Organic gas adsorption gel for dust-free workshop and preparation method thereof

Abstract

The invention discloses an organic gas adsorption gel for a dust-free workshop. The preparation method comprises the following steps: weighing the following preparation raw materials in parts by mass: 60-80 parts of bis (3-aminophenyl) polydimethylsiloxane; 10 to 30 parts of an acid ester compound; 1 to 10 parts of 2, 2 '-azo-2-methyl propionitrile; 1-5 parts of styrene and derivatives thereof; 0.1 to 0.5 part of divinyl benzene; 1 to 50 parts of ultrapure water; a three-dimensional cross-linked flexible network is formed through in-situ free radical polymerization; the structure has the non-polar adsorption capacity of a polysiloxane main chain and the specific effect of an amino / phenolic hydroxyl functional group on polar VOCs, various organic gases such as benzene, methylbenzene and formaldehyde can be efficiently captured, and byproducts are not released; the preparation process comprises the steps of ultrasonic dispersion, vacuum defoaming, gradient heating polymerization and solvent replacement, the specific surface area of the obtained gel is 280-420 m / g, the pore diameter is 3.5-8.2 nm, the gel can be directly coated and used in an ISO Class 1-5 level dust-free workshop, and the gel has the characteristics of high adsorption broad spectrum, structural stability, greenness and recyclability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental functional materials, and particularly relates to an organic gas adsorption gel for a dust-free workshop and a preparation method thereof. BACKGROUND

[0002] In the technical field of environmental functional materials, as the core infrastructure for ensuring product yield and process stability, the environmental control standard of a dust-free workshop is increasingly stringent. In such a controlled environment, in addition to the extreme control of particulate matter concentration, organic volatile compounds have become an important pollution source affecting the health of operating personnel and the cleanliness of the process, because they are widely derived from process materials such as cleaning agents, photoresists, and adhesives. At present, the industry generally uses high-efficiency exhaust systems supplemented by active carbon filtration or chemical catalytic oxidation for centralized processing. These methods can reduce the exposure concentration of VOCs on a macro level, but it is difficult to completely eliminate the local accumulation effect.

[0003] However, the existing VOCs control technology on the market has deep-seated problems: the centralized processing paradigm conflicts with the distributed and low-disturbance operation logic of the dust-free workshop, forced ventilation introduces external air load and disturbs the air flow balance, and fixed adsorption devices are prone to adsorption blind spots; traditional adsorption materials such as activated carbon are prone to saturation, difficult to regenerate, and release dust or secondary pollutants.

[0004] Therefore, it is necessary to provide an organic gas adsorption gel for a dust-free workshop and a preparation method thereof to solve the above technical problems. SUMMARY

[0005] The present application overcomes the shortcomings of the prior art and provides an organic gas adsorption gel for a dust-free workshop and a preparation method thereof.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows: an organic gas adsorption gel for a dust-free workshop, comprising the following ingredients:

[0007] The following preparation raw materials are weighed according to the mass fraction:

[0008] bis 3-aminophenyl polydimethylsiloxane: 60-80 parts;

[0009] acid ester compound: 10-30 parts;

[0010] 2,2'-azobis 2-methylpropionitrile: 1-10 parts;

[0011] styrene and its derivatives: 1-5 parts;

[0012] divinylbenzene: 0.1-0.5 parts;

[0013] ultra-pure water: 1-50 parts.

[0014] In a preferred embodiment of the present application, the gel is formed by in-situ radical polymerization to form a flexible gel body with a three-dimensional cross-linked network structure.

[0015] In a preferred embodiment of the present application, the number average molecular weight of the bis-3-aminophenyl polydimethylsiloxane is 100-5000, the main chain is composed of repeating units, and 3-aminophenyl functional groups are grafted on both ends or side chains.

[0016] In a preferred embodiment of the present application, the acid ester compound includes sorbitan oleate and sorbitan monooleate polyoxyethylene ether, and the mass ratio of sorbitan oleate to sorbitan monooleate polyoxyethylene ether is 1-5:1.

[0017] In a preferred embodiment of the present application, the styrene and its derivatives include 2-methoxy-4-vinylphenol and 3,4-dimethoxy styrene, and the mass ratio of 2-methoxy-4-vinylphenol to 3,4-dimethoxy styrene is 1-5:1.

[0018] In a preferred embodiment of the present application, the divinylbenzene includes meta isomers and para isomers, and the mass ratio of meta isomers to para isomers is 1-5:1, and the total vinyl content is 55-65%.

[0019] In a preferred embodiment of the present application, the resistivity of the ultrapure water is not less than 18.2 MΩ·cm.

[0020] In a preferred embodiment of the present application, a preparation method of an organic gas adsorption gel for a dust-free workshop comprises the following steps:

[0021] S1. 60-80 parts of bis-3-aminophenyl polydimethylsiloxane, 10-30 parts of an acid ester compound, 1-10 parts of 2,2'-azobis 2-methylpropionitrile, 1-5 parts of styrene and its derivatives, and 0.1-0.5 parts of divinylbenzene are placed in a sealed container, and are subjected to oscillation treatment in an ultrasonic oscillator at a frequency of 20-50 MHz for 10-100 min;

[0022] S2. 1-50 parts of water are added, and stirring is continued until the system becomes a uniform viscous fluid;

[0023] S3. The obtained viscous fluid is transferred to a mold, and is placed in a vacuum drying oven to remove bubbles under a vacuum degree of 0.095-0.1 MPa;

[0024] S4. The temperature is programmed to rise at a rate of 1-10 ℃ / min to 40-100 ℃, and the reaction is carried out at this temperature for 2-6 h;

[0025] ​S5. The obtained gel block is immersed in ethanol for 1-10 times of soaking and washing, each time for 30 min, washed with petroleum ether for 1-10 times, each time for 20 min, and finally dried at 30-50℃ under a vacuum degree of 0.08-0.1 MPa for 10-14 h.

[0026] In a preferred embodiment of the present application, in the S2, the apparent viscosity of the viscous fluid is 5000-50000 mPa·s.

[0027] In a preferred embodiment of the present application, in the S3, the time range for removing the bubbles is 30-60 min.

[0028] The present application solves the defects in the background art and has the following beneficial effects:

[0029] (1) The present application provides an organic gas adsorption gel for a dust-free workshop and a preparation method thereof. A three-dimensional cross-linked network structure is formed through in-situ radical polymerization, the three-dimensional cross-linked network structure is rich in various functional groups such as amino groups and phenyl groups, can have physical adsorption and weak chemical interaction with organic gas molecules, so that the gel has a high specific surface area and various adsorption sites, thereby realizing efficient capture of polar and non-polar volatile organic compounds; the gel can continuously adsorb common pollutants such as benzene, toluene, formaldehyde, etc. under normal temperature and humidity conditions, purifying the air in the dust-free workshop; compared with the prior art, traditional adsorption materials such as activated carbon often have limited adsorption capacity or are easy to saturate, and may release dust, further ensuring reliable performance in a complex gas environment, reducing replacement frequency, and improving the air quality standard of the dust-free workshop.

[0030] (2) The present application provides an organic gas adsorption gel for a dust-free workshop and a preparation method thereof. Through controllable setting of the cross-linked network, the material has good mechanical strength and flexibility, can be attached to a vertical wall without flowing or breaking, so that the gel can be conveniently applied to various surfaces of the dust-free workshop, realizes distributed deployment, can avoid installation problems or particle shedding problems caused by traditional rigid adsorbents, meets the strict cleanliness requirements of the dust-free workshop; compared with some solid adsorbents that need additional fixing supports and produce dust during use, affecting cleanliness, the gel of the present application can be directly pasted without secondary pollution risk; further improves construction efficiency, allows layout design, optimizes space utilization, and at the same time ensures stability during long-term use.

[0031] (3) The application provides a kind of organic gas adsorption gel for dust-free workshop and its preparation method, by using ultrasonic oscillation and vacuum defoaming steps, ensure that each component is fully mixed and the uniformity of gel structure, ultrasonic oscillation promotes dispersion at molecular level, and vacuum treatment eliminates internal bubbles, so as to form a complete three-dimensional network, so that the prepared gel has consistent pore structure and adsorption performance, high batch stability;Compared with the performance fluctuation caused by uneven mixing or bubble residue in the prior art preparation method, the method of the application improves the controllability of product quality, and the further optimized preparation process is suitable for industrial production, ensures the reliability and economy of gel in large-scale application, reduces the scrap rate, and improves the overall production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0033] Figure 1 The preparation step flow diagram of the preferred embodiment of the present application is shown. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely in the following description of the embodiments of the present application, obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, therefore, the scope of protection of the present application is not limited by the specific embodiments disclosed below.

[0036] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features referred to. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0037] In the description of the present application, it needs to be explained that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0038] As Figure 1 shown, the present application provides a dust-free workshop organic gas adsorption gel, comprising the following ingredients;

[0039] The following preparation raw materials are weighed by mass fraction:

[0040] Bis 3-aminophenyl polydimethylsiloxane: 60-80 parts;

[0041] Acid ester compound: 10-30 parts;

[0042] 2,2'-azobis 2-methylpropionitrile: 1-10 parts;

[0043] Styrene and its derivatives: 1-5 parts;

[0044] Divinylbenzene: 0.1-0.5 parts;

[0045] Ultrapure water: 1-50 parts.

[0046] As a preferred embodiment of the present application, the gel is formed into a flexible gel body with a three-dimensional cross-linked network structure through in-situ radical polymerization, the surface and internal pores of the flexible gel body are rich in functional groups capable of physical adsorption and weak chemical interaction with a variety of organic volatile compounds, and the flexible gel body can continuously capture typical industrial VOCs components such as benzene, toluene, aniline, styrene, formaldehyde and the like in air under normal temperature and humidity conditions, and does not release any volatile by-products, and is suitable for distributed deployment in ISO Class 1-5 clean rooms.

[0047] Further, the number average molecular weight of the bis-3-aminophenyl polydimethylsiloxane is 100-5000, and the bis-3-aminophenyl polydimethylsiloxane main chain is composed of repeating -SiCH320- units, and 3-aminophenyl functional groups are grafted on both ends or side chains;

[0048] This structure endows the material with excellent flexibility, thermal stability and dual affinity for polar / non-polar VOCs;

[0049] The 3-aminophenyl functional groups form directional adsorption with oxygen-containing and nitrogen-containing VOCs (such as formaldehyde, aniline) through hydrogen bonding, and the polydimethylsiloxane main chain produces strong physical adsorption with non-polar aromatic hydrocarbons such as benzene and toluene through van der Waals force, thereby realizing broad-spectrum and efficient capture of complex mixed VOCs systems.

[0050] Further, the acid ester compound includes sorbitan oleate and sorbitan monooleate polyoxyethylene ether, and the mass ratio of sorbitan oleate to sorbitan monooleate polyoxyethylene ether is 1-5:1;

[0051] The HLB value of sorbitan oleate is 4.3, and the hydrophobic long-chain structure of sorbitan oleate is embedded in the gel network to enhance the solubility and diffusion capacity of non-polar VOCs; the HLB value of sorbitan monooleate polyoxyethylene ether is 15.0, and the hydrophilic polyoxyethylene segment of sorbitan monooleate polyoxyethylene ether forms a micro-aqueous phase region in the gel interior, which helps to maintain the structural stability of the material in a low-humidity environment and promotes the penetration and adsorption of polar VOCs.

[0052] Further, the purity of 2,2'-azobis 2-methylpropionitrile is not less than 99.0%, and as a radical initiator, it decomposes to produce primary radicals at 40-65°C in the gradient temperature process, initiates copolymerization of styrene monomers and polymerizable groups on the side chains of bis-3-aminophenyl polydimethylsiloxane, and the amount is controlled at 1-10 parts, which ensures a moderate polymerization rate and avoids local overheating to cause gel structure defects.

[0053] Further, the styrene and its derivatives include: 2-methoxy-4-vinyl phenol and 3,4-dimethoxy styrene, wherein the mass ratio of 2-methoxy-4-vinyl phenol to 3,4-dimethoxy styrene is 1-5:1;

[0054] The molecular structure of 2-methoxy-4-vinyl phenol contains phenolic hydroxyl and methoxy, which can retain active hydrogen donor sites after polymerization and form hemiacetal structure with aldehyde VOCs (such as formaldehyde); the two ortho methoxy groups of 3,4-dimethoxy styrene produce steric hindrance effect, inhibit excessive π-π stacking of benzene ring, and maintain the openness of gel pore channel.

[0055] Further, the divinylbenzene includes: meta isomer and para isomer, wherein the mass ratio of meta isomer to para isomer is 1-5:1, and the total vinyl content is 55-65%;

[0056] The amount of divinylbenzene is 0.1-0.5 parts, which reacts with the double bonds on the polysiloxane side chain and the styrene monomers in the polymerization process to form a three-dimensional network structure;

[0057] The crosslinking density of the three-dimensional network structure maintains the storage modulus G' of the gel in the range of 10^3-10^4 Pa at 25°C, which not only ensures that the material has sufficient mechanical strength to adhere to the vertical wall without flowing, but also maintains sufficient flexibility to withstand daily cleaning operations without breaking and falling off.

[0058] Further, the resistivity of water is not less than 18.2 MΩ·cm, which is used to adjust the viscosity of the reaction system and participate in the formation of hydrophilic microzones;

[0059] The amount of water added is 1-50 parts, which is adjusted according to the water content requirement of the target gel; when the amount is less than 10 parts, the gel is hydrophobic dominant, which is suitable for low humidity environment; when the amount is more than 30 parts, a hydrated gel phase is formed, which is suitable for high humidity working conditions, but needs to be matched with acid ester compounds to prevent phase separation.

[0060] The application also provides a preparation method of the organic gas adsorption gel for dust-free workshop, which comprises the following steps:

[0061] S1. 60-80 parts of bis-3-aminophenyl polydimethylsiloxane, 10-30 parts of acid ester compound, 1-10 parts of 2,2'-azobis 2-methylpropionitrile, 1-5 parts of styrene and its derivatives, and 0.1-0.5 parts of divinylbenzene are placed in a sealed container and subjected to ultrasonic treatment in an ultrasonic shaker at a frequency of 20-50 MHz for 10-100 min, so that the components are fully dispersed and initially swelled;

[0062] S2. Add 1-50 parts of ultrapure water, continue to stir until the system is a uniform viscous fluid, and the apparent viscosity is 5000-50000 mPa·s (25℃, shear rate 10s⁻¹) ;

[0063] S3. Transfer the obtained viscous fluid into a mold, and place it in a vacuum drying oven to remove bubbles under a vacuum degree of 0.095-0.1 MPa for 30-60 min;

[0064] S4. Program the temperature to rise at a rate of 1-10℃ / min to 40-100℃, and react at this temperature for 2-6 h to complete the free radical polymerization and crosslinking curing;

[0065] S5. Soak the obtained gel block in ethanol for 1-10 times, each time for 30 min, wash with petroleum ether for 1-10 times, each time for 20 min, and finally dry at 30-50℃ under a vacuum degree of 0.08-0.1 MPa for 10-14 h.

[0066] Further, the ultrasonic oscillation treatment adopts a continuous wave mode, and the power density is 5-50 W / cm², so as to ensure that the polysiloxane chain segment is fully disentangled and forms a homogeneous prepolymer system with monomer molecules;

[0067] The pressure fluctuation range of the vacuum treatment stage is not more than ±0.002 MPa, so as to avoid the collapse of micropores in the gel or the wrinkling of the surface;

[0068] The gradient temperature rising process is divided into two stages: the first stage is to rise from room temperature to 65℃ at a rate of 3-5℃ / min, for activating the initiator; and the second stage is to rise from 65℃ to the final temperature of 80-100℃ at a rate of 1-2℃ / min, for promoting the crosslinking reaction to be complete;

[0069] In the ethanol cleaning step, the purity of ethanol is not less than 99.9%, and fresh solvent is replaced each time until the ultraviolet absorbance of the washing-out liquid at 210 nm is less than 0.01; the petroleum ether cleaning is used to remove acid ester compounds and low molecular weight oligomers that do not participate in the reaction, and the end point of cleaning is confirmed by thin layer chromatography detection.

[0070] The three-dimensional network structure of the gel is jointly constructed by a polydimethylsiloxane main chain, a styrene copolymer branch and a divinylbenzene crosslinking point, the specific surface area is 280-420 m² / g as determined by the BET method, the average pore size is 3.5-8.2 nm, and the pore volume is 0.35-0.62 cm³ / g;

[0071] The multi-level pore structure contains micropores (<2 nm) and mesopores (2-50 nm), which is suitable for adsorbing VOCs of different molecular sizes, and the Zeta potential of the gel surface is-8 to-15 mV in the pH range of 5-8, which is beneficial to adsorbing positively charged VOCs molecules through electrostatic action;

[0072] The thermal gravimetric analysis of the gel shows that the mass loss is less than 3% within 200°C, the dynamic mechanical analysis shows that the glass transition temperature is-45 to-30°C, the elongation at break is ≥350%, the tensile strength is ≥0.15 MPa, and the adhesion reaches 4B or above according to the ASTM D3359 standard test.

[0073] In practical application, the gel can be made into a sheet with a thickness of 0.5-3.0 mm, or directly applied to the surface of a clean room wall, ceiling, equipment cover, etc. by means of scraping or spraying, and can be peeled off in whole after the use cycle, avoiding the generation of fine particles. The waste gel is pyrolyzed at 150°C for 2h, and the VOCs desorption rate is >95%, and the residue can be safely landfilled.

[0074] Example 1:

[0075] A preparation method of an organic gas adsorption gel for a clean room, comprising the following steps:

[0076] S1. 70 parts of bis-3-aminophenyl polydimethylsiloxane, 20 parts of acid ester compound (15 parts of sorbitan oleate and 5 parts of sorbitan monooleate polyoxyethylene ether, mass ratio 3:1), 5 parts of 2,2'-azobis 2-methylpropionitrile, 3 parts of styrene and its derivatives (2 parts of 2-methoxy-4-vinylphenol and 1 part of 3,4-dimethoxystyrene, mass ratio 2:1), and 0.3 parts of divinylbenzene (0.2 parts of meta-isomer and 0.1 parts of para-isomer, mass ratio 2:1, total vinyl content 60%) are placed in a sealed container, and are subjected to ultrasonic oscillation treatment in an ultrasonic oscillator at a frequency of 35MHz for 55min, and the power density is 20W / cm², so that the components are fully dispersed and initially swelled.

[0077] S2. 25 parts of ultrapure water are added, and stirring is continued until the system becomes a viscous fluid with an apparent viscosity of 25000mPa·s;

[0078] S3. The obtained viscous fluid is transferred to a mold, and is placed in a vacuum drying oven to remove bubbles under a vacuum degree of 0.095MPa for 45min, and the pressure fluctuation is not more than ±0.002MPa;

[0079] S4. The temperature is programmed to rise to 70°C at a rate of 5°C / min, and the temperature is kept constant at this temperature for 4h to complete the free radical polymerization and crosslinking curing;

[0080] S5. The obtained gel block was immersed in 99.9% pure ethanol for 5 times of soaking and washing, each for 30 min; then washed with petroleum ether for 5 times, each for 20 min; and finally dried at 40°C under a vacuum of 0.09 MPa for 12 h.

[0081] Example 2

[0082] This example is basically the same as Example 1, except that in the step of S1, the amount of bis-3-aminophenyl polydimethylsiloxane is 60 parts, and the types and amounts of the remaining components are the same as in Example 1.

[0083] Example 3

[0084] This example is basically the same as Example 1, except that in the step of S1, the amount of bis-3-aminophenyl polydimethylsiloxane is 65 parts, and the types and amounts of the remaining components are the same as in Example 1.

[0085] Example 4

[0086] This example is basically the same as Example 1, except that in the step of S1, the amount of bis-3-aminophenyl polydimethylsiloxane is 75 parts, and the types and amounts of the remaining components are the same as in Example 1.

[0087] Example 5

[0088] This example is basically the same as Example 1, except that in the step of S1, the amount of bis-3-aminophenyl polydimethylsiloxane is 80 parts, and the types and amounts of the remaining components are the same as in Example 1.

[0089] Example 6

[0090] This example is basically the same as Example 1, except that in the step of S1, the mass ratio of sorbitan oleate and sorbitan monooleate polyoxyethylene ether in the acid ester compound is 1:1.

[0091] Example 7

[0092] This example is basically the same as Example 1, except that in the step of S1, the mass ratio of sorbitan oleate and sorbitan monooleate polyoxyethylene ether in the acid ester compound is 2:1.

[0093] Example 8

[0094] This example is basically the same as Example 1, except that in the step of S1, the mass ratio of sorbitan oleate and sorbitan monooleate polyoxyethylene ether in the acid ester compound is 4:1.

[0095] Example 9

[0096] This example is substantially the same as Example 1, except that in the step of S1, the mass ratio of sorbitan oleate and sorbitan monooleate polyoxyethylene ether in the acid ester compound is 4:1.

[0097] Comparative Example 1

[0098] This comparative example is substantially the same as Example 1, except that in addition to replacing bis-3-aminophenyl dimethicone with an equal amount of ordinary dimethicone (Mn=2500, no amino phenyl group), the remaining steps are the same as Example 1.

[0099] Comparative Example 2

[0100] This comparative example is substantially the same as Example 1, except that in addition to not adding an acid ester compound, the remaining steps are the same as Example 1.

[0101] Comparative Example 3

[0102] This comparative example is substantially the same as Example 1, except that in addition to replacing styrene and its derivatives with an equal amount of ordinary styrene, the remaining steps are the same as Example 1.

[0103] Experimental Example:

[0104] Purpose of the experiment: To verify the physical and chemical properties of the organic gas adsorbing gel for clean room in Examples 1-9 and Comparative Examples 1-3, including specific surface area, pore size distribution, pore volume, surface potential, thermal stability, glass transition temperature, mechanical properties such as elongation at break and tensile strength, and adhesion, to evaluate its adsorption capacity for organic gases (such as VOCs) and suitability in a clean room environment.

[0105] Experimental methods and procedures:

[0106] Sample preparation: The gel samples prepared according to Examples 1-9 and Comparative Examples 1-3 were prepared into samples with a thickness of 0.5 to 3㎜, and cut into standard sizes required for subsequent testing.

[0107] Specific surface area, pore size and pore volume test (results shown in Table 1): Determined by nitrogen adsorption-desorption isotherm BET method; the prepared gel samples were vacuum degassed at 100℃ for 2h to completely remove the adsorbed water and impurities in the samples, and then nitrogen adsorption-desorption test was performed at 77K liquid nitrogen temperature using a specific surface area and pore size analyzer, and the specific surface area, average pore size and pore volume of the sample were calculated by analyzing the obtained isotherm.

[0108] Surface Zeta potential test (results are shown in Table 1): The zeta potential was measured using a zeta potential meter. The gel sample was dispersed in ultrapure water with a resistivity of not less than 18.2 MΩ·cm to prepare a dispersion with a concentration of 0.1% w / v. The pH of the dispersion was adjusted to 5, 6, 7 and 8 with hydrochloric acid or sodium hydroxide solution, respectively. The zeta potential value was then measured at each pH value. The final result was the average of multiple measurements.

[0109] Thermal stability test (results are shown in Table 2): The test was conducted using a thermogravimetric analyzer. Approximately 10 mg of gel sample was weighed and placed in the sample pan of the TGA instrument. Under nitrogen atmosphere protection, the temperature was increased from room temperature to 200°C at a rate of 10°C / min, and the mass change of the sample during this process was continuously recorded.

[0110] Glass transition temperature and mechanical property testing (results are shown in Table 2): The test was conducted using a dynamic mechanical analyzer. The gel sample was first processed into a standard dumbbell-shaped tensile specimen, and then mounted on the DMA fixture. The tensile rate was set to 10 mm / min for tensile testing. The glass transition temperature was determined by analyzing the obtained temperature-modulus curve, and the elongation at break and tensile strength of the material were calculated from the stress-strain curve.

[0111] Adhesion test (results shown in Table 2): The cross-cut adhesion test was performed according to ASTM D3359 standard. The gel was evenly coated or adhered to a clean standard steel plate surface. After complete curing, a 1mm × 1mm grid was cut into the gel surface using a cutting tool. Special adhesive tape was then applied and quickly peeled off. The extent of gel detachment in the grid areas was observed under a microscope, and the adhesion level was determined according to the standard rating chart.

[0112] Table 1:

[0113] Group Specific surface area (m2 / g) Average pore size (nm) Pore volume (cm3 / g) Surface zeta potential (mV, pH 7) Example 1 350.12 5.85 0.48 -11.50 Example 2 320.45 6.12 0.42 -10.75 Example 3 335.67 5.95 0.45 -11.20 Example 4 365.89 5.73 0.52 -12.25 Example 5 380.15 5.55 0.55 -13.11 Example 6 340.25 6.05 0.46 -11.21 Example 7 348.90 5.90 0.49 -11.45 Example 8 360.75 5.75 0.53 -12.50 Example 9 362.42 5.72 0.54 -12.60 Comparative Example 1 250.33 7.51 0.31 -5.24 Comparative Example 2 270.15 7.22 0.32 -9.53 Comparative Example 3 290.65 6.81 0.38 -10.22

[0114] Table 2:

[0115] Group Thermal loss 200°C (%) Glass transition temperature (°C) Elongation at break (%) Tensile strength (MPa) Example 1 1.22 -37.51 380.25 0.28 Example 2 1.85 -35.27 350.60 0.22 Example 3 1.50 -36.84 365.80 0.25 Example 4 1.12 -38.90 395.41 0.31 Example 5 0.97 -40.18 410.75 0.35 Example 6 1.64 -36.01 370.21 0.26 Example 7 1.33 -37.27 385.64 0.29 Example 8 1.05 -39.55 400.35 0.33 Example 9 1.07 -39.81 402.12 0.34 Comparative Example 1 2.87 -30.54 300.45 0.12 Comparative Example 2 2.58 -32.89 320.81 0.15 Comparative Example 3 2.23 -34.26 340.26 0.18

[0116] From Table 1 and Table 2, we can see that:

[0117] Example 1 exhibits the best overall performance, with a specific surface area as high as 350.12 m² / g, an average pore size of 5.85 nm, good thermal stability, and excellent mechanical properties. This is achieved through the formulation ratio to form an ideal three-dimensional network structure.

[0118] The amount of bis(3-aminophenyl)polydimethylsiloxane is 70 parts, which enables the polydimethylsiloxane backbone to effectively adsorb non-polar organic gases through van der Waals forces, while the 3-aminophenyl functional groups of its side chain can capture polar gas molecules through hydrogen bonding.

[0119] Acid ester compounds are combined in a 3:1 mass ratio to regulate the hydrophilic-hydrophobic balance of the gel, ensuring structural stability while providing transport channels for gas molecules of different polarities. The special functional groups in the styrene derivative further enhance the interaction with specific gases, while an appropriate amount of divinylbenzene constructs a cross-linked network with both high specific surface area and good mechanical strength, thereby giving the gel efficient and broad-spectrum adsorption capacity.

[0120] Examples 2 to 5 mainly changed the amount of bis(3-aminephenyl)polydimethylsiloxane. The performance changes in Examples 2 to 5 reveal the decisive influence of this key component on the network structure.

[0121] When the amount is reduced to 60 parts, as in Example 2, the polysiloxane used as the skeleton and the carrier of the main functional groups is insufficient, resulting in a sparse three-dimensional cross-linked network structure. This directly causes the specific surface area to decrease to 320.45 m² / g. At the same time, due to the decrease in cross-linking density, the mechanical strength of the material is weakened and the thermal stability decreases.

[0122] When the amount is increased to 80 parts, as in Example 5, although the specific surface area is improved, excessive long-chain molecules may cause the network structure to be too dense and the pore size distribution to change, which in turn affects the diffusion rate of gas molecules inside the gel.

[0123] Therefore, the dosage of 70 parts in Example 1 is a balance point that can maintain the openness and stability of the network structure while ensuring sufficient adsorption sites.

[0124] Examples 6 to 9 demonstrate the influence of different mass ratios within the ester compounds. The ratio of sorbitan oleate to dehydrated sorbitan monooleate polyoxyethylene ether ranges from 1:1 to 5:1, with each component dominating hydrophobicity and hydrophilicity, respectively.

[0125] When the ratio is 1:1, as in Example 6, there is a relatively large amount of hydrophilic components, which leads to excessively large hydrophilic microdomains inside the gel. This to some extent disrupts the uniformity of the structure, resulting in parameters such as specific surface area and pore volume being slightly lower than the optimal state.

[0126] When the ratio is increased to 4:1, as in Examples 8 and 9, the hydrophobic properties are enhanced, which is more conducive to the adsorption of nonpolar organic gases. However, compared with the 3:1 ratio in Example 1, its hydrophilic-hydrophobic balance is not optimal, and it may not be stable enough, especially in environments with changing humidity.

[0127] The 3:1 ratio in Example 1 allows the two ester molecules to achieve optimal synergy in the microscopic phase of the gel network, jointly constructing an efficient gas adsorption and transport pathway.

[0128] Comparative Example 1 showed that replacing bis-3-aminophenyl polydimethylsiloxane with ordinary polydimethylsiloxane significantly degraded its performance, confirming the importance of the 3-aminophenyl functional group.

[0129] Ordinary polydimethylsiloxane can only rely on van der Waals forces for physical adsorption. The lack of amino functional groups prevents it from forming hydrogen bonds with polar organic gas molecules containing oxygen and nitrogen, resulting in a narrower adsorption spectrum and a significant decrease in its ability to capture key pollutants such as formaldehyde and aniline.

[0130] Meanwhile, the absence of amino groups also affects the polymerization reactivity with monomers such as styrene derivatives, resulting in insufficient integrity of the final three-dimensional network structure. This manifests as a significant reduction in specific surface area and weakened network strength, thereby comprehensively affecting the adsorption performance and mechanical stability of the gel.

[0131] Comparative Example 2 did not contain any ester compounds. The performance data of Comparative Example 2 indicate that these compounds play a key role as surfactants and structure-directing agents in the system.

[0132] The absence of acid ester compounds makes it difficult for hydrophobic polysiloxane segments and monomers to form a uniform and stable prepolymer system with hydrophilic ultrapure water, leading to phase separation. This microscopic heterogeneity directly causes a decrease in the network structure order of the final gel, a reduction in specific surface area, and an unsatisfactory pore size distribution.

[0133] The hydrophobic chains of sorbitan oleate and the hydrophilic chains of dehydrated sorbitan monooleate polyoxyethylene ether originally worked together to construct hydrophilic-hydrophobic microdomains within the gel that facilitate gas diffusion. Their absence reduces the transport efficiency of gas molecules within the gel, thereby affecting the overall adsorption kinetics and capacity.

[0134] Comparative Example 3 replaced specially made styrene and its derivatives with ordinary styrene, sacrificing the specific adsorption capacity brought by the functional groups.

[0135] Ordinary styrene monomers only provide aromatic ring structures after polymerization and mainly rely on π bonds for physical adsorption. However, the 2-methoxy-4-vinylphenol and 3,4-dimethoxystyrene used in this invention introduce active groups such as phenolic hydroxyl and methoxy groups. The phenolic hydroxyl can react with aldehyde gases such as formaldehyde to form hemiacetal, achieving chemical adsorption. The methoxy group prevents excessive stacking of benzene rings through steric hindrance and maintains the openness of the pores.

[0136] Due to the lack of these specific functional groups, the chemical adsorption pathway of Comparative Example 3 is interrupted, and it relies solely on physical adsorption, resulting in a decrease in the adsorption capacity and selectivity for specific polar VOCs. This makes its purification effect in complex gas environments less effective than that of Example 1.

[0137] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An organic gas adsorbing gel for use in a dust-free workshop, characterized by comprising a porous polymer gel and a porous inorganic substance. The gel comprises the following components: The following raw materials are weighed by mass fraction: bis 3-aminophenyl dimethicone: 60-80 parts; acid ester compound: 10-30 parts; 2,2'-azobis 2-methylpropionitrile: 1-10 parts; styrene and its derivatives: 1-5 parts; divinylbenzene: 0.1-0.5 parts; ultra-pure water: 1-50 parts.

2. An organic gas adsorbing gel for a dust-free workshop according to claim 1, characterized by: The gel is formed by in-situ radical polymerization to have a flexible gel body with a three-dimensional cross-linked network structure.

3. The organic gas adsorbent gel for a dust-free workshop according to claim 1, characterized by: The number average molecular weight of the bis 3-aminophenyl polydimethylsiloxane is 100-5000, the main chain of which is composed of repeating units grafted with 3-aminophenyl functional groups at both ends or side chains.

4. The organic gas adsorbent gel for a dust-free workshop according to claim 1, characterized by: The acid ester compound includes sorbitan oleate and sorbitan monooleate polyoxyethylene ether, and the mass ratio of sorbitan oleate to sorbitan monooleate polyoxyethylene ether is 1-5:

1.

5. The organic gas adsorbent gel for use in a dust-free workshop according to claim 1, characterized in that: The styrene and its derivatives include 2-methoxy-4-vinylphenol and 3,4-dimethoxystyrene, and the mass ratio of 2-methoxy-4-vinylphenol to 3,4-dimethoxystyrene is 1-5:

1.

6. The organic gas adsorbent gel for use in a dust-free workshop according to claim 1, characterized in that: The divinylbenzene includes meta-isomer and para-isomer, and the mass ratio of meta-isomer to para-isomer is 1-5:1, and the total vinyl content is 55-65%.

7. The organic gas adsorbent gel for use in a dust-free workshop according to claim 1, characterized in that: The resistivity of the ultra-pure water is not less than 18.2 MΩ·cm.

8. A method for producing an organic gas adsorbing gel for a clean room based on the organic gas adsorbing gel according to any one of claims 1 to 7, characterized by, The method comprises the following steps: S1. Put 60-80 parts of bis 3-aminophenyl dimethicone, 10-30 parts of acid ester compound, 1-10 parts of 2,2'-azobis 2-methylpropionitrile, 1-5 parts of styrene and its derivatives, and 0.1-0.5 parts of divinylbenzene in a sealed container, and perform oscillation treatment in an ultrasonic oscillator at a frequency of 20-50 MHz for 10-100 min; S2. Add 1-50 parts of water and continue stirring until the system becomes a uniform viscous fluid; S3. Transfer the obtained viscous fluid to a mold and place it in a vacuum drying oven to remove bubbles under a vacuum degree of 0.095-0.1 MPa; S4. Program the temperature to rise at a rate of 1-10 ℃ / min to 40-100 ℃, and react at this temperature for 2-6 h; S5. Soak the obtained gel block in ethanol for 1-10 times, each time for 30 min, wash with petroleum ether 1-10 times, each time for 20 min, and finally dry at 30-50 ℃ under a vacuum degree of 0.08-0.1 MPa for 10-14 h.

9. A method of preparing an organic gas adsorbing gel for use in a dust-free workshop according to claim 8, characterized in that: In the S2, the apparent viscosity of the viscous fluid is 5000-50000 mPa·s.

10. A method of preparing an organic gas adsorbing gel for use in a dust-free workshop according to claim 8, characterized in that: In the S3, the time range for removing bubbles is 30-60 min.

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