An apparatus and method for preparing hollow mesoporous silica microspheres

Abstract

This invention belongs to the field of inorganic nanomaterial synthesis technology, specifically relating to a preparation device and method for hollow mesoporous silica microspheres, comprising the following steps: Based on a preset outer diameter of the hollow mesoporous silica microspheres, the addition flow rates of polymer monomers, initiators, and surfactants are automatically calculated and adjusted to prepare a hard template emulsion with a set particle size; the hard template emulsion is transported to a coating synthesis unit for a coating synthesis reaction, and ultrasonic treatment is applied to the hard template emulsion during the transport process; during the coating synthesis reaction, after the hard template emulsion, silicon source, and pore-forming agent are mixed evenly, microwaves are applied to the reaction system, and the pressure of the reaction system is controlled at 0.15-0.5 MPa; after the reaction is completed, the mixture is centrifuged and washed to obtain a solid reactant; the hard template is removed from the solid reactant to obtain hollow mesoporous silica microspheres. This invention can solve the problems of long production cycle and difficulty in systematically and accurately controlling pore size / particle size in the preparation of hollow mesoporous silica microspheres using the hard template method.

Description

Technical Field

[0001] This invention belongs to the field of inorganic nanomaterial synthesis technology, specifically relating to a device and method for preparing hollow mesoporous silica microspheres. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] The most mature and mainstream method for hollow mesoporous silica microspheres (HMSS) is the hard template method. This method typically uses polymer colloidal microspheres as sacrificial templates and surfactants as pore-forming agents. A silica precursor is coated onto the surface of the polymer template through a sol-gel process. Finally, the internal polymer template is removed by high-temperature calcination or chemical solvent etching, thus obtaining the hollow mesoporous structure. However, when applying this method to industrial applications or scenarios requiring high-precision customization, the following drawbacks are easily exposed: The emulsion polymerization synthesis of polymer hard templates, the encapsulation polycondensation of silicon sources, and the subsequent template removal are typically carried out step-by-step in completely separate reaction equipment. This not only leads to long production cycles (a single complete synthesis often takes several days), but also makes it highly susceptible to introducing impurities or agglomeration during the transfer process. More importantly, manual operation results in unstable mass and heat transfer conditions, with significant differences in microsphere diameter and shell thickness between batches, making it difficult to achieve precise industrial-scale reproduction.

[0004] In existing processes, the outer diameter of HMSS mainly depends on the size of the hard template, while the mesopore size mainly depends on the type of porogen and the reaction temperature. Changing the final product's dimensions requires redesigning the polymer template synthesis formulation and conducting manual trial and error.

[0005] Traditional silica coating processes are mostly carried out at room temperature or under conventional water bath heating. This not only results in slow reaction kinetics of TEOS hydrolysis and condensation but also often leads to uneven coating thickness due to temperature gradients. In recent years, some researchers have attempted to introduce microwave-assisted heating into the synthesis of mesoporous materials to shorten the time. However, while microwave heating alone accelerates the reaction, it can easily cause the silica shell to rupture or the pore structure to collapse due to gas escape during rapid condensation. Furthermore, the lack of a pressure field means that it is impossible to dynamically intervene at the microscale in terms of mesopore density and pore size through physical means (rather than adding complex chemical pore-forming agents). Summary of the Invention

[0006] This invention addresses the technical shortcomings of existing technologies in preparing hollow mesoporous silica microspheres using the hard template method, such as long production cycles, difficulty in systematically and precisely controlling pore size / particle size, poor batch consistency, and inability to achieve automated continuous production. It provides a device and method for preparing hollow mesoporous silica microspheres.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides an apparatus for preparing hollow mesoporous silica microspheres, comprising a polymer template synthesis unit, an online homogenization and mixing transition unit, a coating synthesis unit and an automatic separation and template removal unit connected in sequence, as well as a central microcontroller system; The coating synthesis unit includes a second reactor and a microwave generating module. The microwave generating module is located outside the second reactor, and the microwave conduction direction is towards the second reactor. The second reactor is made of microwave-transparent material. The top of the second reactor is equipped with an electronic pressure regulating valve and a raw material inlet, and the bottom is equipped with a material outlet. The electronic pressure regulating valve is connected to the central micro-control system.

[0008] Secondly, the present invention provides a method for preparing hollow mesoporous silica microspheres, comprising the following steps: Based on the preset outer diameter of hollow mesoporous silica microspheres, the addition flow rates of polymer monomers, initiators and surfactants are automatically calculated and adjusted to prepare hard template emulsions with set particle sizes. The hard template emulsion is transported to the coating synthesis unit for coating synthesis reaction, and ultrasonic treatment is applied to the hard template emulsion during the transport process; During the coating synthesis reaction, after the hard template emulsion, silicon source and porogen are mixed evenly, microwaves are applied to the reaction system and the pressure of the reaction system is controlled at 0.15-0.5 MPa. After the reaction was complete, the product was centrifuged and washed to obtain a solid reactant. The hard template was removed from the solid reactants to obtain hollow mesoporous silica microspheres.

[0009] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: This invention introduces a microwave generating module, utilizing the internal heating effect of microwaves on polar molecules to effectively reduce the activation energy of the silica hydrolysis and polycondensation reaction. This shortens the traditional sol-gel coating process from 24-48 hours to just a few hours, significantly improving production efficiency.

[0010] This invention establishes a micro-positive pressure environment through an electronic pressure regulating valve, which not only increases the boiling point of the system and ensures the structural integrity of the coating layer, but also enables nanoscale precision intervention on the mesopore size by real-time fine-tuning of the surfactant micelle arrangement spacing through changes in the pressure field. This solves the industry problem that a single microwave field can easily lead to localized overheating, violent solvent boiling, and thus tearing of the microsphere shell or collapse of the pores.

[0011] This invention innovatively integrates the synthesis of hard templates (determining outer diameter) with shell coating (determining pore size and wall thickness) into a fully automated fluid system. Leveraging the algorithmic calculations of the central microcontroller system, the operator only needs to input the target parameters, and the system automatically calculates and executes the flow rate and reaction conditions, completely eliminating human error and batch instability inherent in traditional step-by-step operations. The central microcontroller system enables fully unmanned continuous production, suitable for industrial scale-up.

[0012] The specially designed online homogenization and blending transition module eliminates the risk of particle agglomeration caused by manual centrifugation, washing and transfer in traditional processes, ensuring the monodispersity of microspheres during the coating stage, and enabling the product quality to meet the stringent standards of high-end industrial applications (such as marine environment anti-corrosion coatings, high-efficiency oil adsorption and targeted drug delivery systems). Attached Figure Description

[0013] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0014] Figure 1 This is a block diagram showing the overall pipeline connection and signal control of the hollow mesoporous silica microsphere preparation device according to an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of the encapsulated synthesis unit with synergistic coupling of microwave field and micro-positive pressure field according to an embodiment of the present invention. Figure 3 This is a flowchart illustrating the steps of a method for preparing hollow mesoporous silica microspheres according to an embodiment of the present invention. Figure 4 The images show electron microscope comparisons of the microstructures of HMSS products prepared under different pressure parameters according to the present invention. Among them, (a) is Comparative Example 1, (b) is Example 3, (c) is Example 2, (d) is Example 4, and (e) is Comparative Example 2.

[0015] Figure 5 The pore size distribution and specific surface area characterization curves of the hollow mesoporous silica microspheres prepared in Example 2 of the present invention are shown. Figure 6 The images show the infrared spectra of the PS microspheres prepared in Example 2 of this invention before and after surface coating. Figure 7 This is a particle size distribution diagram of the HMSS synthesized in Example 2 of the present invention.

[0016] In the diagram: 1-Polymer template synthesis unit; 10-Inert gas exhaust port; 11-Multi-channel feeding system; 12-First reaction vessel; 13-Temperature control jacket; 14-Control flow rate signal; 15-Control stirring speed signal; 16-Temperature adjustment signal; 2-Online homogenization and blending transition unit; 21-Online flow meter; 22-Solvent replenishment valve; 23-Concentration sensor; 24-Ultrasonic array; 25-Solvent replenishment adjustment signal; 26-Ultrasonic control signal; 3-Coating synthesis unit; 31-Microwave generator module; 32-Second reactor; 33-Fiber optic temperature probe; 34-Electronic pressure regulating valve; 35-Silicon source feed pump; 36-Microwave generator module / electronic pressure regulating valve / silicon source feed pump control signal; 37-Temperature control signal; 38-Raw material inlet; 39-Material outlet; 4-Automatic separation and template removal unit; 41-Centrifugal washing assembly; 42-Template removal chamber; 43-HMSS finished product outlet; 44-Send start / stop and program commands; 45-Waste gas / waste liquid discharge outlet. Detailed Implementation

[0017] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0018] Hollow mesoporous silica microspheres (HMSS) have shown great promise for applications in targeted drug delivery, efficient catalyst supports, adsorption separation, and energy storage materials due to their low density, high specific surface area, large pore volume, ease of differentiated functionalization of inner and outer surfaces, and good biocompatibility.

[0019] To address the technical problems existing in the background art, the present invention provides a device for preparing hollow mesoporous silica microspheres, comprising a polymer template synthesis unit, an online homogenization and mixing transition unit, a coating synthesis unit, and an automatic separation and template removal unit connected in sequence, as well as a central micro-control system; The coating synthesis unit includes a second reactor and a microwave generating module. The microwave generating module is located outside the second reactor, and the microwave conduction direction is towards the second reactor. The second reactor is made of microwave-transparent material. The top of the second reactor is equipped with an electronic pressure regulating valve and a raw material inlet, and the bottom is equipped with a material outlet. The electronic pressure regulating valve is connected to the central micro-control system.

[0020] In some embodiments, the interior of the second reactor is provided with a multi-point fiber optic temperature probe.

[0021] In some embodiments, the polymer template synthesis unit includes a first reactor, a temperature control jacket is provided on the side of the first reactor, and the first reactor is connected to a multi-channel precision feeding system.

[0022] Preferably, the multi-channel precision feeding system includes a fluidly connected multi-channel liquid storage array, a pretreatment module, and a pulse-free precision metering pump set. The pretreatment module integrates an automatic liquid separation flow path and an online purification flow path. For the polymer monomer channel containing polymerization inhibitors, the pretreatment module is equipped with a bypass electromagnetic switching valve and a micro-adsorption column filled with an activated alkaline alumina stationary phase.

[0023] In the in-situ removal of monomer polymerization inhibitors, a central microcontroller system drives the monomer concentrate to flow through the micro-adsorption column. Utilizing the specific acid-base complexation and physical adsorption of phenolic polymerization inhibitors such as p-tert-butylcatechol (TBC) in the monomers by alkaline alumina, the online interception of the inhibitors is completed instantaneously within a closed pipeline. The purified free monomer is then filtered through a series of 0.22 μm polytetrafluoroethylene microfiltration membranes to remove impurity particles and directly injected quantitatively into the first reaction vessel by a pulseless precision metering pump. This in-situ removal structure eliminates the cumbersome manual alkaline washing, water washing, and drying processes of traditional methods, achieving zero exposure to toxic substances and ensuring that the monomers entering the reaction vessel have absolutely uniform reactivity. This lays a crucial foundation for the subsequent synthesis of highly monodisperse polymer hard templates.

[0024] Preferably, both the temperature control jacket and the multi-channel precision feeding system are signal-connected to the central microcontroller system.

[0025] Preferably, the top of the first reactor is provided with an inert gas exhaust port and a stirrer, and the motor of the stirrer is connected to the central microcontroller system.

[0026] In some embodiments, the online homogenization and blending transition module includes a mixing chamber, an ultrasonic array, an online flow meter, and a concentration sensor; The inlet of the mixing chamber is connected to the outlet of the polymer template synthesis unit, and the outlet of the mixing chamber is connected to the coating synthesis unit; a solvent replenishment valve is provided on the side of the mixing chamber; An ultrasonic array is arranged around the outside of the mixing cavity; Online flow meters and concentration sensors are used to detect the flow rate and concentration of materials in the mixing chamber online, respectively.

[0027] Preferably, the solvent replenishment valve, online flow meter, and concentration sensor are all connected to the central microcontroller system via signal connection.

[0028] This module is used to break up potential particle agglomeration during template emulsion transfer. The central micro-control system combines the flow rate data from the online flow meter with the concentration signal from the optical concentration sensor to accurately calculate the amount of dispersion medium to replenish. By automatically replenishing the dispersion medium, the system is adjusted to the optimal coating concentration threshold.

[0029] In some embodiments, the automatic separation and template removal unit includes a high-speed centrifugal washing assembly and a high-temperature calcination / solvent reflux extraction chamber.

[0030] In some embodiments, the automatic separation and template removal units are arranged vertically in series by gravity. The high-speed centrifugal washing assembly is located at the top, including a fully enclosed scraper-type microporous filter centrifuge and its built-in automatic programmed spray cleaning ring; the high-temperature calcination / solvent reflux extraction chamber is located at the bottom, and is a double-effect integrated reactor with an external gradient heating jacket and a top solvent condensation reflux tower. The two are flexibly connected by a star-shaped rotary discharge valve with airtight isolation function.

[0031] In the automated process, the coated suspension first enters the upper centrifugal washing unit, where liquid-solid separation and in-situ purification are completed under the alternating action of centrifugal force and automatic spraying. Subsequently, a pneumatic scraper scrapes off the washed core-shell microspheres, which then fall seamlessly by gravity into the lower high-temperature calcination / solvent reflux extraction chamber through the quantitative opening and closing of a star-shaped rotary discharge valve. Within this chamber, the central microcontroller can adaptively switch programs based on the rigid template material: either injecting organic solvent and initiating top condensation reflux for circulating extraction, or blowing oxidizing gas from the bottom and activating an external heating jacket for fluidized high-temperature calcination. This vertically connected and physically isolated structural design completely avoids material loss and environmental pollution caused by manual transfer of filter cake in traditional processes, achieving integrated, fully enclosed, continuous production from solid-liquid separation to template removal.

[0032] Secondly, the present invention provides a method for preparing hollow mesoporous silica microspheres, comprising the following steps: Based on the preset outer diameter of hollow mesoporous silica microspheres, the addition flow rates of polymer monomers, initiators and surfactants are automatically calculated and adjusted to prepare hard template emulsions with set particle sizes. The hard template emulsion is transported to the coating synthesis unit for coating synthesis reaction, and ultrasonic treatment is applied to the hard template emulsion during the transport process; During the coating synthesis reaction, after the hard template emulsion, silicon source and porogen are mixed evenly, microwaves are applied to the reaction system and the pressure of the reaction system is controlled at 0.15-0.5 MPa. After the reaction was complete, the product was centrifuged and washed to obtain a solid reactant. The hard template was removed from the solid reactants to obtain hollow mesoporous silica microspheres.

[0033] The pressure inside the reactor is maintained at a set micro-positive pressure (0.15 MPa-0.50 MPa) by an electronic pressure regulating valve, thereby suppressing the localized and violent vaporization of the solvent in the microwave high-temperature field, and synergistically controlling the self-assembly compactness of the porous micelles, thus achieving precise intervention on the mesopore size of the silica shell.

[0034] In some embodiments, a method for automatically calculating and adjusting the dosing rates of polymer monomers, initiators, and surfactants based on a preset outer diameter of hollow mesoporous silica microspheres.

[0035] Furthermore, the central microcontroller system embeds a multidimensional parameter mapping database based on semi-empirical emulsion polymerization kinetics and an automatic calculation module. Based on the preset outer diameter of the hollow mesoporous silica microspheres (i.e., the particle size of the hard template)... The method for automatically calculating and adjusting the dosing rates of polymer monomers, initiators, and surfactants includes the following calculation and execution steps: Step A: Establish an inverse solution model for the target particle size and substance concentration. The central microcontroller system solves the equation based on the pre-stored emulsion polymerization particle size control equation. The underlying logic of this equation follows a multivariate power-law relationship model: = K

[0036] in, Target hard template particle size; , , , respectively, represent the cumulative concentrations of monomer, surfactant and initiator in the system; T is the real-time reaction temperature fed back by the high-frequency dynamic temperature control jacket; K is a system-specific equipment constant; a, b, and c are all positive empirical exponential coefficients.

[0037] The system uses a multiple nonlinear regression algorithm to inversely solve for the optimal total molar ratio threshold of the three components required to achieve the target particle size, given the boundary conditions of target D and room temperature T.

[0038] Step B: Decomposition of time-series flow rates during the nucleation and growth phases (staged dosing strategy). After obtaining the total molar ratio, the central microcontroller automatically divides the polymerization process into the "micelle nucleation phase" and the "microparticle growth phase," and calculates the dynamic dosing flow rate for each stage: Micelle nucleation stage flow rate control: The system instructs the multi-channel precision feeding system to preferentially inject the surfactant solution at a preset maximum pumping flow rate, ensuring that its instantaneous concentration in the first reactor exceeds the critical micelle concentration (CMC). Subsequently, the initiator feed pump and monomer feed pump are instructed to perform short-term droplets at high pulse flow rates (e.g., 1.5-2.0 times the base flow rate). This stage aims to utilize the high concentration of surfactant to form a large number of uniform initial crystal nuclei, thereby controlling the number of microspheres.

[0039] Microparticle growth phase flow rate control: When the system determines the end of the nucleation period via a built-in timer, the central microcontroller issues a cutoff or deceleration command to the feed pump: reducing the surfactant drop rate to zero or an extremely low value (inhibiting secondary nucleation); simultaneously, based on the remaining monomer amount calculated by the formula, a "constant rate drop" or "starve-fed" strategy is adopted to deliver the polymer monomer at a precisely constant flow rate (e.g., v). m Inject smoothly at a rate of mL / min.

[0040] Step C: Flow control execution and dynamic compensation. The central microcontroller system converts the calculated flow rate profile into an electrical signal, directly driving the stepper motor in the multi-channel precision feeding system. During polymerization, the system uses a PID algorithm to fine-tune the monomer dripping rate v in real time based on the minute temperature fluctuations fed back from the high-frequency dynamic temperature control jacket. m This ensures a constant chain growth rate, thereby completely eliminating batch errors caused by human intervention and controlling the coefficient of variation (CV) of the particle size distribution of the hard template to within 5%.

[0041] In some embodiments, during the process of delivering the hard template emulsion to the coating synthesis unit, while applying ultrasonic treatment to the hard template emulsion, the process also includes an online detection step of the flow rate and concentration of the hard template emulsion.

[0042] Preferably, when the concentration of the hard template emulsion is higher than a set value, solvent is added to it.

[0043] In some embodiments, the applied microwave power is 100-1000W.

[0044] In some embodiments, the coating synthesis reaction process includes a permeation assembly stage and a polycondensation solidification stage. The pressure inside the reactor during the permeation assembly stage is 0.4-0.5 MPa, the microwave power is 100-400 W, and the duration of this stage is 15-45 minutes. The pressure inside the reactor during the polycondensation and solidification stage is 0.15-0.25 MPa, the microwave power is 800-1000 W, and the duration of this stage is 5-20 minutes.

[0045] The synergistic coupling of the microwave field and pressure field in the coating synthesis unit adopts a dynamic adjustment mode. Specifically, in the initial stage of silica precursor drop addition, a low microwave power and high pressure coupling parameter is used to promote efficient penetration and dense assembly of the silicon source; in the polycondensation aging stage, the coupling parameter is switched to high microwave power and medium-low pressure to accelerate the three-dimensional cross-linking and curing of sol-gel.

[0046] The present invention will be further described below with reference to the embodiments.

[0047] Example 1 like Figure 1 and Figure 2 As shown, an apparatus for preparing hollow mesoporous silica microspheres includes a polymer template synthesis unit 1, an online homogenization and mixing transition unit 2, a coating synthesis unit 3, and an automatic separation and template removal unit 4, connected sequentially end to end, as well as a central microcontroller system. The central microcontroller system includes a processor and a memory. The memory stores a control program and a closed-loop control module that adjusts the microwave power and pressure valve opening in real time based on temperature, pressure, and concentration feedback signals. It dynamically and synchronously adjusts the output power of the microwave generator module and the opening of the electronic pressure regulating valve.

[0048] The coating synthesis unit 3 includes a second reaction vessel 32 and a microwave generating module 31. The microwave generating module 31 is located outside the second reaction vessel 32, and the microwave conduction direction is towards the second reaction vessel 32. The second reaction vessel 32 is made of microwave-transparent material. The top of the second reaction vessel 32 is provided with an electronic pressure regulating valve 34 and a raw material inlet 38. The raw material inlet is connected to a silicon source feed pump 35, and the bottom is provided with a material outlet 39. The microwave generating module 31, the silicon source feed pump 35, and the electronic pressure regulating valve 34 are all connected to the central micro-control system and are controlled accordingly using the microwave generating module / electronic pressure regulating valve / silicon source feed pump control signal 36. The interior of the second reaction vessel 32 is provided with a multi-point fiber optic temperature probe 33.

[0049] The synergistic coupling of the microwave field and pressure field in the coating synthesis unit adopts a dynamic adjustment mode. Specifically, in the initial stage of silica precursor drop addition, a low microwave power and high pressure coupling parameter is used to promote efficient penetration and dense assembly of the silicon source; in the polycondensation aging stage, the coupling parameter is switched to high microwave power and medium-low pressure to accelerate the three-dimensional cross-linking and curing of sol-gel.

[0050] The polymer template synthesis unit includes a first reactor 12, with a temperature control jacket 13 on its side, and the first reactor 12 is connected to a multi-channel precision feeding system 11. The multi-channel precision feeding system 11 specifically includes a multi-channel liquid storage array, a pretreatment module, and a multi-channel precision feed pump, which are sequentially fluidly connected. The pretreatment module utilizes an automatic liquid separation flow path and an online purification flow path to remove polymerization inhibitors from the monomers in situ before feeding. Specifically, for the monomer feeding channel containing polymerization inhibitors, the pretreatment module contains, along the fluid transport direction, a bypass electromagnetic switching valve, a micro-adsorption column filled with an activated alkaline alumina stationary phase, and a microfiltration membrane.

[0051] The process and principle of in-situ removal of monomer polymerization inhibitors are as follows: Before the polymerization reaction feed, the central microcontroller controls the bypass electromagnetic switching valve to drive the monomer stock solution containing polymerization inhibitors (such as p-tert-butylcatechol, TBC) through the micro-adsorption column. Utilizing the specific acid-base neutralization and strong hydrogen bond adsorption of slightly acidic phenolic polymerization inhibitors on the surface of alkaline alumina, the online solid-liquid phase micro-separation and interception of the polymerization inhibitor is completed instantaneously within the closed pipeline, while neutral and non-polar styrene monomer molecules flow out smoothly without hindrance. The purified free monomer is then filtered through a downstream series-connected microfiltration membrane (such as a 0.22 μm polytetrafluoroethylene filter membrane) to remove the tiny particles detached from the stationary phase, and is directly and quantitatively injected into the first reactor 12 by the multi-channel precision feed pump to participate in polymerization. A multi-channel precision feed pump and an optional pretreatment module are provided. The pretreatment module uses an automatic liquid separation flow path to remove monomer polymerization inhibitors in situ before feeding. The temperature control jacket 13 and the multi-channel precision feed pump are both connected to the central microcontroller system. The flow rate of the heating medium in the temperature control jacket 13 is adjusted by adjusting the temperature signal 16, and the feed flow rate of the multi-channel precision feed pump is controlled by controlling the flow rate signal 14. An inert gas exhaust port 10 and a stirrer are provided on the top of the first reactor 12. The motor of the stirrer is connected to the central microcontroller system, and the speed of the stirrer is controlled by controlling the stirring speed signal.

[0052] This device is used to automatically calculate and control the droplet flow rate and time of polymer monomers (such as styrene or methyl methacrylate), initiators, and surfactants based on the preset target microsphere outer diameter, thereby preparing a hard template (PS or PMMA) emulsion with a specific particle size.

[0053] The specific process of automatic calculation and control is as follows: The central microcontroller system is embedded with a multidimensional parameter mapping database based on semi-empirical emulsion polymerization kinetics and an automatic calculation module. The system first establishes an inverse solution model for the target particle size and substance concentration. The underlying logic of this model follows a multivariable power-law equation: = K ; in, Target hard template particle size; , , , respectively, represent the cumulative concentrations of monomer, surfactant and initiator in the system; T is the real-time reaction temperature fed back by the high-frequency dynamic temperature control jacket; K is a system-specific equipment constant; a, b, and c are all positive empirical exponential coefficients.

[0054] The central microcontroller system, through multiple nonlinear regression algorithms and the aforementioned equations, inversely solves for the optimal total molar ratio of the three components required to achieve the target particle size under the boundary conditions of a given target outer diameter. Subsequently, the system automatically divides the polymerization process into a "micelle nucleation stage" and a "particle growth stage" for staged droplet flow rate control: during the micelle nucleation stage, the surfactant is preferentially injected at the maximum pump flow rate to make its instantaneous concentration exceed the critical micelle concentration, and then the initiator and monomer are controlled to be added dropwise at a high pulse flow rate for a short time to form uniform initial crystal nuclei; after entering the particle growth stage, the feed of surfactant is cut off to suppress secondary nucleation, and the monomer is controlled to be injected steadily into the first reactor 12 at a precise constant flow rate according to the calculated remaining amount, thereby achieving extremely high monodispersity control of the hard template particle size.

[0055] The online homogenization and blending transition module includes a mixing chamber, an ultrasonic array, an online flow meter 21, and a concentration sensor 23. The inlet of the mixing chamber is connected to the outlet of the polymer template synthesis unit 1, and the outlet of the mixing chamber is connected to the inlet of the coating synthesis unit 3. A solvent replenishment valve 22 is provided on the side of the mixing chamber. The ultrasonic array 24 is arranged around the outside of the mixing chamber. The online flow meter 21 and the concentration sensor 23 are used to detect the flow rate and concentration of the material in the mixing chamber online, respectively. The solvent replenishment valve 22, the online flow meter 21, and the concentration sensor 23 are all connected to the central microcontroller system.

[0056] The online homogenization and blending transition module activates an ultrasonic dispersion array to break up particle agglomeration during emulsion transfer and monitors the emulsion concentration in real time through an optical concentration sensor. When the concentration is higher than the preset coating threshold, the central microcontroller receives a solvent replenishment adjustment signal, adjusts the opening of the solvent replenishment valve, and automatically replenishes solvent into the pipeline.

[0057] The automated separation and template removal unit 4 includes a centrifugal washing assembly 41 and a high-temperature calcination / solvent reflux extraction chamber. It is used to purify the core-shell structured microspheres and remove the polymer hard template in situ to obtain the final HMSS product.

[0058] In terms of spatial relationship, the automatic separation and template removal unit 4 adopts a vertical gravity series layout of "top-bottom". Among them, the centrifugal washing component 41 is located above the overall frame, and the high-temperature calcination / solvent reflux extraction chamber 42 is located directly below it. The two are connected by a fully enclosed solid conveying pipeline. The middle of the pipeline is equipped with a star-shaped rotary unloading valve (or pneumatic double slide valve) controlled by a central micro-control system for airtight isolation and flexible connection.

[0059] In terms of specific mechanical structure, the centrifugal washing assembly 41 is a fully enclosed scraper-type microporous filter centrifuge, which contains a high-speed rotating drum, microporous filter material, and a controlled automatic high-pressure spray cleaning ring and a pneumatic unloading scraper; the high-temperature calcination / solvent reflux extraction chamber 42 is a dual-effect integrated fluidized bed thermochemical reactor, which is surrounded by a programmable temperature-controlled high-temperature heating jacket, connected to a circulating cold water condensation reflux tower and a waste gas discharge port at the top, and equipped with a fluidized air inlet and a liquid outlet with a pneumatic valve at the bottom.

[0060] The specific workflow for automatic separation and template removal in this unit is as follows: First, the suspension containing core-shell microspheres is pumped into the centrifugal washing assembly 41 above. Under the action of centrifugal force and alternating spraying of ethanol / deionized water from the high-pressure spray pipeline, liquid-solid separation and in-situ purification washing are completed. After washing and dehydration, the centrifuge slows down, and the automatic unloading scraper extends to scrape off the filter cake (wet microspheres).

[0061] Subsequently, the star-shaped rotary unloading valve connecting the upper and lower chambers is opened quantitatively, and the wet microspheres fall seamlessly and without contact into the high-temperature calcination / solvent reflux extraction chamber 42 below under the action of gravity. After the material is discharged, the star-shaped valve is immediately closed and sealed to isolate temperature and gas.

[0062] Finally, for the PS rigid template used in this embodiment, the central microcontroller automatically initiates a high-temperature calcination mode in chamber 42: oxidizing gas is blown in from the bottom air inlet to fluidize the microsphere powder, while the high-temperature heating jacket is activated to raise the temperature to 550°C for calcination. The internal PS rigid template is pyrolyzed and oxidized into gas in situ and discharged from the top exhaust port. After cooling, the system can automatically output pure and highly monodisperse hollow mesoporous silica microspheres (HMSS) dry powder from the bottom.

[0063] This automated structural design, featuring vertical serial connection and physical isolation, completely avoids material loss, pore contamination, and dust exposure caused by manual scraping and transferring of filter cake in traditional processes, achieving fully enclosed continuous production from solid-liquid purification to template removal.

[0064] Example 2 like Figure 3 As shown, a method for preparing hollow mesoporous silica microspheres includes the following steps: using the hollow mesoporous silica microsphere preparation apparatus of Example 1, a hollow mesoporous silica microsphere with precisely controlled outer diameter and high pore volume is prepared.

[0065] Step S1: Automated synthesis of monodisperse PS hard templates via soap-free emulsion polymerization Raw material pretreatment and online purification: The central microcontroller system issues instructions to the multi-channel precision feeding system (11) to synthesize HMSS in the range of 400-600 nm; the target synthesis particle size is set to 500 nm (within the preset target range of 400-600 nm) of polystyrene (PS) hard template. First, the pretreatment module is started to perform in-situ removal of polymerization inhibitor: The central microcontroller system controls the bypass electromagnetic switching valve to pump the styrene monomer stock solution containing polymerization inhibitor (p-tert-butylcatechol, TBC) into the micro-adsorption column filled with activated alkaline alumina at a flow rate of 10 mL / min. Since TBC molecules contain phenolic hydroxyl groups and are slightly acidic, while the surface of alkaline alumina is strongly alkaline, the two complete the solid-liquid phase chemical adsorption and interception of TBC instantly in the pipeline through specific acid-base complexation and hydrogen bonding. Subsequently, the fluid passes through a series of 0.22 μm polytetrafluoroethylene microfiltration membranes to filter out any alumina particles that may detach, obtaining absolutely pure free styrene monomer, which then directly enters the subsequent metering process.

[0066] Automatic calculation of flow rate parameters and execution of step-by-step dripping: The central microcontroller system is based on a built-in multivariate power-law model of emulsion polymerization kinetics (…). = K Under the boundary condition of setting the reaction temperature of the first reactor to 75℃, the optimal molar ratio and dropping sequence for achieving a particle size of 500 nm were calculated in reverse. The system then automatically split the addition process of monomer, initiator, and surfactant into two stages for execution: (1) Control of micelle nucleation stage: The system drives a multi-channel precision feed pump to preferentially inject 0.1 mol / L sodium dodecyl sulfate solution at a high flow rate of 5.0 mL / min for 3 minutes, so that its instantaneous concentration in the first reactor quickly exceeds the critical micelle concentration (CMC); simultaneously, 0.05 mol / L potassium persulfate solution is added dropwise at a flow rate of 2.0 mL / min for 5 minutes. During this stage, a large number of uniformly sized initial polymer nuclei are generated through collisions between the high concentration of surfactant and initiator.

[0067] (2) Particle growth period control: After the nucleation period is determined, the central microcontroller immediately cuts off the feed of surfactant, and the flow rate is automatically reduced to 0 mL / min to completely suppress secondary nucleation. At the same time, the purified styrene monomer is continuously and steadily added at a precise constant flow rate of 2.5 mL / min, and the reaction continues for 120 minutes. During this growth period, the central microcontroller uses PID control in conjunction with the temperature feedback from the temperature control jacket to ensure a constant monomer chain growth rate. After the reaction is completed, a monodisperse PS hard template emulsion with a particle size highly concentrated in the range of 500±15 nm is finally obtained.

[0068] Polymerization reaction execution: The styrene monomer, after TBC removal by the pretreatment module, and the initiator are pumped into the first reactor of the polymer template synthesis unit according to a preset ratio. The system automatically activates the high-frequency dynamic temperature control jacket to maintain the reaction temperature. The specific process parameters and execution steps are as follows: The system first automatically activates the high-frequency dynamic temperature control jacket to heat the basic aqueous phase environment in the first reactor and strictly maintains the reaction temperature at a constant 75 ℃. At the same time, it starts the mechanical stirring inside the reactor (the speed is set to 300 rpm) and continuously introduces nitrogen to ensure an oxygen-free environment.

[0069] Subsequently, the central micro-control system executes step-by-step feeding according to the optimal material ratio calculated automatically: First, the surfactant and initiator are introduced: a 0.1 mol / L sodium dodecyl sulfate (SDS) solution is pumped into the first reactor at a flow rate of 5.0 mL / min for 3 minutes; simultaneously, a 0.05 mol / L potassium persulfate (KPS) initiator solution is pumped in at a flow rate of 2.0 mL / min for 5 minutes. This step aims to rapidly form initial active crystal nuclei in the system, reaching the critical micelle concentration.

[0070] Next, the monomer polymerization and growth stage begins: the microcontroller cuts off the surfactant feed and continuously adds the purified styrene monomer dropwise into the first reactor at a precise constant flow rate of 2.5 mL / min. The monomer addition process lasts for 120 minutes (i.e., the total monomer addition is 300 mL).

[0071] After the monomer is added, the central microcontroller controls the temperature-controlled jacket to continue aging at 75 ℃ for 2 hours to ensure that the monomer conversion rate reaches over 98%. After the reaction is completed, the temperature is lowered to obtain a polystyrene (PS) hard template emulsion with uniform particle size (such as the target of around 500 nm).

[0072] Environmental control and stirring: The central microcontroller controls the nitrogen valve to continuously introduce nitrogen into the first reactor to strictly ensure an oxygen-free environment, while simultaneously driving the mechanical stir bar to maintain a constant speed of 300 rpm. The particle size of the generated polystyrene (PS) monodisperse microsphere emulsion is precisely controlled within the range of 400-600 nm.

[0073] Step S2: Fully enclosed online homogenization and concentration adjustment The completed PS microsphere emulsion is drawn out through the automatic discharge valve at the bottom of the first reactor and a dedicated material conveying pump (such as a peristaltic pump or diaphragm pump) and enters the online homogenization and blending transition module.

[0074] The ultrasonic dispersion array within the module is activated, utilizing the ultrasonic cavitation effect to break up slight agglomeration of the emulsion during transport. Simultaneously, an online pipeline filter is connected in series on the feed pipe of the mixing chamber, with an internal filter screen having a pore size of 10-20 μm, to physically intercept the very few macroscopic large-particle polymeric impurities in the emulsion. This synergistic structure of first filtering and interception followed by ultrasonic dispersion ensures that the microsphere templates finally entering the coating synthesis unit have absolute monodispersity. An optical concentration sensor monitors the transmittance in real time. When the solid content of the microspheres in the system is determined to be higher than the preset optimal coating concentration threshold (preferably 2.0 wt%), the central microcontroller system, combined with real-time flow rate data from the online flow meter, accurately calculates the required solvent replenishment amount. Subsequently, it drives the dispersion medium replenishment valve to automatically and quantitatively inject anhydrous ethanol to dilute and adjust the suspension concentration to the optimal coating concentration (2.0 wt%), and then pumps it into the coating synthesis unit (second reaction vessel), which is coupled with a microwave field and a micro-positive pressure field.

[0075] Step S3: Dynamic Co-co-encapsulation of Microwave-Micro-Positive Pressure Multiphysics Fields An appropriate amount of tetraethyl orthosilicate (TEOS) as a silicon source and ammonia water as a catalyst are automatically injected into the second reactor.

[0076] An appropriate amount of tetraethyl orthosilicate (TEOS) as a silicon source and ammonia water as a catalyst are automatically injected into the second reactor (32). Specifically, the solid content after step S2 is... Based on polystyrene (PS) emulsion, 50 mL of anhydrous ethanol, 4.0 mL of ammonia water solution with a mass fraction of 28 wt%, and 0.45 g of hexadecyltrimethylammonium bromide (CTAB) were automatically injected into every 100 mL of the PS emulsion as mesoporous pore-forming agents; under stirring, 5.5 mL of anhydrous tetraethyl orthosilicate (TEOS) was finally precisely added dropwise at a constant flow rate of 2 mL / min.

[0077] Infiltration Assembly Stage (S3-1): The central microcontroller system activates the microwave generator module (outputting low power 300W) and simultaneously adjusts the electronic pressure regulating valve at the top of the reactor to establish a relatively high positive pressure of 0.50MPa inside the reactor. This high pressure promotes the dense adsorption and infiltration of TEOS onto the surface of the PS microspheres. This stage lasts for 20 minutes.

[0078] Condensation curing stage (S3-2): The system automatically increases the microwave power to 800W while simultaneously lowering the electronic pressure regulating valve setting to a low positive pressure of 0.15MPa. Under these parameters, microwave heating rapidly crosses the reaction activation energy, accelerating the three-dimensional cross-linking and curing of the silicon source; the 0.15MPa pressure effectively suppresses violent solvent boiling, perfectly protecting the formed mesoporous channel structure. This stage lasts for 15 minutes.

[0079] Step S4: Automated separation and post-processing modification Washing and extraction: The suspension containing core-shell microspheres is introduced into the automatic separation and template removal unit. After high-speed centrifugation and washing, the internal PS template is removed in situ using solvent reflux extraction.

[0080] (1) Automatic continuous solid-liquid separation and high-speed spray washing The suspension containing core-shell microspheres is introduced through tubing into the upper centrifugal washing assembly (a fully enclosed scraper-type microfiltration centrifuge). The central microcontroller system starts the drum and sets the centrifugation speed to [specified value]. The first stage of dehydration and solid-liquid separation is carried out.

[0081] Subsequently, the system activates its built-in automatic high-pressure spray cleaning ring to... The filter cake was washed in situ by alternating sprays of deionized water and anhydrous ethanol at different flow rates. Each spray lasted for 5 minutes, and the washing was repeated 4 times to thoroughly remove residual ammonia catalyst, unreacted TEOS monomers and free CTAB micelles from the filter cake.

[0082] (2) Scraper unloading and closed gravity seamless material transfer After washing and dehydration are complete, the centrifuge speed automatically drops to [a lower speed]. The microcontroller system drives the pneumatic scraper to extend, smoothly scraping the wet core-shell microsphere filter cake off the drum wall. At this moment, the system automatically and quantitatively opens the star-shaped rotary discharge valve in the middle of the pipeline. Under its own gravity, the wet microspheres fall directly into the high-temperature calcination / solvent reflux extraction chamber directly below through the fully enclosed solid transport pipeline, seamlessly and without exposure. After the discharge is complete, the star-shaped rotary discharge valve immediately closes and seals.

[0083] (3) Solvent reflux extraction (or adaptive programmed high-temperature calcination) in situ removal of PS template For the polystyrene (PS) rigid template in this embodiment, the central microcontroller initiates a high-efficiency solvent reflux extraction process within chamber (42): 300 mL of 0.1 mol / L hydrochloric acid-ethanol solution was automatically pumped into chamber (42) as the extractant; the temperature-controlled heating jacket surrounding the vessel was turned on, and the temperature was raised to 78°C and maintained at a constant temperature under reflux. The circulating cold water condenser reflux tower at the top was also started. The mixture was kept under constant temperature reflux for 8 h. The swelling and dissolution properties of the acidic ethanol fluid on the PS polymer and the ion exchange effect on the CTAB surfactant in the mesoporous channels were used to completely remove the PS polymer in situ.

[0084] After extraction, the extract is drained, and pure ethanol is introduced for automatic circulation washing twice. Finally, the heating mantle is started to raise the temperature to 70°C according to the preset program and dry under low vacuum for 4 hours. Finally, pure hollow mesoporous silica microspheres (HMSS) dry powder product with round shape and long-range ordered mesoporous channels is automatically output from the bottom product outlet.

[0085] To confirm the critical technical effect of the pressure regulation range in the multiphysics field coating synthesis unit, while keeping other control parameters (including template particle size, microwave power and timing, silicon source ratio, etc.) completely consistent with those in Example 2, parallel batch control experiments were conducted by changing the micro-positive pressure parameter in the second reactor only by using an electronic pressure regulating valve. The specific test results are shown in Table 1 below.

[0086] Table 1. Effects of different micro-positive pressure parameters on the morphology of hollow mesoporous silica microspheres

[0087] in accordance with Figure 4 The evolution of SEM morphology confirms that the 0.15 MPa ~ 0.50 MPa micro-positive pressure range defined in this invention is not arbitrarily chosen, but rather possesses clear physicochemical boundaries. Weak pressure fields below 0.15 MPa cannot resist the microwave-induced chemical fluid boiling impact, leading to amorphous substances (…). Figure 4 (a); while a strong pressure field higher than 0.50 MPa, due to the polymer rheological effect, inversely collapses the soft template framework (a). Figure 4 (e). Only under the dynamic synergistic pressure field specified in the instruction manual can HMSS materials possessing both perfectly rounded monodisperse morphology and ordered channels be obtained. Figure 4 (c)

[0088] Figure 5 The graph shows the pore size distribution and specific surface area characterization curves of the hollow mesoporous silica microspheres prepared in Example 2. Figure 5It is evident that the nitrogen adsorption-desorption isotherm of the hollow mesoporous silica microspheres exhibits typical Type IV curve characteristics, and a significant capillary condensation hysteresis loop appears in the relative pressure (P / P0) range of approximately 0.4–1.0. This is a standard characteristic of mesoporous materials, proving the existence of a well-developed and interconnected mesoporous structure within the microsphere shell. Furthermore, the pore size distribution curve (BJH model) in the inset shows that the material has an extremely narrow pore size distribution, exhibiting a sharp single peak, with the main pore size highly concentrated at approximately 2–3 nm. This strongly confirms that, utilizing the multi-physics field coupling automated device and dynamic micro-positive pressure synergistic process of this invention, it is possible to successfully induce highly regular self-assembly of pore-forming agent micelles in the microsphere shell while avoiding microwave boiling, thereby preparing hollow mesoporous silica microspheres with long-range ordered pore structure, extremely uniform pore size, and high specific surface area.

[0089] Figure 6 The images show the infrared spectra of the PS microspheres prepared in Example 2 of this invention before and after surface coating. Figure 6 It can be seen that the core-shell structure design and template removal process of this invention have achieved accurate chemical bond verification: (1) For uncoated polystyrene (PS) rigid template microspheres (black curve): In A typical CH stretching vibration peak of the benzene ring appeared nearby. and The structure exhibits symmetry and antisymmetry in aliphatic backbones. stretching vibration peak, in , and The classical characteristic vibrational absorption peaks of the benzene ring skeleton are displayed at [location], while [location] shows the absorption peaks at [location]. and The presence of extremely strong out-of-plane contraction vibrational peaks of monosubstituted benzene rings nearby fully confirms the successful synthesis of the monodisperse PS hard template emulsion.

[0090] (2) For the silica-coated PS / SiO2 core-shell composite microspheres (red curve): This spectral line exhibits characteristics of both a hard template and a shell. On the one hand, the benzene ring and main chain hydrocarbon vibration peaks of the PS microspheres are still clearly present; on the other hand, in An extremely strong and broad Si-O-Si antisymmetric stretching vibration strong absorption band erupted nearby, and in The corresponding location appeared. Bending vibration peak, at the same time Precursor condensation was observed nearby. The bending vibration characteristics strongly demonstrate that tetraethyl orthosilicate (TEOS) has completed a highly dense three-dimensional cross-linked inorganic coating on the PS template surface according to the preset dynamic law under the synergistic effect of microwave and micro-positive pressure.

[0091] (3) For hollow mesoporous silica microspheres (HMSS, blue curve) after automatic extraction and template removal: Originally present in , , as well as The characteristic peaks of organic hydrocarbons and benzene ring skeletons in the region completely disappeared; at the same time, due to the presence of free silanol groups and adsorbed water on the surface, Nearby and The regions exhibit significant absorption bands for -OH stretching and bending vibrations, respectively; while the characteristic absorption peaks of the inorganic framework Si-O-Si ( and The surface remains extremely sharp and stable. This significant "de-organization" evolution not only confirms that the internal PS hard template and pore-forming agent have been absolutely and completely removed, but also confirms that the inorganic hollow silica framework has not been corroded or damaged, thus producing high-purity, high-stability hollow mesoporous microspheres.

[0092] Figure 7 This is a particle size distribution diagram of HMSS synthesized in Example 2 of the present invention. Figure 7 It can be seen that the hydrodynamic diameter of the finished microspheres in the aqueous phase exhibits an extremely narrow single-peak distribution, with the peak value precisely concentrated at 500 nm and the polydispersity index (PDI) less than 0.05, proving that the automated system of the present invention has extremely high batch consistency and monodispersity control capability.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An apparatus for preparing hollow mesoporous silica microspheres, characterized in that: It includes a polymer template synthesis unit, an online homogenization and blending transition unit, an encapsulation synthesis unit, and an automatic separation and template removal unit connected end to end, as well as a central micro-control system; The coating synthesis unit includes a second reactor and a microwave generating module. The microwave generating module is located outside the second reactor, and the microwave conduction direction is towards the second reactor. The second reactor is made of microwave-transparent material. The top of the second reactor is equipped with an electronic pressure regulating valve and a raw material inlet, and the bottom is equipped with a material outlet. The electronic pressure regulating valve is connected to the central micro-control system.

2. The apparatus for preparing hollow mesoporous silica microspheres according to claim 1, characterized in that: The second reactor is equipped with a multi-point fiber optic temperature probe.

3. The apparatus for preparing hollow mesoporous silica microspheres according to claim 1, characterized in that: The polymer template synthesis unit includes a first reactor, the side wall of which is provided with a temperature control jacket, and the feed end of the first reactor is in fluid communication with a multi-channel precision feed system. The multi-channel precision feeding system includes a multi-channel liquid storage array, a pretreatment module, and a pulse-free precision metering pump group that are fluidly connected in sequence. The pretreatment module integrates an automatic liquid separation flow path and an online purification flow path. In the feed channel corresponding to the polymer monomer, the pretreatment module is provided with a bypass electromagnetic switching valve, a micro-adsorption column filled with activated alkaline alumina stationary phase and a microfiltration membrane in sequence along the fluid transport direction. The outlet of the microfiltration membrane is connected to the pulseless precision metering pump group, and is quantitatively connected to the first reaction vessel by the pulseless precision metering pump group. Preferably, both the temperature control jacket and the multi-channel precision feeding system are signal-connected to the central microcontroller system; Preferably, the top of the first reactor is provided with an inert gas exhaust port and a stirrer, and the motor of the stirrer is connected to the central microcontroller system.

4. The apparatus for preparing hollow mesoporous silica microspheres according to claim 1, characterized in that: The online homogenization and blending transition module includes a mixing chamber, an ultrasonic array, an online flow meter, and a concentration sensor; The inlet of the mixing chamber is connected to the outlet of the polymer template synthesis unit, and the outlet of the mixing chamber is connected to the coating synthesis unit; a solvent replenishment valve is provided on the side of the mixing chamber; An ultrasonic array is arranged around the outside of the mixing cavity; Online flow meters and concentration sensors are used to detect the flow rate and concentration of materials in the mixing chamber online, respectively. Preferably, the solvent replenishment valve, online flow meter, and concentration sensor are all connected to the central microcontroller system via signal connection.

5. The apparatus for preparing hollow mesoporous silica microspheres according to claim 1, characterized in that: The automatic separation and template removal unit is arranged vertically in series by gravity in space. The high-speed centrifugal washing component is located above, and the high-temperature calcination / solvent reflux extraction chamber is located directly below the high-speed centrifugal washing component. The two are connected by a fully enclosed solid conveying pipeline equipped with a star-shaped rotary unloading valve. The high-speed centrifugal washing assembly is a fully enclosed scraper-type microporous filter centrifuge, which includes a high-speed rotating drum, an automatic high-pressure spray cleaning ring controlled by a central micro-control system, and a pneumatic unloading scraper. The high-temperature calcination / solvent reflux extraction chamber is a dual-effect integrated fluidized bed thermochemical reactor. Its body is surrounded by a high-temperature heating jacket with programmable temperature control. The top is connected to a circulating cold water condensation reflux tower and a waste gas discharge port. The bottom is equipped with a fluidized air inlet with a pneumatic valve and a liquid outlet. During the automated separation process, the central microcontroller system drives the pneumatic unloading scraper to scrape the washed wet microsphere filter cake off the drum wall, and uses gravity to quantitatively and seamlessly drop it into the lower chamber through the star-shaped rotary unloading valve for in-situ template removal.

6. A method for preparing hollow mesoporous silica microspheres, characterized in that: Includes the following steps: Based on the preset outer diameter of hollow mesoporous silica microspheres, the addition flow rates of polymer monomers, initiators and surfactants are automatically calculated and adjusted to prepare hard template emulsions with set particle sizes. The hard template emulsion is transported to the coating synthesis unit for coating synthesis reaction, and ultrasonic treatment is applied to the hard template emulsion during the transport process; During the coating synthesis reaction, after the hard template emulsion, silicon source and porogen are mixed evenly, microwaves are applied to the reaction system and the pressure of the reaction system is controlled at 0.15-0.5 MPa. After the reaction was complete, the product was centrifuged and washed to obtain a solid reactant. The hard template was removed from the solid reactants to obtain hollow mesoporous silica microspheres.

7. The method for preparing hollow mesoporous silica microspheres according to claim 6, characterized in that: The method for automatically calculating and adjusting the dosing rates of polymer monomers, initiators, and surfactants based on the preset outer diameter of hollow mesoporous silica microspheres specifically includes the following steps: Step A: Inverse Particle Size Calculation: The central microcontroller calculates the optimal total molar ratio threshold of the three components required to achieve the target particle size based on the pre-stored power-law control equation model for emulsion polymerization particle size in memory. The control equation model is as follows: = K ； in, Target hard template particle size; , , , respectively, represent the cumulative concentrations of monomer, surfactant and initiator in the system; T is the real-time reaction temperature fed back by the high-frequency dynamic temperature control jacket; K is a system-specific equipment constant; a, b, and c are all positive empirical exponential coefficients. Step B: Step-by-Step Time-Sequenced Flow Rate Decomposition: The central microcontroller divides the polymerization feeding process into the "micelle nucleation stage" and the "particle growth stage" for step-by-step dynamic flow rate control. During the micelle nucleation stage, the multi-channel precision feeding system is controlled to preferentially inject the surfactant solution at the preset maximum pumping flow rate, so that its instantaneous concentration in the reactor exceeds the critical micelle concentration. Simultaneously, the initiator and monomer are added dropwise at a high pulse flow rate for a short time to stimulate the generation of a large number of uniform initial crystal nuclei. During the microparticle growth phase, the system determines that the nucleation process is complete and then cuts off the feed of the surfactant. Based on the remaining amount, it controls the pulseless precision metering pump group to smoothly inject the polymer monomer into the reactor at a precise constant flow rate or a starved state dripping strategy to carry out the chain growth reaction. Step C: Flow control execution and dynamic compensation: The central microcontroller system converts the calculated flow rate curve into an electrical signal to drive the stepper motor in the feeding system; during the polymerization reaction, the system uses a PID algorithm to fine-tune the dynamic dripping rate of the monomer in real time based on the real-time feedback of the reaction temperature fluctuation, so as to ensure that the monomer chain growth rate is constant and control the particle size distribution variation coefficient of the hard template within the preset range.

8. The method for preparing hollow mesoporous silica microspheres according to claim 6, characterized in that: During the process of delivering the hard template emulsion to the coating synthesis unit, the hard template emulsion is subjected to ultrasonic treatment, and the flow rate and concentration of the hard template emulsion are also monitored online. Preferably, when the concentration of the hard template emulsion is higher than a set value, solvent is added to it.

9. The method for preparing hollow mesoporous silica microspheres according to claim 6, characterized in that: The applied microwave power is 100-1000W.

10. The method for preparing hollow mesoporous silica microspheres according to claim 9, characterized in that: The coating synthesis reaction includes a permeation assembly stage and a polycondensation solidification stage. The pressure inside the reactor during the permeation assembly stage is 0.4-0.5 MPa, the microwave power is 100-400 W, and the duration of this stage is 15-45 minutes. The pressure inside the reactor during the polycondensation and solidification stage is 0.15-0.25 MPa, the microwave power is 800-1000 W, and the duration of this stage is 5-20 minutes.

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