Polytetrafluoroethylene ultrafine fiber membrane

Abstract

The invention provides a polytetrafluoroethylene fiber membrane. The polytetrafluoroethylene fiber membrane comprises a polytetrafluoroethylene material body; the polytetrafluoroethylene is fiber-shaped and the fiber diameter is 30 to 200 nm; the body is provided with pore cavities with the pore diameters of 10 to 1000 nm, and a cavity wall which is formed by surrounding the pore cavities in the three-dimensional space; the pore cavities are distributed uniformly; each pore cavity runs through in a three-dimensional mode; and the pore cavity uniform distribution means that each pore cavity is uniformly distributed on a porous material and under any unit level volume, the porosity is more than or equal to 65 percent and the light transmittance is more than or equal to 45 percent. A specific and clear measurement mode is provided for the pore cavity uniform distribution of the polytetrafluoroethylene fiber membrane, and the porous material and the pore distribution uniformity of the multi-level structure are measured under the dimension of the small unit level volume, and the porous structure is highly uniform, so that the uniform consistency of each property of the porous material is guaranteed.

Description

technical field [0001] The invention relates to a porous material, in particular to a polytetrafluoroethylene fiber membrane, which is especially suitable for membrane distillation. Background technique [0002] A solid with a certain number of pores is called a porous material, which is a material with a network structure composed of through or closed pores. Compared with continuum materials, porous materials generally have the advantages of low relative density, high specific strength, high specific surface area, light weight, sound insulation, heat insulation, and good permeability. According to the different pore sizes, porous materials can be divided into microporous (pore diameter less than 2 nm) materials, mesoporous (pore diameter 2-50 nm) materials and macroporous (pore diameter greater than 50 nm) materials. [0003] Porous materials can be divided into metal porous materials and non-metal porous materials according to their materials. Non-metallic porous materia...

AI Technical Summary

Problems solved by technology

However, due to the randomness and irregularity of the pore structure, it still cannot meet the performance requirements of many applications.

[0004] In many applications, it is required that the porous material itself is uniform, the pore size and the distribution of the pores are uniform, so that the performance is uniform, but in fact, many porous materials do not meet this requirement, and their uniformity complements; although some materials claim to be Higher uniformity has been achieved, but its uniformity is still the uniformity at the large volume scale. If it is measured with a small volume scale, for example, a plurality of three-dimensional bodies whose volume is not larger than one cubic centimeter are randomly selected on the material, and their volumes are measured respectively. Quality, the difference in uniformity is still very large, so the various properties of PTFE porous membrane materials such as strength, elastic modulus, flux, etc. are not uniform, which seriously affects its function.