CN110642547B

CN110642547B - Graphene slurry and graphene aerated concrete

Info

Publication number: CN110642547B
Application number: CN201911023486.XA
Authority: CN
Inventors: 梁大海
Original assignee: Feida Prefabricated Building Engineering Chongqing Co ltd
Current assignee: Shenzhen Feida Alkene Material Co ltd
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2022-05-27
Anticipated expiration: 2039-10-25
Also published as: CN110642547A

Abstract

The invention discloses graphene slurry, which comprises the following components in percentage by mass, 0.1-5% of graphene oxide; 20% -35% of silicate derivatives; 30% -40% of acid salt; the balance of water. The invention also discloses graphene aerated concrete which has low dry density, high strength and low thermal conductivity.

Description

Graphene slurry and graphene aerated concrete

Technical Field

The invention belongs to the technical field of concrete materials, and particularly relates to graphene slurry and graphene aerated concrete.

Background

The aerated concrete has the characteristics of high strength, light weight and heat preservation and insulation, and is widely applied in China. This has brought the practitioner's pursuit of cumin for higher strength, lower density aerated concrete. The traditional increase in strength of aerated concrete results in increased density and increased cost.

Graphene, as a new material with great attention, has the characteristics of high strength, light density and the like, but a common simple substance of graphene is powdery and easily diffuses with air in the operation process, so that the excellent characteristics of graphene are difficult to introduce into building materials.

In addition, since graphene has excellent thermal conductivity, how to introduce graphene materials into the foamed concrete without increasing the thermal conductivity of the foamed concrete is also an urgent problem to be solved.

Disclosure of Invention

The invention aims to provide graphene slurry which can increase the strength of aerated concrete, can reduce the dry density of the aerated concrete under the condition of ensuring the same strength, and meanwhile, the graphene slurry can increase the thermal conductivity of the aerated concrete less.

The graphene slurry comprises the following components in percentage by mass:

0.1 to 5 percent of graphene oxide

20 to 35 percent of silicate derivative

30 to 40 percent of acid salt

The balance of water.

In one embodiment, the silicate derivative is one or a mixture of more than one of silicate, orthosilicate or silicic acid.

In one embodiment, the acid salt is one or a mixture of more than one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, potassium monohydrogen phosphate, potassium dihydrogen phosphate, potassium phosphate, sodium phosphate and potassium hydrogen sulfate.

In one embodiment, the carbon to oxygen ratio is less than 10.

In one embodiment, the graphene aerated concrete comprises any one of the graphene slurries of claim 4.

The invention also provides graphene aerated concrete which is low in dry density, high in strength and low in heat conductivity.

In one embodiment, the graphene aerated concrete comprises any one or a mixture of more than one of sand, gypsum, lime, silicon dioxide, aluminum powder, phospholime, calcium silicate, aluminum silicate or magnesium silicate.

Method for carrying out the invention

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A graphene paste comprising the following components:

and (3) graphene oxide: graphene oxide is the main effective component of the slurry, on one hand, graphene oxide can be prepared into a solution and is easier to uniformly disperse in operation compared with graphene, and on the other hand, graphene oxide has ductility and compressive resistance similar to graphene and can increase the strength of concrete. Since the ductility and the compressive resistance of the graphene oxide are inversely proportional to the carbon-oxygen ratio of the graphene oxide, the carbon-oxygen ratio used in the slurry needs to be less than 10, preferably less than 5, in order to ensure the strength of the final aerated concrete product.

Silicate derivatives: the introduction of the silicate derivative may allow the slurry to produce silicic acid hydrogel and silica in the foamed concrete. Due to the poor heat-conducting property of the silicon dioxide, the influence of the graphene oxide in the slurry on the heat-conducting property of the foamed concrete can be reduced.

The introduction of the acid salt has two purposes, on one hand, the formation of silicic acid gel can be promoted, and on the other hand, acetic acid, oxalic acid and the like are considered to generate gas easily in the later-stage moisture reaction process, so that the density of aerated concrete is reduced.

The three substances are uniformly stirred to obtain the graphene slurry, and the obtained graphene slurry can be used as an additional component and added into the aerated concrete in the conventional preparation process of the aerated concrete. Preferably, it may be added prior to initial setting. Preferably, the added slurry accounts for one to three thousandths of the total weight of the aerated concrete. On the one hand, this additive can increase aerated concrete's intensity, and on the other hand, when intensity does not have extra requirement, the user can be through adding this additive, when saving material cost, reduces dry density. Meanwhile, compared with common graphene slurry, the slurry has less influence on the original heat conduction effect of concrete.

Examples

10g of graphene oxide, 300g of sodium silicate and 300g of potassium hydrogen sulfate were mixed together, and 390g of water was added. The resulting slurry was designated sample a.

10g of graphene oxide was dispersed in 1KG of water and this was designated as sample B.

1KG of water was taken and recorded as control C.

And then, using a common aerated concrete production process, adding the sample A, the sample B and the control C before the slurry is stirred, and then continuing the process to obtain the aerated concrete. Repeat four times, measure dry density, oven dry strength, thermal conductivity:

absolute dry strength (MPa)	Sample A	Sample B	Control C
				Concrete batch 1	A3.5	A3.0	A2.0
Concrete batch 2	A3.0	A3.0	A2.5
				Concrete batch 3	A3.0	A3.0	A2.0
Concrete batch 4	A3.0	A3.0	A2.5

The graphene slurry provided by the invention can improve the absolute dry strength, reduce the dry density and basically does not change the thermal conductivity of the aerated concrete.

Claims

1. The graphene slurry is characterized by being applied to aerated concrete; the graphene slurry comprises the following components in percentage by mass:

0.1% -5% of graphene oxide;

20% -35% of silicate and/or silicate derivative;

30% -40% of acid and/or acid salt;

the balance of water;

wherein the silicate derivative is at least one of orthosilicate and silicic acid; the acid is at least one of hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid; the acid salt is at least one of potassium dihydrogen phosphate, potassium phosphate, sodium phosphate and potassium hydrogen sulfate; the carbon-oxygen ratio of the graphene oxide is less than 10.

2. A graphene aerated concrete comprising the graphene slurry of claim 1.

3. The graphene aerated concrete of claim 2, further comprising at least one of sand, gypsum, lime, silica, aluminum powder, phospholime, calcium silicate, aluminum silicate, and magnesium silicate.