1 research outputs found
Water-Responsive Internally Structured Polymer–Surfactant Films on Solid Surfaces
Water-insoluble films of oppositely
charged polyion–surfactant
ion “complex salts” (CS) are readily cast on solid surfaces
from ethanolic solutions. The methodology introduces new possibilities
to study and utilize more or less hydrated CS. Direct SAXS measurements
show that the surface films are water-responsive and change their
liquid crystalline structure in response to changes in the water activity
of the environment. In addition to the classical micellar cubic and
hexagonal phases, a rectangular ribbon phase and a hexagonal close-packed
structure have now been detected for CS composed of cationic alkyltrimethylammonium
surfactants with polyacrylate counterions. Added cosurfactants, decanol
or the nonionic surfactant C<sub>12</sub>E<sub>5</sub>, yield additional
lamellar and bicontinuous cubic structures. Images of the surfaces
by optical and atomic force microscopy show that the films cover the
surfaces well but have a more or less irregular surface topology,
including “craters” of sizes ranging from a few to hundreds
of micrometers. The results indicate possibilities to create a wealth
of water-responsive structured CS films on solid surfaces