32results about How to "Enhanced interfacial polarization" patented technology

The invention discloses a multi-phase high-dielectric-constant composite material with an isolation structure and a preparation method thereof. The material is prepared from, by mass, 0-10 parts of conducting packing, 10-50 parts of thermoplastic resin, 0-1 parts of an accelerant, 0-20 parts of a modifying agent, 0-20 parts of isolation balls, 50-100 parts of a curing agent and 100 parts of epoxy resin. By virtue of a suitable solvent and by means of a solution blending method, the modifying agent, the conducting packing, the thermoplastic resin and the epoxy resin are mixed to be uniform, the curing agent is added, the materials are mixed to be uniform, the mixture is poured into a mold and smeared into an electrode plate, heating is conducted for curing, and then the high-dielectric-constant multipolymer-based composite material with the isolation structure can be obtained. The block-shaped and film-shaped composite material can achieve the high dielectric constant and the low dielectric loss when the content of the conducting packing is low, is simple in preparation technology, easy to mold and process and short in molding period and has a very wide application prospect in the micro-electronics field and the motor and cable industries.

The invention discloses a porous Co3O4 / Al2SiO5 low-density wave-absorbing-type composite-phase ceramic and a preparation method thereof. Particles of a Co3O4 wave-absorbing agent in the composite-phase ceramic are evenly dispersed in an Al2SiO5 ceramic fiberboard, which helps to improve the wave-absorbing performance of the material; the Co3O4 wave-absorbing agent in the composite ceramic has dielectric loss and magnetic loss on an electromagnetic wave; a layer of Co simple substance interface layer wraps the surface of each Co3O4 particle. The composite-phase ceramic material is low in density and good in high temperature resistance. According to the preparation method, a dipping method is adopted for introducing the wave-absorbing agent raw material into the porous ceramic, and the wave-absorbing agent in the obtained Co3O4 / Al2SiO5 composite-phase ceramic can be evenly dispersed, which helps to improve the wave-absorbing performance of the material; the selected porous Al2SiO5 ceramic fiberboard is used as a base material and has the advantages of being resistant to high temperature and low in density, in the preparation process, the shape and size of the Al2SiO5 ceramic fiberboard are not changed, and the composite-phase ceramic keeps low density; according to the method, the whole preparation technology is simple in step, short in period, easy to operate and good in repeatability.

The invention discloses a high-dielectric and low-loss resin-based nanocomposite material used in the X-band and a method thereof. One of the preparation methods of the material is: hydrogen peroxide is used to hydroxylate the surface of the dielectric ceramic, and the hydroxylated ceramic Disperse in Tris-HCl buffer solution, add dopamine hydrochloride, make the hydroxylated ceramic surface form a polydopamine shell layer through in-situ polymerization reaction, use silver nitrate aqueous solution and ammonia water to make the dopamine-coated ceramic surface modified with nano-silver particles, and Acetone is used as a solvent to mix and dissolve the core-shell-satellite multi-level structure dielectric ceramic modified by nano-silver particles and thermosetting resin, and the composite material is obtained after removing acetone and gas. The invention improves its dielectric constant in the X-band (ε>8.6@10GHz), and at the same time better suppresses the dielectric loss (tanσ<0.04@10GHz), which is the design of high-frequency, high-dielectric and low-loss nanocomposite materials Provided new ideas.

The invention discloses an iron-based magnetic foam wave-absorbing material with low-frequency broadband wave-absorbing performance and a preparation method thereof, belonging to the technical field of electromagnetic shielding and microwave loss functional materials. In this method, iron-based magnetic powder, resin, curing agent and suspending agent are first mixed, and ultrasonically mechanically stirred to form a uniform suspension slurry; the slurry is hung and applied to the template, and the remaining material is removed and then heated and solidified; the template is removed by high temperature and high pressure; foam reinforcement Resin is sucked into the surface micropores and the pores left after removing the template, and the mechanics are enhanced. The invention solves the problem that the flaky iron-based powder cannot be suspended in the solution by adding the suspending agent to the raw material and using ultrasonic mechanical stirring in the material-hanging process. The iron-based magnetic foam prepared by the invention has a low-frequency broadband wave-absorbing effect, and has better wave-absorbing performance in the 1.14-2.4GHz frequency band.

The invention belongs to the field of a compound medium and particularly relates to a nanofiber / PVDF (polyvinylidene fluoride) compound medium with a sandwich structure and a preparation method of the nanofiber / PVDF compound medium. Upper and lower layers of the sandwich structure of the compound medium are PVDF films, a middle layer is a CFO@BZT-BCT NFs / PVDF compound medium film, and the three layers of structure media are combined through hot pressing, wherein the PVDF films are prepared with a solution tape casting method through quenching treatment, and the CFO@BZT-BCT NFs / PVDF compound medium film is prepared through steps as follows: crystalized BZT-BCT NFs is prepared from a BZT-BCT spinning precursor through electrostatic spinning and high-temperature calcination, CFO is introduced, CFO@BZT-BCT NFs is prepared and subjected to surface modification with dopamine hydrochloride, finally, CFO@BZT-BCT NFs is mixed with PVDF, suspension turbid colloid is prepared and subjected to solution tape casting and quenching treatment, and the nanofiber / PVDF compound medium is prepared. The technical problems of low energy density and high dielectric loss of an inorganic filling phase / polymer based compound medium are solved.

The invention provides a polyimide high-temperature dielectric composite film and a preparation method thereof. The composite film is formed by blending at least one of hexagonal boron nitride nanosheet and molybdenum disulfide nanosheet as well as polyimide. The mass fraction of the hexagonal boron nitride nanosheet is 6% to 12%, and the mass fraction of the molybdenum disulfide nanosheet is 1% to 2%. The introduction of a nanosheet filler not only improves the thermal properties of a polyimide film, but also improves the high temperature dielectric properties that a conventional PI film hasnot been involved. The composite film has the advantages of low dielectric loss, high breakdown strength, energy storage density and energy storage efficiency at normal temperature, and keeps low conductance loss and high breakdown field strength and energy storage density at the temperature of 150 DEG C.