Synthesis of silver nanowires through polyol process

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Metalurji ve Malzeme Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2012

Öğrenci: ŞAHİN COŞKUN

Danışman: HÜSNÜ EMRAH ÜNALAN

Özet:

Nanotechnology enabled synthesis of various shapes and morphologies of conventional materials. Nanotubes, nanoparticles, quantum dots and nanowires are the new form of materials. Especially nanowires have gotten great attention due to their unique physical, chemical and optical properties. Superior properties of nanowires are based on their high surface area and two quantum confinement directions. Silver is one of the most conductive metals and it has the highest thermal conductivity. Due to excellent properties of bulk silver its nanostructures especially silver nanowires have been widely studied. Silver nanowires have been demonstrated to be used in optical polarizers, photonic crystals, surface enhanced Raman spectroscopy and recently transparent and conducting electodes. Hence, production of silver nanowires through a cost-effective and well controlled method could make important contributions to these and other unprecedented. So far, many different methods have been explored for the synthesis of silver nanowires. Vapor-liquid-solid (VLS) technique, hard template techniques such as porous anodic alumina synthesis and soft template techniques such as DNA based synthesis and polyol process are some silver nanowire synthesis methods. Among these methods, solution based polyol process is the most feasible one in terms of cost, yield and simplicity. In this thesis, polyol process, which is a novel and solution based method enabling the synthesis of silver nanowires with precise length and diameter control, is investigated. A detailed parametric study resulting in a full control over the resultant nanowire morphology is provided. The parameters affecting the structure have been determined as temperature, injection rate, poly(vinylpyrrolidone):silver nitrate (PVP:AgNO3) molar ratio, sodium chloride (NaCl) amount and stirring rate. The results show that polyol process method could replace the conventional silver nanowire fabrication methods. It was shown that specific nanowire lengths and diameters for any application can be obtained simply by adjusting the parameters of the process.