Synthesis and characterization of novel functional electrosterically stabilized colloidal particles prepared by emulsion polymerization using a strongly ionized amphiphilic diblock copolymer.

Amphiphilic diblock copolymers such as poly(styrene)-block-poly(styrene sulfonate) (PS-b-PSS) (Matsuoka, H.; Maeda, S.; Kaewsaiha, P.; Matsumoto, K. Langmuir 2004, 20, 7412), belong to a class of new polymeric surfactants that ionize strongly in aqueous media. We investigated their self-assembly behavior in aqueous solutions and used them as an emulsifier to prepare electrosterically stabilized colloidal particles of different diameters between 70 to 400 nm. We determined the size, size polydispersity, effective charge, total dissociable charge, structural ordering, and phase behavior using light scattering, transmission electron microscopy (TEM), small-angle neutron scattering (SANS), and potentiometric titration. These experiments clearly demonstrated that all of the synthesized particles were nearly monodisperse (polydispersity index

Characterization of porous structure through the dynamical properties of ions confined in sulfonated polyimide ionomers films.

The structure of sulfonated PolyImide (sPI) ionomer membrane has been investigated via the transport properties of ions confined inside. Transport coefficients of N(CH(3))(4)(+) and Na(+) ions have been determined by several techniques in order to get a range of time/space scale as wide as possible: a method using radiotracers, conductivity, pulsed field gradient NMR and NMR quadrupolar relaxation rates determination. For N(CH(3))(4)(+), the self-diffusion has been measured in the direction of membrane plan (parallel) and in the perpendicular direction (transverse), whereas for Na(+) only transverse self-diffusion has been measured. The conductivity of both ions has been measured in the transverse direction. The results show a anisotropic and multiscale structure with a separation phase between hydrophilic and hydrophobic domains that is not well-defined.