Bazı geçiş metali tuzlarının mezoyapılı silika sentezi üzerine etkileri

True Liquid Crystal (TLC) templating approach has been extensively used toproduce mesostructured silica films and monoliths. It is known that nonionic surfactants(CnEOm) are suitable templates for this purpose. In this work, we have introduced varioustransition metal salts into mesostructured silica materials through TLC approach. Thework has two aims; one is to introduce large quantities of metal ions into the silicachannels and second is to study the effect of the metal cation and the counter anion to thestructure of the mesophase. Current understanding about the solubility of non-ionicsurfactants in aqueous media is that, the solubility decreases upon dehydration. Salting-out ions (according to the Hofmeister series) that cause dehydration will decrease thesolubility of surfactants. Due to the solubility change the concentration and the type ofsalt will affect the structure of the LC template and as a result the mesostructured silica.The total charge (ionic strength) of the system has also a principal role on the structure ofthe mesophase. High ionic strength will decrease the solubility and influence theassembly of the surfactant molecules into LC mesophases. Although an alkaline metalperchlorate anion makes the surfactant more soluble than nitrate anion in awater:surfactant system, the transition metal perchlorates are harder to dissolvecompared to nitrate salts in a salt:surfactant system. This fact is due to the coordination ofthe nitrate ion to the metal cation. Upon coordination the ionic strength decreases and thisivincreases the solubility of transition metal nitrates. However the perchloriate ion does notcoordinate to a transition metal cation.In this thesis, the structural changes in the transition metal salt(TMS):CnEOm:silica systems were investigated using diffraction (XRD), microscopy(POM) and spectroscopy (FTIR and micro-Raman) techniques. The [Co(H2O)6](NO3)2salt silica systems are hexagonal up to 1.2 salt/C12EO10 mole ratio and over thisconcentration the mesophase is cubic. Usage of a surfactant with longer alkyl chain(C18EO10) increases this phase change over 2.0 mole ratio. However, the[Co(H2O)6](ClO4)2 salt:silica systems have cubic structures at very low salt/C12EO10 moleratios (above 0.2 mole ratio), whereas they are hexagonal when no perchlorate salt isadded.It has been demonstrated that the LC mesophases of the TMS:Pluronic(triblockcopolymer surfactant family) systems exist with a very rich structural chemistry. TheTMS:Pluronic systems have lamella, hexagonal, various types of cubic and a tetragonalmesophases. The TMS:P65 and TMS:P123 systems are ordered and well structured. Thehexagonal mesophase in the [Zn(H2O)6](NO3)2:P65 systems and the tetragonal and cubicLC mesophases in the [Zn(H2O)6](NO3)2:P123 systems were identified. The LCmesophases of TMS:Pluronics can be used as templating agents for the synthesis ofstable mesostructured silica. The lamella mesostructured silica obtained using[Zn(H2O)6](NO3)2:P123 LC mesophase transforms to 2D hexagonal structure uponcalcinations (goes from layered structure to long channel hexagonal tubes).Keywords: Lyotropic liquid crystals, mesophases, transition metal aqua complexes,non-ionic surfactants, Pluronics, mesoporous materials, Hofmeister effect.v