A mortar containing nanomaterials and a preparation method thereof

Abstract

The application relates to the technical field of building materials, and discloses a mortar containing nanomaterials and a preparation method thereof, the mortar being composed of 70-80 parts by weight of cement, 8-12 parts by weight of fly ash, 0.4-0.5 parts by weight of a polycarboxylate water reducing agent, 0.4-0.6 parts by weight of hydroxypropyl methylcellulose, 1-2 parts by weight of nanomaterials, 2-3 parts by weight of modified silk fibroin and 40-50 parts by weight of water. The modified nanosilica is modified by gamma-aminopropyl triethoxysilane, the modified cubic nanometer calcium carbonate is modified by fumaric acid, sodium stearate and palmitic acid, and the modified silk fibroin is prepared by being grafted and modified by a double-aminopropyl-terminated polysiloxane. The mortar is treated by optimizing component collocation, modifying the nanomaterials and the silk fibroin, the mechanical properties, the durability and the crack resistance of the mortar are remarkably improved, and the cost is controllable.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a mortar containing nanomaterials and its preparation method. Background Technology

[0002] Mortar is a fundamental material used extensively in construction projects, primarily for wall plastering, bricklaying, tile installation, and insulation layer protection. Its performance directly affects the durability and safety of building structures. Traditional mortar, mainly composed of cement, sand, and water, is relatively inexpensive but suffers from insufficient compressive strength and poor weather resistance, leading to cracking and peeling during long-term use, severely impacting the quality of construction projects. Existing technologies modify mortar by adding water-reducing agents, water-retaining agents, or mineral admixtures, but the effects are limited.

[0003] Nanoparticles, with their extremely small particle size and large specific surface area, exhibit unique physicochemical properties. Their application in mortar can optimize the mortar's internal structure through a filling effect. However, the addition of single nanomaterials often leads to agglomeration, resulting in uneven dispersion in the mortar and negatively impacting the modification effect. Therefore, developing a high-performance, cost-effective mortar containing nanomaterials is of significant practical importance. Summary of the Invention

[0004] Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a mortar containing nanomaterials and its preparation method, which exhibits good mechanical properties, durability, and crack resistance.

[0006] Technical solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a mortar containing nanomaterials, comprising the following weight components: 70-80 parts by weight of cement, 8-12 parts by weight of fly ash, 0.4-0.5 parts by weight of polycarboxylate superplasticizer, 0.4-0.6 parts by weight of hydroxypropyl methylcellulose, 1-2 parts by weight of nanomaterials, 2-3 parts by weight of modified silk fibroin, and 40-50 parts by weight of water.

[0008] Furthermore, the nanomaterial comprises the following weight components: 0.5-1 parts by weight of modified cubic nano-calcium carbonate and 0.5-1 parts by weight of modified nano-silica;

[0009] The modified nano-silica is prepared as follows: 45 mL of anhydrous ethanol and 15 mL of deionized water are added to a reactor and mixed to obtain a solution. Then, 1-2 g of nano-silica is added to the solution and ultrasonically treated for 35-40 min. Next, 0.04-0.08 g of γ-aminopropyltriethoxysilane is added, and the pH of the system is adjusted to 4 with hydrochloric acid. The system is refluxed at 45-50 °C for 1-2 h. After the reaction is completed, the solution is centrifuged, washed, and dried to obtain the modified nano-silica.

[0010] Furthermore, the preparation method of the modified cubic nano-calcium carbonate is as follows:

[0011] a. Place 2-3g of Ca(OH)₂ in a high-gravity micro-interface reactor, turn on the circulation pump and cooling device, and when the reaction temperature reaches 25℃, turn on the CO₂ gas flow meter and set the volumetric flow rate to 3m³ / g. 3 The reaction continues at a rate of / h (under standard conditions) until the final pH value of 7 is reached. At this point, the reaction ends, the flow meter and the circulating pump are turned off, and nano-calcium carbonate is obtained.

[0012] b. Add fumaric acid, sodium stearate, and palmitic acid to ethanol solvent, sonicate for 10-15 min, mix well to obtain a mixture; then add the mixture to 1-1.8 g of nano calcium carbonate, react at 65-70℃, filter after the reaction is complete, and dry in an oven to obtain modified cubic nano calcium carbonate.

[0013] Furthermore, in step b, the ratio of fumaric acid, sodium stearate, palmitic acid, and ethanol is 0.02-0.03g: 0.031-0.035g: 0.02-0.036g: 8-10mL.

[0014] Furthermore, the reaction time in step b is 40-45 minutes.

[0015] Furthermore, the method for preparing the modified silk fibroin is as follows:

[0016] S1. Add octamethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide to a reaction flask. Under nitrogen protection, stir and heat to 85-90℃ for 3-4 hours, then raise the temperature to 135-140℃ and continue the reaction for 1-1.5 hours. After the reaction is completed, vacuum pump the mixture and distill under reduced pressure to obtain diaminopropyl-terminated polysiloxane.

[0017] S2. Add 40-45 mL of silk fibroin solution and 1-2 g of diaminopropyl-terminated polysiloxane to a reaction flask, then add 0.02-0.04 g of carbodiimide. Stir at room temperature for 10-12 h, then pour into a dialysis bag and dialyze with distilled water on a stirrer for 3 days to obtain modified silk fibroin.

[0018] Further, the ratio of octamethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide in S1 is 20-24g: 19.8-24.6g: 1.31-1.36g.

[0019] Furthermore, the method for preparing the mortar containing nanomaterials is as follows: cement, fly ash, polycarboxylate superplasticizer, hydroxypropyl methylcellulose, nanomaterials, and modified silk fibroin are added to a mixer and stirred for 2-3 minutes. Then water is added and stirred for 50-60 seconds to obtain the mortar containing nanomaterials.

[0020] Beneficial technical effects

[0021] This invention uses modified cubic nano-calcium carbonate and modified nano-silica to form a uniform "skeleton support" inside the mortar, filling the tiny pores between cement hydration products; nano-silica can react with the calcium hydroxide generated by cement hydration to generate more dense calcium silicate hydrate. The two work together to achieve a "physical filling" effect, making the internal structure of the mortar more compact and improving its mechanical properties.

[0022] This invention modifies nano-silica with γ-aminopropyltriethoxysilane, introducing organic groups on the surface of nanoparticles through a silane coupling agent to reduce agglomeration. Nano-calcium carbonate is modified with a composite of fumaric acid, sodium stearate, and palmitic acid. The carboxyl groups of the three organic acids combine with calcium ions on the surface of calcium carbonate to form a hydrophobic coating layer. Simultaneously, ultrasonic treatment ensures uniform adsorption of the modifiers, significantly improving the dispersion stability of nanoparticles in mortar. Modified silk fibroin in the mortar acts as an organic modifier; the amino groups on its molecular chain form hydrogen bonds and chemical bonds with the modified groups (amino and carboxyl groups) on the surface of the nanomaterials and the hydroxyl groups of cement hydration products. This solves the problem of weak interfacial bonding in traditional organic-inorganic composite materials, resulting in more uniform dispersion in the mortar. When cracks occur in the mortar, the nanoparticles can "pin" the crack tips, increasing the resistance to crack propagation and preventing crack expansion, thus improving durability.

[0023] This invention modifies silk fibroin by grafting with diaminopropyl-terminated polysiloxane, introducing highly flexible polysiloxane into the silk fibroin molecular chain. On the one hand, this improves the stability of silk fibroin in alkaline environments, and on the other hand, the flexible segments of polysiloxane alleviate the internal stress during the hardening process of mortar, giving the mortar good toughness and inhibiting the generation and propagation of cracks. The synergistic filling effect of the compounded nanomaterials effectively solves the problem of cracking and falling off of traditional mortar during long-term use.

[0024] In summary, the mortar of this invention uses a composite of modified cubic nano-calcium carbonate and modified nano-silica as nanomaterials. After specific modification treatment, the dispersibility of both is significantly improved, avoiding the problem of easy agglomeration of single nanomaterials. The nanoparticles optimize the internal pore structure of the mortar through a filling effect, forming a dense bond with cement hydration products. Simultaneously, the introduction of modified silk fibroin enhances the bonding force between components, synergistically improving the mechanical properties of the mortar. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The viscosity of hydroxypropyl methylcellulose is Fly ash is classified as Grade II.

[0027] Preparation method of silk fibroin solution: Weigh 10g of silkworm cocoons and boil them in 4L of 0.05mol / L sodium carbonate aqueous solution for 30min. After removing them, repeat the above steps twice. Wash the boiled silkworm cocoons with deionized water and dry them to obtain degummed silk. Immerse 5.2g of degummed silk in about 75ml of calcium chloride-ethanol-water (molar ratio of 1:2:8) solution and stir at 70℃ for 4h. After cooling, centrifuge at room temperature for 6min to remove insoluble impurities. Place the dissolved silk fibroin solution in a dialysis bag with a molecular weight cutoff of 3500 and dialyze it in deionized water at 4℃ for 3d.

[0028] Example 1

[0029] A mortar containing nanomaterials comprises the following weight components: 70 parts by weight of cement, 8 parts by weight of fly ash, 0.4 parts by weight of polycarboxylate superplasticizer, 0.4 parts by weight of hydroxypropyl methylcellulose, 1 part by weight of nanomaterials, 2 parts by weight of modified silk fibroin, and 40 parts by weight of water.

[0030] The nanomaterial comprises the following weight components: 0.5 parts by weight of modified cubic nano-calcium carbonate and 0.5 parts by weight of modified nano-silica.

[0031] The modified nano-silica is prepared as follows: 45 mL of anhydrous ethanol and 15 mL of deionized water are added to a reactor and mixed to obtain a solution. Then, 1 g of nano-silica is added to the solution and ultrasonically treated for 35 min. Next, 0.04 g of γ-aminopropyltriethoxysilane is added to the solution, and the pH of the system is adjusted to 4 with hydrochloric acid. The solution is refluxed at 45 °C for 1 h. After the reaction is completed, the solution is centrifuged, washed, and dried to obtain the modified nano-silica.

[0032] The method for preparing the modified cubic nano-calcium carbonate is as follows:

[0033] a. Place 2g of Ca(OH)₂ in a high-gravity micro-interface reactor, turn on the circulation pump and cooling device, and when the reaction temperature reaches 25℃, turn on the CO₂ gas flow meter and set the volumetric flow rate to 3m³. 3 The reaction continues at a rate of / h (under standard conditions) until the final pH value of 7 is reached. At this point, the reaction ends, the flow meter and the circulating pump are turned off, and nano-calcium carbonate is obtained.

[0034] b. Add 0.02g fumaric acid, 0.031g sodium stearate and 0.02g palmitic acid to 8mL ethanol solvent, sonicate for 10min, mix well to obtain a mixture; then add the mixture to 1g nano calcium carbonate, react at 65℃ for 40min, filter after the reaction, put in an oven to dry, and obtain modified cubic nano calcium carbonate.

[0035] The method for preparing the modified silk fibroin is as follows:

[0036] S1. Add 20g of octamethylcyclotetrasiloxane, 19.8g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and 1.31g of tetramethylammonium hydroxide to a reaction flask. Under nitrogen protection, stir and heat to 85°C for 3 hours, then raise the temperature to 135°C and continue the reaction for 1 hour. After the reaction is completed, vacuum pump is used to evacuate the vacuum and distill under reduced pressure to obtain diaminopropyl-terminated polysiloxane.

[0037] S2. Add 40 mL of silk fibroin solution and 1 g of diaminopropyl-terminated polysiloxane to a reaction flask, then add 0.02 g of carbodiimide. Stir at room temperature for 10 h, then pour into a dialysis bag and dialyze with distilled water on a stirrer for 3 days to obtain modified silk fibroin.

[0038] The method for preparing the mortar containing nanomaterials is as follows: cement, fly ash, polycarboxylate superplasticizer, hydroxypropyl methylcellulose, nanomaterials, and modified silk fibroin are added to a mixer and stirred for 2 minutes. Then water is added and stirred for 50 seconds to obtain the mortar containing nanomaterials.

[0039] Example 2

[0040] A mortar containing nanomaterials comprises the following weight components: 80 parts by weight of cement, 12 parts by weight of fly ash, 0.5 parts by weight of polycarboxylate superplasticizer, 0.6 parts by weight of hydroxypropyl methylcellulose, 2 parts by weight of nanomaterials, 3 parts by weight of modified silk fibroin, and 50 parts by weight of water.

[0041] The nanomaterial comprises the following weight components: 1 part by weight of modified cubic nano-calcium carbonate and 1 part by weight of modified nano-silica.

[0042] The modified nano-silica is prepared as follows: 45 mL of anhydrous ethanol and 15 mL of deionized water are added to a reactor and mixed to obtain a solution. Then, 2 g of nano-silica is added to the solution and ultrasonically treated for 40 min. Next, 0.08 g of γ-aminopropyltriethoxysilane is added to the solution and the pH of the system is adjusted to 4 with hydrochloric acid. The solution is refluxed at 50 °C for 2 h. After the reaction is completed, the solution is centrifuged, washed and dried to obtain modified nano-silica.

[0043] The method for preparing the modified cubic nano-calcium carbonate is as follows:

[0044] a. Place 3g of Ca(OH)₂ in a high-gravity micro-interface reactor, turn on the circulation pump and cooling device, and when the reaction temperature reaches 25℃, turn on the CO₂ gas flow meter and set the volumetric flow rate to 3m³ / g. 3 The reaction continues at a rate of / h (under standard conditions) until the final pH value of 7 is reached. At this point, the reaction ends, the flow meter and the circulating pump are turned off, and nano-calcium carbonate is obtained.

[0045] b. Add 0.03g fumaric acid, 0.035g sodium stearate and 0.036g palmitic acid to 10mL ethanol solvent, sonicate for 15min, mix well to obtain a mixture; then add the mixture to 1.8g nano calcium carbonate, react at 70℃ for 45min, filter after the reaction, put in an oven to dry, and obtain modified cubic nano calcium carbonate.

[0046] The method for preparing the modified silk fibroin is as follows:

[0047] S1. Add 24g of octamethylcyclotetrasiloxane, 24.6g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and 1.36g of tetramethylammonium hydroxide to a reaction flask. Under nitrogen protection, stir and heat to 90℃ for 4h, then raise the temperature to 140℃ and continue the reaction for 1.5h. After the reaction is completed, vacuum pump is used to evacuate the vacuum and distill under reduced pressure to obtain diaminopropyl-terminated polysiloxane.

[0048] S2. Add 45 mL of silk fibroin solution and 2 g of diaminopropyl-terminated polysiloxane to a reaction flask, then add 0.04 g of carbodiimide. Stir at room temperature for 12 h, then pour into a dialysis bag and dialyze with distilled water on a stirrer for 3 days to obtain modified silk fibroin.

[0049] The method for preparing the mortar containing nanomaterials is as follows: cement, fly ash, polycarboxylate superplasticizer, hydroxypropyl methylcellulose, nanomaterials, and modified silk fibroin are added to a mixer and stirred for 3 minutes. Then water is added and stirred for 60 seconds to obtain the mortar containing nanomaterials.

[0050] Example 3

[0051] A mortar containing nanomaterials comprises the following weight components: 75 parts by weight of cement, 10 parts by weight of fly ash, 0.45 parts by weight of polycarboxylate superplasticizer, 0.5 parts by weight of hydroxypropyl methylcellulose, 1.5 parts by weight of nanomaterials, 2.5 parts by weight of modified silk fibroin, and 45 parts by weight of water.

[0052] The nanomaterial comprises the following weight components: 0.7 parts by weight of modified cubic nano-calcium carbonate and 0.8 parts by weight of modified nano-silica;

[0053] The modified nano-silica is prepared as follows: 45 mL of anhydrous ethanol and 15 mL of deionized water are added to a reactor and mixed to obtain a solution. Then, 1.5 g of nano-silica is added to the solution and ultrasonically treated for 38 min. Next, 0.06 g of γ-aminopropyltriethoxysilane is added to the solution, and the pH of the system is adjusted to 4 with hydrochloric acid. The solution is refluxed at 47 °C for 1 h. After the reaction is completed, the solution is centrifuged, washed and dried to obtain modified nano-silica.

[0054] The method for preparing the modified cubic nano-calcium carbonate is as follows:

[0055] a. Place 2.5g of Ca(OH)₂ in a high-gravity micro-interface reactor, turn on the circulation pump and cooling device, and when the reaction temperature reaches 25℃, turn on the CO₂ gas flow meter and set the volumetric flow rate to 3m³ / g. 3 The reaction continues at a rate of / h (under standard conditions) until the final pH value of 7 is reached. At this point, the reaction ends, the flow meter and the circulating pump are turned off, and nano-calcium carbonate is obtained.

[0056] b. Add 0.025g fumaric acid, 0.032g sodium stearate and 0.02g palmitic acid to 10mL ethanol solvent, sonicate for 15min, mix well to obtain a mixture; then add the mixture to 1.5g nano calcium carbonate, react at 65℃ for 43min, filter after the reaction, put in an oven to dry, and obtain modified cubic nano calcium carbonate.

[0057] The method for preparing the modified silk fibroin is as follows:

[0058] S1. Add 22g of octamethylcyclotetrasiloxane, 22.4g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and 1.3g of tetramethylammonium hydroxide to a reaction flask. Under nitrogen protection, stir and heat to 90℃ for 4h, then raise the temperature to 140℃ and continue the reaction for 1h. After the reaction is completed, vacuum pump is used to evacuate the vacuum and distill under reduced pressure to obtain diaminopropyl-terminated polysiloxane.

[0059] S2. Add 42 mL of silk fibroin solution and 1.5 g of diaminopropyl-terminated polysiloxane to a reaction flask, then add 0.03 g of carbodiimide. Stir at room temperature for 11 h, then pour into a dialysis bag and dialyze with distilled water on a stirrer for 3 days to obtain modified silk fibroin.

[0060] The method for preparing the mortar containing nanomaterials is as follows: cement, fly ash, polycarboxylate superplasticizer, hydroxypropyl methylcellulose, nanomaterials, and modified silk fibroin are added to a mixer and stirred for 2.5 minutes. Then water is added and stirred for 60 seconds to obtain the mortar containing nanomaterials.

[0061] Example 4

[0062] A mortar containing nanomaterials comprises the following weight components: 70 parts by weight of cement, 8 parts by weight of fly ash, 0.4 parts by weight of polycarboxylate superplasticizer, 0.4 parts by weight of hydroxypropyl methylcellulose, 1 part by weight of nanomaterials, 2 parts by weight of modified silk fibroin, and 40 parts by weight of water.

[0063] The nanomaterial comprises the following weight components: 0.5 parts by weight of modified cubic nano-calcium carbonate and 0.5 parts by weight of modified nano-silica.

[0064] The modified nano-silica is prepared as follows: 45 mL of anhydrous ethanol and 15 mL of deionized water are added to a reactor and mixed to obtain a solution. Then, 1 g of nano-silica is added to the solution and ultrasonically treated for 35 min. Next, 0.04 g of γ-aminopropyltriethoxysilane is added to the solution, and the pH of the system is adjusted to 4 with hydrochloric acid. The solution is refluxed at 45 °C for 1 h. After the reaction is completed, the solution is centrifuged, washed, and dried to obtain the modified nano-silica.

[0065] The method for preparing the modified cubic nano-calcium carbonate is as follows:

[0066] a. Place 3g of Ca(OH)₂ in a high-gravity micro-interface reactor, turn on the circulation pump and cooling device, and when the reaction temperature reaches 25℃, turn on the CO₂ gas flow meter and set the volumetric flow rate to 3m³ / g. 3(Under standard conditions) until the reaction endpoint pH=7, the reaction ends, the flow meter and circulation pump are turned off, and nano-calcium carbonate is obtained;

[0067] b. Add 0.03g fumaric acid, 0.035g sodium stearate and 0.036g palmitic acid to 10mL ethanol solvent, sonicate for 15min, mix well to obtain a mixture; then add the mixture to 1.8g nano calcium carbonate, react at 70℃ for 45min, filter after the reaction, put in an oven to dry, and obtain modified cubic nano calcium carbonate.

[0068] The method for preparing the modified silk fibroin is as follows:

[0069] S1. Add 22g of octamethylcyclotetrasiloxane, 22.4g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and 1.3g of tetramethylammonium hydroxide to a reaction flask. Under nitrogen protection, stir and heat to 90℃ for 4h, then raise the temperature to 140℃ and continue the reaction for 1h. After the reaction is completed, vacuum pump is used to evacuate the vacuum and distill under reduced pressure to obtain diaminopropyl-terminated polysiloxane.

[0070] S2. Add 42 mL of silk fibroin solution and 1.5 g of diaminopropyl-terminated polysiloxane to a reaction flask, then add 0.03 g of carbodiimide. Stir at room temperature for 11 h, then pour into a dialysis bag and dialyze with distilled water on a stirrer for 3 days to obtain modified silk fibroin.

[0071] The method for preparing the mortar containing nanomaterials is as follows: cement, fly ash, polycarboxylate superplasticizer, hydroxypropyl methylcellulose, nanomaterials, and modified silk fibroin are added to a mixer and stirred for 2.5 minutes. Then water is added and stirred for 60 seconds to obtain the mortar containing nanomaterials.

[0072] Comparative Example 1

[0073] The difference between this comparative example and Example 4 is that nano-calcium carbonate was used instead of modified cubic nano-calcium carbonate.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 4 is that nano-silica was used instead of modified nano-silica.

[0076] Comparative Example 3

[0077] The difference between this comparative example and Example 4 is that a silk fibroin solution was used instead of modified silk fibroin.

[0078] The 14-day tensile bond strength and 28-day compressive strength of the mortars in each example and comparative example were tested according to JGJ / T70-2009 "Standard for Test Methods of Basic Performance of Building Mortar". The cracking index of the mortars in each example and comparative example was tested according to JC / T951-2005 "Test Method for Crack Resistance of Cement Mortar".

[0079] Table 1: Mechanical property tests.

[0080] project 14-day tensile bond properties (MPa) 28-day compressive strength (MPa) Cracking index (mm) Example 1 0.88 47.6 165 Example 2 0.95 48.9 168 Example 3 0.87 49.1 162 Example 4 0.84 45.2 158 Comparative Example 1 0.62 41.6 183 Comparative Example 2 0.60 40.8 187 Comparative Example 3 0.64 42.3 186

[0081] As shown in Table 1, Examples 1-4 of the present invention exhibit better mechanical properties and crack resistance compared to Comparative Examples 1-3. Comparative Examples 1-3 disrupted the synergistic system of "modified nanomaterials + modified silk fibroin" in the examples. The core advantage of Example 4 is that the synergistic effect of modified nano-calcium carbonate (skeleton support), modified nano-silica (secondary reaction), and modified silk fibroin (interfacial bonding and internal stress relief) forms a complete performance system of "dense structure + strong bonding + crack-resistant buffer"; while Comparative Examples 1-3 each disrupted one of these key aspects: Comparative Example 1 weakened "skeleton support," Comparative Example 2 weakened "secondary reaction densification," and Comparative Example 3 weakened "interfacial bonding and stress relief," ultimately leading to a decline in overall performance.

[0082] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0084] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. A mortar containing nanomaterials, characterized in that, It includes the following components by weight: 70-80 parts cement, 8-12 parts fly ash, 0.4-0.5 parts polycarboxylate superplasticizer, 0.4-0.6 parts hydroxypropyl methylcellulose, 1-2 parts nanomaterials, 2-3 parts modified silk fibroin, and 40-50 parts water. The nanomaterial comprises the following weight components: 0.5-1 parts by weight of modified cubic nano-calcium carbonate and 0.5-1 parts by weight of modified nano-silica. The modified nano-silica is prepared as follows: 45 mL of anhydrous ethanol and 15 mL of deionized water are added to a reactor and mixed to obtain a solution. Then, 1-2 g of nano-silica is added to the solution and ultrasonically treated for 35-40 min. Next, 0.04-0.08 g of γ-aminopropyltriethoxysilane is added to the solution, and the pH of the system is adjusted to 4 with hydrochloric acid. The solution is refluxed at 45-50 °C for 1-2 h. After the reaction is completed, the solution is centrifuged, washed and dried to obtain modified nano-silica. The method for preparing the modified cubic nano-calcium carbonate is as follows: a. Place 2-3g of Ca(OH)₂ in a high-gravity micro-interface reactor, turn on the circulation pump and cooling device, and when the reaction temperature reaches 25℃, turn on the CO₂ gas flow meter and set the volumetric flow rate to 3m³ / g. 3 The reaction ends when the pH reaches the final value of 7. The flow meter and circulation pump are then turned off to obtain nano-calcium carbonate. b. Add fumaric acid, sodium stearate, and palmitic acid to ethanol solvent, sonicate for 10-15 min, mix well to obtain a mixture; then add the mixture to 1-1.8 g of nano calcium carbonate, react at 65-70℃, filter after the reaction is complete, and dry in an oven to obtain modified cubic nano calcium carbonate.

2. The mortar containing nanomaterials according to claim 1, characterized in that, In step b, the ratio of fumaric acid, sodium stearate, palmitic acid, and ethanol is 0.02-0.03g: 0.031-0.035g: 0.02-0.036g: 8-10mL.

3. The mortar containing nanomaterials according to claim 1, characterized in that, The reaction time in step b is 40-45 minutes.

4. The mortar containing nanomaterials according to claim 1, characterized in that, The method for preparing the modified silk fibroin is as follows: S1. Add octamethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide to a reaction flask. Under nitrogen protection, stir and heat to 85-90℃ for 3-4 hours, then raise the temperature to 135-140℃ and continue the reaction for 1-1.5 hours. After the reaction is completed, vacuum pump the mixture and distill under reduced pressure to obtain diaminopropyl-terminated polysiloxane. S2. Add 40-45 mL of silk fibroin solution and 1-2 g of diaminopropyl-terminated polysiloxane to a reaction flask, then add 0.02-0.04 g of carbodiimide. Stir at room temperature for 10-12 h, then pour into a dialysis bag and dialyze with distilled water on a stirrer for 3 days to obtain modified silk fibroin.

5. The mortar containing nanomaterials according to claim 4, characterized in that, The ratio of octamethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide in S1 is 20-24g: 19.8-24.6g: 1.31-1.36g.

6. A method for preparing mortar containing nanomaterials as described in any one of claims 1-5, characterized in that, The method for preparing the mortar containing nanomaterials is as follows: cement, fly ash, polycarboxylate superplasticizer, hydroxypropyl methylcellulose, nanomaterials, and modified silk fibroin are added to a mixer and stirred for 2-3 minutes. Then water is added and stirred for 50-60 seconds to obtain the mortar containing nanomaterials.