Why do some microporous membranes need to be treated for hydrophilicity, and some membranes need to be treated for hydrophobicity?
1. Hydrophilic membranes and hydrophobic membranes have their own specific applications. Hydrophilic membranes are more used for sewage treatment, and hydrophobic membranes are more used for gas-water separation.
2. Why are hydrophilic membranes used in sewage treatment?
First, for hydrophobic materials such as PVDF, the membrane prepared by the immersion phase separation method is hydrophilically modified and suitable for dry membrane storage, which reduces membrane performance degradation caused by membrane regain and microbial growth, which is beneficial to transportation and storage!
The second is that in the application process, the colloid, protein, or other organic matter contained in the sewage is easy to adhere to the membrane surface to form a pollution layer, which makes the membrane water flux drop sharply, reducing the production efficiency and the use-value of the membrane. The membrane has a low filtration resistance, relatively low energy consumption, and a relatively long period of membrane fouling, which is conducive to the high output value ratio produced by the use of the membrane.
3. The hydrophobic membrane is used in membrane processes such as air filtration and membrane distillation. The better the hydrophobicity, the better the gas permeability and the improvement of production efficiency and output value ratio. All in all, different treatments for membranes, hydrophobic, or hydrophilization are all to adapt to different applications and achieve the optimal output value ratio!
Hydrophobic and Hydrophilic Forms of Membrane Filter
PVDF filter is made of polyvinylidene fluoride, which is available in two forms of the membrane: hydrophobic and hydrophilic. The protein adsorption of the hydrophilic membrane filter is much smaller than that of nitrocellulose, nylon, and PTFE membranes. It can be used in the protein solution, tissue culture medium, antibiotics, and liquid such as ethanol for de-bacterial filtration.
Removal of particle filtration can also be used for biological testing (e.g. receptor binding studies, TCA precipitation) and other applications. The hydrophobic filter membrane is suitable for gas filtration. Non-sterilizing packaging, if need it can be sterilized under high pressure, high sterilization temperature is up to 126℃; filtration high operating temperature is up to 85℃.
Wide Chemical Compatibility of Membrane Filter Hawach PVDF membrane filter has high flow rates, low extractable, and wide chemical compatibility. Hawach PVDF membranes filter is of less protein than nylon, PTFE membranes, and nitrocellulose.
What’s more, Hawach membrane filter is good for clarifying the filtration of variable solutions such as strong acids, aromatics, and aggressive solvents. It can greatly increase rates of bubbles and the bubble point is higher than 0.07MPa. The range of thickness is from 90-100um and the maximum operating pressure is about 4.2 bar@23 degrees Celsius.