Membrane Filters

Membrane Filters


Chemical compatibility: The membrane material must be compatible with the chemical being filtered to avoid structural failure.

Wettability: Hydrophilic membranes are easily wet with water and are preferred for filtering aqueous solutions. Hydrophobic membranes are recommended for gas filtration and venting, and can be wet in methanol, allowing both aqueous liquids and organic solvents to pass through.

Pore Size: Pore size provides an indication of the largest pore diameter. The bubble-point method is a common method to determine the maximum pore size and pore size distribution of membranes. 

· 0.1 µm: used for mycoplasma removal
· 0.2 or 0.22 µm: sterile filtration of aqueous solutions and organic solvents. The performance of 0.2 and 0.22μm is the same, only the difference being the designation of their pore size rating.
· 0.45 µm: clarification or particle removal of aqueous solutions and organic solvents
· 0.8 µm: coarse particulate removal and removal of bacteria


· Wide variety of pore sizes available: 0.1µm/0.22µm/0.45µm/0.8µm/1.2µm/3.0µm/5.0µm/10.0µm

· Regular diameters for lab analysis: 13mm/25mm/47mm/50mm/90mm/110mm/142mm/293mm

· Customized sizes available

· High flow rate, low extractables


PES Membrane Filters

PES (polyethersulfone) membrane filter is made of a modified polyethersulfone polymer. Cobetter’s PES membrane filter has very low protein binding characteristics, and high liquid flow rates. PES can withstand autoclaving and is the membrane of choice for many clinical applications.


Nylon Membrane Filters

Nylon membrane filters can be wet by water easily because they are naturally hydrophilic, providing an excellent flow rate. It also provides high strength and broad drug compatibility. Cobetter nylon membrane filters do not contain any wetting agents, detergents or surfactants, so they have low extractables, and low protein binding characteristics, often used for sterilizing and clarifying liquids. 


PVDF Membrane Filters

PVDF(Polyvinylidene Difluoride) membranes are naturally hydrophobic. Cobetter offers both hydrophobic and hydrophilic PVDF membrane filters for a wide range of applications like aqueous and non-aggressive solvent-based. These membranes are typically low protein binding and are frequently used for sterilizing filtration.


PTFE Membrane Filters

Cobetter offers both hydrophobic and hydrophilic PTFE (polytetrafluorethylene) membrane filters. The extreme chemical compatibility (pH 1-14) makes them very useful for they are also used for the filtration of solvents and acids or other aggressive chemicals.


MCE Membrane Filters

Cobetterlab MCE (Mixed cellulose ester) membrane filters are composed of cellulose acetate and cellulose nitrate. MCE membrane is biologically inert, it’s one of widely used membranes in research applications, providing superior flow rates.


PP Membrane Filters

Cobetter PP (polypropylene) membrane filter is a preferred choice for aggressive filtration applications. This plastic polymer has very good resistance to a broad range of chemicals even at high temperatures.

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