Nuclear magnetic resonance spectrometry of chemically and physically altered porous silica surfaces under gas chromatographic conditions.
Conventional nuclear magnetic resonance spectrometry in solution, in combination with (13)C labelling, has been utilized to investigate differences in freedom of motion of similar chemically altered and physically modified porous silica sorbents under dry conditions, and the results have been correlated with previously reported results for chemically altered solvated surfaces. Spin-lattice relaxation time of the labelled terminal methyl groups decreases in the order chemically modified solvated ligands, chemically bonded unsolvated ligands, and physically sorbed unsolvated molecules.
Gilpin
R K
RK
Department of Chemistry, Kent State University, Kent, Ohio 44242, U.S.A.
Gangoda
M E
ME