Development of mixed-matrix membranes

A second phase with defined inner interface for polymer membranes

Mixed-matrix membranes (MMM) are made of hybrid materials. These have defined internal interfaces, which in turn are characterized by discontinuously changing material properties. 

We work with both organic-organic and organic-inorganic composites, where the membrane polymer is often filled with particles or fibers. The second phase can improve membrane properties such as permeability and selectivity, add completely new functionalities, or improve swelling behavior or overall stability.

 

Organic-organic mixed matrix membranes

In the case of organic-organic MMM, we use self-developed polymeric sub-micron particles, which are available with a wide range of different surface functions. These particles are fully compatible with the phase inversion process and the resulting membranes can be used as selective membrane adsorbers.

 

Organic-inorganic mixed-matrix membranes

The inorganic particles used are freely available on the market or are manufactured at Fraunhofer IGB using precipitation processes or the sol-gel process. By further modifying the inorganic phase by means of e.g. silanes carrying functional groups, customized membranes for different types of applications (e.g. fuel cells) can be developed.

Application areas of mixed matrix membranes

Micro pollutants

Membrane adsorbers for the separation of micropollutants from drinking water.

Hydrogen

Ionomer mixed-matrix membranes for electrolysis and fuel cells.

CO2 separation

MOF mixed-matrix membranes for the separation of CO2

Reference projects

MAVO MEGA – Functional membranes for save and energy efficient gas separation

 

So far, the industrial use of technical separation membranes has been largely set to liquid filtration and less to gas separation. In the MEGA project, mixed‑matrix membranes were developed at the Fraunhofer IGB in cooperation with three other Fraunhofer institutes, which have great potential for gas separation due to their improved separation properties compared to pure polymer coatings.