Yazar "Mert, Hatice Hande" seçeneğine göre listele

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  • Küçük Resim Yok
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    Evaluation of performance of asphalt binders containing capric acid based form-stable phase change materials
    (Elsevier Sci Ltd, 2024) Yilmaz, Bahadir; Mert, Hatice Hande; Sesli, Hasan; Ozdemir, Ahmet Muenir; Mert, Mehmet Selcuk
    Phase Change Materials (PCMs) are functional and promising materials due to their tailored properties designed for various applications. Considering the wide range of applications, the use of PCMs with asphalt binders has also attracted attention in recent years. This study focuses on the effect of the adding fatty acid-based shapestabilized composite PCM prepared by solvent-assisted impregnation to asphalt binders. For this purpose, a favorable material, capric acid (CA) was used. In addition, pumice (PUM), a natural and abundant material also known as lightweight aggregate, was preferred as the support material. The features of the prepared composite PCM was named CA-PUM, were examined by conducting the well-known methods, namely Fourier transform infrared (FT -IR) spectroscopy, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) analyses. The latent heat of melting of CA-PUM was found to be as 46.58 J/g with the incorporation ratio as 34.96 wt%, while the melting peak temperature was determined as 30.93 degrees C. The performance of modified asphalt binders with 0.5%-2.0% (wt/wt) CA-PUM were evaluated by penetration, softening point, rotational viscosity (RV), dynamic shear rheometer (DSR), rolling thin film oven (RTFO) and pressure aging vessel (PAV) tests. Based on the performance test results, the modified asphalt binder included 1.0 wt% CA-PUM demonstrated distinguishable properties in terms of increased resistance to deformations, the highest softening point and viscosity values besides to highest rutting performance.
  • Küçük Resim Yok
    Öğe
    Oleik asit/nişasta/grafit temelli kompozit faz değiştiren malzemelerin hazırlanması ve ısıl özelliklerinin incelenmesi
    (İdris Karagöz, 2024) Mert, Mehmet Selçuk; Mert, Hatice Hande; Yaldız, Sude; Yüksel, Fikret
    Faz Değiştiren Malzemeler (FDM’ler), faz değişimi esnasında görülen donma ve erime süreçleri boyunca ısıl enerjinin gizli ısı formunda depolanmasına ve salınmasına izin veren akıllı malzemelerdir. Bu çalışmada, ısıl enerji depolama uygulamalarında kullanılmak üzere oleik asit/nişasta temelli kompozit faz değiştiren malzemeler (OA/St) dondurarak kurutma tekniği ile üretilmiş ve karakterize edilmiştir. Ek olarak, ısı transfer hızını iyileştirmek amacıyla yüksek ısıl iletkenliğe sahip genleştirilmiş grafit varlığında benzer örnekler (OA/St/%1GF) hazırlanmıştır. Elde edilen kompozit FDM’lerin; Taramalı Elektron Mikroskobu (SEM), Fourier Dönüşümlü Kızılötesi (FT-IR) ve Diferansiyel Taramalı Kalorimetre (DSC) ile gerçekleştirilen morfolojik, kimyasal ve ısıl karakterizasyon teknikleriyle özellikleri incelenmiştir. Elde edilen OA/St kompozit FDM’nin ısıl enerji depolama kapasitesi 18,23 kJ/kg, erime ve kristalizasyon pik sıcaklıkları sırasıyla, 5,83 °C ve -8,10 °C olarak bulunmuştur. OA/St/%1GF Kompozit FDM’nin ise bu özellikleri sırasıyla; 18,54 kJ/kg, 5,66 °C ve -8,15 °C olarak belirlenmiştir. Buna ilaveten, elde edilen kompozitlerin ısıl davranışları Sıcaklık-Kayıt (T-Kayıt) yöntemiyle araştırılmış ve bir ısıl özellikler analiz cihazı kullanılarak ısıl iletkenlikleri ölçülmüştür. Sonuç olarak, elde edilen bulgular temelinde, hazırlanan kompozit FDM’lerin başta tarımsal seralarda don olaylarının önlenmesi, gıda ve medikal soğuk depolama uygulamaları gibi çok çeşitli pratik uygulama alanlarında ortam sıcaklık gereksinimlerinin karşılanmasında uygun birer aday olarak kullanılabileceği değerlendirilmiştir.
  • Küçük Resim Yok
    Öğe
    Synthesis and characterization of polyHIPE composites from CTAB-modified halloysite nanotube stabilized Pickering emulsions: Effect of CTAB immobilized nanotube on reducing surfactant usage
    (İdris Karagöz, 2025) Şen, Sinan; Mert, Hatice Hande
    In this study, halloysite (HL) nanotubes were used as solid particles contributing to the stabilization of high internal phase emulsions (HIPEs) in the preparation of porous composites. PolyHIPEs were obtained by polymerization of the continuous phase of these HIPEs. Immobilization of cetyltrimethylammonium bromide (CTAB) on the HL surface was carried out using the adsorption in solution (SOL) technique. The stability of HIPE without nanofiller was achieved with the use of 5% surfactant by volume. However, the surfactant requirement for the emulsion stability of HIPE materials with organophilic HL fillers (0.25-1.00 wt%) was reduced to 1%. At constant CTAB-SOL-HL clay amounts, decreasing the surfactant concentration resulted in the formation of pores of different sizes, while increasing the amount of filler while keeping the surfactant concentration constant resulted in a decrease in pore size and improved size distribution. The highest adsorption values of cationic dye (Nile Blue) were exhibited by polyHIPE composites containing 0.50 and 1.00 wt% CTAB-SOL-HL, and about 100% more adsorption was obtained with 1% filler compared to pure polyHIPE. The use of CTAB-SOL-HL at 0.50 wt% and above, higher thermal degradation temperatures were achieved in the composites compared to pure polyHIPE. The use of HL nanotubes in the preparation of porous composites is of great importance in terms of possible engineering and environmental benefits in terms of both improving the thermal performance of the materials and taking an active role in the adsorption of the dye, as well as helping to ensure emulsion stability.