Accession Number : ADA335796

Title :   Site-Selective Spectroscopy of Adsorbates on Mineral Surfaces using FTIR

Descriptive Note : Final rept. Sep 94-Sep 97

Corporate Author : WYOMING UNIV LARAMIE DEPT OF CHEMISTRY

Personal Author(s) : Carron, Keith T.

PDF Url : ADA335796

Report Date : 05 JAN 1998

Pagination or Media Count : 73

Abstract : The montmorillonite clay modification was studied by DRIFT spectroscopy. The modifiers we used were the nonionic modifiers n-heptadecanonitrile (C16 nitrile) and hexadecanamide (C16 amide) which are biologically inert and degradeable. The interaction mechanisms between these modifiers and the montmorillonite clay were investigated. It is found that the polar groups of the modifiers can interact with the specific Si (delta+)-O (delta-)-M(n+) structure of montmorillonite through dipole-ion and dipole-dipole interactions to form a stable complexes. The investigation of a possible hydrolysis of C16 nitrile on the montmorillonite interlayer surface indicated that at a strong acidic condition, the C16 nitrile can be hydrolyzed to form C16 amide which interacts with the montmorillonite clay interface to form a stable ring structure. These results are desirable in the possible application of the modified montmorillonite clay as a waste water treatment agent. The structure of Aldrich humic acid (AHA) and its metal coordination ability are investigated by transmittance Fourier Transform InfraRed (FTIR) spectroscopy, isotopic substitution and reactive substitution were used to assign the IR spectra. A characteristic redox reaction and model compounds were also used for studying a macromolecular AHA. Structure studies have indicated that catechol analogues and phthalic acid analogues are the main functional groups of AHA. It was found that the metal coordination ability of AHA was affected by functional group's characteristics and solution pH. AHA showed higher metal coordination ability at neutral conditions than that at acidic conditions. Catechol analogues coordinate with metal cations to form metal - semiquinone complexes through an oxidation-chelation mechanism.

Descriptors :   *FOURIER TRANSFORMATION, *INFRARED SPECTROSCOPY, *WASTE WATER, *SURFACES, *CLAY, *WASTE TREATMENT, *MINERALS, *FOURIER SPECTROSCOPY, *ADSORBATES, *MONTMORILLONITE, METALS, CATIONS, STABILITY, MODELS, SPECTROSCOPY, SOLUTIONS(MIXTURES), INTERACTIONS, MODIFICATION, CHELATION, REACTIVITIES, TRANSMITTANCE, WATER TREATMENT, DIPOLES, ISOTOPES, SUBSTITUTES, HYDROLYSIS, PH FACTOR, OXIDATION REDUCTION REACTIONS, HETEROCYCLIC COMPOUNDS, ORGANIC ACIDS.

Subject Categories : Organic Chemistry
      Miscellaneous Materials
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE