The Intra/Inter-Molecular Interactions of NOM Components: A Study of Self-Assembly Using Small Angle Neutron Scattering and Pulsed- Field Gradient NMR

摘要

Recent work has shown that natural organic matter (NOM) is a self-assembled material comprised of components of varying chemical composition including humic acid (HA0), a highly aromatic non-amphiphilic fraction (HA1), a lipid-like fraction (L1), and a strongly amphiphilic fraction (HA2) that self-assemble via a hierarchical aggregation process (1). Small Angle Neutron Scattering (SANS) was used to obtain information regarding interactions that occur between NOM components. SANS was also used to establish contrast match points for the lower level components from one material source for future investigation of structural differences between NOM components. Pulsed field gradient (PFG)-NMR data was acquired to generate Diffusion Ordered Spectroscopy (DOSY) spectra to determine the diffusion coefficients of the HA0, HA1, HA2, and L1 humic acid fractions, and the native composite of HA2 and L1 referred to here as L0, from two material sources.