Ion-exchange membranes
The heterogeneous membrane is a highly filled polymeric composite, consisting of very finely ground polymeric particles with ion-exchange functional groups, bound in an inert polymeric matrix and reinforcing textile which improves the mechanical properties of the membrane.
One characteristic feature of the ion-exchange membranes is represented by the functional (ionogeneous) groups, bound covalently to the polymeric skeleton. The electric charge of the bound ions in the membrane is balanced by the equivalent charge of so-called counterion. If the polymer is placed in an aqueous solution, it swells and becomes plastic. In the swelled polymer, counterions can move freely by the diffusion mechanism or due to the influence of the electric field. If electroneutrality is preserved, counterions can leave the membranes and enter it from the outside solution. In the electric field, the membrane behaves as an ion conductor and transmits very selectively ions with one type of electric charge.
Catex membranes transmit cations and anex membranes transmit anions, while both types of membranes prevent the hydrodynamic flow of the solvent. This selectivity and the solvent flow blockage are utilized in various processes in electrodialysis, electrophoresis, electrolysis, electrodeionization etc. Selective permeability for certain substances causes that transmission of certain substances is slowed down or even blocked, while preferred components transmit relatively easily.
The Membrane Department of the company MemBrain s.r.o. deals with the following activities
Optimization of composition of heterogeneous ion-exchange membrane
- to improve the separation characteristics of membranes and the entire separation process
- to modify its composition and properties convenient for various applications
- to reduce prices and to increase competitiveness
Optimization and development of new technologies of production of heterogeneous membranes
- pre-processing of ionex
- preparation of membrane composite
- production of laminated or non-laminated membranes
- swelling and formatting of membranes
Development of new types of heterogeneous membranes for specific purposes
- profiled membranes
- bipolar membranes
- tubular seamless membranes
Cooperation with research institutions and production facilities
- cooperation in development of new types of membranes, e.g. for fuel cells
- modification of membranes by the feedback data from their applications
