Membrane filters are surface filters used to remove particulate or collect microorganism for analysis from solutions, on and near the surface of the filter matrix by mechanical means. Our wide range of membrane materials (PTFE, regenerated cellulose, nylon, cellulose nitrate, polycarbonate, aluminum oxide, etc.) provides the user with an array of solvent compatibility options, porosities, and pore sizes according to individual specific needs. Some membrane materials are also available sterile.
Membrane filters are typically used in both liquid and air filtration. They offer accurately controlled pore size distribution with high strength and flexibility, and are suitable for a wide range of applications such as basic research, environmental testing and pharmaceutical as well as food and beverage industries. We offer membrane filters by industry leaders such as Merck Millipore, Pall, Sartorius & Whatman.
The most common materials are as follows:
Material: CA, CN, MCE, PA, PES, PTFE, PVDF, RC
In the second info box you will find more information about the application areas and the chemical resistance of the individual polymers.
Membrane filter of different materials have specific properties. Therefore, the choice of the correct filter depends greatly on the chemicals used. The following table gives an overview of application areas and chemical resistence of each polymer.
Low protein-binding, well suited for sterile filtration and clear filtration of aqueous solutions, nutrient media, buffers, and sera, they provide superior chemical resistance to alcohol and oil. These hydrophilic membranes offer excellent flow rates as well as thermal stability up to 180° C max.
Cellulose nitrate membranes set the standard in both analytical and microbiological filtration. Cellulose nitrate is available in a range of pore sizes and is well suited for microbial analysis in water, food and beverage applications. Available in dispenser strips or individually sealed.
Membranes are hydrophilic and are widely used in both aqueous and organic solvent filtration applications. Well suited for sterilisation and clear filtration of buffers and nutrient media with a low level of extractables.
PC membranes have uniform, smooth, round pores that pass straight through the membrane creating a precise capillary structure. The smooth, flat surface of the PC membrane offers high visibility of captured particles.
Permanently hydrophobic filter material, very suitable for air and gas filtration. PTFE membranes are extremely resistant to aggressive solvents and acids and can be used to filter particulate from both liquid and gas samples.
Regenerated Cellulose (RC)
Regenerated cellulose membranes are resistant to solvents and are hydrophilic. 0.45 μm pore size is typically used for HPLC sample preparation.