Piezoelectric properties of polyelectrolyte multilayer films

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Kimya Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2015

Tezin Dili: İngilizce

Öğrenci: ÖZLEM SEVER

Asıl Danışman (Eş Danışmanlı Tezler İçin): Göknur Bayram

Eş Danışman: İrem Erel Göktepe

Özet:

Piezoelectric material is the material which converts the electrical energy to the mechanical energy or mechanical energy to the electrical energy. Piezoelectricity is usually considered as a property of ceramic materials because their crystal lattice structure does not have a centre of symmetry, as a result, the unit cells of ceramics contain a small electric dipole. However, after piezoelectric properties of poly(vinylidene fluoride) (PVDF) were discovered, polymeric materials have been preferred over the ceramic ones due to their high flexibility, low cost, high chemical stability, etc.. In order to obtain piezoelectric properties, electrical poling process has to be applied to the materials, which means that they have to be polarized. Layer-by-layer self-assembly is a technique to produce ultra-thin multilayer films. It is based on alternating deposition of oppositely charged polyelectrolytes at the surface. LbL films have been investigated as potential piezoelectric materials due to polarization within the multilayers, eliminating the electrical poling treatment to obtain a piezoelectric material. In this study, piezoelectric characteristics of LbL films of different polyelectrolyte pairs have been examined and contrasted.