Environment-friendly building material regenerated by using organic waste and preparation method of environment-friendly building material

Abstract

The invention discloses an environment-friendly building material regenerated by using organic waste and a preparation method, and belongs to the field of building materials. The invention provides an environment-friendly building material regenerated by using organic waste. The environment-friendly building material is prepared from graphene-VAE coated fibers and microbubble cement paste in a mass ratio of 1: (5-9). The preparation method comprises the following steps: firstly, dispersing graphene-VAE coated fibers into microbubble cement paste, and uniformly mixing to obtain fiber-microbubble cement paste; then, the fiber-microbubble cement paste is poured, and a poured body is obtained through vibration compaction; and finally, scraping modified mortar on the surface of the pouring body when the pouring body is initially set, and hardening to obtain the environment-friendly building material regenerated by using the organic waste. The environment-friendly building material has excellent mechanical performance and sound insulation effect, and the service life of the building material can be prolonged while the light weight of the base material is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of building materials, and in particular relates to an environmentally friendly building material regenerated from organic waste and a preparation method thereof. Background Art

[0002] As global attention to environmental protection and sustainable development continues to grow, environmentally friendly building materials derived from recycled organic waste have become a key development direction in the construction industry. These materials, made from organic waste and processed through specialized processes, not only reduce waste pollution but also provide a new material for the construction industry.

[0003] Traditional organic waste-based building materials are often heavy due to limitations in raw materials and manufacturing processes. This not only increases transportation and construction costs but also limits their application scenarios. Some organic waste-based building materials suffer from slagging due to inadequate raw material processing or poorly designed formulations, reducing their service life and safety. Recycled organic waste-based building materials also have certain drawbacks in terms of sound insulation performance. Due to limitations in raw materials and structure, some recycled building materials offer suboptimal sound insulation and cannot meet the sound insulation requirements of modern architecture. Summary of the Invention

[0004] Based on the deficiencies of the prior art, the purpose of the present invention is to provide an environmentally friendly building material and a preparation method thereof by regenerating organic waste.

[0005] The first aspect of the present invention is to provide an environmentally friendly building material recycled from organic waste, comprising graphene-VAE coated fibers and micro-bubble cement slurry in a mass ratio of 1:5-9; The graphene-VAE coated fiber is prepared by the following steps: (1) Chopping the organic waste and soaking and beating it to obtain fiber pulp; (2) dispersing graphene oxide in deionized water to obtain a graphene oxide dispersion; (3) mixing the fiber slurry into the graphene dispersion liquid, adding a reducing agent and a catalyst to reduce the graphene oxide, and filtering to obtain the fiber residue; (4) Freezing and drying the fiber residue to obtain graphene-coated fibers; (5) The graphene-coated fiber is placed in a VAE (vinyl acetate-ethylene copolymer) emulsion, a silane coupling agent is added dropwise, and the fiber is dried to obtain the graphene-VAE coated fiber.

[0006] It should be noted that the hydroxyl groups on cellulose and the oxygen-containing groups on graphene oxide GO sheets can be physically adsorbed through hydrogen bonds and van der Waals forces. 2+Partial reduction and self-assembly occur under catalysis, and its sheets are directionally stacked on the fiber surface. Under freeze-drying conditions, the graphene sheets are promoted to extend along the fiber axis to form a three-dimensional through-porous network. The graphene network is coated on the fiber surface at the nanoscale, which improves the tensile strength of the fiber. In addition, the present invention cooperates with VAE film formation through silane coupling. The VAE emulsion forms an amphiphilic buffer layer on the fiber surface. The vinyl acetate segment at the hydrophilic end is more likely to anchor the cement product, and the vinyl segment at the hydrophobic end is more likely to coat the fiber to form an elastic protective film, which can buffer stress, reduce the occurrence of slag falling, and ultimately enhance mechanical strength and sound insulation performance.

[0007] In some embodiments, the organic waste is selected from at least one of waste paper, bamboo shoot shells, bamboo fiber, and corn cobs; and the mass ratio of the organic waste to graphene oxide is 18-20:1.

[0008] In some embodiments, the reducing agent is selected from at least one of ascorbic acid and L-cysteine, and the amount of the reducing agent is 50-60% of the amount of graphene oxide; the catalyst is selected from at least one of ferrous chloride, ferric chloride, and ammonium ferric citrate, and the amount of the catalyst is 20-30% of the amount of graphene oxide.

[0009] In some embodiments, in step (4), freezing is performed by placing the organic waste in liquid nitrogen at -196°C for 10-15 seconds, the drying temperature is -80 to -60°C, and the drying time is 2-3 hours; the silane coupling agent is selected from at least one of KH-550, KH-560, and KH-570, and the amount of the silane coupling agent is 2-3% of the amount of the organic waste.

[0010] In some embodiments, the microbubble cement slurry includes the following components in parts by weight: 90-110 parts of cement, 6-8 parts of nano-silica fume, 0.6-0.8 parts of water reducer, and 0.2-0.4 parts of protein foaming agent.

[0011] In some embodiments, the microbubble cement slurry is prepared by the following steps: Step 1: Mix cement, nano silica fume, water reducer and water until there are no clusters to obtain a base slurry; Step 2: Add water to the protein foaming agent to form wet foam; Step 3: Add wet foam to the base slurry to obtain micro-bubble cement slurry.

[0012] In some embodiments, the cement is selected from at least one of Portland cement and sulphoaluminate cement; in step one, the amount of water used is 35-40% of the total amount of cement and nano-silica fume; in step two, the mass ratio of the protein foaming agent to water is 1:38-42.

[0013] It should be noted that nano-silica fume in micro-bubble cement slurry is used to fill the gaps between cement particles and improve density, protein foaming agent is used to stabilize the bubble shape and enhance its elasticity, and water reducer is interspersed between protein molecules to inhibit bubble fusion and merger.

[0014] The second aspect of the present invention is to provide a method for preparing environmentally friendly building materials by regenerating organic waste, comprising the following steps: S1: dispersing graphene-VAE coated fibers into microbubble cement slurry and mixing them evenly to obtain fiber-microbubble cement slurry; S2: pouring the fiber-micro-bubble cement slurry and vibrating and compacting it to obtain a cast body; S3: When the cast body is initially set, the modified mortar is scraped on the surface of the cast body. After hardening, the environmentally friendly building material recycled from organic waste is obtained.

[0015] It should be noted that the vibration frequency and amplitude of the dense vibration in S2 should not be too large. While the vibration eliminates large bubbles, it is necessary to prevent micro bubbles from being dissipated by the vibration.

[0016] In some embodiments, in S1, the mixing method is stirring at 500-650 rpm for 1-3 min; in S2, the vibration frequency is 40-50 Hz, the vibration amplitude is 0.5-0.6 mm, and the vibration time is 20-30 s.

[0017] In some embodiments, the modified mortar is mixed with quartz sand, VAE emulsion, PVA fiber and water in a mass ratio of 1-2:0.1-0.4:0.01-0.03:1-2; the scraping thickness of the PVA modified mortar is 40-60% of the thickness of the cast body.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention creatively modifies fibers from organic waste, creating a graphene network coating that significantly enhances the mechanical properties of the fiber composite. Furthermore, this technical solution uses silane chemical bonding to firmly connect cellulose and VAE molecular chains, forming a continuous, flexible membrane layer that coats the fibers. This mechanism effectively inhibits damage to the fibers caused by cement shrinkage stress, preventing surface fiber shedding and ultimately enhancing mechanical strength and sound insulation.

[0019] 2. The cement slurry used in the present invention significantly optimizes the pore structure distribution of cement-based materials by introducing a bubble structure. The evenly distributed closed pores can absorb freeze-thaw stress. The components in the microbubble cement slurry dynamically cooperate to form bubble dispersion and interface strengthening effects, thereby achieving low density and lightweight of the base material while significantly improving the sound insulation effect of the base material.

[0020] 3. The surface of the environmentally friendly building material provided by the present invention is coated with a modified mortar. The modified mortar is a flexible mesh formed by polyvinyl alcohol (PVA) polymer that fills the mortar microcracks to improve the interface density and bonding strength. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to specific embodiments.

[0022] Example 1 An environmentally friendly building material recycled from organic waste, comprising graphene-VAE coated fibers and micro-bubble cement slurry in a mass ratio of 1:7.

[0023] The graphene-VAE coated fiber is prepared by the following steps: (1) chopping waste paper and bamboo shoot shells, soaking and beating the pieces, and obtaining fiber pulp; (2) dispersing graphene oxide in deionized water to obtain a graphene oxide dispersion; (3) Mixing the fiber pulp into the graphene dispersion, adding ascorbic acid and ferrous chloride to reduce the graphene oxide, and filtering to obtain the fiber residue; wherein the mass ratio of the organic waste to the graphene oxide is 19:1; the amount of the reducing agent is 55% of the amount of the graphene oxide, and the amount of the catalyst is 25% of the amount of the graphene oxide; (4) The fiber residue was frozen in liquid nitrogen at -196 °C for 10 s and then dried at -80 °C for 3 h to obtain graphene-coated fibers; (5) The graphene-coated fiber was placed in a VAE emulsion, KH-550 was added dropwise, and the fiber was dried to obtain the graphene-VAE coated fiber; wherein the amount of silane coupling agent used was 2.5% of the amount of organic waste.

[0024] The micro-bubble cement slurry includes the following components in parts by weight: 100 parts of cement, 7 parts of nano-silica fume, 0.7 parts of water reducer, and 0.3 parts of protein foaming agent.

[0025] The microbubble cement slurry is prepared by the following steps: Step 1: Mix Portland cement, nano silica fume, polycarboxylate water reducer and water until there are no clusters to obtain a base slurry; wherein the amount of water is 35% of the total amount of cement and nano silica fume; Step 2: Adding MCFA foaming agent to water to form wet foam; wherein the mass ratio of protein foaming agent to water is 1:40; Step 3: Add wet foam to the base slurry to obtain micro-bubble cement slurry.

[0026] The above-mentioned environmentally friendly building materials recycled from organic waste are prepared by the following steps: S1: Graphene-VAE coated fibers were dispersed into microbubble cement slurry and stirred at 550 rpm for 2 min to obtain fiber-microbubble cement slurry; S2: Cast the fiber-microbubble cement slurry and vibrate it for 25 s at a frequency of 45 Hz and an amplitude of 0.5 mm to obtain a cast body; S3: When the cast unit is initially set, a modified mortar is applied on the surface of the cast unit. After hardening, an environmentally friendly building material recycled from organic waste is obtained. The modified mortar is made by mixing quartz sand, VAE emulsion, PVA fiber and water in a mass ratio of 1:0.2:0.02:1. The applied thickness of the PVA modified mortar is 40% of the thickness of the cast unit.

[0027] Example 2 It is basically the same as Example 1, except that: The environmentally friendly building material provided in Example 2, which is recycled from organic waste, includes graphene-VAE coated fibers and microbubble cement slurry in a mass ratio of 1:5.

[0028] The above-mentioned environmentally friendly building materials are prepared by the following steps: S1: Graphene-VAE coated fibers were dispersed into microbubble cement slurry and stirred at 500 rpm for 1 min to obtain fiber-microbubble cement slurry; S2: Cast the fiber-microbubble cement slurry and vibrate it for 20 s at a frequency of 40 Hz and an amplitude of 0.5 mm to obtain a cast body; S3: When the cast unit is initially set, a modified mortar is applied on the surface of the cast unit. After hardening, an environmentally friendly building material recycled from organic waste is obtained. The modified mortar is made by mixing quartz sand, VAE emulsion, PVA fiber and water in a mass ratio of 1:0.1:0.01:1. The applied thickness of the PVA modified mortar is 40% of the thickness of the cast unit.

[0029] Example 3 It is basically the same as Example 1, except that: The environmentally friendly building material provided in Example 3, which is recycled from organic waste, includes graphene-VAE coated fibers and microbubble cement slurry in a mass ratio of 1:9.

[0030] The above-mentioned environmentally friendly building materials are prepared by the following steps: S1: Graphene-VAE coated fibers were dispersed into microbubble cement slurry and stirred at 650 rpm for 3 min to obtain fiber-microbubble cement slurry; S2: Cast the fiber-microbubble cement slurry and vibrate it for 30 s at a frequency of 50 Hz and an amplitude of 0.6 mm to obtain a cast body; S3: When the cast unit is initially set, a modified mortar is applied on the surface of the cast unit. After hardening, an environmentally friendly building material recycled from organic waste is obtained. The modified mortar is made by mixing quartz sand, VAE emulsion, PVA fiber and water in a mass ratio of 2:0.4:0.03:2. The applied thickness of the PVA modified mortar is 60% of the thickness of the cast unit.

[0031] Example 4 It is basically the same as Example 1, except that: The graphene-VAE coated fiber provided in this Example 4 was prepared by the following steps: (1) chopping bamboo fiber and corn cobs, soaking and beating the fibers to obtain fiber pulp; (2) dispersing graphene oxide in deionized water to obtain a graphene oxide dispersion; (3) Mixing the fiber pulp into the graphene dispersion, adding L-cysteine ​​and ferric chloride to reduce the graphene oxide, and filtering to obtain the fiber residue; wherein the mass ratio of the organic waste to the graphene oxide is 18:1; the amount of the reducing agent is 50% of the amount of the graphene oxide, and the amount of the catalyst is 20% of the amount of the graphene oxide; (4) The fiber residue was frozen in liquid nitrogen at -196 °C for 10 s and then dried at -80 °C for 2 h to obtain graphene-coated fibers; (5) The graphene-coated fiber was placed in a VAE emulsion, KH-560 was added dropwise, and the fiber was dried to obtain the graphene-VAE coated fiber; wherein the amount of silane coupling agent used was 2% of the amount of organic waste.

[0032] The microbubble cement slurry provided in this Example 4 includes the following components in parts by weight: 90 parts of cement, 6 parts of nano-silica fume, 0.6 parts of water reducer, and 0.2 parts of protein foaming agent.

[0033] The microbubble cement slurry is prepared by the following steps: Step 1: Mix sulphoaluminate cement, nano silica fume, polycarboxylate water reducer and water until there are no clusters to obtain a base slurry; wherein the amount of water is 35% of the total amount of cement and nano silica fume; Step 2: Adding MCFA foaming agent to water to form wet foam; wherein the mass ratio of protein foaming agent to water is 1:38; Step 3: Add wet foam to the base slurry to obtain micro-bubble cement slurry.

[0034] Example 5 It is basically the same as Example 1, except that: The graphene-VAE coated fiber provided in this Example 5 was prepared by the following steps: (1) chopping waste paper, bamboo shoot shells, bamboo fibers and corn cobs, soaking and beating the pieces to obtain fiber pulp; (2) dispersing graphene oxide in deionized water to obtain a graphene oxide dispersion; and mixing the mixture evenly to obtain a graphene reaction solution; (3) Mixing the fiber pulp into the graphene dispersion, adding ascorbic acid and catalyst ammonium ferric citrate to reduce the graphene oxide, and filtering to obtain the fiber residue; wherein the mass ratio of organic waste to graphene oxide is 20:1; the amount of reducing agent is 60% of the amount of graphene oxide, and the amount of catalyst is 30% of the amount of graphene oxide; (4) The fiber residue was frozen in liquid nitrogen at -196 °C for 15 s and then dried at -60 °C for 3 h to obtain graphene-coated fibers; (5) The graphene-coated fiber was placed in a VAE emulsion, KH-570 was added dropwise, and the fiber was dried to obtain the graphene-VAE coated fiber; wherein the amount of silane coupling agent used was 3% of the amount of organic waste.

[0035] The microbubble cement slurry provided in this Example 5 includes the following components in parts by weight: 110 parts of cement, 8 parts of nano-silica fume, 0.8 parts of water reducer, and 0.4 parts of protein foaming agent.

[0036] The microbubble cement slurry is prepared by the following steps: Step 1: Mix sulphoaluminate cement, nano silica fume, polycarboxylate water reducer and water until there are no clusters to obtain a base slurry; wherein the amount of water is 40% of the total amount of cement and nano silica fume; Step 2: Adding MCFA foaming agent to water to form wet foam; wherein the mass ratio of protein foaming agent to water is 1:42; Step 3: Add wet foam to the base slurry to obtain micro-bubble cement slurry.

[0037] Comparative Example 1 It is basically the same as Example 1, except that: In the preparation process of graphene-VAE coated fibers, steps (2), (3), and (4) are omitted, that is, the fibers are not coated with graphene but only with VAE.

[0038] Comparative Example 2 It is basically the same as Example 1, except that: Step (5) is omitted in the preparation process of graphene-VAE coated fibers, that is, the fibers are not coated with VAE but only with graphene.

[0039] Comparative Example 3 It is basically the same as Example 1, with the only difference being: No micro-bubble cement slurry was added, and the same amount of Portland cement was used instead.

[0040] To demonstrate the excellent mechanical properties and lightweight nature of the environmentally friendly building materials recycled from organic waste provided by the present invention, performance tests were conducted on the environmentally friendly building materials prepared in Examples 1-5 and Comparative Examples 1-3. Dry density was determined according to GB / T 5486-2008, compressive strength was determined according to GB / T 2542-2012, and sound insulation improvement (100 mm thickness, 125 Hz) was determined according to GB / T 19889.3. The test results are summarized in Table 1.

[0041] Table 1 It can be seen from Table 1 that Examples 1-5 provided by the present invention have good mechanical properties, low dry density and excellent sound insulation effect. Combined with the comparative examples, it can be seen that comparative example 1 omits the graphene coating and comparative example 2 omits the VAE coating, resulting in a decrease in the mechanical strength and sound insulation performance of the environmentally friendly building materials. Comparative example 3 does not adopt microbubble cement slurry, which greatly reduces the lightweight and sound insulation effect of the environmentally friendly building materials.

[0042] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. An environmentally friendly building material recycled from organic waste, characterized in that: The method comprises graphene-VAE coated fibers and micro-bubble cement slurry in a mass ratio of 1:5-9; The graphene-VAE coated fiber is prepared by the following steps: Chopping the organic waste and then soaking and beating it to obtain fiber pulp; dispersing graphene oxide in deionized water to obtain a graphene oxide dispersion; The fiber pulp is mixed into the graphene dispersion, and a reducing agent and a catalyst are added to reduce the graphene oxide, and the fiber residue is obtained by filtering; Freezing and drying the fiber residue to obtain graphene-coated fibers; The graphene-VAE coated fiber is placed in a VAE emulsion, a silane coupling agent is added dropwise, and the mixture is dried to obtain the graphene-VAE coated fiber.

2. The environmentally friendly building material recycled from organic waste according to claim 1, characterized in that: The organic waste is selected from at least one of waste paper, bamboo shoot shells, bamboo fibers, and corn cobs; and the mass ratio of the organic waste to the graphene oxide is 18-20:

1.

3. The environmentally friendly building material recycled from organic waste according to claim 1, characterized in that: The reducing agent is selected from at least one of ascorbic acid and L-cysteine, and the amount of the reducing agent is 50-60% of the amount of the graphene oxide; the catalyst is selected from at least one of ferrous chloride, ferric chloride, and ammonium ferric citrate, and the amount of the catalyst is 20-30% of the amount of the graphene oxide.

4. The environmentally friendly building material recycled from organic waste according to claim 1, characterized in that: In the step (4), freezing is performed by placing the organic waste in liquid nitrogen at -196°C for 10-15 seconds, the drying temperature is -80 to -60°C, and the drying time is 2-3 hours; the silane coupling agent is selected from at least one of KH-550, KH-560, and KH-570, and the amount of the silane coupling agent used is 2-3% of the amount of the organic waste.

5. The environmentally friendly building material recycled from organic waste according to claim 1, characterized in that: The micro-bubble cement slurry comprises the following components in parts by weight: 90-110 parts of cement, 6-8 parts of nano-silica fume, 0.6-0.8 parts of water reducing agent, and 0.2-0.4 parts of protein foaming agent.

6. The environmentally friendly building material recycled from organic waste according to claim 5, characterized in that: The microbubble cement slurry is prepared by the following steps: Step 1: Mixing the cement, the nano silica fume, the water reducer and water until no clusters are formed to obtain a base slurry; Step 2: adding water to the protein foaming agent to form wet foam; Step 3: adding the wet foam to the base slurry to obtain the microbubble cement slurry.

7. The environmentally friendly building material recycled from organic waste according to claim 6, characterized in that: The cement is selected from at least one of silicate cement and sulphoaluminate cement; in the step 1, the amount of water used is 35-40% of the total amount of cement and nano-silica fume; in the step 2, the mass ratio of protein foaming agent to water is 1:38-42.

8. A method for preparing environmentally friendly building materials regenerated from organic waste according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: dispersing the graphene-VAE coated fibers into the microbubble cement slurry and mixing them uniformly to obtain a fiber-microbubble cement slurry; S2: pouring the fiber-microbubble cement slurry and vibrating and compacting it to obtain a cast body; S3: When the cast body is initially set, the modified mortar is scraped on the surface of the cast body, and after hardening, the environmentally friendly building material recycled from organic waste is obtained.

9. The method for preparing environmentally friendly building materials by regenerating organic waste according to claim 8, characterized in that: In the S1, the mixing method is stirring at 500-650 rpm for 1-3 min; in the S2, the vibration frequency is 40-50 Hz, the vibration amplitude is 0.5-0.6 mm, and the vibration time is 20-30 s.

10. The method for preparing environmentally friendly building materials by regenerating organic waste according to claim 8, characterized in that: The modified mortar is prepared by mixing quartz sand, VAE emulsion, PVA fiber and water in a mass ratio of 1-2:0.1-0.4:0.01-0.03:1-2; the scraping thickness of the PVA modified mortar is 40-60% of the thickness of the cast body.

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