What is the difference between hydrophobic and hydrophilic filter membranes?

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Micro-porous precision filtration is a technique designed to remove particles ranging from 0.1μm to 10μm.

This filtration method is typically categorized into two types: surface-type and deep-type.

In membrane technology, hydrophobicity and hydrophilicity play critical roles in determining the efficiency and effectiveness of membranes across various applications.

Ever wondered why certain materials repel water like a magnet while others attract it just as strongly? Despite their seemingly minor significance, these properties play a pivotal role in both our daily lives and industrial processes.

Consider wastewater treatment plants, where engineers meticulously choose membrane materials to efficiently filter out impurities and contaminants from wastewater. Similarly, in medical devices, selecting the appropriate membranes is crucial for maintaining the purity and efficacy of medications.

We will explore the distinction between hydrophobic and hydrophilic microporous membranes and showcase their applications across various industries. Our aim is to provide you with a deeper understanding of membrane technology, enabling you to apply it more effectively in your field.


What Is a Filter Membrane?

A microporous filter membrane is a thin film material with tiny pores, usually in the nanometer range (typically less than 1 micron).

These tiny pores allow specific components of a liquid or gas to pass through by screening, retention or separation, while preventing the passage of larger molecules or particles. Microporous membranes are structurally analyzed as a porous sponge-like structure.

The preparation of microporous membranes usually uses polymers, ceramics, metals and other materials, the pore structure of these materials can be adjusted according to the needs of the material, so as to realize the selective separation of different sizes and properties of the material or purification.

Microporous membranes are widely used in water treatment, wastewater treatment, pharmaceuticals, food processing, biotechnology and other fields, and their highly efficient separation performance and adjustable pore size structure make them one of the indispensable technologies in many industrial and scientific research fields.

What Is a Filter Membrane

Concepts Of Hydrophilicity And Hydrophobicity

Hydrophilicity and hydrophobicity are fundamental concepts describing how materials interact with water, influencing their design and application across various fields.

Hydrophilicity refers to a material’s attraction to water molecules, enabling it to absorb, adsorb, or retain water on its surface. This affinity creates a stable wetting layer, resulting in a smooth, uniform liquid film on the material’s surface.

Conversely, hydrophobicity describes a material’s resistance to water, causing it to repel water molecules. As a result, water beads up on the surface, making it challenging for the molecules to make contact or spread across it.

It’s worth noting that some membranes exhibit both hydrophilic and hydrophobic regions, rendering them amphiphilic. These membranes find applications in separating hydrophilic and hydrophobic substances, such as emulsion filtration.

Hydrophobic Grains

Difference Between Hydrophilic And Hydrophobic Membranes

Difference Hydrophilic Membranes Hydrophobic Membranes
Interaction Ability Affinity with water Repel water
Application Scenarios Used when water needs to pass through Used when separating water from hydrophobic substances
Performance Differences High water flow rates; suitable for low concentration liquids Low water flow rates; suitable for high concentration liquids

Hydrophilic Membrane

  • Interaction with water: Hydrophilic membrane is hydrophilic, i.e. it has an affinity with water molecules and is capable of absorbing and retaining water molecules or forming a uniform wetting layer.
  • Application scenarios: Suitable for application scenarios that require the passage of water, such as filtration of aqueous solutions. Hydrophilic membranes usually have a high water flow rate and are suitable for liquid filtration and for processing liquids with low concentrations.

Hydrophobic Membranes

  • Interaction with water: Hydrophobic membranes are hydrophobic, i.e. they repel or are incompatible with water molecules and are not easily wetted by water.
  • Application scenarios: Mainly used in scenarios where water needs to be separated from hydrophobic substances, such as filtration of organic solvents. Hydrophobic membranes are usually used to handle situations where the liquid concentration is high and the water flow rate is low.

In practical applications, according to the specific filtration needs and the characteristics of the treatment object, selecting the appropriate hydrophilic membrane or hydrophobic membrane can more effectively achieve the purpose of filtration and separation.

Exploring The Applications Of Polytetrafluoroethylene Filter Membranes

Polytetrafluoroethylene (PTFE) filter membranes are a common type of microporous filter membrane, which can be categorized into hydrophobic and hydrophilic membranes.

The Feature of the PTFE Filter Membrane

  • Main characteristics: isotropic, not divided into positive and negative, can play a role in retaining solid particles above the rated pore size. (It is a terminal filtration membrane)
  • Thermal stability: Heat sterilized at 120 degrees for 30 minutes, good thermal stability.
  • Chemical stability: can filter pH2-13 all kinds of medicinal liquid, also can filter
    Instrument Oil,
    5% Acetic Acid,
    6n Sulfuric Acid,
    6n Potassium Hydroxide,
    Anhydrous Ethanol,
    Conductive Alcohol,
    Trioctyl Metatriurate,
    Polyethylene Glycol,
    all kinds of alcohol,
    Vinegar and so on.
    Glacial Acetic Acid,
    6n Nitric Acid,

PTFE Hydrophobic and Hydrophilic Membranes

  • Hydrophobic membranes: made entirely of PTFE, which is naturally and permanently hydrophobic, they can pass moist air or other gases even at low pressures, but cannot pass through aqueous solutions.
  • Hydrophilic membranes: In contrast to hydrophobic membranes, they are chemically compatible and can be used for filtration of a wide range of organic solvents and highly corrosive chemicals. However, if they are to be used for filtration of aqueous solutions, they must be pre-wetted with ethanol or isopropanol.

PTFE Hydrophobic and Hydrophilic Membranes


  • Liquid filtration: Both hydrophilic and hydrophobic cartridges can be used for liquid filtration.
  • Gas filtration: hydrophobic cartridges are generally used.
  • Hydrophilic and hydrophobic membranes have specific application scenarios and advantages.

For wastewater treatment, hydrophilic membranes are widely used.

Firstly, hydrophilic modification of hydrophobic materials such as polyvinylidene fluoride (PVDF) can make the membrane suitable for dry storage, reduce membrane moisture return and microbial growth, and thus maintain stable performance.

Secondly, colloids, proteins and other organic matter in the wastewater are easy to adhere to the membrane surface to form a contamination layer, resulting in a decrease in flux, while the hydrophilic membrane filtration resistance is smaller, reducing the frequency of membrane contamination, which is conducive to improving the production value ratio and prolonging the service life.

Hydrophobic membranes are more suitable for air filtration and membrane processes, especially when a high gas permeability is required, which can improve productivity and production value ratio.

The surface wettability of PTFE microporous membranes is required for different applications. For ultrafiltration and separation using water as the separation medium, such as in the purification process, hydrophilic membranes can increase permeate flux, reduce membrane contamination and operating pressure.

In membrane processes where water is the separation medium, such as membrane distillation and permeation distillation, hydrophobic membranes are required to reduce liquid penetration and prolong service life.

PTFE microporous membranes, as a kind of hydrophobic membrane, have a wide range of applications in the field of hydrophobic membranes, but sometimes it is necessary to further improve their hydrophobic properties in order to avoid separation failure caused by membrane hydrophilicity.

In hydrophilic membrane applications, PTFE microporous membranes need to be hydrophilically modified for more efficient use.


Hydrophobic and hydrophilic microporous filtration membranes offer diverse applications across environmental protection, healthcare, and food processing.

In environmental protection, hydrophobic membranes aid in efficient oil-water separation, reducing water pollution, while hydrophilic membranes assist in treating organic wastes in wastewater, promoting water reuse and resource recycling.

In healthcare, microporous membranes are vital for drug preparation and blood separation, providing essential technical support for medical procedures.

Moreover, in food processing, these membranes are utilized for clarifying and filtering beverages and liquid foods, ensuring product quality and safety standards are upheld.

As a premier supplier of filter membrane technology, our company is dedicated to delivering top-notch hydrophobic and hydrophilic membrane folded cartridges tailored to diverse industrial and commercial requirements.

Our products transcend mere filtration membranes; they epitomize our dedication to environmental preservation, healthcare, and food safety.

Should you have any inquiries or requirements regarding filter membrane technology or products, please don’t hesitate to reach out to our expert team. We are here to provide you with exceptional service and assistance.

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