| The cylindrical internal reflection (CIR) sampling technique coupled with the rapid scanning capabilities of FTIR spectroscopy proved to be useful for quantitating the speciation of alkoxysilanes in solution. Kinetic and mechanistic data regarding hydrolysis and condensation of methoxysilanes were also obtained. The hydrolysis of trimethylmonomethoxysilane was found to behave under second order kinetics in aqueous organic media; first order with respect to water and methoxysilane. Hydrolysis of the methoxy groups behaved under pseudo-first order kinetics in aqueous medium. The mechanism appears to be an acid catalyzed S{dollar}sb{lcub}rm N{rcub}{dollar}2 bimolecular reaction. The kinetics of the condensation of trimethylmonomethoxysilane were found to be second order with respect to silanol functionalties.; The kinetics of hydrolysis of the three methoxy groups of SiQAC in aqueous solution followed a mechanism consisting of three consecutive-irreversible first order reactions. Similar results for the kinetics of hydrolysis of alkyltrialkoxysilanes in aqueous/organic solution showed that beyond a gamma carbon, steric effects played less of a role in rate of hydrolysis.; DRIFT spectroscopy proved to be a nondestructive, rapid, and sensitive means of obtaining mid-infrared spectra of SiQAC immobilized on nylon 6/6, germanium, and silica gel. At pH 7.9, the loading of SiQAC on the substrates is dependent primarily on the solution behavior of SiQAC. At pH values of 2.7 and 4.6, the initial immobilization of SiQAC is dependent on the surface characteristics of the substrates. Once an initial loading has been established, solution kinetics then determines further loadings.; The use of chemometrics in the study of an industrial silver recovery process has shown that microcomputers with statistical packages are useful tools in the laboratory to identify and solve practical problems. Simple regression and correlation of archival data was able to quickly locate and identify a major source of variability which occasionally reduced the performance of a complex silver recovery process. Two-level fractional factorial design experiments were able to determine from many chemicals the ones which had an important effect on silver removal and provided information on how these chemicals affected the process. |
