CN-121989356-A - Dispersing method and dispersing device for carbon nano tube slurry in cement-based material

CN121989356ACN 121989356 ACN121989356 ACN 121989356ACN-121989356-A

Abstract

The invention provides a dispersing method and a dispersing device of carbon nano tube slurry in cement-based materials, which relate to the technical field of building materials, wherein the carbon nano tube slurry is sprayed into cement-based dry materials under stirring through at least 1 nozzle according to a target mixing ratio, stirring is continued, then a proper amount of water is adopted to flush the nozzle and spray into the cement-based materials under stirring, and meanwhile, a liquid additive and the rest water are poured into the cement-based materials under stirring and are further stirred, so that the uniformly dispersed carbon-doped nano tube cement-based materials are obtained, better dispersion of carbon nano tubes in the cement-based materials can be realized, and the reinforcing effect of the carbon nano tubes on the cement-based materials can be better exerted.

Inventors

YANG YIBO
FANG LIANG
LUO YUMIN
GUO WENYING
WANG HENGCHANG
LIU ZHICHENG

Assignees

江苏天奈科技股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (10)

1. A method for dispersing carbon nanotube slurry in a cement-based material, the method comprising: Preparing cement-based dry materials and carbon nano tube slurry according to a target mixing ratio, wherein water in the carbon nano tube slurry is not more than 40wt% of total water consumption in the target mixing ratio; Spraying the carbon nano tube slurry into the cement-based dry material under stirring through at least 1 nozzle, continuing stirring, then flushing the nozzle with a proper amount of water and spraying into the cement-based material under stirring, simultaneously pouring the liquid additive and the residual water into the cement-based material under stirring, and further stirring to obtain the carbon nano tube-doped cement-based material with uniform dispersion; The total mass of the water in the carbon nano tube slurry, the water in the liquid additive, the water for flushing and the residual water is the total water consumption in the target mixing ratio.
2. The dispersion method according to claim 1, wherein the cement-based dry material comprises a cementitious material, an aggregate, and a powder external additive; Preferably, the stirring time of the cement-based dry material is 0.5-2.0 min before the spraying.
3. The dispersion method according to claim 1 or 2, wherein the carbon nanotube slurry is in a stirring state before the spraying, and the stirring speed is controlled to be equal to or higher than 100r/min, preferably 100-500 r/min; preferably, the carbon nanotube slurry contains 0.25-3.5wt% of carbon nanotube solids, preferably 1.0-2.5wt%; Preferably, the particle size D 90 measured by a laser particle sizer in the carbon nanotube slurry is less than 300 μm, preferably the particle size D 90 is less than 100 μm; Preferably, the carbon nanotube paste has a 60s viscosity of less than 1500 mPa-s, preferably a 60s viscosity of less than 500 mPa-s.
4. A dispersion method according to any one of claims 1-3, characterized in that the pressure of the injection is hydraulic or pneumatic, the nozzles respectively comprising hydraulic or air atomizing nozzles; Preferably, the spray forms droplets having a volume percent characteristic diameter D V0.50 of between 0.05mm and 2.00mm, preferably D V0.50 of between 0.10mm and 0.80 mm; preferably, the number of the nozzles is 1-24, preferably 2-8; Preferably, the maximum clear aperture of the nozzle is not less than 1.0mm, preferably not less than 1.3mm; preferably, the total time of the spraying is 0.5 to 3.5min, preferably 1.0 to 3.0min.
5. A dispersing device used in the dispersing method according to any one of claims 1 to 4, wherein the dispersing device comprises a storage device, a pressurizing device, an injecting device, a control device and a stirrer with a stirring cavity; The storage device comprises a carbon nano tube slurry storage tank, the spraying device comprises a distributor and at least 1 nozzle, the nozzle is arranged above the stirring cavity, the pressurizing device is used for providing spraying required pressure for the spraying device, the control device is in signal connection with the pressurizing device and used for controlling pressurizing pressure and pressurizing time, and the carbon nano tube slurry storage tank, the distributor and the nozzle are sequentially connected, so that carbon nano tube slurry is sprayed into the stirring cavity.
6. The dispersion device of claim 5, wherein the storage device further comprises a water tank, the carbon nanotube slurry storage tank and the water tank being connected to the dispenser, respectively; The storage device further comprises a first metering device and a first valve, wherein the first metering device is respectively arranged at the discharge port of the carbon nano tube slurry storage tank and the discharge port of the water tank, the first valve is respectively arranged at the discharge port of the carbon nano tube slurry storage tank and the discharge port of the water tank, and the control device is respectively in signal connection with the first metering device and the first valve and is used for respectively controlling the adding amount and the adding time of the carbon nano tube slurry and the water.
7. The dispersing apparatus according to claim 5 or 6, wherein the pressurizing means comprises a hydraulic pump or an air pump, and wherein the pressurizing means is directly connected to the nozzle or the pressurizing means is connected to the dispenser.
8. The dispersing device according to any one of claims 5-7, wherein the spraying device further comprises a second metering device and a second valve, wherein the second metering device is arranged between the distributor and the nozzle, the second valve is arranged between the distributor and the nozzle, and the control device is respectively connected with the second metering device and the second valve in a signal manner and is used for controlling the switching state and the flow rate of the nozzle.
9. The dispersion device of any one of claims 5-8, wherein the storage device further comprises an intermediate reservoir disposed between the carbon nanotube slurry reservoir and the dispenser; preferably, stirrers are respectively arranged in the carbon nanotube slurry storage tank and the intermediate storage tank.
10. A dispersion device according to any one of claims 5 to 9, wherein the stirrer with the stirring chamber is a forced stirrer, preferably a shaft vibration stirrer.

Description

Dispersing method and dispersing device for carbon nano tube slurry in cement-based material Technical Field The invention relates to the technical field of building materials, in particular to a dispersing method and a dispersing device of carbon nano tube slurry in a cement-based material. Background Carbon Nanotubes (CNTs) are a novel nanofiber material with a diameter of nano-scale (typically less than 50 nm) and a length of micro-scale (typically 2-50 μm), and have extremely high aspect ratio and excellent mechanical properties, and have been widely studied in the field of cement-based materials in recent years. Research shows that in cement-based materials, carbon nanotubes can provide nucleation sites for cement hydration, accelerate the cement hydration speed, play a role in bridging in microcosmic, inhibit the occurrence and development of cracks, and thus improve the strength of cement-based materials. In order to achieve the purpose of well dispersing carbon nanotubes in cement-based materials, carbon nanotubes and a dispersing agent are generally prepared into carbon nanotube slurry, and then the carbon nanotube slurry is added when the cement-based materials are mixed, and the carbon nanotubes are dispersed in the cement-based materials by mixing. In order to achieve the aim of better dispersing the carbon nano tubes in the cement-based material, the prior art adopts the modes of selecting the adding time of the carbon nano tube slurry, adjusting the rotating speed of a stirrer, adopting a vibration stirrer and the like, which is helpful for improving the dispersing effect of the carbon nano tubes. When the carbon nanotube slurry is added into the cement-based material by adopting the conventional method, the carbon nanotube slurry can be quickly and completely poured into the cement-based material, and then the carbon nanotube slurry is firstly contacted with part of the cement-based material and then uniformly mixed with the cement-based material through the stirring action of the stirrer, but the dispersion efficiency and the dispersion capability of the stirrer are insufficient due to the small size of the carbon nanotube, the dispersion uniformity of the carbon nanotube in the cement-based material is still poor, and the reinforcing effect of the carbon nanotube on the cement-based material is influenced. Therefore, there is an urgent need to develop a more efficient dispersion method and dispersion apparatus of carbon nanotube slurry in cement-based materials to improve the uniformity of dispersion of carbon nanotubes in cement-based materials. Disclosure of Invention In view of the problems existing in the prior art, the invention provides a dispersing method and a dispersing device for carbon nano tube slurry in cement-based materials, according to a target mixing ratio, the carbon nano tube slurry is sprayed into cement-based dry materials under stirring through at least 1 nozzle, stirring is continued, then a proper amount of water is adopted to flush the nozzle and spray into the cement-based materials under stirring, and meanwhile, a liquid additive and the rest water are poured into the cement-based materials under stirring, and further stirring is carried out, so that the uniformly dispersed carbon nano tube-doped cement-based materials are obtained, better dispersion of carbon nano tubes in the cement-based materials can be realized, and the reinforcing effect of the carbon nano tubes on the cement-based materials can be better exerted. To achieve the purpose, the invention adopts the following technical scheme: one of the objects of the present invention is to provide a method for dispersing carbon nanotube slurry in cement-based material, the dispersing method comprising the following steps: Preparing cement-based dry materials and carbon nano tube slurry according to a target mixing ratio, wherein water in the carbon nano tube slurry is not more than 40wt% of total water consumption in the target mixing ratio; Spraying the carbon nano tube slurry into the cement-based dry material under stirring through at least 1 nozzle, continuing stirring, then flushing the nozzle with a proper amount of water and spraying into the cement-based material under stirring, simultaneously pouring the liquid additive and the residual water into the cement-based material under stirring, and further stirring to obtain the carbon nano tube-doped cement-based material with uniform dispersion; The total mass of the water in the carbon nano tube slurry, the water in the liquid additive, the water for flushing and the residual water is the total water consumption in the target mixing ratio. According to the dispersing method, firstly, carbon nano tube slurry is sprayed into cement-based dry materials under stirring through at least 1 spray nozzle according to a target mixing ratio, stirring is continued, then a proper amount of water is adopted to wash the spray nozzle and spray the spray nozzle into th