Electrostatic self-assembly carbon nano tube/nano-carbon black composite mortar as well as preparation method and application thereof

An electrostatic self-assembly and carbon nanotube technology, which is applied in the field of building materials, can solve the problems of reducing the material properties with a large amount of nanocarbon black, and the carbon nanotubes and nanocarbon black are not easy to disperse, etc., to achieve superior pressure sensitivity, pressure sensitive The effect of stability and energy saving

Active Publication Date: 2015-11-18

DALIAN UNIV OF TECH

2 Cites 8 Cited by

AI-Extracted Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that carbon nanotubes and nano carbon black are not easy to disperse in cement mortar, and the large amount of nano carbon black reduces the material p...

Method used

(4) according to the size of admixture in the mould, insert the electrode that is used to connect external circuit, vibrate slightly again, guarantee that electrode and admixture are in good cont...

Abstract

The invention discloses electrostatic self-assembly carbon nano tube/nano-carbon black composite mortar. Raw materials of the mortar comprise cement, silica fume, electrostatic self-assembly carbon nano tubes/nano-carbon black, a water reducing agent, sand and water. The minimum static resistivity of the mortar reaches 0.45 omega*m, the range of an absolute value of the resistivity change rate is 3.3%-22.1%, the change range of stress sensitivity is 0.40%-2.69%/MPa, and the change range of the strain sensitivity is 105-704. Compared with the prior art, the electrostatic self-assembly carbon nano tube/nano-carbon black composite mortar and the preparation method thereof solve the problem about dispersion of nanofiller in the mortar very well, and the carbon nano tubes and the nano-carbon black have the collaborative conductive effect, so that the mortar can acquire very low static resistivity and has excellent pressure-sensitivity by the aid of a small mixing amount of electrostatic self-assembly carbon nano tubes/nano-carbon black.

Technology Topic

Silica fumeSelf-assembly +7

Image

Examples

Experimental program(3)

Example Embodiment

[0041] Example 1

[0042] The electrostatic self-assembled carbon nanotube/nano carbon black composite mortar is prepared according to the following steps:

[0043] (1) Take 90 parts of raw material cement; 10 parts of silica fume; 4 parts of electrostatic self-assembled carbon nanotubes/nano carbon black; 2.5 parts of water reducing agent; 150 parts of standard sand; 42 parts of water;

[0044] (2) Add electrostatic self-assembled carbon nanotubes/nano carbon black, silica fume, water, water reducing agent, cement and standard sand in the cement mortar mixer in sequence, and mix them evenly to obtain a mixture;

[0045] (3) Pour the obtained mixture into a mold, then place the mold on a vibrating table, and vibrate until the surface of the mixture in the mold produces slurry;

[0046] (4) According to the size of the mixture in the mold, insert the electrode used to connect the external circuit, and then vibrate slightly to ensure that the electrode and the mixture are in good contact;

[0047] (5) Put the mold into the mortar curing box, at a temperature of 20±1℃, humidity> Under the condition of 95%, the mortar specimen 1 (40mm×40mm×80mm) was obtained after curing for 24 hours.

[0048] Put the prepared mortar specimens in water at 20±1℃ for curing to 1 day, 3 days, 7 days, 14 days, 28 days, and 80 days of age. Take the specimens out of the curing tank and dry the specimens. Surface water, and let it dry indoors for 3 hours.

[0049] The measured static resistivities are 1.42Ω.m, 1.60Ω.m, 1.43Ω.m, 1.56Ω.m, 1.62Ω.m, 1.68Ω.m, respectively.

[0050] At the age of 80 days, the pressure sensitivity test of specimen 1 was performed. The loading amplitude used in the experiment is 8 MPa (the elastic phase of the specimen), the loading rate is 0.4 mm/min, and the number of cycles of cyclic loading is 7.

[0051] And calculate the resistivity change rate, stress sensitivity and strain sensitivity according to the following formulas. The calculation results are shown in Table 1.

[0052] Δρ max =100%×(ρ min -ρ 0 )/ρ 0 (1)

[0053] Its Δρ max : Maximum resistivity change rate; ρ min :The minimum resistivity of the specimen in the process of applying compressive stress; ρ 0 : The static resistivity of the test piece.

[0054]

[0055] Among them, SES: stress sensitivity; σ max : Maximum compressive stress.

[0056] S A S = - Δρ max ϵ max - - - ( 3 )

[0057] Among them, SAS: stress sensitivity; ε max : Maximum compressive strain.

[0058] Table 1 The resistivity change rate and sensitivity of specimen 1

[0059]

[0060] From image 3 with Figure 4 It can be seen that the pressure sensitivity of specimen 1 has good stability and repeatability. It can be seen from Table 1 that the absolute value of the resistivity change rate of specimen 1 is up to 6.9%, and the stress and strain sensitivity are 0.84%/MPa and 231 respectively.

Example Embodiment

[0061] Example 2

[0062] The electrostatic self-assembled carbon nanotube/nano carbon black composite mortar is prepared according to the following steps:

[0063] (1) Take 90 parts of raw material cement; 10 parts of silica fume; 7 parts of electrostatic self-assembled carbon nanotubes/nano carbon black; 2.5 parts of water reducing agent; 150 parts of standard sand; 56 parts of water;

[0064] (2) Add electrostatic self-assembled carbon nanotubes/nano carbon black, silica fume, water, water reducing agent, cement and standard sand in the cement mortar mixer in sequence, and mix them evenly to obtain a mixture;

[0065] (3) Pour the obtained mixture into a mold, then place the mold on a vibrating table, and vibrate until the surface of the mixture in the mold produces slurry;

[0066] (4) According to the size of the mixture in the mold, insert the electrode used to connect the external circuit, and then vibrate slightly to ensure that the electrode and the mixture are in good contact;

[0067] (5) Put the mold into the mortar curing box, at a temperature of 20±1℃, humidity> Under the condition of 95%, the mortar specimen 2 (40mm×40mm×80mm) was obtained after curing for 24 hours.

[0068] Put the prepared mortar specimens in water at 20±1℃ for curing to 1 day, 3 days, 7 days, 14 days, 28 days, and 80 days of age. Take the specimens out of the curing pool and dry them for testing. Place the water on the surface of the piece and let it dry indoors for 3 hours.

[0069] The measured static resistivity was 0.61Ω.m, 0.66Ω.m, 0.69Ω.m, 0.67Ω.m, 0.65Ω.m, 0.68Ω.m, respectively.

[0070] At the age of 80 days, test piece 2 was subjected to a pressure sensitivity test. The loading amplitude used in the experiment is 8 MPa (the elastic phase of the specimen), the loading rate is 0.4 mm/min, and the number of cycles of cyclic loading is 7.

[0071] According to formulas (1), (2) and (3) respectively, the resistivity change rate, stress sensitivity and strain sensitivity are calculated. The calculation results are shown in Table 2.

[0072] Table 2 The resistivity change rate and sensitivity of specimen 2

[0073]

[0074] From Figure 5 with Image 6 It can be seen that the pressure sensitivity of specimen 2 has good stability and repeatability. It can be seen from Table 2 that the absolute value of the resistivity change rate of specimen 2 is up to 22.1%, and the stress and strain sensitivity are as high as 2.69%/MPa and 704, respectively.

Example Embodiment

[0075] Example 3

[0076] The electrostatic self-assembled carbon nanotube/nano carbon black composite mortar is prepared according to the following steps:

[0077] (1) Take 90 parts of raw material cement; 10 parts of silica fume; 10 parts of electrostatic self-assembled carbon nanotube/nano carbon black compound; 2.5 parts of water reducing agent; 150 parts of standard sand; 72 parts of water;

[0078] (2) Add electrostatic self-assembled carbon nanotubes/nano carbon black, silica fume, water, water reducing agent, cement and standard sand in the cement mortar mixer in sequence, and mix them evenly to obtain a mixture;

[0079] (3) Pour the obtained mixture into a mold, then place the mold on a vibrating table, and vibrate until the surface of the mixture in the mold produces slurry;

[0080] (4) According to the size of the mixture in the mold, insert the electrode used to connect the external circuit, and then vibrate slightly to ensure that the electrode and the mixture are in good contact;

[0081] (5) Put the mold into the mortar curing box, at a temperature of 20±1℃, humidity> Under 95% conditions, after curing for 24 hours, demoulding, mortar specimen 3 (40mm×40mm×80mm) was obtained.

[0082] Put the prepared mortar specimens in water at 20±1℃ for curing to 1 day, 3 days, 7 days, 14 days, 28 days, and 80 days of age. Take the specimens out of the curing pool and dry them. Place the water on the surface of the test piece and let it dry naturally indoors for 3 hours.

[0083] The measured static resistivities are 0.42Ω.m, 0.44Ω.m, 0.42Ω.m, 0.45Ω.m, 0.45Ω.m, 0.45Ω.m, respectively.

[0084] At the age of 80 days, test piece 3 was subjected to a pressure sensitivity test. The loading amplitude used in the experiment is 8 MPa (the elastic phase of the specimen), the loading rate is 0.4 mm/min, and the number of cycles of cyclic loading is 7.

[0085] The maximum resistivity change rate, stress sensitivity and strain sensitivity are calculated according to formulas (1), (2) and (3). The calculation results are shown in Table 3.

[0086] Table 3 The resistivity change rate and sensitivity of electrostatic self-assembled carbon nanotube/nano carbon black mortar

[0087]

[0088] From Figure 7 with Figure 8 It can be seen that the pressure sensitivity of sample 3 has good stability and repeatability. It can be seen from Table 3 that the absolute value of the resistivity change rate of the specimen 3 is up to 19.0%, and the stress and strain sensitivity are as high as 2.31%/MPa and 541 respectively.

PUM

Description & Claims & Application Information

We can also present the details of the Description, Claims and Application information to help users get a comprehensive understanding of the technical details of the patent, such as background art, summary of invention, brief description of drawings, description of embodiments, and other original content. On the other hand, users can also determine the specific scope of protection of the technology through the list of claims; as well as understand the changes in the life cycle of the technology with the presentation of the patent timeline. Login to view more.

Classification and recommendation of technical efficacy words

good pressure sensitivity

Preparation of acrylic ester copolymer emulsion for pressure-sensitive adhesive

ActiveCN101412783AGood pressure sensitivityimprove performance

Owner:HEBEI UNIV OF TECH

Electrostatic self-assembly carbon nano tube/nano-carbon black composite mortar as well as preparation method and application thereof

AI-Extracted Technical Summary

Problems solved by technology

Method used

Abstract

Image

Examples

Example Embodiment

Example Embodiment

Example Embodiment

PUM

Description & Claims & Application Information

Similar technology patents

Colloidal gold test strip for double-amplification system and preparation method thereof

Acceleration sensor and manufacturing method thereof

Ultrasonic method and apparatus for automatically controlling moving doors

Preparation of acrylic ester copolymer emulsion for pressure-sensitive adhesive

Method and device for transmission of light pilot tone signals

CircRNA markers for early diagnosis of lung adenocarcinoma and application thereof

Classification and recommendation of technical efficacy words

Preparation of acrylic ester copolymer emulsion for pressure-sensitive adhesive