Chemical Sensing of N-Nitrosodimethylamine and Methane

Abstract

In Chapter 1, an introduction to chemical sensing is presented. Several modalities are introduced, including optical, gravimetric as well as chemiresistive together with brief in-troductory backgrounds. Subsequently, metrics to assess sensor performance are sum-marized. Finally, some strategies to combat interferants during chemical sensing are dis-cussed.

In Chapter 2, published work on a luminescent method to determine levels of N-nitrosamines is presented. This work involved the synthesis of five phosphines bearing N-heterocycles, followed by coordination with Cu(I) to give luminescent complexes. Emission spectra spanned the visible range, demonstrating the tuneability of these compounds. The complexes’ interactions with N-nitrosamines were also examined through spectroscopy and crystallography.

In Chapter 3, development of free-volume promoting monomers and catalysts for in-sertion polymerization is demonstrated. Insertion polymerized material was compared to that synthesized using Ring Opening Metathesis Polymerization (ROMP), showing that the former had superior properties for methane detection through higher surface areas and po-rosity.

In Chapter 4, the structure activity relationship of components within a previously pub-lished methane sensing assembly was thoroughly examined to identify how changes in humidity levels influenced sensing response. Poly-4-vinylpyridine modification was per-formed under flow conditions, while the chemical composition of the polyoxometalate (POM) component was also varied. Humidity was determined to most significantly affect the POM and influence the electrical contact between carbon nanotubes and gold.

Finally, Chapter 5 presents several modifications of the parent porous framework out-lined reported in Chapter 3. A soluble monomer bearing adamantyl substituents was suc-cessfully synthesized by attachment of isopropyl units. Its propensity to participate in inser-tion polymerization was then examined. Sulfonation and nitration of the parent polymer I-AntN were also conducted and the product analyzed. Attempts at copolymerization of AntN with CO were also described.