Development of polymer membranes

By far the majority of commercially available membranes are made of polymers. This class of materials offers convincing advantages in terms of cost, processability and a wide range of applications. 

 

Flat and hollow fiber membranes from laboratory to pilot scale

We work with both commercially available polymers and modified polymers (e.g. by sulfonation) as well as with (block co-)polymers produced in-house – by radical or anionic polymerization. 

 

Production of dense membranes

The manufacturing processes for porous membranes include both non-solvent-induced and thermally induced phase inversion. With the help of these processes, we produce membranes from cellulose derivatives, polysulfone, polyethersulfone, polyacrylonitrile, polyvinylidene fluoride and biopolymers, for example. For the production of dense membranes we use solvent evaporation processes. With their help, we manufacture, for example, Nafion®, sulfonated polyetheretherketone and polybenzimidazole membranes.

 

Process control and modifications 

To control pore size or to equip membranes with special properties, we use various additives such as hydrophilic polymers, conductivity enhancers, inorganic fillers and different fiber-based carriers. In addition, we have experience in replacing toxic (e.g. NMP, methanol) solvents by non-toxic ones..

Application areas of polymer membranes

Water purification

Forward osmosis membranes for gentle processing of complex mixtures.

Moisture management

Humidifier membranes for water management in mobile fuel cell systems.

Green membranes

New filtration membranes via phase inversion processes with green solvents.

Reference projects

March 2015 - August 2017

BIOBUTANOL

Use of membranes for the processing of biobutanol by osmosis

For fermentatively produced second-generation fuels such as butanol, downstream processing is an energy-intensive and thus cost-intensive step. Through the combined use of optimized gas stripping and an osmosis-driven membrane process, a process has been developed that allows dewatering of the product stream with significantly reduced energy input. For this purpose, customized TFC flat membranes for forward osmosis were developed at the IGB.

September 2022 - August 2025

FLUID

Fluorine-free humidifying membrane and innovative membrane winding element for cathode air humidification in PEM fuel cells

A crucial factor for the performance and long-term stability of polymer electrolyte membrane (PEM) fuel cells is the water management in the fuel cell. The (cathode) humidifier plays a central role in this. Within the framework of the project, novel fluorine-free flat membranes in particular are to be developed and validated at the IGB.

August 2017 – December 2020

HIKS

Highly Integrated Cathode Subsystem: Development and production of a highly integrated air treatment module for use in automotive high-performance PEFCs with production-ready manufacturing technologies to realize automotive performance and cost targets

The management of the water produced played an important role in the performance and lifetime of a fuel cell. Membrane humidifiers can be used for this purpose as an external component to protect the ionomer membrane in the fuel cell from drying out at any time.

May 2021 - October 2023

SULFAMOS

Sulfate depletion by forward osmosis and hollow fiber immersion modules

One of the late effects of opencast lignite mining in Germany is the large-scale iron and sulfate contamination of ground and surface waters. Therefore, the aim of the SULFAMOS project is to develop and demonstrate a process based on forward osmosis to remove sulfate from surface and ground waters so that they can be used as irrigation and drinking water. For this purpose, hollow fibers based on celluslose acetate were developed at the IGB, which carry the separation layer on the outside and were processed from a green solvent.