Fireproof hydrophobic aerogel felt and preparation method thereof

Abstract

The invention discloses a fireproof hydrophobic aerogel felt, which comprises a flexible fiber skeleton, alumina aerogel is uniformly distributed inside and on the surface of the flexible fiber skeleton, an organosilane hydrophobic modifier and a flame retardant synergist are introduced into the alumina aerogel in a chemical bonding manner, and the fireproof hydrophobic aerogel felt is prepared from the flexible fiber skeleton. The flexible fiber skeleton, the aluminum oxide aerogel, the hydrophobic modifier and the flame-retardant synergist are sequentially compounded to form a fireproof hydrophobic aerogel felt finished product layer; according to the invention, an organosilane hydrophobic modifier and a phosphorus-nitrogen compounded flame retardant synergist are synchronously introduced into a three-dimensional network structure of alumina aerogel in a chemical bonding manner, so that functional components become internal components of a gel network instead of simple physical adhesion; the problem that a functional layer is easy to migrate and fall off in a traditional post-treatment process is fundamentally solved, and high stability and durability of super-hydrophobicity and intrinsic flame retardance are ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of thermal insulation materials, and particularly relates to a fireproof hydrophobic aerogel felt and a preparation method thereof. BACKGROUND

[0002] In the field of thermal insulation materials, although the alumina aerogel felt has excellent thermal insulation properties, its inherent hydrophilicity and brittleness limit its application in complex environments such as moisture and fire. The existing technology mainly adopts physical coating or post-soaking process for hydrophobic or flame-retardant treatment, but the modified agent has weak binding force and is easy to fall off, and may block the pores and damage the thermal insulation performance, and the functions are difficult to be coordinated and long-lasting. Direct blending before gelation may easily lead to uneven dispersion of components, affecting the uniformity and strength of the material. Therefore, there is an urgent need for a new type of aerogel felt which can simultaneously realize high hydrophobicity, intrinsic flame retardancy and not sacrifice the core performance, and a preparation method thereof. SUMMARY

[0003] The purpose of the present application is to provide a fireproof hydrophobic aerogel felt to solve the problems in the background art.

[0004] In a first aspect, the present application provides a fireproof hydrophobic aerogel felt, comprising: The flexible fiber skeleton is internally and externally uniformly distributed with alumina aerogel, wherein the alumina aerogel has an organosilane hydrophobic modifier and a flame-retardant synergist introduced by chemical bonding, and the flexible fiber skeleton, alumina aerogel, hydrophobic modifier and flame-retardant synergist are sequentially compounded to form a fireproof hydrophobic aerogel felt product layer.

[0005] In a possible implementation manner of the first aspect, the flexible fiber skeleton is selected from at least one of ceramic fiber felt, glass fiber felt or pre-oxidized silk fiber felt.

[0006] In a possible implementation manner of the first aspect, the organosilane hydrophobic modifier is at least one of hexamethyldisilazane, trimethylchlorosilane or methyltrimethoxysilane.

[0007] In a possible implementation manner of the first aspect, the flame-retardant synergist comprises a complex system of phosphorus-containing compounds and nitrogen-containing compounds.

[0008] In a possible implementation manner of the first aspect, the flame-retardant synergist is uniformly dispersed in the three-dimensional network structure of the alumina aerogel.

[0009] In a possible implementation manner of the first aspect, the contact angle of the aerogel felt when in use is greater than 150°, and the aerogel felt has intrinsic flame retardancy.

[0010] Compared with the prior art, the present application provides a fireproof hydrophobic aerogel felt, which has the following beneficial effects: I. This invention introduces organosilane hydrophobic modifiers and phosphorus-nitrogen compound flame retardant synergists into the three-dimensional network structure of alumina aerogel through chemical bonding, making the functional components an intrinsic part of the gel network rather than a simple physical attachment. This fundamentally solves the problem of easy migration and detachment of functional layers in traditional post-processing, ensuring the high stability and durability of superhydrophobicity and intrinsic flame retardancy. Second, the functionalized aerogel is uniformly distributed within and on the surface of the flexible fiber skeleton, forming a robust composite structure. This method not only effectively maintains the high thermal insulation properties of the aerogel's nanoporous structure, but also, through the uniform dispersion and synergistic effect of the components, enables the final product to simultaneously achieve a superhydrophobic surface with a contact angle greater than 150° and a significantly improved flame retardant rating. It also possesses excellent mechanical flexibility and environmental durability, meeting the long-term thermal insulation protection requirements in harsh environments such as humid conditions and fire hazards.

[0011] Secondly, the present invention provides a method for preparing fire-resistant and hydrophobic aerogel felt, comprising: The porosity characteristics of the flexible fiber skeleton were measured, and the basic chemical performance data of the aerogel precursor, hydrophobic modifier and flame retardant synergist were collected. Based on the porosity characteristics and chemical performance data, the target loading amount of the aerogel precursor in the skeleton was calculated. The chemical compatibility and efficiency of the hydrophobic modifier and the flame retardant synergist were tested to obtain synergistic modification data. Combined with the gelation characteristics determined by the aerogel precursor preparation process, the structural stability and functional binding degree of the aerogel composite were calculated. Based on the structural stability and functional integration, as well as the target load, the molding process requirements of the aerogel are determined, and the preparation process parameters are set accordingly. A composite preparation process is then performed to obtain the fireproof and hydrophobic aerogel felt.

[0012] In one possible implementation of the second aspect, calculating the target loading of the aerogel precursor in the framework based on the pore characteristics and chemical performance data includes: Based on the aforementioned pore characteristics, the available pore volume of the flexible fiber skeleton is calculated. The chemical properties of the aerogel precursor were analyzed, and the volume shrinkage characteristics during the gelation process were combined to calculate the solid content conversion rate of the precursor solution from impregnation to the formation of dry gel. Based on the available pore volume and the solid content conversion rate, the initial theoretical loading of the aerogel precursor solution required to achieve the predetermined pore filling degree is calculated. The chemical performance data of the hydrophobic modifier and flame retardant synergist were obtained, and the degree of influence of their introduction on the gel network structure and volume changes was analyzed. The initial theoretical loading is adjusted based on the degree of influence to determine the target loading of the aerogel precursor in the skeleton.

[0013] In one possible implementation of the second aspect, calculating the structural stability and functional integration of the aerogel composite by combining the synergistic modification data and the gelation characteristics includes: The network strengthening factor under the combined action of the hydrophobic modifier and the flame retardant synergist was extracted from the synergistic modification data. The formation rate and crosslinking density characteristics of the aerogel network were determined from the gelation properties. The structural stability of the aerogel composite is calculated by combining the network strengthening factor, the formation rate, and the crosslinking density characteristics. Analyze the bonding efficiency and distribution uniformity of functional groups in the synergistic modification data; The functional binding degree of the aerogel composite is calculated by combining the bonding efficiency, the distribution uniformity information, and the crosslinking density characteristics.

[0014] In one possible implementation of the second aspect, determining the aerogel molding process requirements based on the structural stability and functional integration, as well as the target loading amount, includes: Based on the structural stability, the basic gel environment after impregnation with the aerogel precursor solution is determined; Based on the functional binding degree, the addition stage of the hydrophobic modifier and flame retardant synergist during the gelation process is determined; Obtain the specific solution volume corresponding to the target loading capacity; Based on the basic gel environment, the addition stage, and the specific solution dosage, the molding process requirements for the aerogel are determined.

[0015] As can be seen, this invention calculates the target loading amount of the aerogel precursor in the skeleton based on the pore characteristics and chemical performance data, which clarifies the optimal impregnation amount of the aerogel precursor solution. This provides a clear basis for the dosage to form a uniform and firmly bonded alumina aerogel composite structure in the flexible fiber skeleton. By combining the synergistic modification data and the gelation characteristics, this invention calculates the structural stability and functional integration of the aerogel composite, which can obtain the strength of the internal structure of the composite and the effective integration level of hydrophobic and flame-retardant functions. This provides a direct basis for determining the preparation process that can simultaneously ensure structural strength and functional durability. By combining the structural stability and functional integration with the target loading amount, this invention determines the molding process requirements of the aerogel, and further clarifies the specific operational points of each step of sol impregnation, gel conversion, and subsequent treatment, so as to improve the synergistic level of structural uniformity and functional reliability of the final product. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the three-dimensional structure of a fire-resistant and hydrophobic aerogel felt according to an embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of a fire-resistant and hydrophobic aerogel felt according to an embodiment of the present invention; Figure 3 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the diagram; Figure 4 A flowchart illustrating a method for preparing a fire-resistant and hydrophobic aerogel felt according to an embodiment of the invention; In the diagram: 1. Flexible fiber skeleton; 2. Alumina aerogel; 3. Organosilane hydrophobic modifier; 4. Flame retardant synergist; 5. Fireproof and hydrophobic aerogel felt finished layer. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figures 1-3 The aerogel material includes a flexible fiber skeleton 1, which serves as a supporting matrix and provides excellent mechanical load-bearing performance, avoiding the inherent brittleness and fragility of alumina aerogel 2. It also ensures the overall structure's flexibility and bendability, facilitating subsequent cutting, laying, and other applications. Alumina aerogel 2 is uniformly distributed within and on the surface of the flexible fiber skeleton 1. This uniform distribution allows the aerogel and fiber skeleton to form a tight composite structure, fully utilizing the extremely low thermal conductivity of alumina aerogel 2 and improving overall thermal insulation performance. The alumina aerogel 2 incorporates an organosilane hydrophobic modifier 3 and a flame retardant synergist 4 through chemical bonding. This chemical bonding ensures stable bonding between the modifier and the three-dimensional network of the aerogel, preventing the modifier from detaching during use and ensuring long-lasting performance. The flexible fiber skeleton 1, alumina aerogel 2, hydrophobic modifier, and flame retardant synergist 4 are sequentially composited to form a fireproof and hydrophobic aerogel felt finished layer 5.

[0019] The flexible fiber skeleton 1 is selected from at least one of ceramic fiber felt, glass fiber felt, or pre-oxidized filament fiber felt. These fiber felts all have excellent high temperature resistance, good flexibility, and high mechanical strength, and can adapt to the use requirements under different working conditions. Among them, ceramic fiber felt has a higher high temperature resistance and is suitable for high temperature insulation scenarios; glass fiber felt has a lower cost and is suitable for conventional insulation environments; and pre-oxidized filament fiber felt has both good flexibility and corrosion resistance and can be used in special media environments.

[0020] The organosilane hydrophobic modifier 3 is at least one of hexamethyldisilazane, trimethylchlorosilane, or methyltrimethoxysilane. The hydrophobic groups contained in the molecules of this type of modifier can be chemically bonded to the silanol groups of alumina aerogel 2, replacing the hydrophilic groups on the surface of the aerogel, thereby significantly reducing the hydrophilicity of the aerogel and preventing the thermal insulation performance of the aerogel from decreasing after absorbing water.

[0021] The flame retardant synergist 4 comprises a compound system of phosphorus-containing compounds and nitrogen-containing compounds. The phosphorus-nitrogen compound system can produce a synergistic flame retardant effect. During combustion, the phosphorus-containing compounds can form phosphoric acid substances, which promote the formation of a carbonized layer on the material surface and block the transfer of oxygen and heat. When the nitrogen-containing compounds burn, they can release non-combustible gases such as nitrogen, dilute the concentration of combustible gases, and reduce the temperature of the combustion zone, thereby further improving the flame retardant effect.

[0022] The flame retardant synergist 4 is uniformly dispersed in the three-dimensional network structure of the alumina aerogel 2. This dispersion method ensures that the flame retardant synergist 4 does not agglomerate in the aerogel, thus fully exerting its flame retardant effect, while not damaging the three-dimensional porous structure of the aerogel and ensuring the original thermal insulation performance of the aerogel.

[0023] The aerogel felt has a contact angle greater than 150° during use and possesses intrinsic flame retardancy, effectively resisting the wetting of liquid moisture and maintaining good thermal insulation performance even in high humidity environments. At the same time, the aerogel felt has intrinsic flame retardancy, achieving a non-combustible rating without the need for additional flame retardants. It does not melt and drip during combustion, has low smoke and toxic emissions, and is highly safe to use. It is suitable for various scenarios such as building thermal insulation, industrial equipment insulation, and new energy battery thermal insulation.

[0024] The working principle and usage process of a fireproof and hydrophobic aerogel felt according to the present invention: Working Principle: The fireproof and hydrophobic aerogel felt of this invention possesses multifunctional integrated characteristics stemming from its unique multi-level composite structure of "skeleton-matrix-functional agent". The flexible fiber skeleton 1 serves as the macroscopic support, providing the material's mechanical strength and overall morphology. The alumina aerogel 2 loaded within and on the surface of the skeleton forms a continuous nanoporous network. Its extremely low solid thermal conductivity and abundant nanoscale pores effectively suppress gas molecule movement and heat radiation transfer, thereby achieving the core thermal insulation function of extremely low thermal conductivity. Furthermore, the organosilane hydrophobic modifier 3, introduced through chemical bonding, forms a stable low surface energy molecular layer on the aerogel skeleton and fiber surface, giving the material overall superhydrophobicity (contact angle > 150°), actively repelling liquid water and preventing the degradation of thermal insulation performance and structural damage caused by water vapor wetting. Meanwhile, phosphorus-nitrogen composite flame retardant synergist 4, also chemically bonded and uniformly dispersed in the three-dimensional network of the aerogel, can exert a synergistic flame retardant effect when exposed to heat or open flame. Through multiple mechanisms such as gas-phase flame retardancy (capturing free radicals) and condensed-phase flame retardancy (promoting char formation), the material is endowed with excellent intrinsic flame retardancy, achieving self-extinguishing upon removal of the flame, low smoke, and no dripping. The fiber skeleton, nanoporous aerogel, hydrophobic layer, and flame retardant are tightly combined through chemical and physical interactions to form a stable composite system that combines high-efficiency thermal insulation, long-lasting waterproofing, and active fire protection.

[0025] Application Process: In practical applications, the aerogel felt rolls or sheets are first cut according to the shape and size of the equipment or structure to be insulated. Then, they are directly wrapped, adhered to, or filled onto the surface of the target object (such as industrial pipelines, storage tanks, building walls, or equipment shells). During service, its nanoporous aerogel structure continuously provides highly efficient thermal insulation, significantly reducing heat loss or cold bridging effects. When the ambient humidity is high or liquid water is splashed, its superhydrophobic surface can quickly repel water droplets, keeping itself dry and ensuring long-term stable thermal insulation performance. If a fire or localized abnormal high temperature occurs in the environment, the intrinsic flame-retardant system in the material will be activated, effectively delaying the spread of flames and inhibiting combustion, buying crucial emergency response time for the protected object. The entire application process requires no additional maintenance; this material provides stable thermal insulation, waterproofing, and fireproof safety protection in one comprehensive solution.

[0026] See Figure 2 The image shows a method for preparing a fire-retardant and hydrophobic aerogel felt according to an embodiment of the present invention, comprising: S1. Measure the porosity characteristics of the flexible fiber skeleton, collect the basic chemical performance data of the aerogel precursor, hydrophobic modifier and flame retardant synergist, and calculate the target loading amount of the aerogel precursor in the skeleton based on the porosity characteristics and chemical performance data.

[0027] This invention calculates the target loading amount of the aerogel precursor in the framework based on the aforementioned pore characteristics and chemical performance data. This clarifies the optimal impregnation amount of the aerogel precursor solution, providing a clear dosage basis for the subsequent formation of a uniform and firmly bonded alumina aerogel 2 composite structure in the flexible fiber framework. The flexible fiber framework is a porous flexible carrier such as ceramic fiber mat or glass fiber mat that constitutes the main structure of the aerogel mat. The pore characteristics mainly refer to the porosity, average pore size, and connectivity of the flexible fiber framework. The basic chemical performance data includes the concentration and viscosity of the aerogel precursor, the reactivity of the hydrophobic modifier, the dispersibility of the flame retardant synergist, and its chemical compatibility with the framework material. The target loading amount refers to the optimal mass or volume of the precursor solution that can fully fill the framework pores while avoiding gel shrinkage, cracking, or performance degradation due to excessive impregnation. Furthermore, the pore characteristics of the flexible fiber framework can be quantitatively obtained through mercury intrusion porosimetry, gas adsorption, or image analysis. The acquisition of the basic chemical performance data can be achieved through chemical characterization methods such as rheological testing, infrared spectroscopy analysis, and dispersion stability experiments.

[0028] As an embodiment of the present invention, the step of calculating the target loading amount of the aerogel precursor in the framework based on the pore characteristics and chemical performance data includes: Based on the aforementioned pore characteristics, the available pore volume of the flexible fiber skeleton is calculated. The chemical properties of the aerogel precursor were analyzed, and the volume shrinkage characteristics during the gelation process were combined to calculate the solid content conversion rate of the precursor solution from impregnation to the formation of dry gel. Based on the available pore volume and the solid content conversion rate, the initial theoretical loading of the aerogel precursor solution required to achieve the predetermined pore filling degree is calculated. The chemical performance data of the hydrophobic modifier and flame retardant synergist were obtained, and the degree of influence of their introduction on the gel network structure and volume changes was analyzed. The initial theoretical loading is adjusted based on the degree of influence to determine the target loading of the aerogel precursor in the skeleton.

[0029] The available pore volume refers to the total pore space in the flexible fiber skeleton that can be effectively filled by the precursor solution; the solid content conversion rate reflects the proportion of the mass or volume of the solid aerogel that is ultimately retained in the skeleton after the precursor solution undergoes the sol-gel process and drying to the mass or volume of the initial impregnation solution; the predetermined pore filling degree is a pore filling target set in advance to meet the thermal insulation, mechanical and other performance requirements of the final product; the degree of influence refers to the possibility that the introduction of hydrophobic modification and flame retardant components may change the crosslinking density of the gel network, thereby affecting the gel shrinkage rate and the final retention rate in the skeleton.

[0030] Optionally, based on the porosity characteristics, the available pore volume of the flexible fiber skeleton can be estimated using geometric calculations or empirical formulas; the mass or volume change of the aerogel precursor from solution to dry gel under specific formulations and processes can be measured through laboratory-scale tests to obtain the solid content conversion rate; combining the available pore volume and the solid content conversion rate, the initial theoretical loading of the precursor solution required for impregnation can be calculated through multiplication and division operations; comparative experiments can be conducted to analyze the changes in gel shrinkage and mechanical strength before and after adding modifiers and synergists to quantify their influence; based on the influence, the initial theoretical loading can be adjusted using a proportional correction method or by establishing empirical coefficients. Generally, if the additive increases shrinkage, the loading is increased; if it strengthens the network, it is decreased as appropriate, ultimately determining a target loading that ensures uniform filling, no cracking, and satisfactory performance.

[0031] S2. Test the chemical compatibility and efficiency of the hydrophobic modifier and the flame retardant synergist to obtain synergistic modification data. Combined with the gelation characteristics determined by the aerogel precursor preparation process, calculate the structural stability and functional binding degree of the aerogel composite.

[0032] By combining the synergistic modification data with the gelation characteristics, this invention calculates the structural stability and functional integration of the aerogel composite, thereby obtaining the robustness of the internal structure of the composite and the effective integration level of hydrophobic and flame-retardant functions. This provides a direct basis for subsequently determining a preparation process that can simultaneously ensure structural strength and functional durability.

[0033] The synergistic modification data refers to a set of data obtained through testing that reflects the interaction between the hydrophobic modifier and the flame retardant synergist, and their impact on the aerogel network. The gelation characteristics refer to the time, temperature, and network formation features exhibited by the aerogel precursor during the transformation from sol to gel under specific conditions. The structural stability refers to the ability of the final aerogel composite to resist cracking, pulverization, and structural collapse. The functional binding degree refers to the firmness and uniformity of the bonding between the hydrophobic and flame retardant functional components and the alumina aerogel 2 network through chemical bonding and other means. Furthermore, the synergistic modification data can be obtained through experiments such as infrared spectroscopy analysis, thermogravimetric analysis, and observation of the dispersion uniformity in a co-solvent after mixing the modifier and synergist in a specific ratio. The gelation characteristics can be confirmed by monitoring the viscosity change of the precursor solution, determining the gel point, and observing the morphology of the wet gel.

[0034] As an embodiment of the present invention, the calculation of the structural stability and functional integration of the aerogel composite by combining the synergistic modification data and the gelation characteristics includes: The network strengthening factor under the combined action of the hydrophobic modifier and the flame retardant synergist was extracted from the synergistic modification data. The formation rate and crosslinking density characteristics of the aerogel network were determined from the gelation properties. The structural stability of the aerogel composite is calculated by combining the network strengthening factor, the formation rate, and the crosslinking density characteristics. Analyze the bonding efficiency and distribution uniformity of functional groups in the synergistic modification data; The functional binding degree of the aerogel composite is calculated by combining the bonding efficiency, the distribution uniformity information, and the crosslinking density characteristics.

[0035] The network strengthening factor characterizes the effect of the introduction of hydrophobic and flame-retardant components on the mechanical strength of the aerogel skeleton; the formation rate affects the homogeneity of the gel network; the crosslinking density characteristic determines the basic rigidity and toughness of the gel network; the bonding efficiency reflects the proportion of hydrophobic silanes and flame retardants effectively bonded to the siloxane network; and the distribution uniformity information describes the dispersion state of the functional components in the three-dimensional network.

[0036] Optionally, the network strengthening factor is quantified by comparing the compressive modulus or strength data of aerogels with and without the modified synergist system; the formation rate and crosslinking density characteristics are jointly determined by monitoring the time of the storage modulus surge point using a rheometer or recording the gelation time by observation, combined with the density estimation of the final dry gel; the network strengthening factor is used as a correction coefficient and multiplied by the basic structural strength value calculated based on the formation rate and crosslinking density to obtain the quantified structural stability. The bonding efficiency can be calculated by elemental analysis or by integrating the infrared peak areas of characteristic functional groups; the distribution uniformity information is evaluated by scanning electron microscopy combined with energy dispersive spectroscopy (EDS) surface distribution maps; the functional binding degree is obtained by substituting the bonding efficiency, distribution uniformity score, and crosslinking density characteristic value into a weighted calculation formula.

[0037] Furthermore, as another optional embodiment of the present invention, the step of calculating the structural stability of the aerogel composite by combining the network strengthening factor, the formation rate, and the crosslinking density characteristics includes: Based on the crosslinking density characteristics, the relative density of the aerogel composite was calculated; The structural stability of the aerogel composite is calculated using the following formula, taking into account the network strengthening factor, the formation rate, and the relative density:

[0038] in, Indicates the structural stability of the aerogel complex. Indicates the process adaptation constant. Indicates relative density. Represents the performance correlation constant. Indicates the network reinforcement factor. Indicates the formation rate.

[0039] The relative density is calculated based on the crosslinking density characteristics to determine the degree of network densification of the aerogel composite. This degree of network densification reflects the fullness of solid material per unit volume of the gel network skeleton at a given crosslinking density. Furthermore, based on the crosslinking density characteristics, the relative density of the aerogel composite is calculated through the correlation between density and porosity. For example, the relative density can be quantitatively characterized by measuring the apparent density of the composite and comparing it with the theoretical density of the silica skeleton used, using the ratio of the two.

[0040] S3. Based on the structural stability and functional integration and the target load, determine the molding process requirements of the aerogel, set the preparation process parameters accordingly, and perform composite preparation to obtain the fireproof and hydrophobic aerogel felt.

[0041] This invention, by combining the aforementioned structural stability and functional integration with the target loading amount, determines the molding process requirements for aerogels, thereby clarifying the specific operational points for each stage of sol impregnation, gel conversion, and subsequent processing, to improve the synergistic level of structural uniformity and functional reliability of the final product. The molding process requirements guide the concentration, temperature, time, and environmental conditions required for precursor solution impregnation of the framework, gelation, and functional bonding. Furthermore, it is necessary to first comprehensively evaluate the quantitative results of structural stability and functional integration to clarify the basic reaction environment required to obtain a robust network and effective bonding, while accurately matching the solution volume limited by the target loading amount. Based on this, and according to chemical principles and preparation experience, suitable process requirements are determined to ensure that the aerogel is uniformly molded within the framework, has a stable network structure, and exhibits durable function, thus guaranteeing that the product performance meets expectations.

[0042] As an embodiment of the present invention, determining the molding process requirements of the aerogel based on the structural stability and functional integration and the target loading amount includes: Based on the structural stability, the basic gel environment after impregnation with the aerogel precursor solution is determined; Based on the functional binding degree, the addition stage of the hydrophobic modifier and flame retardant synergist during the gelation process is determined; Obtain the specific solution volume corresponding to the target loading capacity; Based on the basic gel environment, the addition stage, and the specific solution dosage, the molding process requirements for the aerogel are determined.

[0043] The basic gel environment refers to the combination of temperature, humidity, and standing time required for the aerogel precursor solution to achieve stable network transformation; the addition stage refers to the specific operational point at which the hydrophobic modifier and flame retardant synergist are introduced during solution preparation, impregnation, or the initial stage of gelation; and the specific solution dosage is the precise amount of precursor solution that needs to be impregnated into the flexible fiber skeleton per unit area or volume corresponding to the target loading amount.

[0044] Optionally, based on the structural stability index, the basic gel environment can be determined by consulting the corresponding process guidelines for the material system, such as the specific aging temperature and duration required to achieve a high stability index; based on the functional binding index, the addition stage can be determined by analyzing the reaction compatibility between the functional components and the network precursor, for example, to obtain a high binding index, a uniform blending addition method in the sol stage is required; the calculated target loading value can be directly used as the specific solution dosage.

[0045] Furthermore, as another optional embodiment of the present invention, the molding process requirements of the aerogel are determined by constructing a step-by-step operation list, combining the basic gel environment, the addition stage, and the specific solution dosage. Specifically, based on the specific solution dosage, the number of impregnation operations and the solution volume for each operation are determined; after the impregnation step, the temperature and humidity control values ​​of the gel container are immediately set according to the basic gel environment; according to the addition stage, functional additives are added in the predetermined steps in the operation list and stirred for a specified duration, thereby forming a set of molding process requirements with clear sequence and quantified conditions.

[0046] This invention sets process execution parameters for the composite preparation based on the structural stability, functional integration, and target loading, ensuring that each step from solution preparation to gel formation has clear and executable quantitative standards, providing a precise process control basis for obtaining products with consistent performance. The process execution parameters are specific numerical settings that guide the operation of actual production equipment or experimental apparatus, directly determining the impregnation uniformity, gel network quality, and final product performance.

[0047] As another embodiment of the present invention, the step of setting the preparation process parameters includes: Based on the basic gel environment in the molding process requirements, the control temperature, ambient humidity and standing time of the gelation stage are set. Based on the addition stage in the molding process requirements, the specific operation steps and mixing intensity for adding functional additives are set. Based on the specific solution dosage and skeleton dimensions, the initial solution concentration and replenishment cycle of the impregnation tank are calculated. By combining the control of temperature, ambient humidity, settling time, feeding steps, mixing intensity, solution concentration, and replenishment cycle, the preparation process parameters are set.

[0048] Among them, the control of temperature, ambient humidity and settling time are key environmental conditions affecting the sol-to-gel transformation process and the integrity of the network structure; the feeding steps and mixing intensity are key operational factors to ensure uniform dispersion of functional components and full interaction with the network precursor; the initial concentration of the solution and the replenishment cycle are important material control benchmarks for maintaining the stability of the impregnation solution composition and achieving the target load.

[0049] Optionally, based on the basic gel environment, the control temperature, ambient humidity, and settling time can be directly set via the controller of the environmental test chamber; based on the addition stage, the specific operation steps for adding the functional additive and the mixing intensity set by the stirrer can be clearly specified in the standard operating procedure; based on the specific solution dosage and the size and quantity of the skeleton, the initial concentration of the solution required for the impregnation tank is calculated through material balance, and the solution replenishment cycle is determined based on the evaporation loss data.

[0050] This invention, by combining the molding process requirements and preparation process parameters, performs a composite preparation process of the aerogel precursor, hydrophobic modifier, and flame retardant synergist. This improves the controllability and repeatability of the preparation process, ensuring that the aerogel is shaped as designed within the framework and that its functions are effectively combined. Based on the prepared product, subsequent drying and finishing processes yield a fire-retardant and hydrophobic aerogel felt with a complete structure and meeting performance standards, reducing batch performance differences caused by fluctuations in process conditions. The composite preparation process involves sequentially performing solution preparation, framework impregnation, gelation, and drying. Furthermore, firstly, based on the aforementioned preparation process parameters, each component is accurately weighed, and a precursor solution containing functional additives is prepared under controlled mixing intensity. Then, the flexible fiber skeleton is immersed in the prepared solution, ensuring that the immersion time and number of operations meet the requirements, allowing the solution to fully penetrate according to the specific solution dosage. Subsequently, the impregnated system is placed in an environment that meets the conditions of controlled temperature, ambient humidity, and settling time to complete the gel conversion. Finally, the obtained wet gel composite is dried to obtain a dry aerogel felt product, completing the entire composite preparation process.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fireproof hydrophobic aerogel mat comprising a flexible fibrous skeleton (1), characterized in that: The flexible fiber skeleton (1) is uniformly distributed with alumina aerogel (2) inside and on the surface, wherein the alumina aerogel (2) is introduced with organosilane hydrophobic modifier (3) and flame retardant synergist (4) by chemical bonding, and the flexible fiber skeleton (1), alumina aerogel (2), hydrophobic modifier and flame retardant synergist (4) are sequentially compounded to form a fireproof and hydrophobic aerogel felt product layer (5).

2. A fire resistant hydrophobic aerogel blanket according to claim 1, wherein, The flexible fiber skeleton (1) is selected from at least one of ceramic fiber felt, glass fiber felt or pre-oxidized silk fiber felt.

3. A fire resistant hydrophobic aerogel blanket according to claim 1, wherein, The organosilane hydrophobic modifier (3) is at least one of hexamethyldisilazane, trimethylchlorosilane or methyltrimethoxysilane.

4. A fire resistant hydrophobic aerogel blanket according to claim 1, wherein, The flame retardant synergist (4) comprises a complex system of phosphorus-containing compounds and nitrogen-containing compounds.

5. A fire resistant hydrophobic aerogel blanket according to claim 1, wherein, The flame retardant synergist (4) is uniformly dispersed in the three-dimensional network structure of the alumina aerogel (2).

6. A fire resistant hydrophobic aerogel blanket according to claim 1, wherein, The contact angle of the aerogel felt in use is greater than 150°, and it has intrinsic flame retardance.

7. A method of making a fire barrier hydrophobic aerogel blanket according to any one of claims 1 to 6, characterized in that, The method comprises: measuring the pore characteristics of the flexible fiber skeleton, collecting the basic chemical property data of the aerogel precursor, hydrophobic modifier and flame retardant synergist, and calculating the target load of the aerogel precursor in the skeleton based on the pore characteristics and chemical property data; testing the chemical compatibility and action efficiency of the hydrophobic modifier and flame retardant synergist to obtain synergistic modification data, and combining the gelation characteristics determined during the preparation process of the aerogel precursor to calculate the structure stability and function combination degree of the aerogel composite; based on the structure stability and function combination degree and the target load, determining the forming process requirements of the aerogel, and setting the preparation process parameters accordingly to perform the composite preparation process to obtain the fireproof and hydrophobic aerogel felt.

8. The method of claim 7, wherein, The calculation of the target load of the aerogel precursor in the skeleton based on the pore characteristics and chemical property data comprises: calculating the available pore volume of the flexible fiber skeleton based on the pore characteristics; analyzing the chemical property data of the aerogel precursor, combining the volume shrinkage characteristics during the gelation process, and calculating the solid content conversion rate of the precursor solution from impregnation to dry gel formation; combining the available pore volume and the solid content conversion rate to calculate the initial theoretical load of the aerogel precursor solution required to reach the predetermined pore filling degree; obtaining the chemical property data of the hydrophobic modifier and flame retardant synergist, and analyzing the influence degree of the introduction on the gel network structure and volume change; based on the influence degree, the initial theoretical load is adjusted to determine the target load of the aerogel precursor in the skeleton.

9. The method of claim 7, wherein, The calculation of the structure stability and function combination degree of the aerogel composite based on the synergistic modification data and the gelation characteristics comprises: extracting the network strengthening factor under the joint action of the hydrophobic modifier and flame retardant synergist from the synergistic modification data; determining the formation speed and crosslinking density characteristics of the aerogel network from the gelation characteristics; combining the network strengthening factor, the formation speed and the crosslinking density characteristics to calculate the structure stability of the aerogel composite; analyzing bonding efficiency and distribution uniformity information of the functional groups in the synergistically modified data; combining the bonding efficiency, the distribution uniformity information, and the crosslinking density characteristics to calculate the functional bonding degree of the aerogel composite.

10. The method of claim 7, wherein, determining the molding process requirements of the aerogel based on the structural stability and the functional bonding degree, and the target load amount, including: determining a basic gel environment after the aerogel precursor solution is impregnated according to the structural stability; determining an addition stage of the hydrophobic modifier and the flame-retardant synergist in the gel process according to the functional bonding degree; obtaining a specific solution amount corresponding to the target load amount; determining the molding process requirements of the aerogel in combination with the basic gel environment, the addition stage, and the specific solution amount.

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