Microstructure of Membranes Material
The function of filter membrane material is determined by its microstructure. Knowing and understanding the microstructure of the material of the membrane can help us explain the technical parameters of the filter membrane from the mechanism and finally choose the right product. Below are the microstructure diagrams of the six common membranes:
Careful observation of the microscopic，the results shows that the microporous of GF membrane is composed of numbers of elongated fibers, which determines its relatively low density. GF membranes can accommodate many particles both on the surface and inside the membrane.
Relatively speaking, the structure of PES, MCE, PTFE, NY, PVDF is a regular network system and has a relatively dense interior except for the large gap of the surface. So the particles are mainly retained at the surface of the PES, MCE, PTFE, NY, PVDF membranes.
In general, GF has a strong capacity of holding dirt, but the absolute interception accuracy is not as high as that of the regular network system. Therefore, it is commonly used in coarse filtration and pre-filtration and preferentially retains large particles to protect the latter membrane from being clogged.
It is worth mentioning that the PP filter membranes and the GF structure are similar in characteristics, and are mainly used for pre-filtration to prevent clogging.
Different Materials of Filter Membranes With Different Features
Hawach have Nylon, MCE, CA, PES, PVDF, PTFE, GF membrane material of membrane filters, they have different features.
| Membrane material | Features |
| Nylon | Natural hydrophilicity No need to infiltrate before use Uniform aperture with good mechanical strength Threaded interface design |
| MCE | High porosity and good interception effect Not resistant to strong acids, strong alkali solutions, and most organic solvents Ideal for filtration of aqueous water solutions Unique threaded interface design |
| CA | Natural hydrophilicity Low protein adhesion, suitable for aqueous solution treatment No nitrates, suitable for filtration of groundwater Uniform pore structure Extensive pore size selection Retention of granulosa cells |
| PES | High solvent recovery rate, low residual amount; high throughput High microbial filtration capacity Unique threaded interface design Low protein adsorption, low dissolution |
| PVDF | Hydrophobic membrane, no moisture absorption, easy to maintain weight Temperature resistant, repeated hot pressing Chemical resistant, oxidation resistant Threaded interface design |
| PTFE | Excellent chemical resistance High-temperature resistance, strong acid-resistance, strong alkali, and extremely hydrophobic Both hydrophilic and hydrophobic membranes are available to meet different liquid filtration needs |
| GF | Natural hydrophobicity Large flux and large pollution hold ability Good mechanical strength |
Generally, the PES membrane filters are very suitable for the filtration of aqueous phase samples. The high-performance PES membrane filters have the advantage of low protein adsorption, so they can reduce the loss of samples to a minimum level. Also, in comparison with other membrane filters, the PES membrane filters have a higher flow rate and better handling capacity. As a result, they are always bestsellers among all kinds of like products.
Furthermore, the high-performance PES membrane filters have a high level of consistency as well as a slight batch difference to make sure that when the laboratory worker is filtering unwanted particulate matters, new pollutes will not be produced. In a word, other than sterilization and filtration, the PES membrane filters can also be applied in the regular preparation of samples, the clarification of lysate, and combined filtering of magnetic beads and resin beads.
During sterilization and filtration, the PES membrane filters with the pore size of 0.2 μm are always solid choices. However, there are lots of other options of pore sizes including 0.1 μm, 0.45 μm, and 0.8 μm. Basically, the membrane filters with the pore sizes of 0.45 μm and 0.8 μm are mostly used in the clarification of lysate and pre-filtration.
Parameter of HAWACH Hydrophilic PTFE filter membrane
Features and applied industry
Hydrophilic PTFE filter membrane uses PTFE as raw material, biaxial stretching using the unique node fibrillation of polytetrafluoroethylene membrane, with a smooth surface, chemical resistance, breathable and impermeable, large air permeability, flame retardant, high temperature, strong acid and alkali resistance, non-toxic and other characteristics. The finished product has high filtration efficiency, which can reach 99.99%, zero-emissions; Also, it features low running resistance, fast filtering speed; long service life, reusable, thus reducing running costs.
Hydrophilic PTFE filter membrane is mainly used for anhydrous sample filtration, for caustic acid and caustic solutions, HPLC sample preparation and moving image clarification and for the filtration of flue gas in various industrial furnaces such as chemical industry, steel, metallurgy, carbon black, power generation, cement, waste incineration and so on.
Parameter of filter membrane
Brand: Hawach
Pcs/pack: Membrane of different diameters with different numbers in each pack.
For example, 47mm with 100pcs/pack and 142mm with 50pcs/pack.
Membrane material: Hydrophilic PTFE
Membrane type: surface filter
Maximum operating temperature, °C: 130
Membrane diameter: 13; 25; 47; 90; 142; 293mm
Membrane color: white
Membrane surface: glossy
Porosity%: 80
