Grafen takviyeli nanokompozit malzemelerin üretimi ve karakterizasyonu
Küçük Resim Yok
Tarih
2021
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Bursa Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/embargoedAccess
Özet
Kompozit malzemeler, iki veya daha fazla malzemenin sistematik bir şekilde birleşmesi ile tasarlanan malzeme grubudur. Polimer sistemler ise, üretimi kolay, hafif, uzun ömürlü, kısmen sünek doğası nedeniyle oldukça kullanılan malzemelerdir. Bu özelliklerine rağmen polimerler, metal ve seramiklere kıyasla düşük elastiklik modülü ve mukevemete sahiptirler. Polimer sistemlerde ise yaygın olarak kullanılan iki grup bulunmaktadır; termosetler ve termoplastikler. Epoksi, termosetler grubundan yapıştırıcı bir reçinedir. Epoksi, reçinenin kürlenmesi sonucunda oluşan ve epoksit fonksiyonel grubunun halk arasındaki adıdır. Epoksi, yüksek sertlik, kısmen yüksek sıcaklık direnci ve iyi kimyasal ve korozyon direnci ile kompozitler için oldukça faydalı bir matris malzemesi sayılmaktadır. Grafen (GNP), karbonun sp2 bağı yapan bir allotropudur. Aynı zamanda grafen, bal peteği kristal kafes yapısı içerisinde tek atom kalınlığında düzlemsel bir yüzey oluşturan bir malzemedir. Yüksek mukavemet, yüksek elastisite modülü ve yüksek yüzey alanı gibi özellikler, grafeni en ilgi çekici takviye malzemesi konumuna getirmektedir. Elektrik ark deşarj metoduyla, grafitten elde edilen grafenin saflığı diğer birçok yönteme göre oldukça yüksektir. Prosesin temeli direkt elektrik akımına dayanmaktadır. Oluşan nanoparçacıklar fiziksel olarak biriktirme yolu ile toplanmaktadır. Diğer metotlara kıyasla; ark deşarj metodu, düşük maliyetli üretim ve herhangi kataliz kullanımı olmadan üretme imkanı gibi avantajları bulunmaktadır. Ancak, grafenin en ciddi dezavantajı ise aglomerasyondur. Bu durum uygulanacak matrisin, istenilen özelliklerine yeterince katkı sağlamayabilmektedir. Bu dezavantajı ortadan kaldırmanın en mümkün yolu ise yüzey aktif maddesi ile fonksiyonelleştirilmesidir. Elektrik ark deşarj metodu ile üretilen grafen, Triton X-100 (TX-100) ile beraber saf suda dağıtılarak fonksiyonel hale getirilmiştir. Yine 0,1 gram grafen 100 ml su içerisinde fonksiyonel hale getirilmiştir. 0,1 gram grafen, 0,15 gram TX-100 karışımını 100 ml saf suda başarılı bir şekilde dağıtmak için 1 saat kadar süreyle sonikasyon yapılmıştır. Sonikasyonun ardından 12 saat boyunca karışım, manyetik karıştırıcıda 65°C sıcaklıkta karıştırılmıştır. Ardından filtreleme ve kurutma işlemleri uygulanmıştır. Üç merdaneli haddeleme birbirine zıt yönlerde ve farklı hızlarda dönen üç merdane kullanılarak, malzeme üzerinde kayma gerilmesi oluşturma prensibi ile çalışır. Bu çalışmada grafenin topaklanmasını önlemek amacıyla üç merdaneli haddeleme yöntemi kullanılmıştır. TX-100 / GNP için yapılan TGA analizlerinde 200-400oC sıcaklıklarda önemli bir kütle kaybı bulunabilmektedir. Bu da POPE (polioksietilen oktil fenil eter) moleküllerinin tabakaya başarıyla yapıştığını ortaya koymaktadır. Ayrıca, TX-100 / GNP termal stabilitesi (Grafen oksite (GO) oranla) bozulmamış grafen kadar iyidir. Saflığı ise, 1,22 olarak bulunmuştur. Katman sayısı ise, 5 ile 7 değerleri arasında çıkmaktadır. Fonksiyonel grafenin Raman değerleri ise, 0,9 olarak hesaplanırken; katman sayısı da 10 ile 13 değerleri arasında bulunmaktadır. Basma testi verilerine göre basma mukavemetinin GNP takviyesi ile düşüş gösterdiği ancak TX-100 / GNP takviyesi sonucu saf epoksiye oranla % 5.56 artış gözlemlenmiştir. TX-100 / GNP / Epoksi nanokompozitinin elastik modülü ise saf epoksiye oranla %18,21 ve GNP / Epoksi nanokompozitine oranla %1,9 daha yüksek çıkmıştır. GNP / epoksi nanokompozitin akma dayanımı, saf epoksiye göre %14,30 artış gösterirken TX-100 / GNP / Epoksi nanokompozitin akma dayanımı, saf epoksiye %103 oranında artış ile daha yüksek çıkmıştır. Ağırlık düşürme darbe deneyi sonucunda fonksiyonel hale getirilmiş GNP takviyeli nanokompozitin darbeye karşı kuvvet direnci, GNP takviyeli nanokompozit haline ve saf epoksiye göre neredeyse 2 kat artış göstermektedir. Bununla birlikte, darbe enerjisi ve absorplanan enerji miktarı yine fonksiyonelleştirilmiş GNP takviyeli epoksi nanokompozitin, saf epoksiye ve GNP takviyeli nanokompozite oranla 2 kat daha yüksek olduğu söylenebilmektedir.
Composite materials are a group of materials designed by systematically combining two or more materials. Polymer systems, on the other hand, are materials that are easy to manufacture, light, durable, and widely used due to their partially ductile nature. Despite these properties, polymers have low modulus and strength compared to metals and ceramics. There are two groups commonly used in polymer systems: Thermosets and thermoplastics. Epoxy is an adhesive resin from the thermosets group. Epoxy is the popular name of the epoxide functional group, which is formed because of the curing of the resin. Epoxy is considered a very useful matrix material for composites with its high hardness, moderately high temperature resistance and good chemical and corrosion resistance. Graphene (GNP) is an allotrope of carbon that makes sp2 bonds. Graphene is the thinnest material that forms a single-atom-thick planar surface in a honeycomb crystal lattice. Properties such as high strength, high modulus of elasticity and high surface area make graphene the most interesting reinforcement material. The purity of graphene obtained from graphite by the electric arc discharge method is quite high compared to many other methods. The basis of the process is directly from the electric current. The resulting nanoparticles are collected by physical deposition. Compared to other methods; arc discharge method has advantages such as low-cost production and the possibility of producing without the use of any catalysis. However, the most serious disadvantage of graphene is agglomeration. This situation may not contribute enough to the desired properties of the matrix to be applied. The most possible way to eliminate this disadvantage is to functionalize it with a surfactant. Graphene produced by the electric arc discharge method is made functional by mixing it with Triton X-100 in pure water. 0.15 grams of Triton X-100 (TX-100) is required for 0.1 gram of graphene. Graphene produced by the electric arc discharge method is made functional by mixing it with TX-100 in pure water. Sonication is performed for about 1 hour to successfully disperse a mixture of 0.1 grams of graphene and 0.15 grams of TX-100 in 100 ml of distilled water. After sonication, the mixture is stirred at 65°C in a magnetic stirrer for 12 hours. Then filtering and drying processes are applied. Three-roll milling works with the principle of creating shear stress on the material by using three rollers rotating in opposite directions and at different speeds. In this study, it is planned to use three-roll rolling method to prevent agglomeration of graphene. For TX-100 / GNP, a significant mass loss can be found at temperatures of 200-400°C. This reveals that POPE (polyoxyethylene octyl phenyl ether) molecules have successfully adhered to the layer. Also, the thermal stability of TX-100 / GNP (compared to graphene oxide (GO)) is as good as pristine graphene. Its purity was found to be 1.22. The numbers of layers are between 5 and 7. When we look at functional graphene. While the Raman values of functional graphene were calculated as 0.9; the number of layers is also between 10 and 13 values. According to the compression test data, it was observed that the compression strength decreased with GNP reinforcement, but increased by 5.56% compared to pure epoxy as a result of TX-100 / GNP reinforcement. The elastic modulus of TX-100 / GNP / Epoxy nanocomposite was 18.21% higher than pure epoxy and 1.9% higher than GNP / Epoxy nanocomposite. The yield strength of GNP / epoxy nanocomposite increased by 14.30% compared to pure epoxy, while the yield strength of TX-100 / GNP / Epoxy nanocomposite was higher with a 103% increase to pure epoxy. As a result of the weight drop impact test, the strength resistance of the functionalized GNP reinforced nanocomposite shows an almost 2-fold increase compared to the GNP reinforced composite and pure epoxy. However, it can be said that the impact energy and the amount of energy absorbed are 2 times higher for the functional GNP reinforced epoxy nanocomposite compared to pure epoxy and GNP reinforced nanocomposite.
Composite materials are a group of materials designed by systematically combining two or more materials. Polymer systems, on the other hand, are materials that are easy to manufacture, light, durable, and widely used due to their partially ductile nature. Despite these properties, polymers have low modulus and strength compared to metals and ceramics. There are two groups commonly used in polymer systems: Thermosets and thermoplastics. Epoxy is an adhesive resin from the thermosets group. Epoxy is the popular name of the epoxide functional group, which is formed because of the curing of the resin. Epoxy is considered a very useful matrix material for composites with its high hardness, moderately high temperature resistance and good chemical and corrosion resistance. Graphene (GNP) is an allotrope of carbon that makes sp2 bonds. Graphene is the thinnest material that forms a single-atom-thick planar surface in a honeycomb crystal lattice. Properties such as high strength, high modulus of elasticity and high surface area make graphene the most interesting reinforcement material. The purity of graphene obtained from graphite by the electric arc discharge method is quite high compared to many other methods. The basis of the process is directly from the electric current. The resulting nanoparticles are collected by physical deposition. Compared to other methods; arc discharge method has advantages such as low-cost production and the possibility of producing without the use of any catalysis. However, the most serious disadvantage of graphene is agglomeration. This situation may not contribute enough to the desired properties of the matrix to be applied. The most possible way to eliminate this disadvantage is to functionalize it with a surfactant. Graphene produced by the electric arc discharge method is made functional by mixing it with Triton X-100 in pure water. 0.15 grams of Triton X-100 (TX-100) is required for 0.1 gram of graphene. Graphene produced by the electric arc discharge method is made functional by mixing it with TX-100 in pure water. Sonication is performed for about 1 hour to successfully disperse a mixture of 0.1 grams of graphene and 0.15 grams of TX-100 in 100 ml of distilled water. After sonication, the mixture is stirred at 65°C in a magnetic stirrer for 12 hours. Then filtering and drying processes are applied. Three-roll milling works with the principle of creating shear stress on the material by using three rollers rotating in opposite directions and at different speeds. In this study, it is planned to use three-roll rolling method to prevent agglomeration of graphene. For TX-100 / GNP, a significant mass loss can be found at temperatures of 200-400°C. This reveals that POPE (polyoxyethylene octyl phenyl ether) molecules have successfully adhered to the layer. Also, the thermal stability of TX-100 / GNP (compared to graphene oxide (GO)) is as good as pristine graphene. Its purity was found to be 1.22. The numbers of layers are between 5 and 7. When we look at functional graphene. While the Raman values of functional graphene were calculated as 0.9; the number of layers is also between 10 and 13 values. According to the compression test data, it was observed that the compression strength decreased with GNP reinforcement, but increased by 5.56% compared to pure epoxy as a result of TX-100 / GNP reinforcement. The elastic modulus of TX-100 / GNP / Epoxy nanocomposite was 18.21% higher than pure epoxy and 1.9% higher than GNP / Epoxy nanocomposite. The yield strength of GNP / epoxy nanocomposite increased by 14.30% compared to pure epoxy, while the yield strength of TX-100 / GNP / Epoxy nanocomposite was higher with a 103% increase to pure epoxy. As a result of the weight drop impact test, the strength resistance of the functionalized GNP reinforced nanocomposite shows an almost 2-fold increase compared to the GNP reinforced composite and pure epoxy. However, it can be said that the impact energy and the amount of energy absorbed are 2 times higher for the functional GNP reinforced epoxy nanocomposite compared to pure epoxy and GNP reinforced nanocomposite.
Açıklama
Anahtar Kelimeler
Nanokompozitler, Nanocomposites, Plastik kompozitler, Plastic composites
