Text | Long Yue Tan
Editor|Long Yue Tan
●○ Introduction ○●
Cement-based permeable crystalline waterproof material is a new type of waterproof material with excellent impermeability performance, but with the increase of the use time of waterproof material, its impermeability performance gradually decreases, so it is necessary to find a method that can improve the impermeability of cement-based permeable crystalline waterproofing material.
In recent years, graphene oxide, as a new type of nanomaterial, has been widely studied and widely used in materials science, chemistry, biology and other fields.
This study aimed to explore the effect of graphene oxide on the impermeability of cement-based permeable crystalline waterproofing materials and study its addition mechanism.
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●○ Experimental method ○●
In this study, the experimental materials used mainly include cement, lime, quartz sand, expansion agent, polymer fiber and graphene oxide (GO), cement is the basic material of this experiment for the preparation of cement-based waterproof materials, lime is a common auxiliary material, adjustable the properties and properties of cement-based materials.
Quartz sand is a commonly used filler, which can improve the strength and hardness of cement-based materials, and the expansion agent can make cement-based materials have certain expansion, thereby increasing their crack resistance.
Polymer fiber is a reinforcing material that can increase tensile strength in cement-based materials, and graphene oxide is a two-dimensional nanomaterial that can improve the microstructure of cement-based materials and increase their impermeability.
In the specific experiment, cement, lime, quartz sand and expansion agent are mixed in a fixed proportion, a certain amount of water is added and stirred evenly to prepare a cement-based material, in the preparation process, GO is added to the cement-based material with different content, and appropriate mixing is carried out to ensure that GO is evenly dispersed in the cement-based material.
Then the prepared cement-based material is poured into the standard specimen mold, placed at room temperature for a period of time, and after it is fully solidified, the follow-up experimental test is carried out, and the mechanical properties and impermeability of cement-based materials under different proportions are also tested and analyzed.
The process of this experiment is as follows: first prepare cement, quartz sand, graphene oxide and other raw materials, and mix according to a certain proportion to prepare different content of graphene oxide, doped with cement-based osmotic crystalline waterproof material samples, and then dry the samples to a constant mass through vacuum drying technology.
Microstructure and crystal structure of graphene oxide-doped cementitious materials with different contents were characterized using liquid scanning electron microscopy (SEM) and X-ray diffraction (XRD).
Finally, the permeability test and compressive strength test were carried out by cement permeability tester and pressure pump, and the influence of different contents of graphene oxide on the permeability and mechanical properties of cement-based materials was studied.
After statistical analysis of experimental data, the influence of graphene oxide on the impermeability of cement-based osmotic crystalline waterproofing materials was obtained, which provided experimental basis and theoretical support for in-depth exploration of the application of graphene oxide in cement-based waterproofing materials.
The following experimental methods were used in this study:
Different contents of GO (0.1%, 0.3% and 0.5%) cement-based permeable crystalline waterproofing materials were prepared, in which GO was prepared by chemical reduction, and then mercury pressure was used to determine the porosity and permeability coefficient of cement-based materials with different contents of GO, and their impermeability pressure was measured.
In order to further study the effect of GO on the microstructure of cement-based materials, XRD and SEM were used to analyze the samples, and finally, the compressive strength tests of cementitious materials with different content of GO were carried out to evaluate their mechanical properties.
During the experiment, we first prepared GO aqueous solution, then added different contents of GO to cement-based materials, and stirred and mixed in a blender until it was homogeneous.
The mixed sample is poured into a mold and allowed to stand at room temperature for 24 hours, then cured for 7 days in an incubator at 50 °C, after which the sample is taken out and tested for different experiments.
For the mercury pressure test, we first grind the sample into powder, and wash and dry it with ethanol, then, put the sample into the mercury pressure meter, apply pressure, measure its porosity and permeability coefficient, the impermeability pressure test is carried out in the impermeability meter, put the sample into the instrument, add pressure water and apply pressure, record its permeability and pressure.
XRD and SEM analysis is to scan and analyze the sample to study the effect of GO on the microstructure of cement-based materials, compressive strength test is performed in a universal testing machine, put the sample into the machine, apply pressure, record its compressive strength value, we use a series of standardized experimental methods to conduct research to ensure the reliability and accuracy of experimental results.
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●○ Effect of graphene oxide on anti-seepage properties ○●
Graphene oxide (GO) is a two-dimensional material with a monolayer structure, with high specific surface area and excellent mechanical properties, which is widely used in the field of materials science, and in recent years, researchers have begun to explore the application of GO in cement-based materials to improve its performance.
Cement-based waterproofing materials are commonly used in waterproofing, leakage plugging and basements of buildings, however, due to the large porosity of the cement-based material itself, it is easy to penetrate and erode by moisture, reducing its service life.
Therefore, how to improve the impermeability of cement-based waterproof materials has become one of the research hotspots.
Studies have shown that GO can affect the impermeability of cement-based waterproofing materials through two mechanisms.
The first mechanism is the embedding of GO, which the researchers found can be embedded into cement-based materials, filling the voids of cement-based materials and forming tighter bonds.
This tighter bond can effectively block the penetration of moisture and improve impermeability, for example, one study found that adding 0.1% GO to cementitious waterproofing materials can reduce its permeability coefficient by about 50%.
The second mechanism is the enhancement of GO, the addition of GO can improve the mechanical properties of cement-based materials, further improve their impermeability, researchers found that adding an appropriate amount of GO to cement-based materials, can significantly improve its compressive strength and tensile strength.
For example, one study found that the compressive strength of cementitious materials increased by 42% after adding 0.5% GO.
In addition to the above two mechanisms, the researchers also found that the addition of GO can improve the microstructure of cement-based materials and further improve their impermeability.
For example, the addition of GO can make the surface of cement-based materials smoother and the surface roughness smaller, while GO can form a closer bond with cement-based materials, which can also improve its impermeability.
In summary, the addition of GO can improve the impermeability of cement-based waterproofing materials through two mechanisms: GO embedding and reinforcement.
The addition of GO can also improve the microstructure of cement-based materials and further improve their impermeability, and these research results show that GO has good application potential and can be used to improve the performance of cementitious waterproofing materials and extend their service life.
It should be noted that the amount of GO added and the degree of reduction of GO will affect its performance impact on cement-based waterproofing materials, and the researchers found that when the amount of GO added is too high, it will have a negative impact on the performance of cement-based materials.
This is because excess GO can lead to an increase in porosity in cementitious materials, which in turn reduces its compactness, making it susceptible to moisture attack.
In addition, the degree of reduction of GO will also affect its application effect in cement-based materials, and the researchers found that a higher degree of GO reduction can improve its embedding effect in cement-based materials, thereby improving its impermeability.
Therefore, the preparation process and reduction degree of GO need to be fully considered, GO has the potential to be applied in cement-based waterproof materials, and its addition can improve the impermeability of cement-based materials through two mechanisms: embedding and reinforcement.
With the deepening of the research on the application of GO to cement-based materials, it is believed that the application effect of GO will continue to improve, bringing new ideas and methods for the research and application of waterproof materials.
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●○ Analysis of graphene oxide addition mechanism ○●
Graphene oxide (GO) is a kind of material prepared by graphene by oxidation treatment, which has high surface area, excellent electrical conductivity and thermal stability and other characteristics, adding GO to cement-based materials, can improve the microstructure of cement-based materials, improve its mechanical properties and impermeability.
One possible mechanism is that GO can be embedded in cement-based materials and form tighter bonds, with GO having a high surface area and excellent hydrophilicity.
Therefore, it can effectively interact with water molecules in cement-based materials to form hydrogen bonds and van der Waals forces, thus forming a tighter bond in cementitious materials.
This tighter bond can prevent water molecules from penetrating further, thereby improving the impermeability of the material, and the high conductivity of GO can also improve the conductivity of the material, thereby further enhancing the impermeability of the material.
Another possible mechanism is that GO can improve the microstructure of cement-based materials by forming pore structures, GO has a large number of oxidizing functional groups, which can electrostatically interact with cations such as calcium ions in cement-based materials and react with silicates in cement-based materials to form pore structures.
This pore structure can increase the surface area and porosity of the material, thereby increasing the adsorption of water molecules and reducing the penetration of water molecules inside the material.
The high surface area and porosity of GO can also improve the mechanical strength and stability of the material, further enhancing the impermeability of the material.
The addition of GO can improve the microstructure of cement-based materials by two mechanisms: embedding materials and forming pore structures, thereby improving their impermeability.
This mechanism can not only improve the mechanical properties and stability of the material, but also improve the conductivity and surface area of the material, thereby improving the impermeability of the material.
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●○ Research Summary ○●
The effect of graphene oxide on the impermeability of cement-based osmotic crystalline waterproofing materials was studied experimentally, and the experimental results showed that with the increase of GO addition, the permeability coefficient of cementitious waterproofing materials gradually decreased, the impermeability pressure gradually increased, and the compressive strength gradually increased.
XRD and SEM analysis showed that the addition of GO can improve the microstructure of cement-based materials, form a tighter bond, and improve impermeability.
Therefore, GO can be considered as an effective reinforcing agent for improving the impermeability of cement-based waterproofing materials.