Density functional theory and molecular dynamics simulations of carbon nanotubes, polyetheretherketone and their interfaces

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, Türkiye

Tezin Onay Tarihi: 2018

Öğrenci: GÖZDENUR TORAMAN

Eş Danışman: ERCAN GÜRSES, HANDE TOFFOLİ

Özet:

Carbon nanotubes are allotropes of carbon with a cylindrical nanostructure. A nanotube can roughly be described as a rolled-up graphene sheet, which is a two dimensional hexagonal arrangement of carbon atoms, often referred to as a honeycomb lattice. Carbon nanotubes, much like their parent material graphene, are characterized by high strength, high Young modulus, durability and tunable electronic behavior. As a result of these superior properties, CNTs have been used in diverse technologically relevant applications over the decades since their successful synthesis. In particular, CNT-polymer composites have gained considerable interest in the materials research community in recent years. The testing, manipulating and design of viable mixtures of nanotubes and polymers presents challenges from an experimental point of view. For this reason, numerical modeling of nanotubes and nanotube reinforced polymers is important. The main objective of this thesis is to examine mechanical properties of carbon nanotubes, Poly Ether Ether Ketone (PEEK) polymer and physical properties of their interface by using Density Functional Theory (DFT) and Molecular Dynamics (MD) techniques. PEEK is a semi-crystalline thermoplastic polymer which has remarkable mechanical properties with a Young modulus of 3.6 GPa and a rather high melting temperature ∼ 370◦ C (when it is reinforced with CNTs this melting point can reach 390◦ C). Thanks to these properties, PEEK is suitable for use in extreme conditions, such as spacecraft, nuclear power plants, petroleum and geothermal wells.