Chemical composition and structure of polytetrafluoroethylene (ePTFE) microporous membrane materials

Chemical composition
The main chemical component of polytetrafluoroethylene (ePTFE) microporous filter membrane is polytetrafluoroethylene (PTFE), which is a polymer compound formed by the polymerization of tetrafluoroethylene monomer. PTFE has excellent chemical stability, corrosion resistance, high temperature resistance and electrical insulation properties, and is an ideal material for preparing microporous filter membranes.

Structure

1.Surface morphology:

The surface morphology of the ePTFE microporous filter membrane has a spider web-like microporous structure, with pores formed between microfibers, and the arrangement direction of these microfibers is basically parallel to the stretching direction.

The connection point of the fiber bundle is a node, which is formed by many microfibers entangled and connected.

2.Asymmetric structure:

The ePTFE membrane is an asymmetric membrane, and the micropore size on the front and back sides is different.

The cross-sectional micropore size of the membrane is larger than the micropore size on its surface, and the longitudinal and transverse micropore sizes are also different, with the longitudinal micropores larger than the transverse ones.

3.Complex three-dimensional structure:

The cross-section of the ePTFE membrane presents a network structure, which has very complex changes in the three-dimensional space of the pores, such as mesh connectivity, pore sleeves, and pore bending.

There may be multiple micropores forming a channel, or one micropore may be connected to multiple channels.

4.Micropore structure:

ePTFE microporous filter membrane has extremely high porosity and uniform pore size distribution, which enables it to efficiently filter out tiny particles in the air.

The porosity is as high as 85%, and there are billions of micropores per square centimeter, with pore sizes ranging from 0.02um to 1.5um.

Polytetrafluoroethylene (ePTFE) microporous filter membrane has shown excellent performance and broad application prospects in air purification, industrial manufacturing and other fields with its unique chemical composition and complex structural characteristics.