Super-hydrophobic, antibacterial and corrosion-resistant multifunctional concrete protective agent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of building materials, and discloses a super-hydrophobic-antibacterial corrosion-resistant multifunctional concrete protective agent and a preparation method and application thereof.The preparation method comprises the steps that tetraethoxysilane and tetrabutyl titanate are dissolved in ethyl alcohol, and SiO2 / TiO2 composite sol is prepared through a sol-gel reaction under the catalysis of ammonia water; adding an antibacterial agent, and continuously reacting for 2 hours to obtain a drug-loaded SiO2 / TiO2 composite sol; sequentially adding a silane coupling agent and heptadecafluorodecyl trimethoxysilane into the drug-loaded SiO2 / TiO2 composite sol, reacting at 60-70 DEG C for 6-8 hours, and centrifuging, washing and drying after the reaction is finished, so as to obtain surface-modified functional nanoparticles; mixing the functional nanoparticles with polydimethylsiloxane, a curing agent, a light stabilizer and a flatting agent, and performing ultrasonic dispersion to obtain the super-hydrophobic, antibacterial and corrosion-resistant multifunctional concrete protective agent. The key technical problems that an existing concrete protection technology is single in function, insufficient in durability and the like are effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent, its preparation method, and its application. Background Technology

[0002] Concrete, as the most widely used building material globally, is susceptible to penetration, freeze-thaw cycles, steel reinforcement corrosion, and microbial-induced corrosion (MIC) due to its porous structure and long-term exposure to complex environments such as moisture, chloride ions, acid rain, and microorganisms. This leads to decreased concrete durability and structural deterioration. Existing concrete protection technologies have significant limitations:

[0003] 1. Single function: Traditional organic protective agents (such as acrylates and epoxy resins) have insufficient hydrophobicity (contact angle <130°) and lack antibacterial function; while single antibacterial coatings are difficult to effectively block moisture and ion erosion.

[0004] 2. Poor durability: Physically mixed antibacterial agents are easily lost, and their performance degrades significantly after UV aging, making it impossible to achieve long-term protection.

[0005] 3. Difficulty in Synergy: There is an inherent contradiction between superhydrophobicity and antibacterial properties: hydrophobic surfaces hinder the contact between antibacterial agents and microorganisms, while hydrophilic antibacterial agents can damage the hydrophobic integrity of the coating. Therefore, there is an urgent need to develop a new type of multifunctional concrete protective agent that can synergistically achieve superhydrophobicity, impermeability, long-lasting antibacterial effect, and strong environmental adaptability, which is of great significance for improving the service life of concrete structures. Summary of the Invention

[0006] In view of this, to solve the problems of concrete leakage, corrosion, and microbial erosion mentioned in the background art, the purpose of this invention is to provide a superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent, its preparation method, and its application. It mimics the synergistic structural biomimetic mechanism of the superhydrophobic surface (micro-nano structure) of lotus leaves and the antibacterial peptides of fish scales; it uses mesoporous nano-SiO2 to load a slow-release antibacterial drug, which, together with TiO2 photocatalysis, forms a continuous antibacterial synergistic function day and night; simultaneously, an amphiphilic silane coupling agent is used to bridge the hydrophobic layer and the antibacterial component.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] Option 1

[0009] A superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent, comprising the following components by weight:

[0010] 10–50 parts of drug-loaded SiO2 / TiO2 composite sol;

[0011] 5-15 parts of composite surface modifier;

[0012] 35-50 parts of polydimethylsiloxane;

[0013] 5 to 10 parts of curing agent;

[0014] 0-1 part of light stabilizer;

[0015] 0.3 to 0.8 parts of leveling agent;

[0016] The drug-loaded SiO2 / TiO2 composite sol contains an antibacterial agent as the loaded drug, and the composite surface modifier includes heptadecafluorodecyltrimethoxysilane and a silane coupling agent.

[0017] Preferably, in the drug-loaded SiO2 / TiO2 composite sol, the antibacterial agent is polyhexamethylene biguanide or chitosan quaternary ammonium salt, and the loading of the antibacterial agent is 3-5 wt% of the SiO2 sol.

[0018] Preferably, the preparation steps of the drug-loaded SiO2 / TiO2 composite sol include: dissolving tetraethyl orthosilicate and tetrabutyl titanate in ethanol, and preparing SiO2 / TiO2 composite sol through a sol-gel reaction under the catalysis of ammonia; adding an antibacterial agent and continuing the reaction for 2 hours to obtain the drug-loaded SiO2 / TiO2 composite sol.

[0019] Preferably, the molar ratio of the tetraethyl orthosilicate to the tetrabutyl titanate is 3:1 to 4:1.

[0020] Preferably, the sol-gel reaction includes reacting for 4 to 6 hours under the catalysis of ammonia water at a pH of 9 to 10 and a water bath temperature of 40 to 60°C.

[0021] Preferably, the curing agent is a compound of tetraethyl orthosilicate and dibutyltin dilaurate in a mass ratio of 1:0.5.

[0022] Option 2

[0023] A method for preparing a superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent includes the following steps:

[0024] The silane coupling agent KH550 and heptadecafluorodecyltrimethoxysilane were added sequentially to the drug-loaded SiO2 / TiO2 composite sol, and the reaction was carried out at 60-70℃ for 6-8 hours. After the reaction was completed, the surface-modified functional nanoparticles were obtained by centrifugation, washing and drying.

[0025] The functional nanoparticles are mixed with polydimethylsiloxane, curing agent, light stabilizer and leveling agent, and ultrasonically dispersed at 300W power for 30-45 minutes to obtain the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent.

[0026] Option 3

[0027] The application of the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent as described above in the preparation of superhydrophobic and antibacterial concrete, wherein the superhydrophobic and antibacterial concrete includes a concrete matrix and the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent coated on the surface of the concrete matrix.

[0028] Preferably, the steps for preparing the superhydrophobic antibacterial concrete include: uniformly coating the superhydrophobic-antibacterial and corrosion-resistant multifunctional concrete protective agent onto the surface of the concrete substrate by spraying or brushing, and curing it at room temperature for 24 hours or at 60°C for 2 hours.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. Multifunctional integrated protection: Through the SiO2 / TiO2 hybrid structure and heptadecafluorodecyltrimethoxysilane surface modification, the superhydrophobic properties and photocatalytic self-cleaning function are organically combined; the antibacterial agent (chitosan quaternary ammonium salt) loaded in the SiO2 / TiO2 composite sol and the hydrophobic layer are molecularly composited through the silane coupling agent KH-550, which solves the problem of mutual restriction between hydrophobicity and antibacterial properties in traditional technology; at the same time, it achieves excellent superhydrophobic properties and long-lasting antibacterial effect, with both physical barrier and chemical protection mechanisms.

[0031] 2. Long-lasting protective performance: The present invention extends the slow-release period of antibacterial agents by loading drugs onto mesoporous SiO2; the low surface energy layer formed by modification with heptadecafluorodecyltrimethoxysilane exhibits excellent weather resistance and environmental stability, providing long-lasting protection and significantly extending service life.

[0032] 3. Good engineering applicability: The room temperature curing process (24h / 25℃ or 2h / 60℃) is suitable for on-site construction, has good film-forming properties, adapts to various concrete substrates, and has good deformation adaptability.

[0033] 4. Environmental friendliness and economy: It uses polydimethylsiloxane (PDMS) with low volatile organic compounds (VOCs) as the matrix material, which complies with the building wall coating standard (GB18582-2020); and the slow release of antibacterial agent avoids environmental pollution caused by one-time release.

[0034] In summary, this invention, through innovative formulation design and preparation process, effectively solves key technical problems in existing concrete protection technologies, such as limited functionality and insufficient durability, demonstrating significant advantages in practical engineering applications. Specifically, this invention's superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent can be used to improve the durability of concrete structures in marine engineering, water conservancy engineering, or municipal engineering, and is suitable for scenarios with stringent requirements for the durability and corrosion protection of concrete structures in building engineering, marine engineering, and municipal engineering. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0036] Figure 1 This is a flowchart illustrating the preparation method of the superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent of the present invention. Detailed Implementation

[0037] To further understand the content of this invention, a detailed description of the invention is provided in conjunction with the accompanying drawings and embodiments. The structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art, and are not intended to limit the implementation conditions of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention. It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.

[0038] Example 1

[0039] 1. Raw materials and proportions (parts by weight)

[0040] Tetraethyl orthosilicate (TEOS): 25 parts;

[0041] Tetrabutyl titanate (TBT): 8 parts;

[0042] Chitosan quaternary ammonium salt (HACC): 5 parts;

[0043] Heptadecafluorodecyltrimethoxysilane (FAS-17): 5 parts;

[0044] Silane coupling agent (KH-550): 3 parts;

[0045] Polydimethylsiloxane (PDMS): 45 parts;

[0046] Curing agent (ethyl orthosilicate: dibutyltin dilaurate = 1: 0.5): 7.5 parts;

[0047] Light stabilizer nano-ZnO: 1 part;

[0048] Leveling agent (BYK-306): 0.5 parts;

[0049] 2. Preparation method of superhydrophobic, antibacterial and corrosion-inhibiting multifunctional concrete protective agent:

[0050] (1) Preparation of drug-loaded SiO2 / TiO2 composite sol

[0051] Mix TEOS and TBT at a molar ratio of 3.1:1, add 200 parts of anhydrous ethanol, and stir for 30 minutes until completely dissolved;

[0052] 12 portions of 25wt% ammonia solution were slowly added dropwise using a constant pressure dropping funnel at a rate of 1 mL / min. The reaction system was kept at pH 9.5 ± 0.2 and stirred continuously in a 45°C water bath for 5 hours.

[0053] Add HACC and continue the reaction for 2 hours to obtain a light blue transparent sol (drug-loaded SiO2 / TiO2 composite sol).

[0054] (2) KH-550 and FAS-17 were added sequentially and reacted at 65℃ for 7h; centrifuged, washed 3 times with anhydrous ethanol, and vacuum dried at 60℃ to obtain white powdery surface-modified functional nanoparticles.

[0055] (3) Mix PDMS, functional nanoparticles, curing agent, light stabilizer, nano ZnO and leveling agent, control the temperature to be less than 45℃ and ultrasonically disperse at 300W power for 35min to obtain the superhydrophobic-antibacterial corrosion-inhibiting multifunctional concrete protective agent.

[0056] 3. Preparation method of superhydrophobic antibacterial concrete:

[0057] Provide a concrete substrate (test block), and apply the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent evenly to the surface of the concrete substrate (test block) by spraying or brushing, and cure at 25°C for 24 hours.

[0058] Example 2

[0059] 1. Raw materials and proportions (parts by weight)

[0060] Tetraethyl orthosilicate (TEOS): 28 parts;

[0061] Tetrabutyl titanate (TBT): 7 parts;

[0062] Chitosan quaternary ammonium salt (HACC): 8 parts;

[0063] Heptadecafluorodecyltrimethoxysilane (FAS-17): 7 parts;

[0064] Silane coupling agent (KH-550): 4 parts;

[0065] Polydimethylsiloxane (PDMS): 38 parts;

[0066] Curing agent (ethyl orthosilicate: dibutyltin dilaurate = 1:0.5): 5 parts;

[0067] Light stabilizer nano-ZnO: 0.5 parts;

[0068] Light stabilizer UV-531: 0.5 parts;

[0069] Leveling agent BYK-306: 0.5 parts;

[0070] 2. Preparation method of superhydrophobic, antibacterial and corrosion-inhibiting multifunctional concrete protective agent:

[0071] (1) Preparation of drug-loaded SiO2 / TiO2 composite sol

[0072] Mix TEOS and TBT at a molar ratio of 4:1, add 240 parts of anhydrous ethanol, and stir for 30 minutes until completely dissolved.

[0073] 12 portions of 25wt% ammonia solution were slowly added dropwise using a constant pressure dropping funnel at a rate of 1 mL / min. The reaction system was kept at pH 9.5 ± 0.2 and stirred continuously in a 45°C water bath for 5 hours.

[0074] Add HACC and continue the reaction for 2 hours to obtain a light blue transparent sol (drug-loaded SiO2 / TiO2 composite sol).

[0075] (2) KH-550 and FAS-17 were added sequentially and reacted at 65℃ for 7h; centrifuged, washed 3 times with anhydrous ethanol, and vacuum dried at 60℃ to obtain white powdery surface-modified functional nanoparticles.

[0076] (3) Mix PDMS, functional nanoparticles, curing agent, light stabilizer, nano ZnO and leveling agent, control the temperature to be less than 45℃ and ultrasonically disperse at 300W power for 35min to obtain the superhydrophobic-antibacterial corrosion-inhibiting multifunctional concrete protective agent.

[0077] 3. Preparation method of superhydrophobic antibacterial concrete:

[0078] Provide a concrete substrate (test block), and apply the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent evenly to the surface of the concrete substrate (test block) by spraying or brushing, and cure at 60°C for 2 hours.

[0079] Comparative Example 1 (Unmodified nanocomposite protective agent)

[0080] 1. Raw materials and proportions (parts by weight)

[0081] Tetraethyl orthosilicate (TEOS): 30 parts;

[0082] Tetrabutyl titanate (TBT): 8 parts;

[0083] Polydimethylsiloxane (PDMS): 50 parts;

[0084] Curing agent (ethyl orthosilicate: dibutyltin dilaurate = 1:0.5): 7.5 parts;

[0085] Light stabilizer nano ZnO: 1 part;

[0086] Leveling agent BYK-306: 0.5 parts;

[0087] 2. Preparation method of unmodified nanocomposite protective agent:

[0088] (1) Preparation of SiO2 / TiO2 composite sol

[0089] Mix TEOS and TBT at a molar ratio of 3.8:1, add 240 parts of anhydrous ethanol, and stir for 30 minutes until completely dissolved;

[0090] 12 portions of 25wt% ammonia solution were slowly added dropwise using a constant pressure dropping funnel at a rate of 1 mL / min. The reaction system was kept at pH 9.5 ± 0.2 and stirred continuously in a 45℃ water bath for 5 hours to obtain a light blue transparent sol (SiO2 / TiO2 composite sol).

[0091] Centrifugation, washing three times with anhydrous ethanol, and vacuum drying at 60°C yielded white powdery nanoparticles.

[0092] (2) Mix PDMS, nanoparticles, curing agent, nano ZnO and leveling agent, control the temperature to be less than 45℃ and ultrasonically disperse at 300W power for 35min to obtain the unmodified nanocomposite protective agent.

[0093] 3. Preparation method of unmodified nanocomposite protective concrete:

[0094] Provide a concrete substrate (test block), and apply the unmodified nanocomposite protective agent evenly to the surface of the concrete substrate (test block) by spraying or brushing, and cure at 25°C for 24 hours.

[0095] Comparative Example 2 (Single hydrophobic protective agent)

[0096] 1. Raw materials and proportions (parts by weight)

[0097] Tetraethyl orthosilicate (TEOS): 36 parts;

[0098] Heptadecafluorodecyltrimethoxysilane (FAS-17): 6 parts;

[0099] Polydimethylsiloxane (PDMS): 50 parts;

[0100] Curing agent (ethyl orthosilicate: dibutyltin dilaurate = 1:0.5): 7.5 parts;

[0101] Leveling agent BYK-306: 0.5 parts;

[0102] 2. Preparation method of a single hydrophobic protective agent:

[0103] (1) Preparation of SiO2 sol

[0104] Add TEOS to 200 parts of anhydrous ethanol and stir for 30 minutes until completely dissolved;

[0105] 12 portions of 25wt% ammonia solution were slowly added dropwise using a constant pressure dropping funnel at a rate of 1 mL / min. The reaction system was kept at pH 9.5 ± 0.2 and stirred continuously in a 40℃ water bath for 5 hours to obtain a light blue transparent sol (SiO2 sol).

[0106] (2) Add FAS-17 and react at 65℃ for 7h; centrifuge, wash 3 times with anhydrous ethanol, and vacuum dry at 60℃ to obtain powdered surface-modified single nanoparticles.

[0107] (3) Mix PDMS, single nanoparticles, curing agent and leveling agent, control the temperature to be less than 45℃ and ultrasonically disperse at 300W power for 35min to obtain the single hydrophobic protective agent.

[0108] 3. Preparation method of single hydrophobic protective concrete:

[0109] Provide a concrete substrate (test block), and apply the single hydrophobic protective agent evenly to the surface of the concrete substrate (test block) by spraying or brushing, and cure at 25°C for 24 hours.

[0110] Comparative Example 3 (Physical Mixed Antibacterial Protective Agent)

[0111] 1. Raw materials and proportions (parts by weight)

[0112] Tetraethyl orthosilicate (TEOS): 28 parts;

[0113] Tetrabutyl titanate (TBT): 8 parts;

[0114] Chitosan quaternary ammonium salt (HACC): 5 parts;

[0115] Polydimethylsiloxane (PDMS): 50 parts;

[0116] Curing agent (ethyl orthosilicate: dibutyltin dilaurate = 1:0.5): 7.5 parts;

[0117] Light stabilizer nano ZnO: 1 part;

[0118] Leveling agent BYK-306: 0.5 parts;

[0119] 2. Preparation method of physically mixed antibacterial protective agent:

[0120] (1) Preparation of SiO2 / TiO2 composite sol

[0121] Mix TEOS and TBT at a molar ratio of 3.5:1, add 220 parts of anhydrous ethanol, and stir for 30 minutes until completely dissolved;

[0122] 12 portions of 25wt% ammonia solution were slowly added dropwise using a constant pressure dropping funnel at a rate of 1 mL / min. The reaction system was kept at pH 9.5 ± 0.2 and stirred continuously in a 45℃ water bath for 5 hours to obtain a light blue transparent sol (SiO2 / TiO2 composite sol).

[0123] Centrifugation, washing three times with anhydrous ethanol, and vacuum drying at 60°C yielded white powdery nanoparticles.

[0124] (2) Mix PDMS, HACC, nanoparticles, curing agent, nano ZnO and leveling agent, control the temperature to be less than 45℃ and ultrasonically disperse at 300W power for 35min to obtain the physical mixed antibacterial agent protective agent.

[0125] 3. Preparation method of physically mixed antibacterial agent type protective concrete:

[0126] Provide a concrete substrate (test block), and apply the physical mixed antibacterial agent to the surface of the concrete substrate (test block) by spraying or brushing, and cure at 25°C for 24 hours.

[0127] The test performance of the embodiments and comparative examples in this invention is shown in the table below:

[0128] Test Project Test Standards Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Water contact angle / ° GB / T30693-2014 158 162 113 155 124 Roll angle / ° GB / T30693-2014 4.2 2.1 30 6.8 15.2 Antibacterial rate / % ISO 22196-2011 99.5 98.0 42.3 12.8 94.3 Contact angle retention rate after 2000 hours of QUV aging / % GB / T 1766-2008 93.5 96.3 45.2 82.6 75.2 Freeze-thaw cycle (50 cycles) mass loss / % GB / T 50082-2009 1.8 1.2 12.5 5.6 3.8 Adhesion / MPa GB / T 5210-2006 3.8 4.1 1.2 2.8 2.5 VOCs content (g / L) GB 18582-2020 42 38 55 50 65

[0129] The comprehensive comparative analysis in the table above shows that the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent (example) of this invention significantly and reasonably outperforms all comparative examples in terms of core properties such as hydrophobicity, antibacterial properties, durability, and adhesion. This fully demonstrates the innovation and necessity of the "sol-gel hybrid + surface modification + drug loading" technical route of this invention. Specific analysis is as follows:

[0130] (1) Hydrophobic properties (water contact angle, roll-off angle)

[0131] Examples 1 and 2 compared to Comparative Example 1: Comparative Example 1 (unmodified) only contains hydrophilic nano-SiO2 / TiO2 with a contact angle of only 113°, which is a hydrophilic surface. However, after modification with FAS-17 (low surface energy material) and KH-550 (improved dispersion), the examples obtained superhydrophobicity (water contact angle >150°, roll-off angle less than 5°).

[0132] Examples 1 and 2 compared to Comparative Example 2: Comparative Example 2 (single hydrophobic) only contained SiO2 and FAS-17, and also achieved a high contact angle (155°), proving that the FAS-17 modification is effective. However, the roll-off angle (6.8°) was significantly higher than that of Examples 1 and 2 (2.1°~4.2°). The TiO2 and more complex hybrid structure introduced in the examples of this invention, together with PDMS, constructed a superior micro-nano hierarchical structure, thereby achieving a lower roll-off angle (i.e., a better "lotus effect").

[0133] Examples 1 and 2 compared to Comparative Example 3: In Comparative Example 3 (physical mixing), the hydrophilicity of HACC disrupts the low chemical energy of the coating surface, resulting in a significantly inferior contact angle (124°) and roll-off angle (15.2°) compared to the examples. This fully demonstrates that "surface modification" has a clear advantage over "physical mixing".

[0134] (2) Antibacterial properties (antibacterial rate)

[0135] Compared to Comparative Examples 1, 2, and 3, Examples 1 and 2: Comparative Example 1 (unmodified) showed only weak antibacterial activity (42.3%), possibly due to the physical effects of the nanoparticles themselves or trace metal ions; Comparative Example 2 (single hydrophobic) showed almost no antibacterial activity (12.8%), as expected. The near 100% antibacterial rate of Examples 1 fully demonstrates the successful loading and release of HACC; Comparative Example 3 (physical mixing) showed a higher initial antibacterial rate (94.3%), which is related to the "physical mixing of a large amount of HACC," however, its durability (e.g., resistance to aging, resistance to water immersion) was far inferior to Examples 3 because its antibacterial agent was physically adsorbed rather than chemically bonded, making it prone to rapid loss.

[0136] (3) Durability (QUV aging contact angle retention rate, freeze-thaw loss)

[0137] QUV aging: Example 2 showed the highest retention rate (96.3%) due to the addition of the light stabilizer UV-531, which works synergistically with nano-ZnO. Nano-ZnO acts as the first line of defense, reflecting and scattering most ultraviolet light, while UV-531 acts as the second line of defense, absorbing residual ultraviolet light that has penetrated the ZnO shielding layer. Furthermore, the higher FAS-17 content provides a more stable low surface energy layer. Comparative Example 1 (unmodified) showed the worst retention rate (45.2%) because its nanoparticles readily photocatalytically decomposed the organic matrix. Comparative Example 2 (single hydrophobic component) and Comparative Example 3 (physical mixture) showed moderate retention rates, but not as good as the examples, due to insufficient structural stability.

[0138] Freeze-thaw cycle: Comparative Example 1 (unmodified) suffered the most severe mass loss (12.5%) due to its strong hydrophilicity, which allowed moisture to easily penetrate. The superhydrophobicity of the embodiment effectively blocked moisture, resulting in minimal loss (<2%). The losses of Comparative Examples 2 and 3 were in between, consistent with their performance positioning.

[0139] (4) Adhesion

[0140] The adhesion strength of Examples 1 and 2 relative to Comparative Examples 1, 2, and 3 is as follows: Examples 1 > Comparative Example 2 > Comparative Example 3 > Comparative Example 1.

[0141] Example 2 (4.0 MPa) is the best because the KH-550 coupling agent forms a strong chemical bridge (Si-O-Si bond) between the inorganic nanoparticles and the organic PDMS, which greatly improves the interfacial bonding.

[0142] Comparative Example 1 (unmodified) performed the worst (1.2 MPa) because the hydrophilic nanoparticles had poor compatibility with the organic PDMS matrix, resulting in a noticeable interface. Comparative Examples 2 and 3 lacked this effective coupling, and their adhesion was significantly lower than that of the Examples.

[0143] (5) Environmental performance (VOCs content)

[0144] Compared with Comparative Examples 1, 2, and 3, the VOCs content in the protective agents of Examples 1 and 2 all met the national standard (GB 18582-2020 requires ≤80g / L).

[0145] The VOC content was low in the examples because the modified nanoparticles have good compatibility with the resin, the system is more stable, and the amount of small molecule solvent used is reduced. Comparative Example 3 had the highest VOC content because the physical mixing of HACCP disrupted the system's stability, requiring more solvent to maintain the application viscosity.

[0146] In the description of this invention, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0147] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent, characterized in that, Based on parts by mass, it includes the following components: 10–50 parts of drug-loaded SiO2 / TiO2 composite sol; 5-15 parts of composite surface modifier; 35-50 parts of polydimethylsiloxane; 5 to 10 parts of curing agent; 0-1 part of light stabilizer; 0.3 to 0.8 parts of leveling agent; The drug-loaded SiO2 / TiO2 composite sol contains an antibacterial agent as the loaded drug, the composite surface modifier includes heptadecafluorodecyltrimethoxysilane FAS-17 and silane coupling agent KH550 in a mass ratio of 3-10:2-5, and the light stabilizer includes nano ZnO and / or light stabilizer UV-531.

2. The superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent according to claim 1, characterized in that, Based on parts by mass, it includes the following components: 35–45 parts of drug-loaded SiO2 / TiO2 composite sol; 8-11 parts of composite surface modifier; 38–45 parts of polydimethylsiloxane; 5 to 8 parts of curing agent; 1 part light stabilizer; 0.5 parts of leveling agent.

3. A superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent according to claim 1 or 2, characterized in that: In the drug-loaded SiO2 / TiO2 composite sol, the antibacterial agent is polyhexamethylene biguanide or chitosan quaternary ammonium salt, and the loading of the antibacterial agent is 3 to 5 wt% of the SiO2 sol.

4. The superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent according to claim 3, characterized in that, The preparation steps of the drug-loaded SiO2 / TiO2 composite sol include: Tetrabutyl orthosilicate and tetrabutyl titanate were dissolved in ethanol and reacted with ammonia to obtain SiO2 / TiO2 composite sol. An antibacterial agent was added and the reaction was continued for 2 hours to obtain drug-loaded SiO2 / TiO2 composite sol.

5. The superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent according to claim 4, characterized in that: The molar ratio of the tetraethyl orthosilicate to the tetrabutyl titanate is 3:1 to 4:

1.

6. The superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent according to claim 4, characterized in that, The sol-gel reaction includes reacting for 4 to 6 hours under the catalysis of ammonia water at a pH of 9 to 10 and a water bath temperature of 40 to 60°C.

7. A superhydrophobic, antibacterial, and corrosion-inhibiting multifunctional concrete protective agent according to claim 1 or 2, characterized in that: The curing agent is a compound of tetraethyl orthosilicate and dibutyltin dilaurate in a mass ratio of 1:0.

5.

8. A method for preparing a superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent as described in any one of claims 1-7, characterized in that, Includes the following steps: A silane coupling agent and heptadecafluorodecyltrimethoxysilane were sequentially added to the drug-loaded SiO2 / TiO2 composite sol, and the mixture was reacted at 60-70°C for 6-8 hours. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain surface-modified functional nanoparticles. The functional nanoparticles are mixed with polydimethylsiloxane, curing agent, light stabilizer and leveling agent, and ultrasonically dispersed at a temperature of less than 45°C for 30-45 minutes at 300W power to obtain the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent.

9. The application of the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent as described in any one of claims 1-7 in the preparation of superhydrophobic and antibacterial concrete, wherein the superhydrophobic and antibacterial concrete comprises a concrete matrix and the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent coated on the surface of the concrete matrix.

10. The application according to claim 9, characterized in that, The steps for preparing the superhydrophobic antibacterial concrete include: uniformly coating the superhydrophobic-antibacterial and corrosion-inhibiting multifunctional concrete protective agent onto the surface of the concrete substrate by spraying or brushing, and curing it at room temperature for 24 hours or at 60°C for 2 hours.

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