Biochar amendments can impart favorable structural and fertility characteristics
to soil, but can also be useful for studying some of the more esoteric
properties of humics, such as solubility, chelation, and surfactancy.
Previous studies showed that aromatic-rich humics stabilize nanoparticle
dispersions, while more recently, we presented evidence suggesting
that aromatic-rich humics showed diminished surfactancy with increased
O-alkyl and O-alkyl C-O functional group content. Thus, we present
detailed structural studies on the surfactive ability of low quality
biochars, which in addition to aromatics, are expected to contain
fatty acid groups, but limited in glycosidic-type groups. In particular,
we characterize the size and shape of the aromatic clusters using
solid-state 13C NMR techniques, including a long-range C-H dipolar
dephasing method. Theoretical calculations of aromatic cluster size
and geometry will be compared to experimental data collected from
condensed standards. Aromatic descriptions will be compared to biochar
dissolution and potential to stabilize nanosilver dispersions.