Mixed-matrix membranes (MMM) are made of hybrid materials, where defined internal interfaces exist with a discontinuous change in material properties. We are working both with organic-organic and organic-inorganic composite materials, where the membrane polymer is often filled with particles or fibers. The second phase can improve the membrane properties such as permeability and selectivity, can add completely new functionalities or can improve swelling behavior or the overall stability.
In case of organic-organic MMM we often use self-made polymeric sub-micron particles which are available with a broad range of different surface functions. These particles are completely compatible with the phase inversion process and the resulting membranes can be used as selective membrane adsorbers.
The inorganic particles used are commercially available or formed at Fraunhofer IGB via precipitation or sol-gel chemistry. Due to further modification of the inorganic phase by means of silanes bearing functional groups, tailor-made membranes can be prepared for various kinds of application (e.g. fuel cells).