INVESTIGADORES
CORREA Nestor Mariano
artículos
Título:
On the Characterization of NaDEHP/n-Heptane Nonaqueous Reverse Micelles. Effect of the Polar Solvent.
Autor/es:
SILVINA QUINTANA; R. DARIO FALCONE; JUANA J. SILBER; N. MARIANO CORREA *; FERNANDO MOYANO
Revista:
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Editorial:
ROYAL SOC CHEMISTRY
Referencias:
Lugar: CAMBRIDGE; Año: 2015 vol. 17 p. 7002 - 7011
ISSN:
1463-9076
Resumen:
The behavior of two polar solvents, ethylene glycol (EG) and dimethylformamide (DMF), entrapped in
sodium bis-(2-ethylhexyl) phosphate (NaDEHP)/n-heptane reverse micelles (RMs) was investigated using
dynamic light scattering (DLS), molecular probe absorption and FT-IR spectroscopy. DLS results reveal
the formation of RMs containing EG and DMF as a polar component. To the best of our knowledge this
is the first report where both polar solvents are entrapped by the NaDEHP surfactant to effectively
create RMs. We use the solvatochromism behavior of the molecular probe, 1-methyl-8-oxyquinolinum
betaine (QB), and FT-IR spectroscopy to investigate the physicochemical properties of the non-aqueous
RMs. Our results demonstrate that the NaDEHP surfactant interacts through hydrogen bonds with EG at
the EG/NaDEHP interface and this interaction is responsible for destroying the bulk structure of pure
solvent EG when entrapped in NaDEHP RMs. On the other hand, when DMF is incorporated inside the
RMs the bulk structure of DMF is destroyed upon encapsulation by the Na?DMF interaction at the DMF/
NaDEHP interface. Our results are completely different than the one observed for DMF/n-heptane/AOT.
Our results show how the physicochemical properties, such as micropolarity, microviscosity and
hydrogen bond interaction, of nonaqueous NaDEHP/n-heptane RMs interfaces can be dramatically
changed by simply using different non-aqueous polar solvents. Thus, these results can be very useful to
employ these novel RMs as nanoreactors since the dimensions of the RMs are around 10 to 20 nm.