Katanyonik Moleküller Kullanılarak Kendiliğinden Kümeleşme Yöntemiyle Nano/Mikro Boyutlu Yapıların Oluşturulması ve Karakterizasyonu

Abstract

Tubular morphologies are widely investigated and used in fundamental science such as chemistry, biology and physics, also these aggregates are used in medical areas to diagnose or treatment so many diseases. Besides their shapes, dimensions and applications, it’s very important that how they are obtained. One of these method’s heating and cooling process of amphiphilic molecules. But not every molecule‘s easy to find or some molecules’re very expensive and because of energy and time consumption, self assembly processes can cost so much for large scale production. For these reasons different methods are investigated to obtain tubular morphologies. Lately, anionic and cationic molecules are used for self assembly of amphiphilic molecules to get tubular aggregates. Mixtures of anionic and cationic molecules are called as ‘catanionic mixtures’. The reasons of using anionic and cationic molecules to obtain self assembled tubular nano/micro structures, it’s easy to find these molecules commercially and they’re synthesized simply. It’s already known for a long time that vesicular structures are formed by anionic and cationic molecules mixtures, and in recent years it’s found that these vesicles create tubular structures with time or tubular structures’re formed as soon as anionic and cationic molecules’re mixed. This study’s aim is getting self assembled nano/micro sized tubular structures spontaneously with using anionic and cationic molecules that are found easily and investigation of optimum conditions to obtain tubular structures. At this study as anionic molecules, Aqua molecule (C25H29NO4) which is pH responsive, has a redox active group in its molecular structure and is synthesized in our laboratory and lithocholic acid (LCA) were used. As cationic molecules, cetyltrimethylammonium hydroxyl (CTAOH) and hexadecyltrimethylammonium hydroxyl (HTAOH) which is also synthesized in our laboratory were used. Aionic Aqua and LCA molecules mixed with cationic CTAOH and HTAOH molecules at different concentration and mixing ratios in order to get catanionic mixtures. These catanionic mixtures’ characterizations were done to specify the optimum conditions. To find the optimum conditions, light scattering, surface tensions, fourier transform infrared spectroscopy (FT-IR), zeta-potential and X-ray diffraction (XRD) iv

datas were used, for observing the obtained structures, optical microscope, atomic force microscope (AFM) and scanning electron microscope’s (SEM) images were taken. The best interactions between the anionic and cationic molecules in the catanionic mixtures with Aqua were observed when the ethanol amine was added after the anionic and cationic molecules mixed. Also with SEM images it’s understood that the best fibril-like structure and size distribution were occured when the molar mixing ratio was 9:1 Aqua:CTAOH/HTAOH and concentration of Aqua was 1% by weight. Also these nanofibrils potential applications were investigated. In order to understant the effects of different types of molecular structures on self assembled aggregations, LCA and CTAOH/HTAOH catanionic mixtures were examined. It was seen that the vesicular shapes was formed as soon as LCA and HTAOH were mixed but this situation didn’t occur for LCA:CTAOH. Also the fibrils had tendency to twist for LCA:CTAOH but there was just elongation of fibrils at LCA:HTAOH mixtures.