Novel view at hybrid membranes containing star macromolecules using neutron scattering and pervaporation dehydration of acetic acid

Abstract

Hybrid membranes based of polyphenylene oxide matrix and star macromolecules (up to 5 wt%) containing six polystyrene and six poly-2-vinylpyridine arms attached to a common fullerene C60 center were prepared and successfully used for pervaporation separation of acetic acid – water mixtures. The peculiarities of the hybrid membrane structure and properties were studied by small-angle neutron scattering in two states (dry and swollen in deuterated acetic acid). It was established that star macromolecules are non-uniformly distributed in the matrix and form aggregates; they increase in the size up to ~60% during swelling of membranes in deuterated acetic acid. In pervaporation, the total flux through the membrane rises with increasing both the star macromolecule content in membrane and water concentration in the feed. Separation factor reaches its greatest value when the hybrid membrane contains 5 wt% star macromolecules. Keywords: Pervaporation, Neutron scattering, Membrane, Polyphenylene oxide, Star macromolecules, Acetic acid – water mixture