Surface Coating / Alfa Chemistry

Membrane Coating


Membranes are inherently subject to fouling by numerous contaminants due to long-term usage or interaction with the outside world, which limits their performance and use of membrane technology. Alfa Chemistry provides a number of surface coating methods that can be used to optimize the performance of various specialty membranes for medical applications. Membrane surface coatings can be hydrophilic, hydrophobic, or oleophobic, all of which can have a substantial impact on their surface behavior. To maintain regulatory compliance, all of our membrane coatings are devoid of PFOS and PFOA. Please get in touch with us so we can work together to produce a successful membrane!

Why Do You Need A Membrane Coating?

Our medical thin film surface modification technology can be applied to a wide range of membrane issues. Here are some examples of when you might want to use our membrane coatings to improve the quality of your membrane goods.

  • Certain liquids should not be allowed to enter through the membrane.
  • The filtered liquid's contact with your membrane isn't great.
  • Issues with regulatory compliance that your product now has PFOA/PFOS.

Membrane Coating

Suitable Membrane Coating Solution

Alfa Chemistry's membrane protection technique creates a thick, long-lasting hydrophobic/oleophobic surface on your membrane. Surface energy measurements show that the water contact angle can reach 115°-120°, whereas the oil contact angle can reach 75°-85°. We also use hydrophilic technology to create optically clean and long-lasting nanoscale hydrophilic coatings on your membrane surfaces. Surface energy measures a water contact angle of fewer than 10 degrees. All of the procedures listed above are compatible with a wide range of liquid-phase methods and maintain the product's optical clarity.

Alfa Chemistry created a new bilayer composite membrane for oil-fouling resistance by electrospinning a hydrophilic polyvinyl alcohol coating on a hydrophobic PTFE membrane and then cross-linking with glutaraldehyde. The wettability of the produced composite membrane is asymmetric, the coating surface is oleophobic underwater, and the PTFE substrate surface is hydrophobic. The adhesion of oil droplets to the film surface was tested, and the results suggest that the produced film has an optimum anti-oil adhesion surface. The modified PTFE membrane outperforms the original PTFE membrane in terms of performance and oil resistance.

Membrane CoatingFig 1. SEM images of the pristine PTFE membrane (a1-a3), the PTFE/PVA composite membrane (b1-b3), and the PTFE/PVA-GA composite membrane (c1-c3). (Wang K. P, et al. 2018)

Why Choose Alfa Chemistry?

  • Our surface coating technology allows us to alter the membrane's surface behavior while preserving full breathability.
  • In common membrane applications, our coating solutions are scalable and capable of attaching to a wide variety of surfaces.
  • Our membrane coatings are free of PFOA and PFOS and comply with regulatory requirements.


  • Wang K. P, et al. (2018). "Hydrophilic Surface Coating on Hydrophobic PTFE Membrane for Robust Anti-oil-fouling Membrane Distillation." Applied Surface Science. 450(30): 57-65.

Our products and services are for research use only and cannot be used for any clinical purpose.

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