To Know PVDF Membrane Filter, We Need to Know the PVDF First

What is PVDF?

PVDF, the abbreviation of polyvinylidene fluoride, mainly refers to the homopolymer of vinylidene fluoride or the copolymer of vinylidene fluoride and a small amount of other fluorine-containing vinyl monomers. Membrane manufacturer provide to us, PVDF has the characteristics of both fluorine resin and general resin. In addition to good chemical resistance, high-temperature resistance, oxidation resistance, weather resistance, and radiation resistance, it also has special properties such as piezoelectricity, dielectric properties, and pyroelectric properties. It ranks second in the production of fluorine-containing plastics. The annual production capacity is more than 43,000 tons.

The chemical structure is combined with a fluorine-carbon bond. This structure with short bond properties forms a stable and firm bond with hydrogen ions. Therefore, fluorocarbon coatings have specific physical and chemical properties, not only have strong wear resistance and impact resistance but also have high fading resistance and UV resistance in harsh and harsh environments.
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What is PVDF membrane filter?

As a kind of hydrophobic membrane and solid support commonly used in Western blotting with high mechanical strength, the PVDF membrane filters’ pore size can be small and large. The membrane’s binding ability to low-molecular-weight proteins will become more firmly, with the membrane continuing to decrease. The use of PVDF membrane requires pretreatment with methanol, which aims to activate the positively charged groups, making it easier to bind to negatively charged proteins. PVDF membrane filters are an ideal choice for various staining applications and multiple immunoassays; and the lane copy of a single gel can be used for multiple purposes, especially when N-terminal protein sequencing is required.

Three categories

From the main applications, the PVDF membranes can be divided into three categories.
1. PVDF membranes for water treatment are divided into ultrafiltration membranes and microfiltration membranes. They are mainly used for pre-treatment of sewage and seawater desalination to remove impurities such as macromolecules, bacteria, and sediment;
2. PVDF membranes for outdoor construction, the main use is the protection of outdoor construction glass, exterior walls, outdoor billboards, etc., mainly for aging resistance and wear resistance;
3. PVDF membranes for different batteries, such as the lithium-ion polymer battery and fuel cells, and so on.

The main performance of PVDF membrane filters

• High mechanical strength and toughness
• Anti-fungal resistance
• High abrasion resistance
• High permeability resistance to gases and liquids
• Good heat resistance stability
• Flame retardant, low smoke
• Good creep resistance during temperature increase
• High purity
• Easy melt processing
• Resistance to most chemicals and solvents
• Both rigid and flexible form
• Anti-ultraviolet and nuclear radiation
• Impact resistance
• Weather resistance
• Low-temperature resistance up to -40℃

PVDF membrane soaking steps

PVDF is essentially a hydrophobic polymer and will not wet out in an aqueous solution. In order to use PVDF membranes in aqueous buffers and systems, they must first be immersed in a 50% (v/v) or higher concentration alcohol solution. Other suitable solutions for soaking this membrane are methanol, ethanol, and isopropanol. As the appearance of the membrane changes from opaque to translucent, complete wetting is evident. After that, it must be rinsed repeatedly with water to remove the alcohol, and the pre-treated membrane can now be directly placed in the transfer buffer to equilibrate.

Wet transfer:
(1) Soak the membrane in methanol for 30 seconds. The membrane should change uniformly from opaque to translucent.
(2) Carefully put the membrane into double distilled water and soak for 2 minutes.
(3) Carefully put the membrane in the transfer buffer and equilibrate for at least 5 minutes.

Semi-dry transfer:
The first methanol soaking takes only 15 seconds, and the other steps are the same as above.