Date of Award

2013

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemistry

First Advisor

Jimmie C. Oxley

Abstract

The first part of this work mainly focuses on distinguishing and characterizing two white solids namely urea nitrate (UN) and nitrourea (NU) with similar melting point (~160oC). Urea Nitrate is an inorganic salt. It has found use as an improvised explosive and was used in the first world trade center bombings. Nitrourea, a dehydrated product of UN, is an organic salt. In this study we reported and compared two routes to NU synthesis. We also proposed a decomposition route for UN.

The second part of the work investigates perchlorate contamination in soils following fireworks displays. A total of two hundred and twenty two soil specimens were collect before and after ten individual July 4th fireworks display events from 2007 to 2012. Soils were extracted in water and analyzed using ion chromatography by a modified EPA Method 314.0. Our study showed that soils are free of perchlorates before and four months after fireworks, but the soil samples collected within 24 hrs of fireworks showed perchlorate contamination from below the detection limit up to hundreds or thousands of nanograms per gram of soil. Through this study we also suggest that poor adsorption of perchlorates by soil matrices results in ground water contamination.

The third part of the manuscript explores the methodologies used to prevent solid phase changes in ammonium nitrate (AN) for expanding its usage in applications. These solid phase changes occur because of absorption of moisture from the atmosphere. AN was thoroughly dried to stop these phase changes and then attempts were made to maintain dryness of AN by coating with polymers. Dried AN and polymer coated AN performance was tested using differential scanning calorimetry (DSC). We have succeeded in drying and encapsulating AN. Many questions are unanswered at this moment, such as the amount of polymerization, the uniformity of coating, the amount of absorption of moisture and if there are any more methodologies or other polymers which would improve the performance. This study is underway.

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