From raincoats to oil-water separation systems, oleophobic membranes designed to repel oils and other low surface tension liquids play a quiet but essential role in modern life. These membranes keep liquids either in or out, depending on the application: protecting electronics, enabling fuel purification, extending the life of HVAC systems, and supporting industrial processes across food, pharma, and chemical sectors.
In filtration, their role is especially critical. Separating oil from water or air is key to maintaining safety, cleanliness, and performance.
For decades, the performance benchmark for these membranes has been PFAS-based materials especially fluoropolymers like PTFE or ePTFE. Known for their thermal stability, chemical resistance, and excellent oil repellency, these substances have been the default.
But that default is rapidly changing.
PFAS in Oleophobic Membranes: Performance at a Price
PFAS (per- and polyfluoroalkyl substances), often dubbed “forever chemicals,” are now being found everywhere from remote rainwater to human bloodstreams. The documentary “How One Company Secretly Poisoned the Planet” by Veritasium highlights just how far-reaching the impact of industrial PFAS use has become, including its links to water pollution and long-term health risks.
As awareness grows, so does regulation. In the U.S., the EPA is finalizing national limits for six PFAS chemicals in drinking water. The European Union is weighing restrictions on over 10,000 PFAS compounds. Meanwhile, chemical giants like 3M are exiting PFAS production entirely. That has driven up costs and introduced major supply chain uncertainty.
For industries that rely on oleophobic membranes, the question is no longer if PFAS need to be replaced but how.
Applications That Rely on Oleophobic Membranes
PFAS use in membranes isn’t niche it’s embedded across a wide range of industries. Some key examples include:
- Hydraulic filters in aerospace and automotive systems, where oil-water separation is critical
- Protective garments that must resist oil-based contaminants
- Oil/water separation membranes for environmental cleanup or industrial wastewater management
- Packaging and food grade materials, where oil repellency preserves quality and safety
- Medical textiles and wound dressings, where controlled fluid interaction supports hygiene and wearability.
In nearly all of these applications, ePTFE and other fluoropolymers have been dominant because they work and work well.
The Challenge of Replacement
Unfortunately, replacing PFAS isn’t as simple as swapping out one polymer for another. Fluorinated materials perform so well because of their carbon-fluorine bonds, which create ultra-low surface energy. Most conventional polymers can’t match this property.
Even when new materials look good in the lab, real-world hurdles remain:
- Can they withstand high temperatures, pressures, and harsh chemicals?
- Are they compatible with existing manufacturing lines?
- Can they scale affordably?
- Will they maintain performance over time?
Few solutions check all the boxes.
The Emerging Landscape of PFAS-Free Oleophobic Membranes
Replacing PFAS means rethinking how oil-repellency is achieved. Researchers are developing new strategies that don’t rely on fluorinated chemistry but instead redesign the materials and surfaces themselves. These approaches fall into three major categories:
- Novel Polymer Chemistries: Non-fluorinated materials like thermoplastic polyurethanes (TPUs), polyimides (PIs), and certain silicones are being studied for their chemical resistance, flexibility, or processability. While their oil-repellent properties may not match PFAS, they provide a starting point for safer alternatives.
- Surface Functionalization: Some research teams apply plasma treatments, chemical grafting, or nanoparticle coatings to lower the surface energy of conventional membranes and induce oil repellency.
- Biomimicry and Surface Texturing: Inspired by natural oil-repellent surfaces like lotus leaves or insect wings, micro- and nanoscale surface structures are being developed to physically reduce liquid adhesion without relying on fluorinated compounds.
These strategies often require trade offs between performance, cost, scalability, and compatibility with existing membrane production. But collectively, they represent a growing ecosystem of innovation.
What Makes Nanofiber Membranes Different?
Electrospun nanofiber membranes offer a fundamentally new design space for oleophobic membranes one that doesn’t need to mimic fluoropolymer chemistry to succeed.
Unlike traditional membranes, nanofibers are produced through electrospinning, a process that creates nonwoven mats of fibers with diameters in the submicron range. This structure enables:
- High surface area and tunable porosity
- Excellent breathability and low pressure drop
- Customizable chemistry and surface properties
Most importantly, nanofiber membranes introduce two distinct and synergistic methods for achieving oil repellency:
- Nanofiber Composites: Oleophobic compounds such as PDMS, silicones, or other low-surface-energy materials can be blended directly into the polymer solution. The resulting fibers have inherent oil-repellent properties embedded throughout their structure.
- Biomimetic Surface Structures: Electrospinning enables the design of multiscale fiber architectures that mimic natural surfaces like lotus leaves. These features reduce contact between oil droplets and the membrane, enhancing repellency without any chemical treatment.
Together, these techniques allow for the development of PFAS-free oleophobic membranes that achieve both chemical and physical repellency while maintaining the lightweight, efficient, and breathable properties that make nanofibers so powerful.
Our Work at Matregenix
At Matregenix, we’re advancing PFAS-free oleophobic nanofiber membranes through direct electrospinning. Our proprietary process enables us to incorporate low-surface-energy materials directly into nanofibers and fine-tune their morphology to achieve targeted performance.
Our goal is to deliver scalable, high-performance membranes that meet regulatory requirements without compromising on oil repellency, durability, or breathability.
Want to learn more? Visit Matregenix or contact us to explore our PFAS-free nanofiber innovations.