Design and characterization of magneto-sensitive PVA hydrogel membranes

A. MANJUA; F. VACA CHAVEZ; PEDRO J. SEBASTIÃO; J. CRESPO; C. PORTUGAL

Congreso; IX IBERO-AMERICAN CONGRESS ON MEMBRANE SCIENCE AND TECHNOLOGY; 2014

The structural and topographical design of surfaces assume a high importance in the performance of several membrane based processes. A suitable combination of the surface topography and chemical characteristics may generate membranes with extreme hydrophilic or hydrophobic characteritics [1]. Membrane hydrophilic/hydrophobic character and surface topography itself (e.g. roughness) are important parameters in separation processes, since it regulates the adsorption/deposition of solutes at the membrane surface and thus fouling, fluid dynamics and ultimately mass transport [2]. Also, these membrane surface properties are quite relevant in the performance of biocatalytic processes, membrane sensors and biomedical devices (e.g. tissue scaffolds). The efficiency of these processes is intemately related with the mode that specific molecules (e.g. proteins) or cells sense the surface and the impact that it may produce on their activity [3]. The ability to adjust the surface chemical and topographic design in a non-invasive and reversible mode is forseen as an important membrane functionality that may contribute for the improvement of the effciency of different membrane based processes. Aiming the design of magneto-sensitive hydrogel membranes for biocatalytic and medical applications, polyvinil alcohol (PVA) membranes with embedded magnetic responsive particles, such as magnetite Fe3O4, were prepared in the absence and presence of an external magnetic field. As shown in Fig 1. (a) and (b), the use of a low magnetic field < 0.1 T allowed for a complete allignment of the particles towards the magnetic field direction.