Geçiş metal tuzları:pluronik sıvı kristal mezofazları kullanarak mezoyapılı metal sülfürlerin sentezlenmesi

The Liquid Crystalline Templating (LCT) approach has been extensively usedto produce mesostructured Metal Sulfides (MS) powders by using nonionicsurfactants (CnEOm). The aim in this work is to synthesize larger pore sizemesostructured MS at high salt concentrations by mixing Pluronics(PEOxPPOyPEOx, EO = -OCH2CH2-, PO = -OCH(CH3)CH2-) with transition metalsalts (TMS) [M(H2O)4](NO3)2 in a dilute media. This enables to synthesize thinfilms of mesostructured MS. In this thesis, the MS (M= Cd, Zn, Cd1-xZnx, Cd1-xCoxand Cd1-xMnx) were synthesized by the LCT approach using Pluronic P85((PEO)26(PPO)40(PEO)26) and TMS. The P85 and salts can be dissolved in varioussolvents to obtain clear solution that enables one to increase the salt to pluronicmole ratio up to 30:1. However, the LC mesophases form in theiv[Cd(H2O)4](NO3)2:P85 mole ratio range of 3:1 to 11:1 with a 3D hexagonalstructure and P63/mmc space group having unit cell parameters of a = 99.5 Å andc = 162.5 Å with a c/a ratio of 1.633.The CdS thin film samples, obtained by exposing the [Cd(H2O)4](NO3)2:P85LC phase to H2S gas, could retain the mesostructure of the LC mesophase in themole ratio range of 3:1 to 11:1. The film samples that consist of 50-100 nmmesostructured CdS and free surfactant molecules are uniform and soft in earlystages of the H2S reaction. However, in time, the free surfactant molecules diffuseout of the mesostructured CdS and form dendritic structures, producing CdS thinfilms with huge domains. The CdS thin film samples consist of 4.3 nm CdSnanoparticles that emit orange light under UV irradiation. Well homogenized LCmesophases produce cracked well structured film samples upon H2S reaction.This method can be used to fine tune both the composition (between x=0.0and 1.0) and the optical band-gap of Cd1-xZnxS nanocrystallites between 2.60 eVand 4.00 eV. The Zn(II) and Cd(II) ions are homogenously doped throughout themesostructure and nanocrystallites synthesized by this approach are slightly largerin every composition compared to the ones synthesized in the mesostructured silicachannels. Also both Co(II) and Mn(II) ions could be incorporated into the CdSlattice with x ≤ 0.15 for stable Cd1-xCoxS and Cd1-xMnxS film samples, respectively.The Co(II) ions occupy the isolated tetrahedral holes in the CdS lattice until x =0.15 for stable samples.In this thesis, the structure and structural changes in the LC mesophase duringthe synthesis of MS and particle size analysis of the nanocrystallites wereinvestigated using diffraction (XRD), spectroscopy (FT-IR, micro-Raman and UV-Vis absorption) and microscopy (OM and SEM) techniques.Keywords: Liquid Crystal Templating, Pluronics, Transition Metal Complexes,Mesostructured Metal Sulfides, Doping CdS, Mesostructured Thin Films,Nanocrystallites.v