Selection for Filter Membrane: NYLON or PVDF?

The choice between using a nylon (polyamide) or PVDF (polyvinylidene fluoride) membrane for filtration depends on the specific properties of the substances you are working with and the intended application. Both nylon and PVDF membranes have distinct characteristics that make them suitable for different types of filtration. Here’s difference between PVDF and Nylon filters:

1. Nylon Membrane

The first kind of membrane material is nylon. Nylon chemical filter has good temperature resistance and good chemical stability. The nylon membrane can withstand disinfection by saturated steam at 121°C for 30 minutes, and its highest working temperature is 60°C.

The material of the nylon membrane filter is aliphatic nylon. It has good hydrophilicity, the appropriate concentration of acid and alkali resistance, and applies not only acid and alkaline aqueous solutions, but is also suitable for organic solvents, such as alcohols, hydrocarbon, ethers, esters, ketones, benzene and benzene homologs, dimethylformamide, and dimethyl sulfoxide.

Nylon membrane filters are one of the most widely applicable scopes of microporous membrane filters. (belonging to the terminal filtration membrane), the aperture of which is 0.22 – 5.0 μm and the size of which is φ400 –φ25mm.

Features of the nylon membrane filters

  1. Hydrophilic, partially resistant organic, solvent, not resistant to strong acids. Protein binding ability is higher, so it is not suitable for protein recycling.
  2. Matters needing attention when using the nylon membrane filter
  3. The filtrate must be prefiltered when there are too many particles or bacteria in it.

Application fields of the nylon membrane filters

  1. Terminal filtration of API, medicinal solvent, injection water, injection and infusion solution, etc.
  2. Terminal filtration of high-purity water, mineral water, fruit juice, soft drinks, grape wine, liquor, beer, and dairy products.
  3. Plasma filtration.
  4. For the folding filter element.

And on the other hand, it can withstand many organic and inorganic compounds, such as dilute acid, dilute alkali, alcohols, esters, oils, hydrocarbons, halogenated hydrocarbons, and organic oxides.

The nylon filter membrane is applied to many industries. Nylon chemical filters may be used for water filtration in the electronic, microelectronic, and semiconductor industries, filtration of tissue culture medium, filtration of drug solutions, beverages, and high purification chemical products, and filtration of aqueous solutions and organic mobile phases.

0.45 Nylon Membrane Filters
0.45 PP Membrane Filters
0.22 Nylon Membrane Filters

2. PVDF Membrane

The other membrane is PVDF. This kind of membrane has high mechanical strength and high tensile strength. More than this, the PVDF membrane has good heat resistance, good chemical stability, low protein adsorption rate, strong negative static electricity, and hydrophobicity. The membranes have two forms: the hydrophobic one and the hydrophilic one. However, it can’t tolerate acetone, DMSO, THF, DMF, dichloromethane, and chloroform.

Features of PVDF Filter Membrane

  • PVDF is with high mechanical strength, high tensile strength, good heat resistance, chemical stability, and low protein adsorption rate.
  • Strong negative electrostatic and hydrophobic, however, it cannot tolerate acetone, DMSO, THF, DMF, dichloromethane, chloroform, etc.
  • Acid and alkali resistance, outstanding dielectric, biocompatibility, high separation accuracy, and high-efficiency characteristics.
  • PVDF filter membranes have the practical features of economy, durability, and advantages in acoustic performance.
  • thermal insulation performance, fire performance, mechanical performance, optical performance, and self-cleaning performance.
  • A PVDF filter membrane is a new kind of membrane material with excellent comprehensive performance, which has broad application prospects in the field of filter membrane separation.

Applications of PVDF Filter Membrane

PVDF filter could be widely used in many ways, such as used for binding nucleic acids to proteins. The pore size of the membrane is usually 0.45 μm, which size is widely compatible with common solvents. The background value of PVDF membranes for chemiluminescence detection is very low. And the color will be durable during the whole progress and not fade.

The applications of PVDF membranes may include the interactions between protein and nucleic acid, immunoblotting research, ELISA, radioimmunoassay, the detection of fluorescence or chemiluminescence, the development of drugs using binding biomolecules and EliSpots.

Hydrophobic PVDF filters are mainly used in gas and steam filtration and high-temperature liquid filtration.

The hydrophilic polyvinylidene fluoride membrane filter is commonly used for the purification and filtration such as tissue culture media, additives, and other sterilization filtration solvents, chemical raw materials, aseptic processing of reagents, and for filtration of high-temperature liquid, etc.

The summary is summarized as follows:

  1. Gas filtration and high-temperature liquid filtration;
  2. Filtration of gas and steam;
  3. Filtration and purification of oxidizing reagents;
  4. Filtration of high-temperature liquid;
  5. Oil and water separation;
  6. Engineering application of PVDF filter, mainly used for industrial wastewater and municipal sewage treatment of electrophoresis paint, printing, dyeing, electroplating, and others;
  7. Recovery of protein and starch in food industry wastewater;
  8. Removal of bacteria for drinking water and preparation of ultrapure water; clarification and concentration of TCM preparations.

3. Difference between PVDF and nylon filters. Nylon vs PVDF filter

NYLON or PVDF

PVDF (polyvinylidene fluoride) and nylon are both types of membrane filters commonly used in various laboratory applications, such as filtration and separation of substances. Here are some Nylon vs PVDF filter difference between PVDF and nylon filters:

  1. Material Properties: PVDF is a highly hydrophobic material that resists wetting, making it ideal for filtering non-polar and aqueous solutions. It has excellent chemical and thermal resistance and can withstand high temperatures. Nylon, on the other hand, is hydrophilic, which makes it ideal for filtering polar solvents. It has good chemical resistance but is not as resistant to high temperatures as PVDF.
  2. Pore Size: PVDF membrane filters have a smaller pore size than nylon membrane filters, making them suitable for finer filtration, such as sterilizing solutions, biological fluids, and gases. Nylon membrane filters have larger pore sizes and are used for coarse filtration of solvents, particulate matter, and other materials.
  3. Membrane Thickness: PVDF membrane filters have a thinner membrane compared to nylon membrane filters, making them more flexible and easier to handle. Nylon membrane filters, on the other hand, have thicker membranes and are more rigid, which can make them challenging to manipulate.
  4. Protein Binding: Nylon vs PVDF filter. Nylon membrane filters tend to bind proteins more readily than PVDF membrane filters, making them more suitable for protein filtration and sample preparation applications.
  5. Chemical Compatibility: PVDF membrane filters are more chemically compatible with a broader range of solvents, including strong acids and bases, organic solvents, and polar and nonpolar liquids. Nylon membrane filters are not as compatible with strong acids and bases, and some organic solvents can dissolve or swell the nylon membrane.
  6. Hydrophilic vs. Hydrophobic: The most obvious difference between PVDF vs nylon is considering whether a hydrophilic (nylon) or hydrophobic (PVDF) nature is more suitable for the intended application.

In summary, due to the difference between PVDF and nylon filters, the choice of them depends on the specific application, solvent, and sample type being filtered. PVDF membrane filters are better suited for finer filtration of non-polar and aqueous solutions, while nylon membrane filters are ideal for coarse filtration of polar solvents and materials that require protein binding. PVDF membrane filters are more chemically compatible with a broader range of solvents than nylon membrane filters.

The success of the experiment depends on the good sample. A good sample depends on good filtration. Good filtration depends on the selection of membrane materials. In a word, with the further development of material technology, filtering technology will play an increasingly important role in our experiments.

The Hawach polyvinylidene fluoride and nylon membrane filters are available from discs and roll.

Hawach also produces the nylon, or hydrophobic and hydrophilic PVDF syringe filter is available in non-sterile and sterile filters, with complete filter size and pore size in supply for customers’ choice. membrane@hawach.com