Growth and characterization of branched gold nanoparticles on surfaces

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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: 2014

Öğrenci: NİMET İLKEM EVCİMEN

Eş Danışman: HÜSNÜ EMRAH ÜNALAN, EMREN NALBANT ESENTÜRK

Özet:

Branched gold nanoparticles, having sharp edges and tips, provide very high sensitivity to local changes in the dielectric environment, as well as large enhancements of the electric field around the nanoparticles. This makes them very attractive for the applications where special optical properties are needed such as sensing, therapeutic treatments and photovoltaic devices. Nanostructures are needed to be stabilized on some type of support for most of these applications.. This can be achieved either by dispersing synthesized nanoparticles onto the surfaces or by directly synthesizing them on the surface. Second approach can be more practical as it is eliminating the extra step of nanoparticle dispersion by methods such as spin coating or drop casting. In this study, branched Au nanoparticles were synthesized on surfaces of three different supports (glass, ITO, Si-wafer). Parametric study was performed to investigate the effect of reactant concentrations, seed type and pH of the growth media on the quality of products. Optimum conditions were determined for synthesizing nanostructures in high yield and structural purity. Characterization of nanostructures was done by detailed analysis via scanning electron microscope (SEM), energy dispersive X-Ray (EDX) and X-Ray Diffraction (XRD) methods. The analyses showed that all of the nanostructures synthesized at optimum conditions have branched morphologies with sizes of ca. 450 nm and they are well dispersed on the support surface.