The encapsulation of pyrene substituted amphiphilic polymers within core/shell structured silica gels and their sensor application

In recent years, there has been great interest in the development of fast and reliable chemical sensors to detect trace amounts of hazardous chemicals. These sensors have potential applications in environmental cleanup and homeland security. Polynitro aromatic compounds (NACs) such as picric acid (PA), 2,4,6-trinitrotoluene (TNT) and its degradation product dinitrotoluene (DNT) are widely used as key components in many known explosives. Among the various known detection methods, fluorescence techniques have recently gained special interest. Pyrene and its derivatives are widely used in fluorescence-based sensor systems due to their fluorescent properties and high stability. In this thesis, a new explosive detection sensor system was developed by encapsulating amphiphilic polymers containing pyrene into mesoporous silica gels with a core/shell structure consisting of a hydrophilic core and a hydrophobic outer shell by pore size reduction. The SiO2 core synthesized by the Stöber method was coated with hydrophobic BTME (1,2(bistrimethoxysilyl)ethane), an organosilane derivative, in the presence of pyrene-containing amphiphilic polymers and small organic molecules (resorcinol, etc.) were used as templates to create an interphase gap during coating. The bilayer structure was then etched with ammonia solution to shrink the core, which increases the phase gap between the core and the shell. In this way, the high surface area and fast adsorption properties provided by the interphase and pore size allowed this structure to be used as a sensor for the detection of nitroaromatic compounds. The obtained material with pyrene containing core/shell structure was characterized by TEM, BET, TGA, DLS methods. The photophysical properties of the related compound were determined by UV-VIS and Fluorescence spectroscopy.