Polytetrafluoroethylene superfine fiber membrane

Abstract

The invention provides a polytetrafluoroethylene fiber membrane. The polytetrafluoroethylene fiber membrane comprises a polytetrafluoroethylene material main body. Polytetrafluoroethylene is in a form of fibers, the fiber diameter is in a range of 30-200 nm, the main body has hole cavities having hole diameters of 10-1000 nm and cavity walls formed from 3D spaces around the hole cavities, the hole cavities are uniformly distributed in the porous material in any unit volume and are communicated in a way of 3D communication, porosity is 70% or more, light transmittance is 50% or more, tensile strength is 20 N / mm<2> or more and water pressure resistance of 4 kg / cm<2> or more. The technical scheme provides a clear measurement method of uniform distribution of hole cavities of the polytetrafluoroethylene fiber membrane and realizes measurement of the porous material in a small unit volume scale and hole distribution uniformity of the multi-grade structure. The porous structure is highly uniform and ensures uniformity consistency of performances of the porous material.

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.