A dense mycelium-based high-efficiency, durable sound insulation composite material and its rapid preparation method

Abstract

The invention discloses a dense mycelium-based high-efficiency and durable sound-insulating composite material and a rapid preparation method thereof, relating to the field of biological building materials. The method comprises the following steps: uniformly mixing straw powder, corn cob powder, sawdust powder, bran powder, soybean meal powder and an alkaline mixed additive, adding aerogel particles, graphene nanosheets and water, and stirring to form a culture medium; simultaneously and uniformly inoculating oyster mushroom species or ganoderma fungus species on the culture medium by multi-point injection, with the injection depth being the same; then controlling the temperature to 30-35°C and the humidity to 65%-75%, heating the culture medium by microwave heating under ventilation conditions, and obtaining a culture system after the mycelium completely covers the culture medium; and pressing the culture system into shape under a pressure of 2-5 MPa, and then vacuum drying the culture system to control the total water content to below 4%, thereby obtaining a dense mycelium-based high-efficiency and durable sound-insulating composite material, thereby improving production efficiency and material performance, and avoiding chemical pollution.

Description

Technical Field

[0001] The present 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 easily recyclable and the production process is environmentally friendly. Therefore, finding environmentally friendly and sustainable alternatives to sound insulation materials has become a challenge that needs to be overcome.

[0003] Mycelium is the vegetative part of fungi, consisting of numerous interconnected, slender, tubular hyphal cells. These cells are typically colorless, have transverse septa, and often contain a nucleus. Mycelium is widely found in soil and organic matter, significantly impacting both ecosystems and human life. The mycelium, interwoven to form a network-like structure, is flexible, durable, and, after treatment, can impart insulating properties. It is resilient, safe, and strong, offering moisture and water resistance, flame retardancy, and the ability to withstand significant pressure. It also provides heat and sound insulation, making it a sustainable alternative to plastic. Sound insulation materials made from mycelium can be made entirely from renewable and biodegradable ingredients, meeting environmental requirements. The open cell walls and porous structure of mycelium create an ideal sound insulation system with high sound absorption efficiency. Furthermore, using mycelium as a raw material helps conserve resources, making mycelium-based composite sound insulation materials a viable renewable and biodegradable alternative to sound insulation materials.

[0004] The common method for preparing sound insulation materials using mycelium mainly includes the following steps: (1) culture medium preparation, i.e., using crop residues (such as sawdust, corn husks, straw, etc.) as the nutrient substrate for mycelium, crushing them and mixing them with water to form a culture medium; (2) inoculation of 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 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. This method has a slow mycelium growth rate, resulting in a long material preparation cycle, and requires precise control of environmental conditions, high energy consumption and high cost. For certain specific raw materials, chemical adhesives need to be used, which will cause a certain degree of environmental pollution. Summary of the Invention

[0005] In response to 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, which improves production efficiency and material performance and has no chemical pollution.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for rapidly preparing a dense mycelium-based, high-efficiency, and durable sound-insulating composite material comprises the following steps:

[0008] S1, uniformly 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;

[0009] S2, inoculating the culture medium with Pleurotus ostreatus spawn or Ganoderma lucidum spawn simultaneously and evenly by multi-point injection at the same injection depth, then heating the culture medium by microwave heating under ventilation conditions at a temperature of 30-35°C and a humidity of 65%-75%, until the mycelium completely covers the culture medium, thereby obtaining a culture system;

[0010] S3, pressing the culture system into shape under a pressure of 2-5 MPa, and then vacuum drying it to control the total moisture content below 4%, thereby obtaining a dense mycelium-based high-efficiency and durable sound insulation composite material.

[0011] A further improvement of the present invention is:

[0012] 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).

[0013] 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).

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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 from top to bottom at the bottom of the reactor. An array of through holes is 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.

[0018] The microwave heating system has a pulsed microwave output with a frequency of 2400-2500 MHz and a power of 500-1000 W. Each working time is 10-20 minutes, and then it stops for 25-35 minutes before the next working cycle begins.

[0019] S2 is inoculated with Pleurotus ostreatus or Ganoderma lucidum fungi, and stirred for 4-6 minutes every 5-7 hours within 48 hours.

[0020] A dense mycelium-based high-efficiency, long-lasting sound-insulating composite material obtained by the rapid preparation method of any one of the dense mycelium-based high-efficiency, long-lasting sound-insulating composite materials described above.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] The present invention provides a rapid method for preparing a dense mycelium-based, high-efficiency, and durable sound-insulating composite material. Pleurotus ostreatus or Ganoderma species are simultaneously and evenly inoculated onto a culture medium using a multi-point injection method. The injection depth is consistent, ensuring uniform distribution of the species. By controlling the appropriate temperature and humidity, and then microwave heating, the culture medium is quickly and evenly heated, shortening the mycelial growth period and further promoting mycelial growth. Straw, corncobs, and sawdust provide the primary solid matrix and nutrients for mycelial growth. Cellulose and hemicellulose serve as carbon sources after being degraded by enzymes secreted by the mycelium. Extracellular enzymes (such as cellulase and xylanase) secreted by the mycelium degrade the fibrous tissue of straw, corncobs, and sawdust, converting it into absorbable sugars. As the mycelium grows, these materials become the supporting framework of the mycelial network, entwining with the mycelium to form a dense structure. Wheat bran and soybean meal provide the nitrogen, vitamins, and other nutrients required for mycelial growth, improving the nutritional balance of the culture medium and accelerating mycelial expansion. During the initial cultivation phase, proteases secreted by the mycelium break down the proteins in bran and soybean meal into amino acids and small peptides for absorption. This nutrient supply promotes rapid mycelial growth and increases the density of the mycelial network. Aerogel particles provide a uniformly distributed microporous structure that effectively absorbs and scatters sound waves, enhancing the aeration and water retention of the culture medium, and improving the sound insulation and mechanical strength of the final material. Aerogel particles are evenly distributed throughout the culture medium, interweaving with the growing mycelial network. This porous structure provides attachment points for mycelial growth and absorbs water and nutrients from the culture medium, forming a stable mycelial composite structure. Graphene nanoplatelets enhance the material's mechanical strength, durability, and thermal conductivity, improving the composite's impact resistance. The high surface area of ​​graphene nanoplatelets provides numerous attachment sites for mycelium to spread and entangle. The cross-linking of the two-dimensional graphene sheet structure with the mycelial filamentous network increases the density and uniformity of the composite, ultimately resulting in a more durable and effective sound insulation effect. During the culture medium preparation and mycelial growth process, these components gradually integrate into a complex composite material: Initially, the solid matrix (straw, corn cobs, sawdust) serves as the mycelium's skeleton, providing structural support. Nutrients (bran, soybean meal) are rapidly decomposed, prompting the mycelium to quickly attach and expand on the solid matrix surface. During the mycelial growth phase, the mycelium expands on the matrix surface while gradually penetrating the material's pores, forming a network with aerogel particles and graphene nanosheets. Extracellular enzymes in the mycelium further decompose portions of the matrix, enhancing its physical strength and biocompatibility. In the final molding phase, the mycelium completely covers the culture medium, forming a highly dense composite structure through entanglement, interlocking, and cross-linking. After drying and pressing, the mycelium and various components combine to form a uniform and stable material.Mycelium is the core skeleton, connecting and integrating all components. Straw, corn cobs, and wood chips serve as the supporting matrix; 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

[0023] Figure 1a This is a front view of the mycelium growth container structure of the present invention.

[0024] Figure 1b It is a left view of the mycelium growth container structure of the present invention.

[0025] Figure 1c This is a top view of the internal structure of the mycelium growth container structure of the present invention.

[0026] Figure 1d This is a top view of the external structure of the mycelium growth container structure of the present invention.

[0027] Figure 2a This is an optical microscope image of the mycelium material in Example 1 of the present invention.

[0028] Figure 2b This is an electron microscope image of the mycelium material in Example 1 of the present invention.

[0029] Figure 3a This is an optical microscope image of the cultured mycelium material of Comparative Example 1.

[0030] Figure 3b This is an electron microscope photo of the mycelium material cultured in Comparative Example 1.

[0031] Figure 4 Comparison of mycelial biomass of different fungal strains cultured in Example 1 of the present invention and by traditional methods.

[0032] In the figure: 1- stirrer; 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

[0033] The present invention will be further described in detail below with reference to specific embodiments, which are intended to explain the present invention rather than to limit it.

[0034] The present invention provides a rapid preparation method for a dense mycelium-based high-efficiency and durable sound insulation composite material, and the preparation steps are as follows:

[0035] (1) Preparation of culture medium:

[0036] By weight percentage, 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 an 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% by weight of the mixture of 5-10 mm aerogel particles, 1-3% by weight of the mixture of graphene nanosheets, and water are added and stirred to form a culture medium;

[0037] (2) Inoculation strains and environmental control:

[0038] The culture medium is inoculated with Pleurotus ostreatus or Ganoderma species simultaneously and evenly at multiple injection points. The injection depth is the same. A matrix-type multi-channel microinjector is used for multiple injections. The injection volume at each injection point is 0.1 mL, and the distance between the syringes is 2 cm. This facilitates the rapid and uniform development of the mycelial material. The injection depth is half the thickness of the culture medium. After the injection is completed, the injection port is closed to ensure uniform distribution of the strains. Within 48 hours of inoculation with Pleurotus ostreatus or Ganoderma species, the mixture is stirred for 4-6 minutes every 5-7 hours, and no stirring is performed thereafter.

[0039] Then, the temperature is controlled at 30-35°C and the humidity is 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;

[0040] (3) Drying and shaping:

[0041] The culture system is pressed into shape under a pressure of 2-5 MPa and then vacuum-dried to control the total moisture content below 4% to obtain a dense mycelium-based, efficient, and durable sound insulation composite material.

[0042] The present invention designs a container for mycelium growth, and the specific design scheme is as follows:

[0043] Reactor type: fermenter or incubator to ensure a sterile environment.

[0044] 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.

[0045] Capacity and shape: Choose an appropriate capacity based on production scale, generally ranging from 10L to 500L. The shape should be a cuboid to facilitate uniform growth of mycelium.

[0046] 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 from top to bottom with a microwave heating system 9 and a humidity control system 10, the humidity control system 10 is placed in a water tray above the microwave heating system to add water, and is designed to be pull-out type. The bottom of the reactor is evenly provided with an array of through holes, and 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 longitudinal direction is 2 cm. The upper surface of the reactor is provided with two bayonet ports 6 connected to the outside world. The bayonet ports 6 are long and symmetrically distributed on both sides of the center line of the reactor in the width direction. The top cover 12 is inserted into the bayonet port 6, so that the top cover 12 can be slid open. Figure 1d As shown, the top cover 12 is arrayed with injection holes 13 spaced 2 cm apart. A matrix of multi-channel microinjectors is located on the top for uniform injection of the bacterial inoculum. The outer ends of the top cover 12 in both width and length directions are 2 cm away from the outer edge of the reactor. Figure 1b In the figure, the stirring blade 7 is the stirring blade of the stirrer, and the vent 8 is embedded with a filter screen.

[0047] Ventilation system: Equipped with high-efficiency filtered vents to ensure the supply of fresh air while avoiding contamination by bacteria.

[0048] 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).

[0049] Humidity Control: Built-in humidity control system maintains internal humidity at 65-75%.

[0050] Based on this, the process of preparing the culture medium is as follows:

[0051] The reactor cover 12 is opened, and pre-mixed and evenly shredded straw, corn cobs, sawdust, bran, and soybean meal, as well as an alkaline mixed additive, are loaded into the reactor, measured by mass percentage. The reactor cover 12 is closed to obtain a mixture, to which 5-10 mm aerogel particles (5-10% of the mixture mass) and graphene nanosheets (1-3% of the mixture mass) are added. Finally, water is added to maintain a certain humidity, and the mixture is stirred using the stirring paddle 7 in the stirrer 1. Sodium bicarbonate releases carbonate ions and hydroxide ions in aqueous solution, providing a weakly alkaline environment, but its action time is relatively short. Calcium carbonate, due to its low solubility, can stably release alkaline ions over a long period of time, providing a long-term buffering effect. The combined action of the two can provide a relatively stable pH buffering environment, enhance long-term pH stability, react slowly, slowly release alkalinity, stabilize pH, and be suitable for long-term culture. Calcium carbonate provides calcium and can also enhance the strength of the mycelium skeleton, forming a culture medium.

[0052] The specific process of temperature and humidity control is:

[0053] 1) Initialization and setting target value

[0054] The user sets the target temperature (such as 30-35°C) and humidity (such as 65-75%) on the control panel of the temperature and humidity controller.

[0055] After the system starts, it automatically detects the current environmental parameters.

[0056] 2) Temperature and humidity control logic

[0057] 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.

[0058] Logical reasoning:

[0059] 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 and heats at the set power (e.g., 200W, low-power microwave).

[0060] If the actual temperature is close to the target temperature (e.g., target temperature ±0.5°C), the controller adjusts the microwave power through PWM (pulse width modulation) technology to maintain temperature stability.

[0061] If the actual temperature exceeds the target temperature, the microwave heating is turned off and the cooling device is activated.

[0062] 3) Humidity control logic

[0063] Real-time humidity monitoring:

[0064] If the humidity is lower than the set range, the controller (using the PID (Proportional-Integral-Derivative) 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.

[0065] If the humidity is too high, increase ventilation appropriately or use desiccant to control it.

[0066] Microwave heating directly acts on the water molecules in the culture medium and the mycelium, resulting in fast temperature rise and high efficiency.

[0067] The stirrer can make the culture medium heated more evenly and avoid local overheating or unevenness.

[0068] Temperature control and humidity coordination

[0069] Since microwave heating reduces humidity (through water evaporation), the system requires synchronous humidity compensation (by adding a water tray above the microwave heating system to replenish humidity and prevent rapid temperature rise from damaging the mycelium) to maintain the stability of the culture environment.

[0070] Aerogels can be silica aerogels or organic aerogels. Silica aerogels are heat-resistant, chemically stable, and have high porosity, offering excellent sound and heat insulation properties. They are used as the primary component of sound insulation materials, providing a nanoscale porous structure that absorbs sound waves and enhances sound insulation. Organic aerogels, such as polyurethane aerogels and polystyrene aerogels, offer excellent flexibility and are suitable for composite applications. They also have lower density and higher toughness, improving the mechanical properties, flexibility, and impact resistance of materials. They are also less likely to affect the mycelium growth environment in culture media.

[0071] The ratio of sawdust and corncobs improves the material's mechanical strength and sound insulation. The sawdust and corncobs form a denser structure within the mycelium, effectively blocking sound transmission.

[0072] Aerogel particles, with a diameter between 5 and 10 microns, maintain the material's lightweight properties while enhancing sound insulation. Aerogel particles have a high specific surface area and a nanoscale porous structure, forming uniformly distributed micropores within the culture medium. These micropores effectively absorb and scatter sound waves, significantly improving the material's sound insulation performance. The microporous structure also increases the material's internal surface area, contributing to its overall stability and mechanical strength. The uniform distribution of aerogel particles ensures a more uniform and stable sound insulation effect. Aerogel particles have an extremely low density and do not significantly increase the weight of the material when added to the culture medium, facilitating the preparation of lightweight and highly effective sound insulation materials. Cabot Corporation offers the Silica Aerogel series of aerogels, with particle sizes and porosities suitable for a variety of applications, including sound and thermal insulation. Aspen Aerogels offers aerogel products for industrial thermal insulation, with customizable particle sizes. Blueshift's aerogel products feature a high specific surface area and low density, making them suitable for use as lightweight sound insulation materials.

[0073] The graphene nanosheets have a thickness of 1-3 nanometers and a diameter of 3-10 microns. This size effectively enhances the material's mechanical strength, electrical conductivity, and thermal conductivity without compromising the uniformity of the culture medium. The high elastic modulus and strength of the graphene nanosheets give the final material greater durability and impact resistance. The uniform distribution of the graphene nanosheets in the culture medium further enhances the material's structural uniformity and prevents internal stress concentration.

[0074] When the environment is controlled:

[0075] Activate the temperature and humidity control systems to control the temperature (30-35°C) and humidity (65-75%). Open the vents to ensure ventilation and air circulation, creating an optimal environment for mycelial growth. Use a high-efficiency microwave heating system, activate the microwave heating plate, and use pulsed microwave output at a frequency of 2450 MHz and a power of 500-1000W. Each cycle lasts 10-20 minutes, followed by a 25-35 minute pause before the next cycle. This allows for rapid and even heating of the culture medium, shortening the mycelial growth period and further promoting mycelial growth.

[0076] Continuously monitor temperature, humidity, and air circulation, and check mycelium growth every 6-8 hours to ensure uniform growth and no contamination from foreign bacteria.

[0077] Transparent reactors facilitate direct observation of mycelial growth. Visually inspect the extent to which mycelium covers the medium and ensures uniform distribution. Use a magnifying glass or portable microscope to examine the mycelial structure for structural integrity and the presence of abnormal areas (e.g., uncovered areas or areas of overcrowding).

[0078] Use a high-definition camera or mobile phone to take photos of the mycelium inside the culture container to record its growth progress. Take photos from the same angle at regular intervals to compare and analyze whether the mycelium is expanding evenly.

[0079] Use image processing software (such as CellProfiler or Fiji) to quantify mycelial coverage and density to determine uniform growth. CellProfiler, designed specifically for biological research, is suitable for automated image analysis of cells, microorganisms, and mycelia. It supports batch image processing and can measure hyphal coverage, number of branches, density, and more. Fiji (an advanced version of ImageJ) integrates many plug-ins suitable for analyzing mycelial extension, density, and coverage. For example, the SimpleNeurite Tracer plug-in is ideal for tracking and analyzing hyphal structures.

[0080] 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 other bacteria.

[0081] To prevent bacterial contamination, ensure the cleanliness of the culture environment, containers, and tools. Disinfect incubator surfaces and gloves with 75% alcohol or hypochlorous acid. Use a high-efficiency particulate air (HEPA) filter to purify the air inside the incubator to prevent bacteria from entering through airflow. Ensure that the lids of culture medium containers are tightly sealed and only opened briefly when necessary.

[0082] When drying and styling:

[0083] 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 under appropriate pressure (2-5 MPa). Subsequently, vacuum drying is used to dry the material at low temperature (40-50°C) and low pressure (20-50 kPa) for 6-8 hours, and the total moisture content is controlled below 4% to obtain a finished product.

[0084] By increasing the ratio of sawdust and corncobs, and adding aerogel particles and graphene nanosheets, the material's mechanical strength and sound insulation were enhanced. Microwave heating rapidly raised the culture medium temperature, shortening the mycelium growth cycle and improving production efficiency. Finally, vacuum drying the material at low temperature and low pressure resulted in a uniform internal structure, enhancing its performance.

[0085] Example 1:

[0086] A method for preparing a mycelium-based composite sound insulation material, comprising the following specific steps:

[0087] Preparation and proportion of culture medium:

[0088] The culture medium is prepared by finely grinding and mixing straw (45%), corn cobs (15%), sawdust (15%), bran (10%), an alkaline mixed additive (3%), and soybean meal (3%). Aerogel particles (8%) and graphene nanosheets (1%) are then added, evenly distributed to form a uniform microporous structure. This structure enhances sound absorption and scattering, significantly improving sound insulation performance, while also increasing the mechanical strength of the final material.

[0089] Vaccination process:

[0090] Select high-quality (white, cotton-like, thick, dense, evenly distributed, and free of variegated hyphae) oyster mushroom mycelium and inoculate the culture medium. Cultivate under sterile conditions for 72 hours to obtain expanded mycelium. Use sterile tools (such as tweezers or a spatula) to gently scrape the mycelium from the surface of the solid culture medium. Suspend the mycelium in a sterile liquid (such as sterile water or buffer) and evenly disperse it, for example, to a concentration of 0.5 g wet weight of mycelium per ml. Aseptically dispense the prepared mycelium suspension into a multichannel microsyringe. Use an inoculation device with a number of multichannel microsyringes that matches the number of inoculation wells in the culture medium. Place the culture medium under the inoculation device, ensuring that the inoculation wells are aligned with the needles. Adjust the injection volume of the inoculation device (1 mL per well). Start the syringes, and the mycelial suspension is simultaneously injected into the culture medium via the multichannel microsyringes. After inoculation, cover the top of the culture container with a sterile, breathable membrane to prevent contamination while allowing for adequate air exchange.

[0091] Culture environment control and mycelium growth:

[0092] Immediately after inoculation, the temperature (30-35°C) and humidity (65-75%) control systems are activated to maintain optimal mycelial growth conditions. Temperature and humidity probes collect data every 30 minutes and feed it back to the temperature and humidity controller to adjust the microwave heating system's duration. Microwave heating also accelerates the diffusion of moisture from the water pan above, increasing humidity.

[0093] The microwave heating system operates at a frequency of 2450MHz, with a power of 1000W and pulsed microwave output. Each microwave exposure lasts 10 seconds, followed by a 30-second rest period. This prevents heat stress on the mycelium, quickly and evenly elevates the culture temperature, and shortens the mycelial growth cycle. Ventilation ports (with embedded filters) ensure adequate oxygen supply to the culture and prevent contamination by foreign bacteria. For 48 hours after inoculation, the incubator is agitated for 5 minutes every 6 hours to ensure efficient oxygen diffusion. Stirring is discontinued after 48 hours.

[0094] Monitoring and maintenance:

[0095] Check the mycelial growth every 6-8 hours, take some samples for microscopic observation to see if the growth is uniform, and record and analyze the mycelial coverage progress.

[0096] Pressing and drying:

[0097] Once the mycelium completely covered the culture medium, the material was transferred to a mold and subjected to controlled pressure (3.5 MPa). Subsequently, it was vacuum-dried at low temperature (45°C) and low pressure (30 kPa) for six hours to reduce the material's moisture content to 3%. This process preserved the integrity of the microporous structure and optimized the material's acoustic and mechanical properties.

[0098] Comparative Example 1:

[0099] The remaining methods and steps were the same as in Example 1, with the exception of step 1, where the ratios of corncobs and sawdust were lower than in the Example (the ratio of corncobs was 6-12%, and the ratio of sawdust was 7.5-24%, respectively, a decrease of approximately 20%-50% compared to the Example). This reduction resulted in a decrease in the density of the mycelium material's internal structure. Standard acoustic testing equipment was used to measure the material's sound insulation performance, and the results showed a 30% improvement in the sound insulation effect of the material prepared in the Example. The sound insulation effect of the comparative example was found to be inferior to that of the Example.

[0100] Comparative Example 2:

[0101] The remaining steps were the same as in Example 1, with the exception of step 2, in which aerogel particles and graphene nanosheets were not introduced to prepare the mycelium. Standard acoustic testing equipment was used to measure the sound insulation performance of the material prepared with the new method, and the results showed a 30% improvement in sound insulation. Compressive strength testing equipment was used to measure the compressive strength of the material prepared with the new method, and the results showed a 20% improvement in compressive strength. The environmental performance of the material was evaluated, and the results showed that the new method uses natural raw materials, is chemically free, and is completely biodegradable.

[0102] Comparative Example 3:

[0103] The remaining steps were the same as in Example 1, with the exception of step 5, where a conventional insulated box was used to heat and culture the mycelium. Compared with the example, the introduction of efficient microwave heating and vacuum drying technology shortened the material preparation cycle by 50% and reduced energy consumption by 25%.

[0104] The sound insulation effect of the material is determined by measuring its effect on the transmission of sound waves; the compressive strength of the material is determined 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.

[0105] Figure 2a and Figure 2b The optical microscope and electron microscope photos of the mycelium material under the embodiment of the present invention are respectively shown. It can be seen from the figure that the diameter of the mycelium is larger than that of the Figure 3a and Figure 3b The mycelium material is thicker and more densely entangled, presenting a uniformly distributed three-dimensional network structure, indicating that the present invention optimizes the mycelium growth environment (nutrient supply, culture medium porosity, and humidity control). The absence of obvious impurities or contamination indicates that the environmental conditions during mycelial growth are well controlled. Figure 3a and Figure 3b The mycelium is thin in diameter, indicating weak growth due to insufficient carbon source or other nutrients in the culture medium. The mycelium is not tightly wound, with some areas exhibiting loose structures or large gaps. Localized impurities or uneven growth reflect instability in the culture environment.

[0106] The following is a data comparison table:

[0107]

[0108] The advantages of the present invention in terms of sound insulation, mechanical properties, production costs, environmental friendliness, and production efficiency are demonstrated through comparative data. For example, the material produced by the present invention has a 30% improvement in sound insulation, a 20% increase in compressive strength, a 50% reduction in production cycle time, and a 25% reduction in production costs.

[0109] Figure 4The figure shows a comparison of mycelial biomass of different fungal strains cultured for the same time period using Example 1 of the present invention and traditional methods. Mycelial biomass was measured using standard laboratory equipment under consistent culture conditions. The data was averaged by calculating the average value through repeated experiments 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 using a filter screen or filter paper. To ensure purity, the mycelium could be gently washed with deionized water or a buffer solution to remove residual culture medium components. The separated mycelium was placed in a drying oven (e.g., 60-80°C) until its weight remained constant. The weight of the dried mycelium was recorded as the dry weight. The measured dry weight data was collated and expressed as the amount of mycelium produced per unit volume or unit mass of culture medium (e.g., g / L or g / kg). To ensure data accuracy, each set of experiments was typically repeated multiple times, and the average and standard deviation were calculated.

[0110] The mycelial biomass in Example 1 was significantly higher than that achieved using the traditional method, demonstrating that the optimized culture medium (with the addition of aerogel particles and graphene nanosheets) and environmental conditions (high-efficiency microwave heating) effectively promoted mycelial growth. Different fungal strains exhibited similar trends using both methods, indicating that the inventive examples outperformed the traditional method. The bar chart data shows that the biomass increase ranged from 10% to 35%.

Claims

1. A method for rapidly preparing a dense mycelium-based, high-efficiency, and durable sound-insulating composite material, characterized in that: The following steps are involved: S1, uniformly mixing straw powder, corn cob powder, sawdust powder, bran powder, soybean meal powder, and an alkaline mixed additive, wherein the alkaline mixed additive comprises sodium bicarbonate and calcium carbonate in a molar ratio of 1:2, and 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 the culture medium with Pleurotus ostreatus spawn or Ganoderma lucidum spawn simultaneously and evenly by multi-point injection at the same injection depth, then heating the culture medium by microwave heating under ventilation conditions at a temperature of 30-35°C and a humidity of 65%-75%, until the mycelium completely covers the culture medium, thereby obtaining a culture system; The processes S1 and S2 are carried out in a sterile reactor. A microwave heating system and a water tray are arranged from top to bottom at the bottom of the reactor. The bottom of the reactor is evenly provided with an array of through holes. Water is placed in the water tray. When the microwave heating system is in operation, the water in the water tray is evaporated to replenish the humidity of the culture medium. The microwave heating system has a pulsed microwave output with a frequency of 2400-2500 MHz and a power of 500-1000 W. Each working time is 10-20 minutes, followed by a 25-35 minute pause before the next working cycle begins. S3, pressing the culture system into shape under a pressure of 2-5 MPa, and then vacuum drying it to control the total moisture content below 4%, thereby obtaining 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 mass ratio of the alkaline mixed additive and sawdust powder described in S1 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 microinjection syringe 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: S2 is inoculated with Pleurotus ostreatus or Ganoderma lucidum fungi, and stirred for 4-6 minutes every 5-7 hours within 48 hours.

8. A dense mycelium-based high-efficiency, long-lasting sound insulation composite material obtained by the rapid preparation method of a dense mycelium-based high-efficiency, long-lasting sound insulation composite material according to any one of claims 1 to 7.

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