Preparation method of PTFE-based nano functional composite membrane and use

A preparation method of a polytetrafluoroethylene (PTFE)-based nano functional composite membrane, comprising the following steps:

• (1) preparing the PTFE-based nano functional composite membrane through polymerization of monomers;
• wherein,
• 1) preparing a rod by blending, pre-compressing and pushing;
• wherein,
• a PTFE resin is infiltrated with vinyl silicone oil having a PTFE softening function, the infiltrated PTFE resin is blended, and hot pre-compressing and hot pushing are performed at a temperature of 60-90° C. at a rate of 20-30 m/min under a pressure of 5-8 MPa to prepare a monomer polymerized PTFE rod material;
• 2) preparing the membrane by hot calendering and polymerization, wherein,
• the prepared PTFE rod material is subjected to a polymerization under an action of hot calendering at a temperature of 60-90° C. at a rate of 20-30 m/min, and a part of vinyl silicone oil mixed in the PTFE resin and having a monomer polymerization effect is extruded by a hot calendering machine to prepare the PTFE-based nano functional composite membrane with micron pores;
• the PTFE-based nano-functional composite membrane has a thickness of 100-120 micrometer and is milky white, and a surface morphology of the membrane exhibits that a micron miniature concave-convex surface structure with an average size of 20-40 micrometer, a height of 10-20 micrometer and a spacing of 30-50 micrometer is uniformly distributed in a longitudinal and latitudinal direction;
• and
• 3) preparing a homogeneous membrane through miere a polymerization, wherein,
• the PTFE-based nano functional composite membrane with the micron miniature concave-convex surface structure is subjected to the polymerization in a 180-200° C. degreasing oven at a rate of 6-8 m/min, and a part of vinyl silicone oil which is not extruded by the hot calendering machine and mixed into the PTFE resin for monomer polymerization is polymerized under an action of temperature to be consolidated in the PTFE resin, so as to prepare a homogeneous PTFE-based nano functional composite membrane which is reeled under an action of traction caused by rotation of a roller arranged outside the degreasing oven;
• (2) preparing the PTFE-based nano functional composite membrane through high-temperature high-linear pressure micro eutectics;
• wherein,
• a temperature in a high-temperature high-linear pressure micro eutectic cavity is set to 70-420° C., the PTFE-based nano functional composite membrane is spread on an unpowered roller bracket in the cavity, pulled by a uniform traction force caused by rotation of the roller arranged outside the cavity to be pushed forward at a rate of 6-8 m/min, a molecular chain of the membrane is shrunk through the high temperature in the cavity and eutectics are produced, and micropores become nano pores and micron pores, a linear pressure of the surface of the PTFE membrane is controlled to 50-80 N/m so that a width of the membrane is shrunk, a density of the membrane is improved, and the eutectic which has a shrunk membrane width and an increased density, a transparent membrane changed from the milky white membrane and uniform transparency has nano macromolecular aggregates and nano and micron concave-convex geometrical structure surface morphologies with an average surface size of 10-20 micrometer, a height of 5-10 micrometer and a spacing of 10-20 micrometer;
• and
• (3) preparing the PTFE-based nano functional composite membrane through nano deep surface activation;
• wherein,
• after functional surfaces of the nano and micron concave-convex geometrical structure surface morphologies of the PTFE-based nano functional composite membrane are covered with a polyethylene (PE) membrane, a single surface of the PTFE-based nano functional composite membrane applied with a bonding adhesive is subjected to surface activation under a vacuum environment where a nitrogen-hydrogen mixed medium atmosphere of less than 40° C. is provided at a rate of 1.5-3 m/min so that an activated structure layer with a nano depth is formed on a sizing surface of the PTFE-based nano functional composite membrane;
• the bonding adhesive is applied to the surface of the membrane having the activated structure layer so that chemical bonding occurs between a characteristic group of the adhesive and the activated structure layer of the PTFE-based nano functional composite membrane to form a membrane-adhesive complex.