Ankara : The Department of Chemistry and the Institute of Engineering and Sciences of Bilkent University, 2009.Thesis (Master's) -- Bilkent University, 2009.Includes bibliographical references leaves 86-100.Mesostructured [Cd(H2O)4](NO3)2 - titania - P123
((PEO)20(PPO)70(PEO)20, PEO = -OCH2CH2-, PPO = -OCH(CH3)CH2-) materials
have been investigated by changing the [Cd(H2O)4](NO3)2 and titania content of the
structures. This has been achieved by making thick samples by casting and thin film
samples by spin coating of a butanol solution of [Cd(H2O)4](NO3)2, P123, nitric acid
and Ti(OC4H9)4. The film samples are named as meso-xCd(II)-yTiO2, where x is the Cd(II)/P123 and y is TiO2/P123 mole ratios. Increasing the titania amount in the
media has transformed the samples from LC-like to soft and then to rigid
mesostructured materials. Changing the amount of [Cd(H2O)4](NO3)2 salt in the
media only influenced the mesostructure, such that no change on the mechanical
properties is observed. However, the synthesis of rigid mesostructured titania
materials required controlled humidity. The rigid film samples were prepared first by
spin coating and then by aging under a 50% humidity oven.
The mesostructure remains stable upon H2S reaction, in the soft and rigid
materials region. However, only rigid samples stand to removal of nitrates from the
media that is important to keep the CdS nanoparticles stable in or on the pore walls
of mesostructured film samples. The phase behavior of the meso-Cd(II)-TiO2, the
structural properties of the meso-xCdS-yTiO2 samples, coordination and elimination
of the NO3
-
ions and the particle size of the CdS nanocrystallites were investigated
using diffraction (XRD), spectroscopy (FT-IR, Raman and UV-Vis absorption, EDS)
and microscopy (POM, SEM, and TEM) techniques.Okur, Halil İbrahimM.S