cytotoxicity. An entirely different payload release approach can be based on metal–organic frameworks (MOFs), which offer tunable porosity, high surface area, and internal diffusion channels. Here, we report a thermally stabilized Ti-based MOF [NH<inf>2</inf>-MIL-125(Ti)] functionalized with Ag+via reactive deposition, enabling high Ag loading (∼14.7 wt %) and sustained release. Annealing at 250 °C enhances aqueous stability, allowing diffusion-governed Ag+delivery over >48 h, with 77% of the Ag still present in the MOF after a 24 h release. The system exhibits dose-dependent antibacterial activity in powders and comparable efficacy in coatings, with a more gradual release profile. This scalable platform is promising for long-acting coatings, wound interfaces, and implantable materials. © 2025 Elsevier B.V., All rights reserved.