Composite waterproof material, preparation method and integrated preparation device thereof

Abstract

The application provides a composite waterproof material and a preparation method and an integrated preparation device thereof, and the preparation method comprises the following steps: subjecting graphite and / or graphene to plasma treatment to obtain activated graphene; depositing inorganic nanoparticles on the surface of the activated graphene by using a plasma-enhanced atomic layer deposition method to obtain armored graphene; mixing the armored graphene with a molten asphalt matrix in an electric field, and then cooling to obtain the composite waterproof material. The application realizes in-situ exfoliation of graphite and / or graphene and induces epitaxial growth of inorganic nanoparticles on the surface of the graphene, forms armored graphene with a core-shell structure, and subsequently uses field guidance to enable the armored graphene to have strong interaction in the asphalt and self-assemble to form a three-dimensional interpenetrating hydrophobic and high-strength barrier network, thereby improving the waterproofness, interfacial bonding force, structure controllability and performance stability of the composite waterproof material.

Description

Technical Field

[0001] This invention belongs to the field of waterproof materials technology, and relates to a composite waterproof material, its preparation method and integrated preparation device. Background Technology

[0002] Asphalt, as a basic component of waterproofing materials, is widely used in waterproofing systems for building roofs, underground engineering, and bridges and tunnels, primarily in the form of waterproof coatings and waterproof membranes. The waterproofing principle of asphalt relies on its high viscosity and excellent water repellency, enabling it to form a continuous and dense waterproof layer on structural surfaces. However, traditional asphalt materials are prone to problems such as thermo-oxidative aging, cracking, leakage, and poor weather resistance during long-term service. Especially under conditions of high temperature, ultraviolet radiation, or structural deformation, their waterproofing performance deteriorates significantly, becoming a key bottleneck to building durability.

[0003] To improve the overall performance of asphalt, existing technologies disclose methods for modification using nanomaterials. Nanomaterials, with their high specific surface area and unique interfacial effects, can form a nanoscale spatial network structure within the asphalt matrix, playing a dual role of "barrier effect" and "skeleton reinforcement." On the one hand, nanoparticles can block the penetration channels of water molecules or oxygen, extending the diffusion path and thus significantly improving waterproofing and seepage prevention capabilities. On the other hand, the interaction between nanoparticles and asphalt molecules can enhance the adhesion and crack resistance of the matrix, and improve high-temperature fluidity and low-temperature toughness.

[0004] Among numerous nanomaterials, graphene exhibits the best waterproofing enhancement effect due to its unique two-dimensional honeycomb structure and superior physicochemical properties. Its layered structure significantly extends the diffusion path of water molecules and oxygen, achieving a "maze-like barrier" effect. Furthermore, its excellent mechanical strength significantly improves the tensile, tear, and aging resistance of asphalt films. Simultaneously, graphene's excellent thermal conductivity disperses localized stress and heat accumulation, reducing the risk of thermal fatigue cracking. Moreover, compared to traditional nano-oxides, graphene exhibits better dispersibility, stronger interfacial bonding, and superior thermal conductivity and protective properties in asphalt systems, making it an ideal modifying additive for upgrading high-durability and high-performance waterproof materials.

[0005] Existing graphene-modified asphalt waterproofing materials mainly focus on introducing graphene oxide prepared by chemical oxidation-reduction method or graphene prepared by physical exfoliation into the asphalt system through physical dispersion or chemical modification to improve its waterproof, anti-aging and mechanical properties. However, introducing graphene into asphalt using traditional modification methods has problems such as poor dispersibility, weak interfacial bonding and insufficient process stability.

[0006] Specifically, the existing technical routes for modified bitumen materials include the following categories:

[0007] The first type is the direct physical mixing method: graphene powder or graphene oxide is directly added to the matrix asphalt through high-shear stirring, ultrasonic dispersion or high-temperature mixing to form a graphene / asphalt composite system. This method is simple and low-cost, and can be used for the production of waterproof coatings and waterproof membranes. However, graphene is prone to agglomeration in high-viscosity asphalt systems, and its dispersibility and stability are poor.

[0008] The second category is chemical modification: this method improves the interfacial compatibility between graphene and polar components in asphalt by introducing oxygen-, amino, or silane functional groups onto the graphene surface. Specifically, it utilizes the carboxyl and hydroxyl groups on the surface of graphene oxide to react with asphalt molecules or form hydrogen bonds, thereby enhancing the bonding strength and uniformity of the composite system. For example, the non-curing asphalt-based waterproof coating provided in CN120365852A introduces alkylamine-modified graphene oxide into the waterproof coating to improve the interfacial compatibility of the components. While this method can improve dispersibility and interfacial bonding to some extent, the preparation process often involves strong oxidants and reducing agents, leading to problems such as environmental pollution, high cost, and numerous structural defects in graphene.

[0009] The third type is the emulsion composite method: graphene oxide or graphene is dispersed in the asphalt emulsion system, and a relatively stable dispersion state is achieved through emulsifiers or surfactants. This method is used in water-based waterproof coating systems. However, the dispersion stability and water aging resistance of this method are still limited during long-term service.

[0010] Therefore, existing asphalt modification technologies, regardless of the advanced nanofillers added, are essentially "two-step methods": first, the nanofillers are prepared, and then they are physically blended with asphalt as an admixture. This simple addition faces fundamental and insurmountable obstacles:

[0011] (1) Huge interfacial energy barrier: Nanomaterials have extremely high specific surface energy, while asphalt is a high-viscosity nonpolar organic system. When the two are mixed, the huge interfacial energy difference leads to severe agglomeration of nanoparticles, forming defect points rather than reinforcement points.

[0012] (2) Limitations of “wet mixing”: Although high shear and ultrasonic methods can temporarily break up agglomeration, they consume a lot of energy in viscous asphalt, and once the external force is removed, the nanoparticles still tend to re-agglomerate.

[0013] (3) Weak interfacial bonding: Simple physical coating or weak van der Waals forces result in a clear "interface" between the filler and the asphalt matrix. Under stress or water molecule erosion, this interface becomes the weakest link, leading to premature failure of waterproofing performance.

[0014] (4) Uncontrollable structure: The distribution of fillers in asphalt is random and disordered, and cannot form an efficient and synergistic macroscopic functional structure.

[0015] Based on the above research, although existing methods for modifying asphalt with graphene have made some progress in improving waterproofness, impermeability and aging resistance, they generally suffer from problems such as complex preparation, high cost, uneven component dispersion, weak interfacial bonding, uncontrollable structure and unstable performance. Summary of the Invention

[0016] The purpose of this invention is to provide a composite waterproof material and its preparation method and integrated preparation device. The preparation method involves in-situ exfoliation of graphite and / or graphene and induction of inorganic nanoparticles to grow epitaxially on its surface to form a core-shell structured armored graphene. Subsequently, field guidance is used to enable the armored graphene to undergo strong interactions in asphalt and self-assemble into a three-dimensional interpenetrating hydrophobic, high-strength barrier network, thereby improving the waterproofness, interfacial bonding, structural controllability and performance stability of the composite waterproof material.

[0017] To achieve this objective, the present invention adopts the following technical solution:

[0018] In a first aspect, the present invention provides a method for preparing a composite waterproof material, the method comprising the following steps:

[0019] (1) Graphite and / or graphene are subjected to plasma treatment to obtain activated graphene;

[0020] (2) Inorganic nanoparticles were deposited on the surface of the activated graphene described in step (1) using plasma-enhanced atomic layer deposition to obtain armored graphene;

[0021] (3) The armored graphene described in step (2) is mixed with the molten asphalt matrix in an electric field and then cooled to obtain the composite waterproof material.

[0022] This invention first involves plasma treatment of graphite and / or graphene to obtain activated graphene through in-situ exfoliation. Then, plasma-enhanced atomic layer deposition (PEALD) is used to induce the epitaxial growth of inorganic nanoparticles on its surface, forming a core-shell structured armored graphene. The armored graphene is then mixed with a molten asphalt matrix in an electric field. The armored graphene migrates along the electric field direction and self-assembles to form a hydrophobic, high-strength, three-dimensional interpenetrating network that penetrates the entire asphalt matrix. After cooling, the three-dimensional interpenetrating network is "frozen" and fixed in the asphalt, eliminating the clear interface between the graphene and the asphalt matrix, thus forming a dense composite waterproof material. Furthermore, when microcracks are generated and propagate in the asphalt, once they encounter the three-dimensional network composed of armored graphene, the stress at the crack tip is effectively passivated and dispersed by the network, or even "pinned" and unable to advance, thereby endowing the material with extremely high toughness and fatigue resistance, and even possessing the potential for self-healing microcracks.

[0023] The armored graphene of the present invention has the following advantages: (1) It can eliminate the aggregation of graphene: Since the "shell" of inorganic nanoparticles is like a rivet, it physically opens up the graphene sheets, fundamentally eliminating the stacking and aggregation of graphene; (2) It can bridge the interface: The "shell" material is an "interface conversion layer", and its outer surface can be formed by plasma afterglow or subsequent treatment to form active sites that are easy to chemically bond or strongly physically adsorb with asphalt molecular chains, realizing efficient stress transfer and seamless interface connection from graphene (core) to asphalt (matrix); (3) It synergistically constructs a waterproof barrier: The aspect ratio of graphene provides an extremely tortuous "maze" path, while the inorganic armor completely seals any tiny gaps between graphene sheets. The two synergistically construct a near-perfect "zero-permeability" waterproof barrier.

[0024] Preferably, the plasma gas source used in step (1) includes a mixture of oxygen and argon.

[0025] Preferably, in the mixture of oxygen and argon, the volume content of argon is 70%-90%, for example, it can be 70%, 75%, 80%, 85% or 90%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the plasma treatment time in step (1) is 30s-300s, for example, it can be 30s, 40s, 50s, 60s, 100s, 150s, 200s, 250s or 300s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, preferably 40s-240s.

[0027] If the plasma treatment time described in this invention is too short, it may lead to insufficient activation; however, if the time is too long, it may introduce unnecessary damage to the graphene.

[0028] Preferably, the power of the plasma treatment in step (1) is 30W-300W, for example, it can be 30W, 50W, 150W, 200W, 250W or 300W, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] This invention employs a low-power inductively coupled plasma source to avoid irreversible damage to the graphene lattice caused by high-energy particles.

[0030] Preferably, the temperature of the plasma treatment in step (1) is 450℃-600℃, for example, 450℃, 475℃, 500℃, 525℃, 550℃, 575℃ or 600℃, and the gas pressure is 40mTorr-60mTorr, for example, 40mTorr, 45mTorr, 50mTorr, 55mTorr or 60mTorr, but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0031] Preferably, the thickness of the graphite (highly oriented pyrolytic graphite HOPG) in step (1) is 1mm-2mm, for example, it can be 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm or 2mm, and the purity is ≥99.9wt%, for example, it can be 99.992wt%, 99.994wt%, 99.996wt%, or 99.998wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] Preferably, the activated graphene in step (1) has 1 to 5 layers, for example, 1, 2, 3, 4 or 5 layers, and a lateral dimension of 0.5 to 2 μm, for example, 0.5 μm, 1 μm, 1.5 μm or 2 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] The activated graphene obtained by this invention not only has a small number of layers but also exhibits surface activation with a CH bond density of ≈10. 13 cm -2 .

[0034] Preferably, the armored graphene in step (2) has a core-shell structure, wherein the core includes activated graphene (Csp). 2 >95%), the shell comprises inorganic nanoparticles, which include metal oxides and / or non-metal oxides.

[0035] Preferably, the inorganic nanoparticles have an amorphous or microcrystalline structure.

[0036] The core of the armored graphene described in this invention is few-layer activated graphene obtained by plasma exfoliation; its shell is an amorphous or microcrystalline inorganic nanoparticle island or continuous film grown in situ on the surface of graphene sheets under the induction of a plasma field.

[0037] Preferably, the shell has a coverage of ≥95%, such as 95%, 96%, 97%, 98% or 99%, and a thickness of 5nm-20nm, such as 5nm, 10nm, 15nm or 20nm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the metal oxide includes any one or a combination of at least two of aluminum oxide, magnesium oxide, or titanium oxide, and the non-metal oxide includes silicon oxide.

[0039] The type of shell for the armored graphene described in this invention can be selected according to requirements, such as SiO₂. x Provides insulation and UV shielding, TiO x It provides photocatalytic self-cleaning and other functions, enabling a single filler to possess composite functions.

[0040] Preferably, the plasma-enhanced atomic layer deposition method in step (2) includes the following steps:

[0041] At temperature T, activated graphene is pulsed using a metal source and / or a non-metal source, followed by oxygen plasma exposure and nitrogen purging. The pulse, oxygen plasma exposure and nitrogen purging steps are repeated to obtain armored graphene.

[0042] This invention employs pulses of metal and / or non-metal sources to chemically adsorb metal and / or non-metal sources onto the surface of activated graphene, followed by oxygen plasma exposure treatment to react with the adsorbed metal and / or non-metal sources to generate metal oxides and / or non-metal oxides.

[0043] Preferably, the temperature T is 80℃-90℃, for example, it can be 80℃, 82℃, 84℃, 86℃, 88℃ or 90℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0044] Preferably, the pulse duration is 0.01s-0.03s, for example, it can be 0.01s, 0.015s, 0.02s, 0.025s or 0.03s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] Preferably, the oxygen plasma exposure time is 0.01s-0.03s, for example, it can be 0.01s, 0.015s, 0.02s, 0.025s or 0.03s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0046] Preferably, the nitrogen purging time is 25s-35s, for example, it can be 25s, 27s, 29s, 31s, 33s or 35s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0047] Preferably, the number of repetitions is 50 to 200 times, for example, 50, 100, 150 or 200 times, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0048] This invention can precisely control the thickness of the inner shell of armored graphene by controlling the number of cycles.

[0049] Preferably, the amount of armored graphene added in step (2) is 0.3wt%-1.0wt% of the mass of the molten asphalt matrix, for example, it can be 0.4wt%, 0.6wt%, 0.8wt% or 1.0wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0050] The amount of armored graphene added in this invention affects the performance of the resulting composite waterproof material. If the amount of armored graphene added is too small, a continuous and effective two-dimensional barrier network cannot be formed in the asphalt matrix, and the penetration paths of water vapor and liquid water cannot be sufficiently blocked, resulting in a lack of significant improvement in waterproof performance. The physical cross-linking enhancement effect on the asphalt molecular chains is insufficient, and the improvement in tensile strength, elongation at break, and crack resistance is limited. If the amount of armored graphene added is too large, the graphene sheets are prone to secondary agglomeration due to van der Waals forces, forming micron-sized agglomerates, which become stress concentration points and defect sources in the material. This leads to a sharp decrease in tensile strength and elongation at break, a significant increase in low-temperature brittleness, a sharp increase in the viscosity of the composite material, and a serious deterioration in construction performance. The coating cannot be properly leveled and coated, and process defects such as surface roughness, uneven thickness, and even breakage occur during the extrusion and calendering of the roll material. Excessive graphene will also weaken the interaction between asphalt molecules, causing the softening point to decrease, the penetration to increase, and severe flow phenomena to occur at high temperatures, resulting in the loss of the dimensional stability that the waterproof roll material should have.

[0051] Preferably, the electric field in step (3) is a DC electric field.

[0052] Preferably, the voltage of the electric field in step (3) is 2000V-4000V, for example, it can be 2000V, 2500V, 3000V, 3500V or 4000V, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0053] In this invention, the DC electric field is the core external field driving the directional migration, alignment, and eventual construction of a three-dimensional interpenetrating network of armored graphene in molten pitch. The magnitude of the applied voltage directly determines the degree of order and final performance of the self-assembled structure. The voltage applied by the electric field described in this invention affects the self-assembly of the armored graphene:

[0054] If the applied voltage is too small, the electric field force is insufficient to overcome the viscous resistance of the asphalt melt and the van der Waals attraction between the armored graphene sheets, resulting in a slow sheet migration rate. The armored graphene cannot be effectively oriented along the direction of the electric field and remains dispersed in the asphalt in a random and disordered state, eventually forming only island-like or local clusters, and cannot construct a three-dimensional interpenetrating network that runs through the entire matrix.

[0055] If the applied voltage is too high, the excessively strong electric field force causes the armored graphene sheets to migrate too quickly. The sheets do not have time to effectively overlap and interlock with other sheets during migration and are directly "thrown" onto the electrode surface, forming severe uneven deposition near the two electrodes. This results in obvious electrophoretic delamination and damages the overall uniformity of the material. Locally high concentration areas generate large internal stress during rapid cooling, leading to microcracks or delamination inside the material after cooling. Macroscopically, this manifests as "electrical impact marks" or "dendritic" enrichment areas on the material surface, a decrease in impermeability, and brittle cracking along the electric field direction during low-temperature bending.

[0056] Preferably, before mixing in step (3), the armored graphene described in step (2) is also initially stirred with the molten asphalt matrix.

[0057] Preferably, the stirring rate of the initial stirring is 150 rpm to 250 rpm, for example, 150 rpm, 170 rpm, 190 rpm, 210 rpm, 230 rpm or 250 rpm, and the time is 5 min to 15 min, for example, 5 min, 7 min, 9 min, 11 min, 13 min or 15 min, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0058] Preferably, the mixing temperature in step (3) is 150℃-180℃, for example, it can be 150℃, 155℃, 160℃, 165℃, 170℃, 175℃ or 180℃, the stirring rate is 40rpm-70rpm, for example, it can be 40rpm, 50rpm, 60rpm or 70rpm, and the time is 10min-30min, for example, it can be 10min, 15min, 20min, 25min or 30min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0059] Preferably, the cooling method in step (3) is quenching.

[0060] Preferably, the cooling rate in step (3) is ≥5℃ / min, for example, it can be 5℃, 10℃ / min, 15℃ / min or 20℃ / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0061] Preferably, the molten asphalt matrix in step (3) is obtained by heating and stirring the asphalt matrix.

[0062] Preferably, the temperature for heating and stirring the asphalt matrix is ​​150℃-180℃, for example, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃ or 180℃, the stirring rate is 90rpm-120rpm, for example, 90rpm, 100rpm, 110rpm or 120rpm, and the stirring time is 25min-35min, for example, 25min, 27min, 29min, 31min, 33min or 35min, but not limited to the listed values, other unlisted values ​​within the range are also applicable.

[0063] Preferably, the penetration of the asphalt matrix is ​​60-80 (0.1 mm), for example, it can be 60 (0.1 mm), 70 (0.1 mm) or 80 (0.1 mm), and the softening point is 45-55℃, for example, it can be 45℃, 50℃ or 55℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0064] Preferably, step (3) of the preparation method is carried out in an integrated preparation device, including the following steps: first, the asphalt matrix in the third chamber is melted, the first door is opened to allow the armored graphene to fall into the second chamber, the first door is closed, the second door is opened to allow the armored graphene to fall into the third chamber for preliminary stirring, then an electric field is applied in the third chamber to mix the armored graphene and the molten asphalt matrix in step (2) in the electric field, and then the mixture is cooled to obtain the composite waterproof material.

[0065] In a second aspect, the present invention provides a composite waterproof material, which is prepared by the preparation method described in the first aspect.

[0066] In the composite waterproof material, armored graphene is dispersed in the asphalt matrix and forms a through-network.

[0067] Thirdly, the present invention provides an integrated preparation apparatus for preparing the composite waterproof material as described in the second aspect. The integrated preparation apparatus includes a first cavity, a second cavity connected to the lower end of the first cavity, and a third cavity connected to the lower end of the second cavity. The first cavity and the second cavity are separated by a first hatch, and the second cavity and the third cavity are separated by a second hatch.

[0068] The third chamber includes a stirring device and a DC electrode.

[0069] The integrated preparation device of this invention is a three-chamber pitch composite reactor. The first chamber is the armored graphene preparation zone, used to prepare armored graphene. The second chamber is the transition dispersion zone, and the third chamber is the main reaction zone, used to composite the armored graphene and the pitch matrix. The third chamber includes an pitch reactor, an electric field system, a stirring system, and a cooling system. The electric field system includes a DC high-voltage power supply with an adjustable voltage of 0-5000V and an electrode spacing of 5cm. The stirring system includes an anchor-type + propeller dual stirrer, which can provide a speed of 50-300rpm. The cooling system is an external circulation ethylene glycol cooling system.

[0070] Preferably, a material bin is connected to the upper end of the first cavity, and the material bin is separated from the first cavity by a material baffle.

[0071] Preferably, a plasma electrode is also provided in the first cavity.

[0072] The first cavity of this invention is provided with a plasma electrode for generating plasma, thereby performing plasma treatment on graphite and / or graphene and exfoliating it in situ to obtain activated graphene; and the upper end of the first cavity is connected to a material bin for storing graphite and / or graphene raw materials. Before the raw materials enter the first cavity, they are pre-vacuumed to facilitate the first cavity to maintain a vacuum state, reduce the vacuuming time, and enable continuous production.

[0073] Preferably, the material bin, the first chamber, the second chamber, and the third chamber are externally connected to a vacuum pump.

[0074] Preferably, the third cavity is provided with a jacket containing liquid, and the third cavity is heated by heating the liquid through an external heater.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] This invention first involves plasma treatment of graphite and / or graphene to obtain activated graphene through in-situ exfoliation. Then, plasma-enhanced atomic layer deposition (PEALD) is used to induce the epitaxial growth of inorganic nanoparticles on its surface, forming a core-shell structured armored graphene. The armored graphene is then mixed with a molten asphalt matrix in an electric field. The armored graphene migrates along the electric field direction and self-assembles to form a hydrophobic, high-strength, three-dimensional interpenetrating network that penetrates the entire asphalt matrix. Upon cooling, the three-dimensional interpenetrating network is "frozen" and fixed in the asphalt, eliminating the clear interface between the graphene and the asphalt matrix, thus forming a dense, truly "nanocomposite waterproof material." Furthermore, when microcracks are generated and propagate in the asphalt, once they encounter the three-dimensional network composed of armored graphene, the stress at the crack tip is effectively passivated and dispersed by the network, or even "pinned" and unable to advance, thereby endowing the material with extremely high toughness and fatigue resistance, and even possessing the potential for self-healing microcracks. Attached Figure Description

[0077] Figure 1 This is a schematic diagram of the integrated preparation apparatus used in this invention.

[0078] Among them, 1-first cavity, 1-1-plasma electrode, 1-2-first hatch, 2-second cavity, 2-1-second hatch, 3-third cavity, 3-1-DC electrode, 3-2-stirring motor, 3-3-stirring blade, 3-4 jacket, 4-material bin, 4-1-material baffle, 5-vacuum pump, 6-heater. Detailed Implementation

[0079] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0080] The following schematic diagrams show the structure of the integrated preparation apparatus used in the embodiments and comparative examples. Figure 1 As shown, the integrated preparation device includes a first cavity 1, a second cavity 2 connected to the lower end of the first cavity 1, and a third cavity 3 connected to the lower end of the second cavity 2. The first cavity 1 and the second cavity 2 are separated by a first door 1-2, and the second cavity 2 and the third cavity 3 are separated by a second door 2-1. A stirring motor 3-2 is provided at the upper end of the third cavity 3 to drive the stirring blades 3-3 inside the third cavity 3. A DC electrode 3-1 is also provided on the inner wall of the third cavity 3. The third cavity contains a jacket 3-4 containing liquid. The third cavity 3 is heated by heating the liquid through an external heater 6.

[0081] The upper end of the first cavity 1 is connected to a material bin 4, and the material bin 4 is separated from the first cavity 1 by a material baffle 4-1; a plasma electrode 1-1 is also provided inside the first cavity 1;

[0082] The material bin 4, the first cavity 1, the second cavity 2 and the third cavity 3 are also externally connected to a vacuum pump 5.

[0083] Example 1

[0084] This embodiment provides a method for preparing a composite waterproof material, the method comprising the following steps:

[0085] (1) Evacuate the sample chamber to a high vacuum (vacuum degree of 5×10⁻⁶). -6A mixture of oxygen and argon (argon volume content 80%) was introduced as the plasma source. Graphite (directionally pyrolytic graphite, thickness 1.5 mm, purity 99.995 wt%) was plasma-treated for 40 s at a power of 80 W, a temperature of 550 °C, and a pressure of 50 mTorr to obtain activated graphene with a layer distribution of 1-5 layers and a lateral size distribution of 0.5-2 μm.

[0086] (2) At a temperature of 85°C, the activated graphene described in step (1) was pulsed for 0.02s using trimethylaluminum, then exposed to oxygen plasma (power 100W, O2 flow rate 20sccm) for 0.02s, and finally purged with nitrogen gas at a flow rate of 200sccm for 30s. The pulse, oxygen plasma exposure and nitrogen purging steps were repeated 100 times to obtain armored graphene. The armored graphene has a core-shell structure, wherein the core includes activated graphene and the shell includes inorganic nanoparticles. The inorganic nanoparticles are amorphous Al2O3 (refractive index 1.65@632nm), the shell thickness is 10nm, and the coverage is 96%.

[0087] (3) The armored graphene obtained in step (2) is combined with the asphalt matrix in an integrated preparation device. The first cavity 1 of the integrated preparation device is the armored graphene preparation area, the second cavity 2 is the transition dispersion area for pre-dispersing the armored graphene, and the third cavity 3 is the asphalt composite area for combining the armored graphene with the asphalt.

[0088] First, the asphalt matrix (70# petroleum asphalt, penetration of 72 (0.1 mm), softening point of 48℃) in the third chamber 3 is heated to 170℃ and stirred at 100 rpm for 30 minutes to form a molten asphalt matrix. With the second door 2-1 closed, the first door 1-2 is opened to allow the armored graphene to fall into the second chamber 2. The first door 1-2 is then closed, nitrogen gas is introduced into the second chamber 2, and the second door 2-1 is opened to allow the armored graphene to fall into the third chamber 3 for preliminary stirring. The stirring rate for the preliminary stirring is 200 rpm and the time is 10 minutes.

[0089] Then close the second door 2-1 and evacuate the second chamber 2 to prepare for the next preparation; maintain the temperature of the third chamber 3 at 170°C, apply a DC electric field of 3000V (field strength 600V / cm) in the third chamber 3, and mix the armored graphene and molten asphalt matrix described in step (2) in the electric field at a stirring rate of 50rpm for 20min, the amount of armored graphene added is 0.5wt% of the mass of the molten asphalt matrix;

[0090] Finally, stop stirring and discharging, start external circulation cooling, and the cooling rate is 11℃ / min, specifically reducing the temperature to 60℃ within 10 minutes to obtain the composite waterproof material.

[0091] Example 2

[0092] This embodiment provides a method for preparing a composite waterproof material, the method comprising the following steps:

[0093] (1) Evacuate the sample chamber to a high vacuum (vacuum degree of 5×10⁻⁶). -6 A mixture of oxygen and argon (70% argon by volume) was introduced as the plasma source. Graphite (directionally pyrolytic graphite, 1 mm thick, 99.99 wt% pure) was plasma-treated for 60 s at a power of 30 W, a temperature of 450 °C, and a pressure of 40 mTorr to obtain activated graphene with a layer distribution of 1-5 layers and a lateral size distribution of 0.5-2 μm.

[0094] (2) At a temperature of 90°C, the activated graphene described in step (1) was pulsed for 0.03s using trimethylaluminum, then exposed to oxygen plasma (power 100W, O2 flow rate 20sccm) for 0.03s, and finally purged with nitrogen gas at a flow rate of 200sccm for 25s. The pulse, oxygen plasma exposure and nitrogen purging steps were repeated 50 times to obtain armored graphene. The armored graphene has a core-shell structure, wherein the core includes activated graphene and the shell includes inorganic nanoparticles. The inorganic nanoparticles are amorphous Al2O3 (refractive index 1.65@632nm), the shell thickness is 5nm, and the coverage is 95%.

[0095] (3) The armored graphene obtained in step (2) is combined with the asphalt matrix in an integrated preparation device. The first cavity 1 of the integrated preparation device is the armored graphene preparation area, the second cavity 2 is the transition dispersion area for pre-dispersing the armored graphene, and the third cavity 3 is the asphalt composite area for combining the armored graphene with the asphalt.

[0096] First, the asphalt matrix (70# petroleum asphalt, penetration of 80 (0.1 mm), softening point of 55℃) in the third chamber 3 is heated to 150℃ and stirred at a rate of 120 rpm for 35 minutes to form a molten asphalt matrix. With the second door 2-1 closed, the first door 1-2 is opened to allow the armored graphene to fall into the second chamber 2. The first door 1-2 is then closed, nitrogen gas is introduced into the second chamber 2, and the second door 2-1 is opened to allow the armored graphene to fall into the third chamber 3 for preliminary stirring. The stirring rate for the preliminary stirring is 250 rpm and the time is 5 minutes.

[0097] Then close the second door 2-1 and evacuate the second chamber 2 to prepare for the next preparation; maintain the temperature of the third chamber 3 at 150°C, apply a DC electric field of 4000V in the third chamber 3, and mix the armored graphene and molten asphalt matrix described in step (2) in the electric field at a stirring rate of 40rpm for 30min, wherein the amount of armored graphene added is 1.0wt% of the mass of the molten asphalt matrix;

[0098] Finally, stop stirring and discharging, start external circulation cooling, and the cooling rate is 11℃ / min, specifically reducing the temperature to 60℃ within 10 minutes to obtain the composite waterproof material.

[0099] Example 3

[0100] This embodiment provides a method for preparing a composite waterproof material, the method comprising the following steps:

[0101] (1) Evacuate the sample chamber to a high vacuum (vacuum degree of 5×10⁻⁶). -6 A mixture of oxygen and argon (90% argon by volume) was introduced as the plasma source. Graphite (directionally pyrolytic graphite, 2 mm thick, 99.99 wt% pure) was plasma-treated for 240 s at a power of 300 W, a temperature of 500 °C, and a pressure of 60 mTorr to obtain activated graphene with a layer distribution of 1-5 layers and a lateral size distribution of 0.5-2 μm.

[0102] (2) At a temperature of 80°C, the activated graphene described in step (1) was pulsed for 0.01s using trimethylaluminum, then exposed to oxygen plasma (power 100W, O2 flow rate 20sccm) for 0.01s, and finally purged with nitrogen gas at a flow rate of 200sccm for 35s. The pulse, oxygen plasma exposure and nitrogen purging steps were repeated 200 times to obtain armored graphene. The armored graphene has a core-shell structure, wherein the core includes activated graphene and the shell includes inorganic nanoparticles. The inorganic nanoparticles are amorphous Al2O3, the shell thickness is 20nm, and the coverage is 97%.

[0103] (3) The armored graphene obtained in step (2) is combined with the asphalt matrix in an integrated preparation device. The first cavity 1 of the integrated preparation device is the armored graphene preparation area, the second cavity 2 is the transition dispersion area for pre-dispersing the armored graphene, and the third cavity 3 is the asphalt composite area for combining the armored graphene with the asphalt.

[0104] First, the asphalt matrix (70# petroleum asphalt, penetration of 60 (0.1 mm), softening point of 45℃) in the third chamber 3 is heated to 180℃ and stirred at a rate of 90 rpm for 25 minutes to form a molten asphalt matrix. With the second door 2-1 closed, the first door 1-2 is opened to allow the armored graphene to fall into the second chamber 2. The first door 1-2 is then closed, nitrogen gas is introduced into the second chamber 2, and the second door 2-1 is opened to allow the armored graphene to fall into the third chamber 3 for preliminary stirring. The stirring rate for the preliminary stirring is 150 rpm and the time is 15 minutes.

[0105] Then close the second door 2-1 and evacuate the second chamber 2 to prepare for the next preparation; maintain the temperature of the third chamber 3 at 180°C, apply a DC electric field of 2000V in the third chamber 3, and mix the armored graphene and molten asphalt matrix described in step (2) in the electric field at a stirring rate of 70rpm for 10min, wherein the amount of armored graphene added is 0.3wt% of the mass of the molten asphalt matrix;

[0106] Finally, stop stirring and discharging, start external circulation cooling, and the cooling rate is 11℃ / min, specifically reducing the temperature to 60℃ within 10 minutes to obtain the composite waterproof material.

[0107] Example 4

[0108] This embodiment provides a method for preparing a composite waterproof material. Except for the plasma treatment time of 30s in step (1), the preparation method is the same as that in embodiment 1.

[0109] Example 5

[0110] This embodiment provides a method for preparing a composite waterproof material. Except for the plasma treatment time of 300s in step (1), the preparation method is the same as that in embodiment 1.

[0111] Example 6

[0112] This embodiment provides a method for preparing a composite waterproof material. The preparation method is the same as in Example 1, except that the amount of armored graphene added is 0.1 wt% of the mass of the molten asphalt matrix.

[0113] Example 7

[0114] This embodiment provides a method for preparing a composite waterproof material. The preparation method is the same as in Example 1, except that the amount of armored graphene added is 1.5 wt% of the mass of the molten asphalt matrix.

[0115] Example 8

[0116] This embodiment provides a method for preparing a composite waterproof material. Except for the DC electric field voltage of 1000V in step (3), the preparation method is the same as that in embodiment 1.

[0117] Example 9

[0118] This embodiment provides a method for preparing a composite waterproof material. Except for the DC electric field voltage of 5000V in step (3), the preparation method is the same as that in embodiment 1.

[0119] Comparative Example 1

[0120] This comparative example provides a waterproof material, which is the asphalt matrix described in step (3) of Example 1.

[0121] Comparative Example 2

[0122] This comparative example provides a method for preparing a composite waterproof material. The preparation method is the same as in Example 1 except that steps (1) and (2) are not performed, and the armored graphene in step (3) is replaced with commercially available graphene (the thickness of the graphene sheet is in the range of 1-10 nm, and the lateral size is distributed in the range of several hundred nanometers to several micrometers).

[0123] Comparative Example 3

[0124] This comparative example provides a method for preparing a composite waterproof material. The preparation method is the same as in Example 1 except that step (2) is not performed and the armored graphene in step (3) is replaced with the activated graphene obtained in step (1).

[0125] Comparative Example 4

[0126] This comparative example provides a method for preparing a composite waterproof material. The preparation method is the same as that in Example 1, except that a DC electric field is not applied in step (3).

[0127] The composite waterproof materials obtained in Examples 1-9 and Comparative Examples 2-4, and the waterproof material described in Comparative Example 1, were tested for impermeability, penetration, softening point, low-temperature flexibility, tensile strength, elongation at break, oxygen index, and strength retention after aging. The test methods are as follows:

[0128] (1) Impermeability: Refer to GB / T 328.9-2007 "Test Methods for Waterproofing Membranes - Part 9: Impermeability of Waterproofing Membranes" or Appendix A of GB 55030-2022; Test conditions and key parameters are: pressure: 0.3MPa, holding time: 24h, specimen size: Φ80 mm or 150 mm × 150 mm, observe whether there are any seepage points.

[0129] (2) Penetration: Refer to GB / T 4509-2010 "Asphalt Penetration Test Method", the test conditions and key parameters are: temperature: 25℃±0.1℃, load: 100g±0.05g, penetration time: 5s±0.1s, reading unit 0.1mm, and take the average value of 5 points.

[0130] (3) Softening point: Refer to GB / T 4507-2014 "Determination of softening point of asphalt (ring and ball method)" and the test conditions and key parameters are as follows: heating rate: 5℃ / min±0.5℃, water or glycerol medium, steel ball mass 3.5g±0.05g, and record the temperature when the steel ball falls.

[0131] (4) Low temperature flexibility: Refer to GB / T 328.13-2007 "Test methods for waterproof membranes for buildings - Part 13: Low temperature flexibility" or GB 18242-2008. The test conditions and key parameters are: -20℃±1℃. After maintaining for 2 hours, observe whether cracks appear on the surface.

[0132] (5) Tensile strength: Refer to GB / T 328.10-2007 "Test methods for waterproof membranes - Part 10: Tensile properties" or GB / T 16777-2008. The test conditions and key parameters are as follows: specimen size: 50mm×200mm (dumbbell type), tensile rate: 100mm / min±10mm / min, temperature: 23℃±2℃, record the maximum force divided by the width.

[0133] (6) Elongation at break: The same test as the tensile strength test, the calculation formula is (L1-L0) / L0×100%, and the median value of 5 specimens is taken, where L1 is the size after stretching and L0 is the size before stretching.

[0134] (7) Oxygen index: Refer to GB / T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method - Part 2: Room temperature test", the test conditions and key parameters are: specimen size: 80-150mm×10mm×4mm, after ignition, it burns upward / downward, and the minimum oxygen concentration (%) for maintaining combustion is determined.

[0135] (8) Strength retention rate after aging: Refer to GB / T 18244-2000 "Test Method for Aging of Building Waterproofing Materials" for ultraviolet aging or GB / T 3511-2018 for test conditions and key parameters: Equipment: Ultraviolet aging chamber (UVA-340 lamp), irradiation intensity: 0.68W / m 2 @340nm, black mark temperature: 60℃±3℃, after continuous irradiation for 1000h aging, the tensile strength is measured again according to the method in item 5. Strength retention rate = (strength after aging / strength before aging) × 100%.

[0136] The test results are shown in Table 1 below:

[0137] Table 1

[0138]

[0139] As can be seen from Table 1 above:

[0140] As can be seen from Example 1 and Comparative Example 1, compared with unmodified traditional asphalt, the present invention, through specific modification, yields a composite waterproof material with excellent waterproof performance, high stability, and high strength; As can be seen from Example 1 and Comparative Example 2, and from Example 1 and Comparative Example 3, if step (2) of the present invention is not performed, i.e., if the graphene is not armored, even if the graphene is activated by plasma treatment, the graphene is prone to stacking and agglomeration due to the gaps between the graphene sheets, and the bonding strength with the asphalt decreases, thus significantly reducing the performance of the resulting composite waterproof material; As can be seen from Example 1 and Comparative Example 4, if the armor... When graphene is composited with an asphalt matrix without an applied electric field, the armored graphene cannot self-assemble to form a hydrophobic and high-strength three-dimensional interconnected network, thus significantly reducing the performance of the resulting composite waterproof material. As shown in Examples 1 and 4-5, the plasma treatment time affects the activation and damage levels of graphene, preferably within a specific range. As shown in Examples 1 and 6-7, the amount of armored graphene added in this invention affects the performance of the composite waterproof material. As shown in Examples 1 and 8-9, the voltage applied by the electric field in this invention affects the self-assembly of the armored graphene, preferably within a specific range.

[0141] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a composite waterproof material, characterized in that, The preparation method includes the following steps: (1) Graphite and / or graphene are subjected to plasma treatment to obtain activated graphene; the plasma gas source used in step (1) includes a mixture of oxygen and argon, wherein the volume content of argon in the mixture of oxygen and argon is 70%-90%; (2) Inorganic nanoparticles were deposited on the surface of the activated graphene described in step (1) using plasma-enhanced atomic layer deposition to obtain armored graphene; Step (2) of the plasma-enhanced atomic layer deposition method includes the following steps: At temperature T, activated graphene is pulsed using a metal source and / or a non-metal source, followed by oxygen plasma exposure and nitrogen purging. The pulse, oxygen plasma exposure and nitrogen purging steps are repeated to obtain armored graphene. (3) The armored graphene described in step (2) is mixed with the molten asphalt matrix in an electric field and then cooled to obtain the composite waterproof material; The voltage of the electric field in step (3) is 2000V-4000V.

2. The preparation method according to claim 1, characterized in that, The plasma treatment time in step (1) is 30s-300s; And / or, the power of the plasma treatment in step (1) is 30W-300W; And / or, the temperature of the plasma treatment in step (1) is 450℃-600℃ and the gas pressure is 40mTorr-60mTorr; And / or, the graphite in step (1) has a thickness of 1 mm-2 mm and a purity of ≥99.9 wt%; And / or, the activated graphene in step (1) has 1 to 5 layers and a lateral dimension of 0.5 to 2 μm.

3. The preparation method according to claim 1 or 2, characterized in that, The armored graphene in step (2) has a core-shell structure, wherein the core includes activated graphene and the shell includes inorganic nanoparticles, wherein the inorganic nanoparticles include metal oxides and / or non-metal oxides; The shell has a coverage of ≥95% and a thickness of 5nm-20nm; The metal oxide includes any one or a combination of at least two of aluminum oxide, magnesium oxide, or titanium oxide, and the non-metal oxide includes silicon oxide.

4. The preparation method according to claim 1 or 2, characterized in that, Step (2) of the plasma-enhanced atomic layer deposition method includes the following steps: At temperature T, activated graphene is pulsed using a metal source and / or a non-metal source, followed by oxygen plasma exposure and nitrogen purging. The pulse, oxygen plasma exposure and nitrogen purging steps are repeated to obtain armored graphene. The temperature T is 80℃-90℃; The duration of the pulse is 0.01s-0.03s; The oxygen plasma exposure treatment time is 0.01s-0.03s; The nitrogen purging time is 25s-35s; The number of repetitions is between 50 and 200.

5. The preparation method according to claim 1 or 2, characterized in that, The amount of armored graphene added in step (2) is 0.3wt%-1.0wt% of the mass of the molten asphalt matrix; And / or, the electric field in step (3) is a DC electric field; And / or, before the mixing in step (3), the armored graphene in step (2) is also initially stirred with the molten asphalt matrix at a stirring rate of 150 rpm to 250 rpm for 5 min to 15 min.

6. The preparation method according to claim 1 or 2, characterized in that, The mixing temperature in step (3) is 150℃-180℃, the stirring rate is 40rpm-70rpm, and the time is 10min-30min; And / or, the cooling method described in step (3) is quenching; And / or, the cooling rate of step (3) is ≥5℃ / min; And / or, the molten asphalt matrix in step (3) is obtained by heating and stirring the asphalt matrix. The heating and stirring temperature of the asphalt matrix is ​​150℃-180℃, the stirring rate is 90rpm-120rpm, and the time is 25min-35min.

7. The preparation method according to claim 1 or 2, characterized in that, Step (3) of the preparation method is carried out in an integrated preparation device, including the following steps: first, the asphalt matrix in the third chamber is melted, the first door is opened to allow the armored graphene to fall into the second chamber, the first door is closed, the second door is opened to allow the armored graphene to fall into the third chamber for preliminary stirring, and then an electric field is applied in the third chamber to mix the armored graphene and the molten asphalt matrix in step (2) in the electric field, and then cooling is performed to obtain the composite waterproof material.

8. A composite waterproof material, characterized in that, The composite waterproof material is prepared by the preparation method according to any one of claims 1-7; In the composite waterproof material, armored graphene is dispersed in the asphalt matrix and forms a through-network.

9. An integrated preparation apparatus for preparing the composite waterproof material as described in claim 8, characterized in that, The integrated preparation device includes a first cavity, a second cavity connected to the lower end of the first cavity, and a third cavity connected to the lower end of the second cavity. The first cavity and the second cavity are separated by a first door, and the second cavity and the third cavity are separated by a second door. The third chamber includes a stirring device and a DC electrode.

10. The integrated preparation apparatus according to claim 9, characterized in that, The upper end of the first cavity is connected to a material bin, and the material bin is separated from the first cavity by a material baffle. And / or, a plasma electrode is also provided in the first cavity.

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