Amphiphilic
polymer conetworks (APCNs) are hydrogels with hydrophobic
regions synthesized by cross-linking well-defined copolymers. Due
to their amphiphilicity, they have oil solubilization ability. In
this paper, we present a small-angle neutron scattering (SANS) study
of the oil solubilization at the mesoscopic level in APCNs swollen
in D2O, where for better contrast conditions, the hydrophobic
monomer (M) was deuterated. The study was carried out on a series
of APCNs where we systematically varied the mol fraction of the hydrophobic
methyl methacrylate (M) monomer repeating units (from 0.1 to 0.9)
with respect to the hydrophilic 2-(dimethylamino)ethyl methacrylate
(D) monomer repeating units as well as the general block copolymer
architecture (MDM vs DMD). First, the structure of the D2O-swollen APCNs was characterized by means of SANS, which showed
a well-defined structure with a repeat spacing of the domains, d, that scales directly with the architecture of the building
blocks of the APCNs. In the second step, the solubilization of oils
of different polarities (octane, toluene, eugenol, and 1-hexanol)
was probed, and a clear correlation of oil solubilization with the
oil polarity was observed. The most unpolar oil, octane, did not solubilize
at all, while the much more polar toluene and 1-hexanol were incorporated
very well but in a markedly different fashion. Toluene completely
swelled the M part, while 1-hexanol appeared to be much more associated
with the amphiphilic interface. This demonstrates that the studied
APCNs are very selective with respect to their solubilization properties
and efficient for distinguishing different types of oils.