Award Date

1-1-1994

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Number of Pages

89

Abstract

Computerized molecular modeling methods supplemented with chemometric methods may be used to provide information regarding sensitivity, selectivity, and other properties of solid/vapor sorption interactions for chemically coated Quartz Crystal Microbalances (QCMs). When exposed to the individual vapors of a homologous series of carboxylic acid vapors, a QCM coated with varying thicknesses of poly(ethylenimine) (PEI) coating, produces a linear response that is sensitive and selective. The selectivity of the PEI coating toward analytes increases with aliphatic chain length probably due to dispersive interactions. A linear relationship between calculated van der Waals force values and experimental dispersion force values may exist. BET isotherm plots indicate that heats of adsorption values for the interactions fall within the range of physical adsorption. At high analyte concentrations, PEI coated sensors may behave differently because multilayering interactions increase. At low concentrations, monolayer adsorption appears to predominate and the values of the coating coefficients become constant.

Keywords

Coating; Crystal; Microbalances; Quartz; Recognition; Responses; Study

Controlled Subject

Chemistry, Analytic; Chemistry, Physical and theoretical

File Format

pdf

File Size

2109.44 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

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