i3 FlexiPor

Aluminum oxide membrane

In their use, aluminum oxide membranes are typified chiefly by low adsorption, high chemical inertness and the exclusion of extractables.

i3 FlexiPor membranes are made from nanoporous aluminum oxide. The ceramic material is made from pure aluminum using electrochemical etching processes. It is known not to dissolve in any chemical compound and has no organic extractable constituents. It thus has less extractable material than polymer filter membrane (one 1000th of that in polymer membrane)1 and the adsorption is very low. The material is directly usable as a transparent to white (depending on pore size) hard membrane or as a template that is closed on one side for the manufacture of specific nanostructures. The product is an amorphous oxide that can be changed into a crystalline oxide by heating. The pore diameters can be set exactly in the nanometer range.

Uniform pore arrangement delivers optimal cut-off

The inorganic membrane material possesses many close-packed pores distributed in honeycomb form; it is highly porous. The membranes have two different sides. The upper side possesses large-diameter pores whose diameter remains constant along their length. The effective filtration barrier is created by the underside of the membrane. Here, the diameter of the pore openings is smaller and can be set as required by the customer.

i3 FlexiPor membranes are characterized by rapid filtration, efficient separation and high purity. When they are moistened the membranes become nearly transparent and demonstrate minimal fluorescence.

Sterile filtration

Sterile filtration in biotechnology, food chemistry and medical technology requires reliable membranes.

i3 FlexiPor membranes are ideal for microscopic analyses (Raman spectroscopy, SEM with X-ray microanalysis (EDX), FTIR spectroscopy), including sterility testing, because particles are held back on the smooth surface. The membranes offer complete protection against infectious pathogens, bacteriophages and viruses. The material is not cytotoxic and provides a good surface for cell cultures.

Other areas of application

The nanoporous membranes can also be used in tissue engineering for the cultivation of cells in tissue reconstruction and tissue culture. One current focal area of research is the use of nanoporous membranes as three dimensional biochip arrays, e.g. to detect DNA and RNA fragments or specific proteins.

Specific rates of flow through aluminum oxide membranes are dictated by the pore size, porosity and membrane thickness.

The membranes are available in different packaging units, including small ones, each with assorted pore sizes.

i3 FlexiPor - Aluminum oxide membrane


You are interested?

We would be happy to send you an individual offer for our i3 FlexiPor. You can reach us at +49 40 2576748-0 or send us your request.


  • Filtration and degassing of mobile phases for HPLC

  • HPLC sample preparation

  • Filtration of aggressive organic media

  • Virus concentration and virus analysis

  • Microplastics in water

  • Epifluorescence microscopy

  • 3-D biochips

  • Sensors

  • Cell growth and cell culture

  • Liposome extrusion

  • Synthesis of nanostructures such as nanotubes

Technical data

Pore size0.02 µm0.1 µm0.2 µm
Membrane material Anodized alumina Anodized alumina Anodized alumina
Thickness (µm) 60 60 60
Porosity 25-50% 25-50% 25-50%
Maximum  operating temperature 400° C 400° C 400° C
Autoclavable yes yes yes
Hydrophilic yes yes yes
Solvent resistance high high high
Protein adsorption low low low
Refractive index 1.6 1.6 1.6
Supporting ring no no no

Linking knowledge

As your companion for life science filtration, we support you with new, effective separation technologies in the Lab/Pharma, Medical and Biotech fields.

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01454 Radeberg
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22761 Hamburg