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C/SiO2/SiC wave-absorbing composite material and preparation method thereof

A composite material and composite technology, applied in the field of functional composite materials, can solve the problems of complex preparation process, narrow absorption frequency band, poor applicability, etc., and achieve the effect of high dielectric loss, stable performance, improved conversion rate, and thinner thickness.

Inactive Publication Date: 2012-06-20
HUNAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Traditional absorbing materials include: ferrite, metal micropowder, barium titanate, etc., which usually have shortcomings such as narrow absorption frequency band and high density; new absorbing materials include: nanomaterials, metal fibers, "chiral" materials, conductive polymers And circuit simulation absorbing materials, etc., high cost, complicated preparation process, poor applicability

Method used

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  • C/SiO2/SiC wave-absorbing composite material and preparation method thereof
  • C/SiO2/SiC wave-absorbing composite material and preparation method thereof
  • C/SiO2/SiC wave-absorbing composite material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] A tubular reactor such as Figure 6-8As shown, it is a cylindrical body, one end is provided with an air inlet (1), and the other end is provided with an air outlet (2). The inner wall of the tubular reactor is provided with 2 to 4 spirals with a width of 1mm to 100mm (a). The sheet (5), the helical sheet (5) maintains an inclination angle of 35° with the central axis of the reactor; and the inner wall of the tubular reactor is regularly arranged with tapered knife edges (4) with a height of 2 mm to 5 mm. Wherein, the inclination angle between the helical piece (5) and the central axis of the reactor can be designed as different angles according to needs, and 20°-60° are all suitable angles. The helical sheets (5) can be 2 to 4 continuous or discontinuous helical sheets, and the pitch (b) between the helical sheets can be designed according to requirements, and 100 mm to 500 mm is more suitable.

Embodiment 2

[0042] With the tubular reactor described in embodiment 1 as reaction equipment, prepare C / SiO 2 / SiC absorbing composite material:

[0043] At 20°C, take 100g of activated carbon and put it in a beaker, add 10% (w / w) KH550 relative to the activated carbon and 100ml of absolute ethanol and stir evenly for surface adsorption. Then place the beaker in a 60°C water bath for ultrasonic dispersion for 2 hours, and then perform curing treatment in a tubular reactor at 80°C. The solidified sample was taken out and placed in a tubular reactor, and the temperature was raised to 900°C at a rate of 3°C / min and kept for 2 hours for carbonization treatment. Take it out at room temperature. The scanning electron microscope image of the composite material is shown in figure 1 As shown, the XRD diffraction pattern is as figure 2 as shown, figure 1 The medium cube is β-SiC crystal, and the small round particles are SiO 2 attached to the carbon substrate; figure 2 The peaks at 36°, 6...

Embodiment 3

[0045] With the tubular reactor described in embodiment 1 as reaction equipment, prepare C / SiO 2 / SiC absorbing composite material:

[0046] At 25°C, put 100g of activated carbon in a beaker, add 30% (w / w) TEOS and 100ml of absolute ethanol relative to the activated carbon, stir evenly, perform surface adsorption, and add 10ml of 5% (w / w) ammonia water , ultrasonically dispersed for 30 minutes, and then solidified in a tubular reactor at 120°C after standing overnight. The cured sample is taken out, ground and sieved into a 300-mesh powder and put into a tubular reactor, and the temperature is raised to 1000°C at a rate of 5°C / min for 1 hour for carbonization treatment, and the carbonized product is transferred to a high-temperature atmosphere furnace at a temperature of 15°C / min. The heating rate of min is 1400 ° C for 2 hours, and it can be taken out after cooling to room temperature. The scanning electron microscope effect and diffraction effect of the composite material ...

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Abstract

The invention belongs to the field of functional composite materials, and particularly relates to a C / SiO2 / SiC wave-absorbing composite material and a preparation method thereof. The composite material is prepared through the raw materials and the method as follows: 1, silane reagent and matrix carbon are subject to surface adsorption treatment under the condition of 20 to 25 DEG C, and then are subject to curing treatment in a tube-type reactor at the temperature of 60 to 160 DEG C to obtain a cured compound, wherein the mass ratio of the silane reagent to the matrix carbon is 0.1 to 0.5: 1; the cured compound is mechanically crushed into powder; and 3, the powder is loaded in the tube-type reactor, and then the tube-type reactor is put in a slewing tube furnace to undergo high-temperature carbonizing treatment under the protection of inert gas. The composite material provided by the invention is 1.2 to 3.0 g / cm3 in volume density and 1multiplied by10 to 2-1multiplied by 103 Omega.m in specific resistance, and has an excellent wave-absorbing property in X-band and Ku-band microwave frequency bands.

Description

technical field [0001] The invention belongs to the field of functional composite materials, and relates to a wave-absorbing material and a preparation method thereof, in particular to a wave-absorbing composite material with a carbon material as a matrix and a preparation method thereof. Background technique [0002] With the development of modern electronic generation technology, the number of electronic products has increased sharply, and the various electromagnetic radiations generated thereby have a great impact on the environment. Electronic products leak out and emit electromagnetic waves, forming electromagnetic wave public hazards and becoming serious environmental pollution. Electromagnetic wave absorbing materials can convert electromagnetic wave energy into heat energy or other forms of energy, thereby effectively reducing and reducing electromagnetic pollution. Absorbing materials are widely used in electromagnetic shielding such as television broadcasting, mic...

Claims

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Application Information

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IPC IPC(8): C09K3/00B01J19/24B01F5/06
Inventor 李劲刘洪波邵南子
Owner HUNAN UNIV
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