Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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2011 - 20153

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Author: search.filters.author.Tanoğlu, MetinSubject: search.filters.subject.Polymers

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  • Master Thesis
    Development of Antibacterial Polymer Based Nanocomposite Materials
    (Izmir Institute of Technology, 2015) Abatay, Ezgi; Arslanoğlu, Alper; Tanoğlu, Metin
    Human beings are often infected by microorganisms such as bacterium, mold, yeast, virus, etc. in the living environment. It became a requirement and a necessity to create sterile fields in areas. Composite stones are one of the main materials that can be used for the contact surfaces in indoor and outdoor places due to their being of highly resistant to abrasives, chemicals and impacts. Research has been intensive in antibacterial material containing various inorganic substances. The aim of this thesis is investigating the antibacterial effect of inorganic substances such as silver, zinc oxide, calcium oxide, titanium oxide and magnesium oxide on stone products. This study also deals with the silver doped zinc oxide powder and their antibacterial efficacies. Stone product is formed of mainly two type compound which are quartz aggregates as reinforced and filler and thermoset polyester resin as matrix. The manufacturing process begins with selection of raw quartz materials. They are crushed and blended in the ratio of 90 % quartz aggregates to 10% polyester matrix and other additives such as antibacterial agent, pigment. These united constituents are used for production of composite stones by applying those combined vacuum, vibration and pressing processes which are named as vibropress, simultaneously. Following it, they are subjected to surface preparation and polishing processes. In this study, mechanical, thermal, and morphological properties of the particles, polyester matrix and stone product were investigated. Antibacterial efficacies of these were investigated based on colony-count method against gram negative (E.coli) and gram positive (Bacillus subtilis) bacteria. Silver-containing stone samples showed best antibacterial property about ninety-nine percent reduction.
  • Master Thesis
    Development of Liquid Body Armor Systems
    (Izmir Institute of Technology, 2013) Çolpankan, Oylum; Tanoğlu, Metin
    Body armors consist of fabrics made of high performance fibers which are characterized by low density, high strength, high tenacity and high energy absorption. Soft body armors are produced with lamination of 20-50 layers of fabrics and hard body armors consist of ceramic/metal plates along with the fabric. However, these armors are bulky, heavy, non-flexible. In order to eliminate disadvantages of traditional armors, new armor concept has been come into use with impregnation of shear thickening fluids (STFs) onto soft body armors called as liquid body armors. STFs are used within the fabrics to improve the ballistic and stab resistances due to its flowable behavior under ordinary conditions and become a rigid solid when a strong impact is applied. Objective of this study is to develop flexible, lightweight and high protection level soft body armors with the impregnation of shear thickening fluids onto fabrics. In this study, for the production of STFs, colloidal and fumed silica nanoparticles were employed. As the carrier fluid polyethylene glycols (PEG) with three different molecular weights were used. The STFs were prepared by sonication of nanoparticles within the carrier fluid. The rheological behaviours of STFs were investigated using a rheometer. Two types of composites were fabricated by impregnating of STFs onto aramid and UHMWPE mat fabrics. The stab resistances (quasi-static and dynamic), flexibility and ballistic features of composites were tested and compared with neat fabrics. The microstructural surface coating features of STF and composites were also characterized by using scanning electron microscope (SEM).
  • Master Thesis
    Development of Liquid Armor Materials and Rheological Behavior of Shear Thickening Fluids (stfs)
    (Izmir Institute of Technology, 2011) Erdoğan, Taner; Tanoğlu, Metin
    Colloidal dispersions have been extensively used in many industrial applications such as cosmetic, paint, cement, lubricant and ceramic. Shear thickening is non- Newtonian flow behavior often observed in concentrated colloidal dispersions as an increase in viscosity with increasing shear rate or applied stress. Shear thickening fluids (STFs) exhibit fluid and solid-like properties depending on the shear rate and thus can be used in a variety of applications. In the present study, STFs have been synthesized with various weight fractions of silica nanoparticles in polyethylene glycol (PEG)/ethyl alcohol by mechanical mixing method. The steady and dynamic rheological behavior of shear thickening fluids (STFs) was investigated with rheometer. STFs thermal properties were investigated through thermogravimetric analysis. STFs have been used to improve the performance of Kevlar woven fabrics for protective applications in ballistic and stab. STFs/Kevlar fabric composites have been prepared with different impregnation techniques to evaluate the effects of the STFs. The ballistic performance and stab resistance of STFs impregnated Kevlar fabrics were investigated. Rheological measurements revealed the shear thickening effect of silica nanoparticles/PEG systems depending on the shear rate. In dynamic experiments, the strain thickening behavior was found at critical combination of strain amplitude and frequency. The viscous G modulus values were found to be greater than the elastic G modulus. The elastic G and the viscous G modulus values were found to increase when the strain amplitude is kept constant and frequency is increased. The same strain thickening behavior was also found when the frequency was kept constant and the strain amplitude was increased. The puncture resistance of STFs/Kevlar fabric composites exhibited significant improvements as compared to the neat Kevlar targets. Based on the SEM results, STFs were uniformly impregnated over the entire surface on the Kevlar fabric and Kevlar fabrics completely coated with STFs. The ballistic test results revealed STF/Kevlar fabric composites have potential to obtain liquid armor materials.