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Öğe 2 years of monitoring results from passive solar energy storage in test cabins with phase change materials(Pergamon-Elsevier Science Ltd, 2020) Cellat, Kemal; Beyhan, Beyza; Konuklu, Yeliz; Dundar, Cengiz; Karahan, Okan; Gungor, Caner; Paksoy, HalimeBuildings are one of the major consumers of global energy with a significant share reaching to 40%. Phase change materials (PCMs) are used in building materials and structures for energy saving in buildings. PCM absorbs heat from solar energy during daytime and releases that heat when temperatures cool down at night. The benefits of using PCMs in building materials are to reduce peak load and energy demand for heating and cooling and attain smaller temperature fluctuations. The aim of this study is to demonstrate passive utilization of solar energy storage in buildings with a new microencapsulated bio-based PCM (mPCM). The demonstration involves several development steps, which start in the laboratory for development of mPCM suitable for concrete and go to the building application with an innovative panel design under real climate conditions in the field. Monitoring of the test buildings with and without mPCM showed that developed microencapsulated PCM-concrete composite panels helped to maintain thermal comfort in buildings with a change in indoor air temperature with respect to reference building reaching 2 degrees C, which corresponds to up to 13% energy savings.Öğe An ultrasonic-assisted direct impregnation method for preparation of diatomite-based phase change material nanocomposites(Bulgarian Acad Science, 2016) Konuklu, Yeliz; Ersoy, OrkunDiatomite is an important natural raw material and the nanotube structures of diatomite are important in the preparation of composites. The nanotube structure of diatomite protects the phase change material from their environment. This work aims to develop leakage- free, thermally stable natural diatomite/phase change material nanocomposites (NanoCPCMs) by the ultrasonicassisted direct impregnation method for thermal energy storage applications. This work uses diatomite and paraffin as the supporting and phase change materials, respectively. The diatomite- based form- stable nanoCPCMs were analyzed via scanning electron microscopy and differential scanning calorimetry. Paraffin leakage of nanoCPCMs was determined at 95 C by water bath for 45 minutes. At the end of test, thermal stability at 95 C evaluated with DSC analysis. The results show that the leakage- free NCPCMs were synthesized successfully for thermal energy storage applications.Öğe Developing of capric acid @ colemanite doped melamine formaldehyde microcapsules and composites as novel thermal energy storage materials(Elsevier, 2023) Turan, Abdul Malik; Konuklu, YelizIn recent years, polymer/mineral composites with desired properties have been produced by adding natural minerals to polymers due to being a natural resource, their low costs and ease of use. In this study, capric acid (decanoic acid, CA) microencapsulated with melamine formaldehyde (MF) and colemanite doped MF composites (cMF) as thermal energy storage materials. Thermal, chemical, and morphological properties of cMF based PCM microcapsules and microcomposites was determined. The analysis results indicate that the addition of suitable amounts of colemanite has a positive impact on both the thermal stability and the capacity for thermal energy storage of the prepared microcapsules. The produced cMF based CA microcapsules melts at -28 degrees C with corresponding latent heat of -89 J/g. It can be stated that the usage of cMF based CA microcapsules and microcomposites in buildings can reduce the increasing energy load which results in the contribution to the formation of a clean environment by preventing the increase of greenhouse gases because of less use of fossil fuels.Öğe Easy and industrially applicable impregnation process for preparation of diatomite-based phase change material nanocomposites for thermal energy storage(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Konuklu, Yeliz; Ersoy, Orkun; Gokce, OzgurThe high porosity, high oil and water absorption capacity and low density of diatomite make it ideal for industrial applications. The porous structure of diatomite protects phase change materials (PCMs) from environmental factors as a supporting matrix and phase changes occur in nanopores of diatomite. Previous research on diatomite/PCMs composites aimed optimal composite preparation but many methods were feasible only in laboratory scale. In large scale industrial fabrication, easy, continuous and steady state methods are need to be performed. The main purpose of this study was to prepare leakagefree, thermally stable nanocomposite PCMs (nanoCPCMs) by an easy, continuous and steady state method for high temperature thermal energy storage applications. A series of nanoCPCMs with different paraffin:diatomite mass ratios were prepared. The properties of nanoCPCMs have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (MR). The leak (exudation) test was performed on prepared composites at higher temperatures (95 degrees C) in comparison with literature. As the optimum composite for thermal energy storage applications, thermal reliability of nanoCPCM was evaluated after 400 cycles of melting and freezing. NanoCPCM melted at 36.55 degrees C with latent heat of 53.1 J/g. (C) 2015 Elsevier Ltd. All rights reserved.Öğe Effect of pre-treatment methods on natural raw materials-based phase change material composites for building applications(Elsevier Sci Ltd, 2020) Konuklu, Yeliz; Ersoy, Orkun; Akar, Hasan Burak; Erzin, FatmaThis study focuses on the effect of pre-treatment methods of natural raw materials to the properties of diatomite or sepiolite-based heptadecane composites for building applications. In order to see the effects of different pre-treatment methods, the composites were prepared using impregnation method without pre-treatment, with microwave treatment and calcination treatment of raw materials before compounding. Chemical (FTIR), morphological (SEM) and thermal (DSC) analysis results showed that shapestabilized diatomite- and sepiolite-based hexadecane composites were successfully prepared by impregnation method. It was observed that the pre-treatment performed in the diatomite with microwave for no more than 1 min increased the percentages of PCM and latent heats from 28,36% and 51.71 J/g to 35,78% and 65.24 J/g, respectively. The percentage of PCM and latent heat increased from 22,23% and 40.541/g to 32,38% and 59.54 J/g, respectively, after the microwave treatment of sepiolite for 3-6 min. The results showed that pre-treatment with calcination in raw material-based PCM composites did not have a positive effect as much as pre-treatment with microwave. The success of the microwave pretreatment against calcination has been attributed to the homogeneous microwave heating process. Leak tightness tests and thermal performance tests of composites in cement-based grouting mortar have also proven that composites store excess heat and can provide thermal regulation in building applications as leakage-free energy storage materials. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Encapsulation of Phase Change Materials(Elsevier, 2022) Paksoy, Halime; Şahan, Nurten; Konuklu, YelizThermal energy storage (TES) has to be an integral part of future energy systems to achieve net zero emissions vision (NZEV) by 2050. Among the many roles TES can play in NZEV are providing uninterrupted use of renewable energy for heating and cooling, flexibility options for power generation and secure and long-life use of electronics that are becoming more and more important in the digitized world. TES can be done using sensible heat, latent heat and thermochemical concepts. Latent heat storage has the capability of charging and recharging at a high capacity and constant temperature, which makes it stand out among the other TES concepts. Phase change materials (PCM) are employed in latent heat storage to provide these features. Solid-liquid and solid-solid phase changes are preferred in PCM applications to avoid complexity of dealing with gas phase. © 2022 Elsevier Inc. All rights reservedÖğe Fabrication and characterization of form-stable phase change material/xonotlite microcomposites(Elsevier, 2017) Konuklu, Yeliz; Ersoy, OrkunIn this research novel microcomposites composed of phase change materials (PCMs) and xonotlite were fabricated and characterized. Xonotlite mineral and its composites have wide application areas in building materials industry due to their thermo-insulating properties. Lauric acid, decanoic acid and paraffin were used as phase change materials. Xonotlite was prepared as composite matrix. In order to analyse the composite structure and thermal performance of microcomposites, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used. The experimental results demonstrate that paraffin/xonotlite composites were synthesized successfully and paraffin was the most suitable phase change material for preparation of phase change material/xonotlite composites. However, this study emphasized the correct choice of PCM that will be used in xonotlite including composites. Fatty acids have dissolution effect on xonotlite matrix. The melting and freezing temperatures were measured through differential scanning calorimetry analysis and found to be 35.05 and 40.42 degrees C, respectively. The melting and crystallization heats were determined to be 65.8 and -63.5 kJ/kg. We recommended that the fabricated nanocomposite-PCMs offer proper phase transition temperature range heat enthalpy values for thermal energy storage applications.Öğe Facile synthesis of resorcinol-melamine-formaldehyde microcapsules containing hexadecane for thermal energy storage(Elsevier, 2021) Erzin, Fatma; Konuklu, YelizIn this study, it is aimed to synthesize and characterize microencapsulated phase-change material (PCM) which can be used in thermal energy storage applications with thermoregulating properties. Within this study, hexadecane was used as core material. Microcapsules of PCMs were synthesized using both melamine-formaldehyde (MF) resin and resorcinol-melamine-formaldehyde (RMF) resin. To produce microcapsules with high thermal resistance and good energy storage capacity; 3 different amounts of resorcinol (1,5 g, 2 g, and 2,5 g) were added during the process. The color of hexadecane/RMF capsules turns into reddish-brown color depending on the amount of added resorcinol. The thermal, morphological, and chemical properties of the composites were analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, respectively. It can be revealed from the characterization results that leakage free colored hexadecane microcapsules were synthesized successfully and they offer good thermal properties and mechanical stability for thermal energy storage applications.Öğe ISIL ENERJİ DEPOLAMA UYGULAMALARI İÇİN BİYOBOZUNUR ESASLI FAZ DEĞİŞTİREN MADDE/ÇAM KOZALAĞI KOMPOZİTLERİNİN ÜRETİLMESİ(2020) Konuklu, YelizBu çalışmada ısıl enerji depolama özellikli ve biyobozunur esaslı FDM/çam kozalağı kompozitleri doğrudan emdirme yöntemi kullanılarak hazırlanmış ve analiz edilmiştir. Miristik asit ve palmitik asit FDM, doğal çam kozalağı kompozit matrisi olarak kullanılmıştır. Üretilen kompozit malzemelerin morfolojik, termal ve kimyasal yapısını incelemek için sırasıyla; taramalı elektron mikroskobu (SEM), diferansiyel taramalı kalorimetre (DSC), Fourier dönüşümlü kızıl ötesi spektroskopisi (FTIR)kullanılmıştır. Üretilen kompozitlerin termal dayanımı 100oC’de test edilmiştir. DSC analizleri sonucunda üretilen miristik asit ve palmitik asit kompozitlerin erime noktası ve gizli ısı depolama kapasitelerinin sırasıyla 51,82°C: 74,60J/g ve 59,36°C: 71,22J/g olduğu belirlenmiştir. Tüm analiz sonuçlarına göre üretilen FDM/çam kozalağı kompozitlerinin ısıl enerji depolama uygulamaları için uygun bir enerji depolama materyali olduğu belirlenmiştir.Öğe Latent Heat Storage Systems(Elsevier Inc., 2018) Konuklu, Yeliz; Şahan, Nurten; Paksoy, HalimeThermal energy storage is a key technology to address the challenges in the transition to a low carbon energy system. Latent heat storage (LHS) is one of these technologies that have special features of enabling isothermal and compact storage. Recently, there has been an increasing interest in LHS applications and phase change material development. This chapter gives an overview on fundamentals, applications, and recent trends on LHS materials. © 2018 Elsevier Inc. All rights reserved.Öğe Microencapsulation of a fatty acid with Poly (melamine-urea-formaldehyde)(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Konuklu, Yeliz; Paksoy, Halime O.; Unal, Murat; Konuklu, SuleymanThe main purpose of this study is to obtain leakage-free, thermally stable decanoic acid microcapsules (microPCMs) for thermal energy storage applications. Decanoic acid (capric acid) is an environmentally friendly fatty acid since it is obtained from vegetable and animal oils. MicroPCMs were prepared with different capsule wall materials via a one-step in situ polymerization technique. The properties of microencapsulated PCMs have been analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), Fourier transform infrared (FTIR) spectra analysis and particle size analyzer. The microPCMs prepared using Poly(urea-formaldehyde) (PUF) exhibit higher heat capacities and the microPCMs prepared using Poly(melamine-formaldehyde) (PMF) exhibit higher thermal stabilities. In order to obtain microPCMs with better properties such as suitable latent heat and better heat resistance at high temperatures, we microencapsulated decanoic acid with Poly (melamine-urea-formaldehyde) (PMUF). Furthermore, the effects of surfactants on microPCMs with PMUF were investigated by SEM, a particle size analyzer, DSC, and TGA. The results show that the binary surfactant system was a suitable emulsifier for this process. We determined that the melting temperature was close to 33 degrees C, the latent heat storage capacity was about 88 J/g, and the mean particle diameter was 0.28 mu m for microPCMs with PMUF. We recommend decanoic acid microencapsulated with PMUF for thermally stable and leakage-free applications above 95 degrees C. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Microencapsulation of caprylic acid with different wall materials as phase change material for thermal energy storage(ELSEVIER SCIENCE BV, 2014) Konuklu, Yeliz; Unal, Murat; Paksoy, Halime O.In this study, caprylic acid (octanoic acid) suitable for thermal energy storage applications was microencapsulated with different wall materials, including urea-formaldehyde resin, melamine-formaldehyde resin, urea+melamine-formaldehyde resin. Microcapsules were prepared using coacervation method. Hardening process of microencapsulated phase change material (PCM) was done with formaldehyde. The morphology and particle sizes of microencapsulated PCM were analyzed by scanning electron microscopy, (SEM). The latent heat storage capacities of caprylic acid and microencapsulated caprylic acid were determined with differential scanning calorimetry (DSC). The chemical characterization of microcapsules was determined by Fourier transformed infrared (FTIR) spectroscopy. It is concluded that urea-formaldehyde resin was the best capsule wall material for caprylic acid. Based on all results, it can be considered that the microcapsules were synthesized successfully and that, the phase change enthalpies of melting and freezing were about 93.9 J/g and 106.1 J/g, respectively, the particle diameter was 200 nm-1.5 mu m. (C) 2013 Elsevier B.V. All rights reserved.Öğe Microencapsulation of phase change material with poly (ethylacrylate) shell for thermal energy storage(WILEY-BLACKWELL, 2014) Konuklu, YelizMicrocapsules containing caprylic acid and polyethylacrylate shells were prepared using an emulsion polymerization technique for thermal energy storage applications. Ethylene glycol dimethacrylate was used as a crosslinking agent. The influence of the crosslinking agent concentration on the phase change properties of microcapsules was examined. The caprylic acid microcapsules (MicroPCMs) were analyzed by Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy, and differential scanning calorimetry. The results showed that microcapsules were synthesized successfully and that the best shell material:crosslinking agent concentration ratio was 1:0.2. The melting and freezing temperatures were measured through differential scanning calorimetry analysis and found to be 13.3 and 7.1 degrees C, respectively. The melting and crystallization heats were determined to be 77.3 and -77.0kJ/kg, and the mean particle diameter was 0.64m. The thermal cycling tests of the microcapsules were performed for 400 heating/cooling cycles, and the results indicate that the synthesized microcapsules have good thermal reliabilities. Air stability test proved that the thermal properties and physical form of microcapsules were not affected by air. We recommend the prepared thermal, air, and chemically stable caprylic acid microcapsules for thermal energy storage applications as novel microPCM with latent heat storage capacities and properties. Copyright (c) 2014 John Wiley & Sons, Ltd.Öğe Mikrokapsüllenmiş Faz Değiştiren Madde İçeren Sıcaklık Kontrollü Ambalajların Gıdalarda Kullanımı(2015) Konuklu, Yeliz; Ayhan, Zehra; Paksoy, Halime Ömür; Göktürk, TolgaBu projede mikrokapsüllenmis FDM?ler gıda ambalajlarına yerlestirilerek ambalajlara ısı depolama özelligi kazandırılmıstır. Böylece olusan sıcaklık kontrollü ambalajlar termal bir tampon bölgesi olusturarak, gıdaların istenilen sıcaklık aralıklarında kalmasını saglayabilmektedir. Bu amaçla ilk olarak; ergime sıcaklıkları çikolata ve birçok gıda için uygun olan FDM?ler belirlenmis ve mikrokapsülleme islemi kimyasal olarak gerçeklestirilmistir. Proje süresince mikroenkapsülasyon proseslerinde hem optimizasyon hem de kullanım amacıyla birçok farklı dıs duvar polimerleri (üre-formaldehit; melaminformaldehit; üre+melamin-formaldehit; jelatin-arap zamkı; polietilakrilat; polistiren; polistirenetilakrilat; jelatin-kitosan) incelenmistir. Elde edilen mikrokapsüllerin erime donma davranıslarının incelemek ve termal enerji depolama kapasitelerini belirlemek amacıyla DSC analizleri, termal stabilitelerini belirlemek amacı ile termal gravimetrik analizleri (TGA), uzun erime donma döngüsü sonunda kimyasal bir degisimin olusup olusmadıgını belirlemek amacıyla FTIR analizleri, morfolojik özelliklerinin belirlenmesi için taramalı elektron mikroskobu (SEM) analizleri yapılmıstır. Ayrıca mikrokapsülleme proseslerini etkileyen birçok parametre incelenmistir. Bu proje süresince 500?ü askın mikrokapsülleme denemesi yapılmıs ve sentezlenen ürünler karsılastırılarak amacımıza en uygun olanı; kaprilik asidin polistirenli ve polistiren-koetilakrilatlı oldugu mikro-nanokapsüller olarak belirlenmistir. Belirlenen mikrokapsüllerin seri üretimleri gerçeklestirildikten sonra karton ambalajlarda oluklu bölmelere yerlestirilmis ve ambalajlara ısı depolama özelligi kazandırılmıstır. Mikrokapsüllerin termal tampon bölgesi olusturarak ürünleri 2 saat boyunca dıs ortam sıcaklıklarından korudugu belirlenmistir. Ayrıca hazırlanan sıcaklık kontrollü ambalajların buzdolabı içerisinde gerçeklesen sıcaklık dalgalanmalarından minumum oranda etkilendigi belirlenmistir. Sıcaklık kontrollü ambalajlar içerisinde kullanılan kapsüllenmis FDM?lerin ambalaj içerisindeki gıda ürünlerine migrasyon yapıp yapmadıgını belirlemek için çikolatalar 3 ay boyunca bu ambalajlarda depolanmıstır. 1. ve 3. ayın sonunda çikolata örneklerinin FTIR analizleri yapılmıs ve ambalajlara eklenen FDM?lerin çikolatalara herhangi bir migrasyon yapmadıgı belirlenmistir. Bu proje kapsamında gelistirilen sıcaklık kontrollü ambalajın ileride prestijli ürünlerle tüketicilere sunulabilecegi, bu ambalajların kullanımıyla özellikle soguk zincirde satılan ve çok çabuk bozulabilen dondurma, tavuk, et gibi ürünlerin güvenle müsterinin evine veya isyerine ulastırılabilecegi düsünülmektedir.Öğe Nanoencapsulation of n-alkanes with poly(styrene-co-ethylacrylate) shells for thermal energy storage(ELSEVIER SCI LTD, 2015) Konuklu, Yeliz; Paksoy, Halime O.; Unal, MuratIn this work, we synthesized a series of four nanocapsules containing n-alkanes (CnH2n+2), namely tetradecane, pentadecane, hexadecane, and heptadecane, in poly(styrene-co-ethylacrylate) using an emulsion copolymerization method. The nanocapsules were characterized according to their geometric profiles, phase transition temperatures, phase transition heats, mean particle sizes, and chemical stabilities by means of scanning electron microscopy, differential scanning calorimetry, thermal gravimetric analysis and Fourier transform infrared spectroscopy. Furthermore, we also focused on the effect of the core/shell mass ratio on the phase change properties of the nanocapsules. We found that microcapsules were synthesized successfully and that the best core/shell mass ratio was 3:1 for this study. These results indicate that encapsulated n-alkanes with poly(styrene-co-ethylacrylate) have an excellent potential for energy storage. (C) 2014 Elsevier Ltd. All rights reserved.Öğe Niğde Üniversitesi Ar-Ge Strateji Belgesi (Nanoteknoloji Araştırmaları)(2017) Konuklu, Yeliz; Zan, Recep; Soylu, Asım; Ersoy, OrkunNanoteknoloji birçok alandaki uygulamalarından dolayı yüksek bir potansiyele sahip bir alandır. Uluslararası platformda Nanoteknolojik araştırma ve uygulamalar için yapılan yatırımlar günden güne artmaktadır. Dünyadaki bilimsel ve teknolojik gelişmeleri her alanda takip edebilmek ve uluslararası standartlara ulaşmak için Nanobilim ve Nanoteknoloji konusundaki çalışmaların ülkemizde de yoğunlaşması gerekmektedir. Hazırlanan strateji belgesinin temel amacı Ömer Halisdemir Üniversitesi'nin Nanoteknoloji Araştırmaları alanında mevcut araştırma - geliştirme potansiyelinin belirlenerek arttırılması, ayrıca üniversite-sanayi arasında işbirliğinin geliştirilmesi ve bu alanda ?Ar-Ge Strateji Belgesinin? hazırlanmasıdır. Hazırlanan Nanoteknoloji Araştırmaları Ar-Ge Strateji belgesi ile üniversite-sanayi işbirliği yapılarak katma değeri yüksek teknolojik ürünlerin ortaya çıkarılması ve geliştirilmesi hedeflenmektedir. Ömer Halisdemir Üniversitesi Nanoteknoloji Uygulama ve Araştırma Merkezimiz Nanoteknoloji alanında üç ana konu üzerinde yog?unlas?mıs?tır. Bunlar 1)fonksiyonel özellikli nanokompozit ve nanoenkapsülasyon çalışmaları 2) nanoyapıların üretimi ve optimizasyonu çalışmaları 3)karbon temelli nanomalzemelerin sentezi, karakterizasyonu ve farklı endüstrilerde kullanılabilirlikleri üzerine yapılan çalışmalardır. Ayrıca bazı araştırmacılarımız nano ölçekte manyetik özellik gösteren örneklerin üretimi ile ilgili çalışmalara başlamıştır. Ömer Halisdemir Üniversitesi, sahip olduğu insan kaynağı ve altyapı olanakları açısından Nanoteknoloji alanında ülkemizin ihtiyaç duyduğu Ar-Ge çalışmalarını yapacak ve bu alanda ilk beş üniversite arasına girebilecek potansiyele sahiptir. TÜBİTAK 1000 kodlu ?Üniversitelerde Ar-Ge Strateji Belgesi Hazırlatılması ve Uygulatılması? çağrısı kapsamında hazırlanan beş yıllık Ar-Ge Strateji Belgesi ile Ömer Halisdemir Üniversitesi?nin Nanoteknoloji Araştırmaları alanındaki mevcut potansiyelinin en iyi şekilde değerlendirilmesi ve ülkemizde ilk beş üniversite içerisine girmesi için gerekli yol haritası çizilmiştir. Ömer Halisdemir Üniversitesi Nanoteknoloji Araştırmaları alanında yapacağı çalışmalarla gelecek on yıl içerisinde sadece Türkiye?deki ilk beş üniversite arasına girmeyi değil aynı zamanda bu alanda dünyada da önemli bir eğitim ve Ar-Ge merkezi olmayı hedeflemektedir. Ömer Halisdemir Üniversitesi Nanoteknoloji Araştırmaları alanında Ar-Ge strateji Belgesi?nin hazırlanması esnasında üniversite-sanayi işbirliğinin desteklenmesi ve teşvik edilmesi konusunda üniversitenin Nanoteknoloji Araştırmaları Ar-Ge altyapısındaki eksiklikler tespit edilmiş ve bu eksikliklerin giderilmesine yönelik beş yıl içerisinde atılacak olan adımlar Üniversite üst yönetimi desteğiyle bes? adet is? paketi ile gerçekleştirilmiştir. Bunlar; 1.Nanoteknoloji Araştırmaları Mevcut Durum ve Sektörel ihtiyaç çalışmaları çalıs?tayının düzenlenmesi 2.Web Sayfası, Bros?ür, Posterlerin hazırlanması 3.I?s?birlig?i ve Tanıtım Toplantıları 4.Proje Hazırlama Eg?itimi: Nig?de Üniversitesinde Nanoteknoloji alanında çalıs?ma yapan ve bu alanda projeler yapmak isteyen üniversite personeline projeler hakkında bilgi verilecektir. 5.Nanoteknoloji Aras?tırmaları Ar-Ge Strateji Belgesinin Hazırlanması olarak özetlenebilir. Ömer Halisdemir Üniversitesi ?Nanoteknoloji Aras?tırmaları? alanındaki stratejik amaçları; 1. Nanoteknoloji alanında Ar-Ge faaliyetlerini artırmak, 2. Araştırma sonucunda ortaya çıkan bilginin geniş kitlelere ulaşmasını sağlamak, 3. Nanoteknoloji alanında işbirliğinin sağlanmasına yönelik akademik ve bilgilendirme toplantıları yapmak, 4. Nanoteknoloji alanında Ar-Ge altyapısının iyileştirilmesi ve geliştirilmesini sağlamak olarak belirlenmiştir.Öğe Polystyrene-based caprylic acid microencapsulation for thermal energy storage(Elsevier Science Bv, 2017) Konuklu, Yeliz; Paksoy, Halime O.In this study, caprylic (octanoic) acid microcapsules were synthesized with polystyrene shell material using the emulsion polymerization method. The influence of the type and concentration of the cross linking agent on the phase-change properties of the microcapsules was examined. The structure and properties of the microcapsules have been characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). A second main contribution of this work is to investigate whether we could synthesize microcapsules with the same thermal properties during serial production. The effects of serial production on microencapsulated caprylic acid (microPCMs) have been investigated by thermal methods. The results show that reproducibility is an important parameter in the microencapsulation process. It was determined that when the synthesis amount is increased, we obtained lower efficiency in the microencapsulation of caprylic acid. (C) 2016 Elsevier B.V. All rights reserved.Öğe Preparation and characterization of form-stable phase change material/end-of-life tires composites for thermal energy storage(Tubitak Scientific & Technological Research Council Turkey, 2020) Konuklu, YelizThe management of end-of-life tires (ELT) waste gains importance in aspect of possible environmental and economic issues so the waste recycling becomes unavoidable. This study describes the fabrication and characterization of a new phase changing material (PCM)/ELT microcomposites that could be used in thermal energy storage. Paraffin together with the 4 fatty acids and ELT rubber powder are used as PCMs and as the supporting material, respectively. Paraffin/ELT composites are fabricated, as well, by the vacuum impregnation method in order to investigate the effect of the preparation method. The thermal, morphological, and chemical properties of the prepared PCM/ELT rubber microcomposites are determined with differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and FTIR, respectively. Additionally, the effects of the PCM amount on the composite materials are investigated. As a result of DSC results, the melting temperature and latent heat of the paraffin/ELT rubber microcomposites are determined as 37.2 degrees C and 80.79 J/g for direct impregnation method and 36.8 degrees C and 80.69 J/g for vacuum impregnation method, respectively. Based on the findings of this study, it can be claimed that PCM/ELT rubber microcomposites can be used as energy-saving materials in thermal energy storage applications.Öğe Preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage(PERGAMON-ELSEVIER SCIENCE LTD, 2016) Konuklu, Yeliz; Ersoy, OrkunThis paper is one of the first study about the preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage applications. Sepiolite is an important natural fibrous raw material. Nanoscale fibrous tubular structure of sepiolite becomes important in nanocomposite preparation. In this study, sepiolite/paraffin and sepiolite/decanoic acid nanocomposites were manufactured by the direct impregnation method. By the preparation of nanocomposites, PCM move in tubular channels of sepiolite, phase changing occurs in these tubes and surface area increases like as in microencapsulation. The structure and properties of nanocomposites PCMs (CPCM) have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The SEM results prove the successful preparation of phase change material/sepiolite nanocomposites and point out that the fibers of sepiolite is modified with phase change materials in the nanocomposite. The phase change enthalpies of melting and freezing were about 62.08 J/g and 62.05 J/g for sepiolite/paraffin nanocomposites and 35.69 J/g and -34.55 J/g for sepiolite/decanoic acid nanocomposites, respectively. The results show that PCM/sepiolite nanocomposites were prepared successfully and their properties are very suitable for thermal energy storage applications. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Promising palmitic acid/poly(allyl methacrylate) microcapsules for thermal management applications(Pergamon-Elsevier Science Ltd, 2023) Konuklu, Yeliz; Akar, Hasan BurakThis study aimed to develop a promising thermal energy storage material based on poly(allyl methacrylate (AMA))-based palmitic acid (PA) microencapsulation using emulsion polymerization. Poly(AMA) and PA were chosen as the capsule shell and core materials, respectively. The synthesized microcapsules exhibited a good latent heat storage capacity of 143-188 J/g. This study also aimed to evaluate the effect of the core material ratio of the microcapsules on the thermal, structural, and chemical properties of PA microcapsules. To determine the thermal performance of the prepared microcapsules, mortar-based composite materials containing PA micro -capsules were prepared at a ratio of 90/10 (wt% mortar/micro phase change material) and analyzed during heating and cooling using infrared techniques. The analysis showed that the temperature of the composite materials containing PA microcapsules was 6.6 degrees C lower than that of the reference composite after 60 min of heating. This indicates that mortar composites containing PA microcapsules are less affected by heating and cooling and can therefore be applied as promising energy storage materials for thermal management applica-tions, particularly in buildings.
