MULTI-STAGE FOAM SOUND-ABSORBING BLACK BODY MATERIAL AND PREPARATION METHOD THEREOF

Abstract

In the present invention, a multi-stage foam sound-absorbing black body material is provided for the first time. A graphene aerogel is introduced into a commercialized polymer foam skeleton by using a solvent plasticizing and foaming technology, so as to embed ultra-thin graphene drums in the foam skeleton. When sound waves enter the foam black body, a large number of graphene drums generate a severe resonance effect, thereby rapidly achieving attenuation of the sound waves, and combined with the friction loss of the porous structure of the polymer foam on the sound waves, excellent sound-absorbing performance is achieved in a wide frequency range. The present solution is provided on the basis of commercialized foam materials, has a simple method, low costs, and the potential of wide industrial application.

Claims

1. A multi-stage foam sound-absorbing black body material, comprising a polymer foam skeleton having a pore size of 10 um or more and a continuous graphene resonant cavity attached thereto, wherein a cavity wall of the graphene resonance cavity is graphene having a thickness of 100 nm or less; and wherein the polymer foam skeleton forms a primary foam structure, and the graphene resonant cavity forms a secondary foam structure.

2. The multi-stage foam sound-absorbing black body material according to claim 1, wherein the polymer foam is a common sound-absorbing foam material.

3. A preparation method for the multi-stage foam sound-absorbing black body material according to claim 1, comprising steps of: immersing the polymer foam into a graphene oxide dispersion, with the graphene oxide filling into an inner of the foam, adding the obtained dried foam in a foaming agent solution for foaming, and drying after foaming to obtain the sound-absorbing black body foam material.

4. The preparation method according to claim 3 wherein the graphene oxide is prepared by a Hummers method, an improved Hummers method or an electrochemical method.

4. The preparation method according to claim 3, wherein the graphene oxide dispersion has a concentration of 0.1-50 mg/g.

5. The preparation method according to claim 3, wherein the foaming agent solution is one of hydrazine hydrate solution, sodium borohydride solution, sodium bicarbonate solution and sodium carbonate solution.

6. The preparation method according to claim 3, further comprising reducing after the foaming.

7. The preparation method according to claim 3, wherein the sound-absorbing black body foam material has an average sound-absorbing coefficient of 0.8 or more at 100-10000 Hz.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0018] FIG. 1 is a physical view of the sound-absorbing foam black body material prepared according to Example 1.

[0019] FIG. 2 shows a sound-absorbing curve of the sound-absorbing foam black body prepared according to Example 1 at 200-6000 Hz.

[0020] FIG. 3 is a scanning diagram of the sound-absorbing foam black body prepared according to Example 1.

[0021] FIG. 4 shows a sound-absorbing curve of the foam prepared according to Comparative 1.

[0022] FIG. 5 shows a sound-absorbing curve of the foam prepared according to Comparative 2.

[0023] FIG. 6 is a schematic diagram of an apparatus constructed in Application 1.

[0024] FIG. 7 shows the sound attenuation of the sound-absorbing foam black body according to Application 1 at the frequency of 200-6000 Hz.

DESCRIPTION OF EMBODIMENTS

[0025] The invention is further described below in connection with examples. However, the scope of the present invention is not limited thereto.

EXAMPLE 1

[0026] Melamine foam with a thickness of 20 mm (pore size of 50-200 um) was immersed with 10 mg/ml aqueous graphene oxide (purchased from Hangzhou Gaoxi Technology Co., Ltd., average size of 20 um) for 2 h, and then the dried foam was added into 30% hydrazine hydrate for foaming for 2 h. After natural drying, a multi-stage foam sound-absorbing black body material having high performance was obtained, as shown in FIG. 3, in which the wall thickness of graphene in the secondary foam structure was 20 nm, the average sound-absorbing coefficient at 100-10000 Hz was 0.78, and the average sound-absorbing coefficient at 200-6000 Hz was 0.86.

EXAMPLE 2

[0027] Similar to Example 1, the melamine foam had a pore size of 50-200 um and a thickness of 30 mm, a multi-stage foam sound-absorbing black body material having high performance was obtained, in which the wall thickness of graphene in the secondary foam structure was 20 nm, the average sound-absorbing coefficient at 100-10000 Hz was 0.8, and the average sound-absorbing coefficient at 200-6000 Hz was 0.89.

EXAMPLE 3

[0028] Similar to Example 2, the melamine foam was replaced with a polyurethane foam having a pore size of 10-100 um, a multi-stage foam sound-absorbing black body material having high performance was obtained, in which the wall thickness of graphene in the secondary foam structure was 15 nm, the average sound-absorbing coefficient at 100-10000 Hz was 0.75, and the average sound-absorbing coefficient at 200-6000 Hz was 0.83.

EXAMPLE 4

[0029] Similar to Example 1, the concentration of graphene oxide was 5 mg/ml, a multi-stage foam sound-absorbing black body material having high performance was obtained, in which the wall thickness of graphene in the secondary foam structure was 12 nm, the average sound-absorbing coefficient at 100-10000 Hz was 0.65, and the average sound-absorbing coefficient at 200-6000 Hz was 0.71.

EXAMPLE 5

[0030] Similar to Example 1, the hydrazine hydrate was replaced with a sodium borohydride solution of 1% by mass, a multi-stage foam sound-absorbing black body material having high performance was obtained, in which the wall thickness of graphene in the secondary foam structure was 50 nm, the average sound-absorbing coefficient at 100-10000 Hz was 0.77, and the average sound-absorbing coefficient at 200-6000 Hz was 0.87.

[0031] Comparative 1

[0032] Similar to Example 1, the foam immersed in the graphene oxide was directly chemically reduced to obtain a sample having an average sound-absorbing coefficient of 0.25 at 100-10000 Hz and an average sound-absorbing coefficient of 0.3 at 200-6000 Hz.

[0033] Comparative 2

[0034] Similar to Example 1, the melamine foam was not subjected to any treatment, the sample had an average sound-absorbing coefficient of 0.17 at 100-10000 Hz and 0.21 at 200-6000 Hz.

[0035] Application 1

[0036] As shown in FIG. 6, a sounder was placed in a sound-absorbing foam black body box prepared according to Example 1, wherein the sounder was driven by a signal sounder, and then the signal of the sound wave was detected by an acoustic probe, and was displayed on an oscilloscope in real time through an amplification circuit. The signal of the sound wave was detected without the sound-absorbing black body as a comparison. The results, as shown in FIG. 7, showed that the sound-absorbing black body foam prepared according to Example 1 had a higher attenuation rate for 200-6000 Hz of sound.