| Modification of the surface of zeolites with organosilane coating materials was performed through the introduction of a dried zeolite with an organosilane-hydrocarbon solution resulting in a covalent linkage between coating and zeolite. Gravimetric techniques (TGA) and spectroscopic techniques (NMR) aided to identify the presence of coating material. This study looks specifically at modifying the surfaces and subsequent characterization of four zeolites: synthetic Linde Type A (LTA): 4Å and 5Å, two natural zeolites that were obtained from sites in the Bay of Fundy, Nova Scotia, with the following coating materials: SurfaSiI™ (SS), trimethylchlorosilane (TMCS) and a novel, synthetic pyrene-containing organosilane, pyrene-1-(4-butyl-dimethylchlorosilyl) ether (Pyrene-Cl). Through solvent uptake experiments with water, methanol and ethanol, it was found that the coated materials experienced the same degree of solvent uptake as the uncoated material. This was verified through preliminary TGA studies as well as duplicate uptake experiments. Solid state 13C NMR experiments were done to verify the presence of the coating material by looking at the resonance of methyl carbons, specifically adjacent to silicon, shown at 0 ppm. 29Si SS NMR showed that 5 chemical environments were found in both natural zeolite samples, indicating the presence of impurities. Powder X-ray diffraction also provided evidence of impurities within the samples; in addition, correlation of the sample powder patterns to literature values was not successful. 27Al SS NMR showed that only tetrahedrally coordinated aluminum was present in both natural samples. |
