Biomimetic cooperativity of hydration effect and effect of ethanol favorable for binding of bad organic sorbates were observed for their vapor sorption by cross-linked poly(N-6-aminohexylacrylamide) (PNAHAA) in the absence of liquid phase. The vapor sorption isotherms were determined for these systems by the static method of gas chromatographic headspace analysis at 298 K. The hydration above 0.09-0.13 g of H(2)O/(g of polymer) gives a cooperative increase in the PNAHAA binding affinity for benzene, cyclohexane, dioxane, and propanols up to a level which does not change by further hydration, indicating the polymer antiplasticization. Bad sorbates (dioxane, benzene) were observed to have a biomimetic cooperative influence on the binding of ethanol by the dried PNAHAA. This cooperativity does not occur in ternary systems with good nonhydroxylic sorbate acetonitrile.
A comparative analysis
of the composition of vanadyl porphyrins
isolated from heavy oil using two different sulfocationites has been
carried out. As a source of vanadyl porphyrins, heavy oil of Volga-Ural
basin characterized by a high vanadium content was used. The N,N-dimethylformamide extract of asphaltenes
was derived from this oil and subjected for isolation of primary vanadyl
porphyrin concentrate on a SiO2 column, which was then
chromatographically purified with sulfocationite by our improved method.
Strongly acidic cation-exchange resin and asphaltene sulfocationite
recently developed in our laboratory were used as sulfocationites.
According to ultraviolet–visible spectroscopy, both sulfocationites
showed excellent applicability for purification, providing isolation
of a broad (>50%) fraction of vanadyl porphyrins with higher spectral
purity compared to results of conventional methods. Results of matrix-assisted
laser desorption/ionization time-of-flight mass spectrometry analysis
showed that composition of isolated vanadyl porphyrins depends upon
the chemical nature of sulfocationite. Despite the same range of vanadyl
porphyrin homologues (C26–C40, with maximum
falling on C32) isolated by both sulfocationites, purification
with asphaltene sulfocationite resulted in a 1.4-fold decrease in
the content of the most abundant DPEP type of vanadyl porphyrins,
with a corresponding 1.1–1.9-fold increase in the content of
the rest of the types. It was also established that, when purification
is accomplished, a significant part of the same vanadyl porphyrins
still remains in the column, which can be explained by their associations
with non-porphyrin components of the oil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.