Compact mycelium-based high-efficiency durable sound insulation composite material and rapid preparation method thereof

Abstract

The invention discloses a compact mycelium-based high-efficiency durable sound insulation composite material and a rapid preparation method thereof, and relates to the field of biological building materials.The method comprises the steps that straw powder, corncob powder, wood chip powder, bran powder, soybean meal and an alkaline mixed additive are mixed to be uniform, aerogel particles, graphene nanosheets and water are added and stirred, and a mixture is obtained; a culture medium is formed, oyster mushroom strains or ganoderma fungus strains are evenly inoculated on the culture medium at the same time in a multi-point injection mode, the injection depth is the same, then the temperature is controlled to be 30-35 DEG C, the humidity is controlled to be 65%-75%, heating is conducted in a microwave heating mode under the ventilation condition, and after mycelia completely cover the culture medium, a culture system is obtained; the culture system is subjected to compression molding under the pressure of 2-5 Mpa, then vacuum drying is performed, the total water content is controlled to be 4% or below, the compact mycelium-based efficient and durable sound insulation composite material is obtained, the production efficiency and the material performance are improved, and no chemical pollution exists.

Description

Technical Field

[0001] The invention relates to the field of biological building materials, and in particular to a dense mycelium-based high-efficiency and durable sound-insulating composite material and a rapid preparation method thereof. Background Art

[0002] Traditional sound insulation materials are mainly made of synthetic or mineral-based materials, which are not easy to recycle and the production process will burden the environment. Therefore, finding environmentally friendly and sustainable alternatives to sound insulation materials has become a difficult problem that needs to be overcome.

[0003] Mycelium is the nutrient part of fungi. Mycelium is composed of many slender, tubular mycelial cells connected to each other. These cells are usually colorless, have transverse septa, and usually contain nuclei. Mycelium is widely present in soil and organic matter, and has an important impact on ecosystems and human life. Mycelium is interwoven to form a mesh-like structure of mycelium. Mycelium is flexible and durable. After treatment, the mycelial network has an insulating effect, elastic, safe, and strong characteristics. It can be moisture-proof, waterproof, flame-retardant, and support a lot of pressure. It can also insulate and soundproof, and can be used as a sustainable plastic substitute. Sound insulation materials made of mycelium can be made entirely of renewable and biodegradable ingredients, which meets environmental protection requirements. The open cell wall and porous structure of mycelium constitute an ideal sound insulation system with high sound absorption efficiency. Using mycelium as a raw material helps save resources. Therefore, mycelium-based composite sound insulation materials provide the possibility of renewable and degradable replacement of sound insulation materials.

[0004] The common method of using mycelium to prepare sound insulation materials mainly includes the following steps: (1) culture medium preparation, that is, using crop residues (such as sawdust, corn husks, straw, etc.) as the nutrient base of mycelium, crushing them and mixing them with water to form a culture medium; (2) inoculating fungi: inoculating fungal spores into the culture medium; (3) controlling environmental conditions: controlling the carbon dioxide, humidity, temperature and other conditions of the culture medium to allow the mycelium to grow in the culture medium; (4) cultivation and molding: after the mycelium grows to completely cover the culture medium, it is placed in a mold, dried and shaped to obtain the finished mycelium material. The mycelium growth rate of this method is slow, resulting in a long material preparation cycle, and the environmental conditions need to be precisely controlled, with high energy consumption and high cost; chemical adhesives are required for certain specific raw materials, which will cause a certain degree of environmental pollution. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a dense mycelium-based high-efficiency and durable sound-insulating composite material and a rapid preparation method thereof, which solves the problems of slow mycelium growth, the need for precise control of environmental conditions, high energy consumption, high cost and environmental pollution, and obtains a dense, high-efficiency and durable sound-insulating composite material, improves production efficiency and material properties, and has no chemical pollution.

[0006] The present invention is achieved through the following technical solutions: A method for rapidly preparing a dense mycelium-based high-efficiency and durable sound-insulating composite material comprises the following steps: S1, mixing straw powder, corn cob powder, sawdust powder, bran powder, soybean meal powder and alkaline mixed additives, wherein the mass ratio of corn cob powder to sawdust powder is (12-16): (15-30), and then adding aerogel particles, graphene nanosheets and water and stirring to form a culture medium; S2, inoculating Pleurotus ostreatus strains or Ganoderma lucidum strains simultaneously and evenly on the culture medium by multi-point injection, with the same injection depth, and then controlling the temperature to 30-35° C. and the humidity to 65%-75% under ventilation conditions, heating by microwave heating, and obtaining a culture system after the mycelium completely covers the culture medium; S3, pressing the culture system into shape at a pressure of 2-5 MPa, and then vacuum drying it, and controlling the total moisture content below 4%, to obtain a dense mycelium-based high-efficiency and durable sound insulation composite material.

[0007] A further improvement of the present invention is: The mass ratio of the straw powder, bran powder, soybean meal powder and sawdust powder in S1 is (40-55): (8-12): (2.5-3.5): (15-30).

[0008] The alkaline mixed additive described in S1 is composed of sodium bicarbonate and calcium carbonate in a molar ratio of 1:2, and the mass ratio of the alkaline mixed additive to the sawdust powder is (3-4): (15-30).

[0009] The aerogel particles and graphene nanosheets described in S1 account for 5%-10% and 15%-30% of the total mass of straw powder, corn cob powder, sawdust powder, bran powder, soybean meal powder and alkaline mixed additives respectively.

[0010] The particle size of the aerogel particles is 5-10 mm, the thickness of the graphene nanosheets is 1-3 nm, and the sheet diameter is 3-10 mm.

[0011] S2 used a multi-channel microinjector for multi-point injection, with an injection volume of 0.1 mL at each injection point, a syringe spacing of 2 cm, and an injection depth of half the thickness of the culture medium.

[0012] The processes described in S1 and S2 are carried out in a sterile reactor, wherein a microwave heating system and a water tray are arranged at the bottom of the reactor from top to bottom, and an array of through holes are evenly opened at the bottom of the reactor, and water is placed in the water tray. When the microwave heating system is working, the water in the water tray is evaporated to replenish the humidity of the culture medium.

[0013] The microwave heating system has a pulsed microwave output, a frequency of 2400-2500 MHz, a power of 500-1000 W, and each working time is 10-20 minutes, and then stops for 25-35 minutes before the next working cycle.

[0014] S2 is inoculated with Pleurotus ostreatus or Ganoderma lucidum fungi and stirred for 4-6 minutes every 5-7 hours within 48 hours.

[0015] A dense mycelium-based high-efficiency, durable sound-insulating composite material obtained by the rapid preparation method of the dense mycelium-based high-efficiency, durable sound-insulating composite material described in any one of the above.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The invention provides a method for rapidly preparing a dense mycelium-based high-efficiency and durable sound-insulating composite material. The culture medium is inoculated with Pleurotus ostreatus strains or Ganoderma lucidum strains at the same time and evenly by multi-point injection, and the injection depth is the same, so that the strains can be evenly distributed. The culture medium can be quickly and evenly heated by controlling the appropriate temperature and humidity and then microwave heating, so as to shorten the growth time of the mycelium and further promote the growth of the mycelium. The straw, corn cobs and sawdust provide the main solid matrix and nutrition for the mycelium growth, and cellulose and hemicellulose are the carbon sources after the mycelium secretes enzyme degradation. The extracellular enzymes (such as cellulase and xylanase) secreted by the mycelium degrade the fiber tissues of the straw, corn cobs and sawdust and convert them into absorbable sugars. As the mycelium grows, these materials become the supporting skeleton of the mycelium mesh structure and are intertwined with the mycelium to form a dense structure. Bran and soybean meal provide the nitrogen source, vitamins and other nutrients required for the mycelium growth, improve the nutritional balance of the culture medium, and accelerate the expansion of the mycelium. In the early stage of cultivation, the protein in bran and soybean meal is decomposed into amino acids and small molecule peptides by proteases secreted by hyphae for absorption by hyphae. The supply of nutrients promotes the rapid proliferation of mycelium and enhances the density of mycelium network. Aerogel particles provide evenly distributed microporous structures, which can effectively absorb and scatter sound waves, enhance the air permeability and water retention of the culture medium, and improve the sound insulation performance and mechanical strength of the final material. Aerogel particles are evenly distributed in the culture medium and intertwine with the network of mycelium growth. The porous structure provides attachment points for mycelium growth and absorbs water and nutrients in the culture medium to form a stable mycelium composite structure. Graphene nanosheets enhance the mechanical strength, durability and thermal conductivity of the material and improve the impact resistance of the composite material. The high surface area of ​​graphene nanosheets provides a large number of attachment sites on which mycelium can be distributed and entangled with each other. The two-dimensional sheet structure of graphene is cross-linked with the filamentous network of mycelium, increasing the density and uniformity of the composite material, and ultimately making the sound insulation effect more durable and efficient. During the process of medium preparation and mycelium growth, these components are gradually integrated into a complex composite material: Initial stage: solid matrix (straw, corn cobs, sawdust) serves as the skeleton of mycelium, providing structural support, and nutrients (bran, soybean meal) are rapidly decomposed, prompting mycelium to quickly attach and expand on the surface of the solid matrix; Mycelium growth stage: mycelium expands on the surface of the matrix, while gradually penetrating into the pores of the material, forming a network mosaic with aerogel particles and graphene nanosheets, and the extracellular enzymes of mycelium further decompose part of the matrix, enhancing its physical strength and biological binding. Final molding stage: mycelium completely covers the culture medium, and through winding, mosaic and cross-linking, a highly dense composite structure is formed. After drying and pressing, the mycelium is combined with each component into a uniform and stable material.Mycelium is the core skeleton that connects and integrates all the components. Straw, corn cobs, and wood chips serve as supporting matrices; bran and soybean meal provide nutrition, aerogel particles and graphene nanosheets enhance functionality (sound insulation, strength, thermal conductivity). The interaction between biology and physics forms a unified composite structure, which is finally pressed and formed with appropriate pressure. Vacuum drying can make the internal structure of the material uniform, and the total moisture content is controlled to obtain a dense mycelium-based, efficient, and durable sound insulation composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1a It is a front view of the mycelium growth container structure of the present invention.

[0018] Figure 1b It is a left view of the mycelium growth container structure of the present invention.

[0019] Figure 1c This is a top view of the internal structure of the mycelium growth container structure of the present invention.

[0020] Figure 1d This is a top view of the external structure of the mycelium growth container structure of the present invention.

[0021] Figure 2a This is an optical microscope image of the mycelium material in Example 1 of the present invention.

[0022] Figure 2b This is an electron microscope image of the mycelium material in Example 1 of the present invention.

[0023] Figure 3a This is an optical microscope image of the mycelium material cultured in Comparative Example 1.

[0024] Figure 3b This is an electron microscope photo of the cultured mycelium material of Comparative Example 1.

[0025] Figure 4 Comparison of mycelial biomass of different fungal strains cultured in Example 1 of the present invention and by traditional methods.

[0026] In the figure: 1- agitator; 2- temperature display; 3- humidity display; 4- temperature and humidity controller; 5- temperature and humidity detection probe; 6- bayonet; 7- stirring paddle; 8- vent; 9- microwave heating system; 10- humidity control system; 11- motor; 12- top cover; 13- injection hole. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0028] The present invention provides a method for rapidly preparing a dense mycelium-based high-efficiency and durable sound-insulating composite material, and the preparation steps are as follows: (1) Preparation of culture medium: In percentage by mass, straw powder (40-55%), corn cob powder (12-16%), sawdust powder (15-30%), bran powder (8-12%), soybean meal powder (2.5-3.5%) and alkaline mixed additive (3-4%, sodium bicarbonate and calcium carbonate in a molar ratio of 1:2) are uniformly mixed to obtain a mixture, and 5-10% of the mass of the mixture and 5-10 mm aerogel particles, 1-3% of the mass of the mixture and graphene nanosheets, as well as water are added and stirred to form a culture medium; (2) Inoculation strains and environmental control: The oyster mushroom species or the genus Ganoderma fungus species are inoculated simultaneously and evenly on the culture medium by multi-point injection. The injection depth is the same. A matrix-type multi-channel microinjector is used for multi-point injection. The injection volume at each injection point is 0.1 mL. The distance between the syringes is 2 cm, which is conducive to the rapid and uniform development of the mycelium material. The injection depth is half of the culture medium thickness. After the injection is completed, the injection port is closed to ensure that the species are evenly distributed. Within 48 hours of inoculation of the oyster mushroom species or the genus Ganoderma fungus species, stir for 4-6 minutes every 5-7 hours, and then no longer stir; Then, the temperature is controlled at 30-35°C and the humidity is controlled at 65%-75% under ventilation conditions, and microwave heating is used to heat the culture medium until the mycelium completely covers the culture medium to obtain a culture system; (3) Drying and shaping: The culture system is pressed into shape at a pressure of 2-5 Mpa, and then vacuum dried, with the total moisture content controlled below 4%, to obtain a dense mycelium-based, efficient, and durable sound-insulating composite material.

[0029] The present invention designs a container for mycelium growth, and the specific design scheme is as follows: Reactor type: Fermenter or incubator to ensure a sterile environment.

[0030] Material selection: The reactor should be made of non-toxic, corrosion-resistant and high-temperature resistant materials, such as stainless steel or high-density polyethylene.

[0031] Capacity and shape: Choose the appropriate capacity according to the production scale, generally ranging from 10L to 500L. The shape is a rectangular parallelepiped to facilitate the uniform growth of mycelium.

[0032] like Figure 1a and Figure 1cAs shown, the low-speed stirrer 1 is connected to the motor 11 to prevent precipitation, the temperature display 2 is connected to the temperature and humidity controller 4, the humidity display 3 is connected to the temperature and humidity controller 4, the input ends of the temperature display 2 and the humidity display 3 are connected to the temperature and humidity detection probe 5, and the temperature and humidity detection probe 5 is in contact with the culture medium; the temperature and humidity controller 4 is connected to the power supply of the microwave heating system; the bottom of the reactor is arranged with a microwave heating system 9 and a humidity control system 10 from top to bottom, the humidity control system 10 is placed in a water tray above the microwave heating system to add water thereto, and is designed to be pull-out type, the bottom of the reactor is evenly provided with array-type through holes, the distance between the bottom of the microwave heating system 9 and the top of the reactor is 12 cm (the thickness of the prepared culture medium is 10 cm), in this embodiment, the interior of the reactor is 50 cm long, the reactor is 22 cm wide, and the wall thickness in the length direction is 2 cm, and the upper surface of the reactor is provided with two bayonet ports 6 connected to the outside world, the bayonet ports 6 are long strips, symmetrically distributed on both sides of the center line of the reactor in the width direction, and the top cover 12 is inserted in the bayonet port 6, so that the top cover 12 can be slid open, as shown in FIG. Figure 1d As shown, the top cover 12 is provided with injection holes 13 in an array with a spacing of 2 cm, and a matrix of multi-channel micro-injectors is provided on the top for uniform injection of the bacterial liquid. The distance between the outer ends of the top cover 12 in the width and length directions and the outer edge of the reactor is 2 cm. Figure 1b In the figure, the stirring blade 7 is a stirring blade of the stirrer, and a filter screen is embedded in the vent 8.

[0033] Ventilation system: Equipped with high-efficiency filtered vents to ensure the supply of fresh air while avoiding contamination by bacteria.

[0034] Temperature control system: Built-in precise temperature control system ensures that the internal temperature of the reactor is constant within the set range (30-35°C).

[0035] Humidity Control: Built-in humidity control system maintains internal humidity at 65-75%.

[0036] Based on this, the process of preparing the culture medium is as follows: Open the top cover 12 of the reactor, and fill the pre-mixed and evenly shredded straw, corn cobs, sawdust, bran and soybean meal, and alkaline mixed additives into the reactor in percentage by mass, cover the top cover 12 to obtain a mixture, add 5-10 mm aerogel particles (5-10% of the mass of the mixture) and graphene nanosheets (1-3% of the mass of the mixture), and finally add water to maintain a certain humidity, and stir with the stirring paddle 7 in the stirrer 1. Sodium bicarbonate will release carbonate ions and hydroxide ions in the aqueous solution, providing a weak alkaline environment, but its action time is relatively short. Calcium carbonate, due to its low solubility, can stably release alkaline ions for a long time, playing a long-term buffering role. The two can work together to provide a relatively stable pH buffering environment, which can enhance long-term pH stability, have a slow reaction, can slowly release alkalinity, stabilize pH, and are suitable for long-term culture. Calcium carbonate provides calcium elements and can also enhance the strength of the mycelium skeleton to form a culture medium; The specific process of temperature and humidity control is: 1) Initialization and setting target value The user sets the target temperature (eg, 30-35°C) and humidity (eg, 65-75%) on the control panel of the temperature and humidity controller.

[0037] After the system starts, it automatically detects the current environmental parameters.

[0038] 2) Temperature and humidity control logic Real-time monitoring: The temperature and humidity detection probe collects data at regular intervals (such as 30 minutes) and sends the data to the controller.

[0039] Logical reasoning: If the actual temperature is lower than the target temperature, the controller (using the PID (proportional-integral-differential) algorithm) turns on the microwave heating system according to the feedback signal from the temperature and humidity detection probe to heat at the set power (e.g., 200W, low-power microwave).

[0040] If the actual temperature is close to the target temperature (such as the target temperature ± 0.5°C), the controller adjusts the microwave power through PWM (pulse width modulation) technology to maintain temperature stability.

[0041] If the actual temperature exceeds the target temperature, the microwave heating is turned off and the cooling device is activated.

[0042] 3) Humidity control logic Real-time humidity monitoring: If the humidity is lower than the set range, the controller (using the PID (proportional-integral-differential) algorithm) starts the humidity control system (which can be an ultrasonic humidifier or a spray device) based on the feedback signal from the temperature and humidity detection probe.

[0043] If the humidity is too high, increase ventilation appropriately or use desiccant to control it.

[0044] Microwave heating directly acts on the water molecules in the culture medium and the mycelium, with fast heating and high efficiency.

[0045] The stirrer can make the culture medium heated more evenly and avoid local overheating or unevenness.

[0046] Temperature control and humidity coordination Since microwave heating will reduce humidity (through water evaporation), the system needs to perform humidity compensation synchronously (by adding a water tray design above the microwave heating system, which can both replenish humidity and prevent the mycelium from being damaged by rising temperature too quickly) to maintain the stability of the culture environment.

[0047] Aerogels can be silica aerogels and organic aerogels. Silica aerogels are resistant to high temperatures, have stable chemical properties, high porosity, and excellent sound insulation and heat insulation properties. They are used as the main component of sound insulation materials, provide nano-scale porous structures, absorb sound waves, and enhance sound insulation effects. Organic aerogels can be polyurethane aerogels and polystyrene aerogels, which have good flexibility and are suitable for composite material applications. They have lower density and high toughness, can improve the mechanical properties of materials, and improve the flexibility and impact resistance of materials. They are not easy to affect the mycelium growth environment in the culture medium.

[0048] The ratio of sawdust and corncobs improves the mechanical strength and sound insulation of the material. Sawdust and corncobs form a denser structure in the mycelium, which can effectively block the propagation of sound.

[0049] Aerogel particles have a particle diameter between 5 and 10 microns, which can maintain the lightweight characteristics of the material while enhancing the sound insulation effect. Aerogel particles have a high specific surface area and a nano-scale porous structure, which can form evenly distributed micropores in the culture medium. These micropores can effectively absorb and scatter sound waves, thereby significantly improving the sound insulation performance of the material. The microporous structure can also increase the internal surface area of ​​the material, which helps to improve the overall stability and mechanical strength of the material. Through the uniform distribution of aerogel particles, the sound insulation effect of the material is more uniform and stable. Aerogel particles have an extremely low density, and adding them to the culture medium will not significantly increase the weight of the material, which is conducive to the preparation of lightweight and efficient sound insulation materials. The Silica Aerogel series of aerogels provided by Cabot Corporation have particle sizes and porosities suitable for a variety of applications such as sound insulation and heat insulation. Aspen Aerogels provides aerogel products for industrial insulation, and the particle size can be customized. Blueshift's aerogel products have a high specific surface area and low density, which are suitable for use as lightweight sound insulation materials.

[0050] The thickness of the graphene nanosheet is 1-3 nanometers. The diameter of the sheet is 3-10 micrometers. This size can effectively enhance the mechanical strength, electrical conductivity and thermal conductivity of the material without affecting the uniformity of the culture medium. The high elastic modulus and strength of the graphene nanosheet make the final molded material have higher durability and impact resistance. The uniform distribution of graphene nanosheets in the culture medium helps to further enhance the structural uniformity of the material and avoid stress concentration inside the material.

[0051] When the environment is controlled: Start the temperature control system and humidity control system, control the temperature (30-35℃), humidity (65-75%), open the vents, ensure ventilation conditions, ensure air circulation, and create the best environment for mycelium growth. Use a high-efficiency microwave heating system, start the microwave heating plate, pulse microwave output, microwave heating frequency of 2450 MHz, power of 500-1000W, each working time is 10-20 minutes, then stop for 25-35 minutes, and then proceed to the next working cycle, which can quickly and evenly heat the culture medium, shorten the growth time of mycelium, and further promote mycelium growth; Continuously monitor temperature, humidity and air circulation, and check the mycelium growth every 6-8 hours to ensure uniform growth and no contamination from foreign bacteria.

[0052] When the reactor is transparent, it is easy to directly observe the growth of mycelium. Use visual inspection to check the degree of mycelium covering the culture medium and observe whether it is evenly distributed. Use a magnifying glass or portable microscope to check whether the structure of the mycelium is intact and whether there are abnormal areas (such as uncovered areas or areas with dense growth).

[0053] Use a high-definition camera or mobile phone to take photos of the mycelium inside the culture container to record the growth progress. Take photos from the same angle at regular intervals to facilitate comparative analysis of whether the mycelium expansion is uniform.

[0054] Use image processing software (such as CellProfiler or Fiji) to quantify the coverage area and density of mycelium and determine whether the growth is uniform. CellProfiler is designed for biological research and is suitable for automatic image analysis of cells, microorganisms and mycelium. It supports batch processing of images and can measure mycelium coverage area, number of branches, density, etc. Fiji (an advanced version of ImageJ) integrates many plug-ins suitable for analyzing mycelium extension, density, coverage, etc. For example, the SimpleNeurite Tracer plug-in is very suitable for tracking and analyzing mycelial structures.

[0055] Observe the surface of the culture medium to see if there are colonies of different colors or textures (such as green or black spots of mold). If the culture environment has an odor (such as sour or musty), it is sometimes a sign of contamination by foreign bacteria.

[0056] Measures to prevent contamination by foreign bacteria include ensuring the cleanliness of the culture environment, containers, and tools. Use 75% alcohol or hypochlorous acid to disinfect the surface of the incubator and gloves. Use a high-efficiency filter (HEPA) to purify the air in the incubator to prevent foreign bacteria from entering with the airflow. Ensure that the lid of the culture medium container is tightly sealed and only opened briefly when necessary.

[0057] Drying and styling: After the mycelium completely covers the culture medium, the top cover 12 is opened, the basically formed mycelium is taken out, placed in a plate mold, and pressed into shape by applying appropriate pressure (2-5 MPa), followed by vacuum drying, and the material is dried for 6-8 hours at a low temperature (40-50°C) and low pressure (20-50 kPa) environment, and the total moisture content is controlled below 4% to obtain a finished product.

[0058] By increasing the proportion of sawdust and corncobs and adding aerogel particles and graphene nanosheets, the mechanical strength and sound insulation of the material were improved. Microwave heating was used to quickly increase the temperature of the culture medium, shorten the mycelium growth cycle, and improve production efficiency. Finally, the material was vacuum dried under low temperature and low pressure to make the internal structure of the material uniform and improve the material performance.

[0059] Embodiment 1: A method for preparing a mycelium-based composite sound insulation material, the specific steps are as follows: Preparation and proportion of culture medium: The culture medium is prepared by finely crushing and mixing straw (45%), corn cobs (15%), sawdust (15%), bran (10%), alkaline mixed additives (3%) and soybean meal (3%). Aerogel particles (8%) and graphene nanosheets (1%) are then added, which are evenly distributed to form a uniform microporous structure. This structure enhances the absorption and scattering of sound, significantly improving the sound insulation performance, while also improving the mechanical strength of the final material.

[0060] Vaccination process: Select high-quality (white, cotton-like, thick and dense, evenly distributed, without variegated mycelium) oyster mushroom mycelium to inoculate the culture medium, culture it in a sterile environment for 72 hours to obtain the expanded mycelium, and gently scrape the mycelium on the surface of the solid culture medium with a sterile tool (such as tweezers or a scraper). Suspend the mycelium in a sterile liquid (such as sterile water or buffer) and disperse it evenly, such as 0.5g per milliliter of mycelium wet weight concentration. The prepared mycelium suspension is dispensed into a multichannel micro-syringe by aseptic operation. Use an inoculation device with a multi-channel micro-syringe, the number of which matches the number of inoculation holes in the culture vessel. Place the culture vessel under the inoculation device to ensure that the inoculation holes are aligned with the needle. Adjust the injection volume of the inoculation device (1mL per hole). Start the syringe, and the mycelium suspension is synchronously injected into the culture medium through the multi-channel micro-syringe. After inoculation, cover the top of the culture container with a sterile breathable membrane to avoid contamination by foreign bacteria while allowing moderate air exchange.

[0061] Culture environment control and mycelium growth: Immediately after inoculation, the temperature (30-35°C) and humidity (65-75%) control systems are activated to maintain optimal growth conditions for mycelium. The temperature and humidity detection probe collects data every 30 minutes and feeds back to the temperature and humidity controller to adjust the microwave heating system action time. While microwave heating, the moisture in the water pan above is accelerated to diffuse and increase humidity.

[0062] The frequency of the microwave heating system is 2450MHz, the power is 1000W, and the microwave output is pulsed. The microwave action time is 10 seconds each time, and the rest time is 30 seconds. This prevents the microwave from causing heat stress to the mycelium, quickly and evenly increases the temperature of the culture medium, and shortens the mycelium growth cycle. The vent (with a filter embedded) ensures that the culture medium is adequately supplied with oxygen and prevents contamination by foreign bacteria. Within 48 hours after inoculation, the incubator is equipped with a stirrer for 5 minutes every 6 hours to ensure the efficiency of oxygen diffusion. No stirring operation is performed after 48 hours.

[0063] Monitoring and maintenance: Check hyphae growth every 6-8 hours, take some samples for microscopic observation to see if the growth is uniform, and record and analyze the hyphae coverage progress.

[0064] Pressing and drying: When the mycelium completely covers the culture medium, the material is transferred to a mold and pressure (3.5 MPa) is applied under controlled conditions. Subsequently, vacuum drying is carried out at low temperature (45°C) and low pressure (30 kPa) for 6 hours to ensure that the moisture content of the material is reduced to 3%. This process preserves the integrity of the microporous structure and optimizes the acoustic and mechanical properties of the material.

[0065] Comparative Example 1: The remaining methods and steps are the same as those in Example 1, except for step 1, in which the ratio of corn cobs and sawdust is lower than that in the example. (The ratio of corn cobs is 6-12%, and the ratio of sawdust is 7.5-24%, which are respectively reduced by about 20%-50% compared with the example.) This reduction leads to a decrease in the compactness of the internal structure of the mycelium material. The sound insulation performance of the material is measured by standard acoustic testing equipment, and the results show that the sound insulation effect of the material prepared in the example is improved by 30%. It is found that the sound insulation effect in the comparative example is not as good as that in the example.

[0066] Comparative Example 2: The remaining method steps are the same as those in Example 1, except for step 2, in which aerogel particles and graphene nanosheets are not introduced to prepare mycelium in step 2 of the comparative example. The sound insulation performance of the material was measured by standard acoustic testing equipment, and the results showed that the sound insulation effect of the material prepared by the new method was improved by 30%. The compressive performance of the material was measured by compressive strength testing equipment, and the results showed that the compressive strength of the material prepared by the new method was improved by 20%. The environmental performance of the material was evaluated, and the results showed that the new method used natural raw materials, had no chemical pollution, and the material was completely biodegradable.

[0067] Comparative Example 3: The remaining steps are the same as those in Example 1, except for step 5, in which a common incubator is used to heat and culture the mycelium in step 5. Compared with the example, by introducing efficient microwave heating technology and vacuum drying technology, the material preparation cycle is shortened by 50% and the energy consumption is reduced by 25%.

[0068] The sound insulation effect of the material is determined by measuring the influence of the material on the transmission of sound waves; the compressive strength of the material is obtained by dividing the force or load at the breaking point by the initial cross-sectional area; and the production cost and production cycle are calculated; through these measurements, the differences between the traditional method and the method of the present invention are obtained, and the improvement effect of the method of the present invention is observed.

[0069] Figure 2a and Figure 2b The optical microscope and electron microscope photos of the mycelium material in the embodiment of the present invention are shown in the figure. It can be seen from the figure that the diameter of the mycelium is Figure 3a and Figure 3b The mycelium material is thicker, the mycelium is more densely wound, and presents a uniformly distributed three-dimensional network structure, indicating that the present invention optimizes the mycelium growth environment (nutrient supply, culture medium porosity, humidity control). There are no obvious impurities or pollution, indicating that the environmental conditions are well controlled during the mycelium growth process. Figure 3a and Figure 3b The diameter of the hyphae is relatively thin, and the hyphae grow weakly due to insufficient carbon source or other nutrients in the culture medium. The mycelium is not tightly wound, and some areas have loose structures or large gaps. The presence of impurities or uneven growth in some areas reflects the instability of the culture environment control.

[0070] The following is a data comparison table:

[0071] Through specific data comparison, the advantages of the method of the present invention in terms of sound insulation effect, mechanical properties, production cost, environmental protection and production efficiency are demonstrated. For example, the sound insulation effect of the material prepared by the present invention is improved by 30%, the compressive strength is improved by 20%, the production cycle is shortened by 50%, and the production cost is reduced by 25%.

[0072] Figure 4 This is a comparison chart of mycelial biomass of mycelium cultured for the same time of different fungal strains under Example 1 of the present invention and the traditional method. Under consistent culture conditions, mycelial biomass was measured by standard experimental equipment. The data was calculated by repeating the experiment to ensure the reliability of the results. After the set culture time, the culture was stopped and the mycelium in the culture medium was collected. The mycelium was separated from the culture medium with a filter screen or filter paper. To ensure purity, the mycelium can be gently washed with deionized water or buffer to remove residual culture medium components. The separated mycelium was placed in a drying oven (such as 60-80°C) until its weight was constant. The weight of the mycelium after drying was recorded as the dry weight. The measured dry weight data was sorted and expressed as the amount of mycelium produced per unit volume or unit mass of culture medium (such as g / L or g / kg). To ensure the accuracy of the data, each group of experiments is usually repeated multiple times, and the average and standard deviation are calculated.

[0073] The mycelial biomass in Example 1 is significantly higher than that in the traditional method, which shows that the optimized culture medium (addition of aerogel particles and graphene nanosheets) and environmental conditions (high-efficiency microwave heating technology) can effectively promote the growth efficiency of mycelium. Different fungal strains showed similar trends under both methods, that is, the embodiments of the invention are superior to the traditional method. The data in the bar graph show that the increase in biomass is between 10% and 35%.

Claims

1. A method for rapidly preparing a dense mycelium-based, efficient, and durable sound-insulating composite material, characterized in that: The following steps are involved: S1, mixing straw powder, corn cob powder, sawdust powder, bran powder, soybean meal powder and alkaline mixed additives, wherein the mass ratio of corn cob powder to sawdust powder is (12-16): (15-30), and then adding aerogel particles, graphene nanosheets and water and stirring to form a culture medium; S2, inoculating Pleurotus ostreatus strains or Ganoderma lucidum strains simultaneously and evenly on the culture medium by multi-point injection, with the same injection depth, and then controlling the temperature to 30-35° C. and the humidity to 65%-75% under ventilation conditions, heating by microwave heating, and obtaining a culture system after the mycelium completely covers the culture medium; S3, pressing the culture system into shape at a pressure of 2-5 MPa, and then vacuum drying it, and controlling the total moisture content below 4%, to obtain a dense mycelium-based high-efficiency and durable sound insulation composite material.

2. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 1, characterized in that: The mass ratio of the straw powder, bran powder, soybean meal powder and sawdust powder in S1 is (40-55): (8-12): (2.5-3.5): (15-30).

3. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 1, characterized in that: The alkaline mixed additive described in S1 is composed of sodium bicarbonate and calcium carbonate in a molar ratio of 1:2, and the mass ratio of the alkaline mixed additive to the sawdust powder is (3-4): (15-30).

4. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 1, characterized in that: The aerogel particles and graphene nanosheets described in S1 account for 5%-10% and 15%-30% of the total mass of straw powder, corn cob powder, sawdust powder, bran powder, soybean meal powder and alkaline mixed additives respectively.

5. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 4, characterized in that: The particle size of the aerogel particles is 5-10 mm, the thickness of the graphene nanosheets is 1-3 nm, and the sheet diameter is 3-10 mm.

6. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 1, characterized in that: S2 used a multi-channel microinjector for multi-point injection, with an injection volume of 0.1 mL at each injection point and an injection depth of half the thickness of the culture medium.

7. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 1, characterized in that: The processes described in S1 and S2 are carried out in a sterile reactor, wherein a microwave heating system and a water tray are arranged at the bottom of the reactor from top to bottom, and an array of through holes are evenly opened at the bottom of the reactor, and water is placed in the water tray. When the microwave heating system is working, the water in the water tray is evaporated to replenish the humidity of the culture medium.

8. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 7, characterized in that: The microwave heating system has a pulsed microwave output, a frequency of 2400-2500 MHz, a power of 500-1000 W, and each working time is 10-20 minutes, and then stops for 25-35 minutes before the next working cycle.

9. The rapid preparation method of the dense mycelium-based high-efficiency and durable sound insulation composite material according to claim 1, characterized in that: S2 is inoculated with Pleurotus ostreatus or Ganoderma lucidum fungi and stirred for 4-6 minutes every 5-7 hours within 48 hours.

10. A dense mycelium-based high-efficiency, durable sound insulation composite material obtained by the rapid preparation method of a dense mycelium-based high-efficiency, durable sound insulation composite material according to any one of claims 1 to 9.

Images