A method for preparing an organosilicon porous polymer and its derivatives, its applications, and a humidity sensor and its preparation method.

Abstract

This invention provides a method for preparing organosilicon porous polymers and their derivatives, their applications, and a humidity sensor and its preparation method, relating to the field of humidity sensing materials technology. This invention prepares a series of organic-inorganic hybrid porous materials based on octaphenylcyclotetrasiloxane (OPCTS) via a Friedel-Craft reaction. By introducing three functional hydrophilic groups—-NH2, -OH, and -SO3—into the porous polymer's own pores through chemical reactions, it achieves a wide response range (11%RH–97%RH, 6 orders of magnitude) and rapid response (0.6 s) in humidity sensors, while maintaining good long-term stability at both 11%RH and 97%RH.

Description

Technical Field

[0001] This invention relates to the field of humidity sensing materials technology, specifically to a method for preparing and applying an organosilicon porous polymer and its derivatives, and a humidity sensor and its preparation method. Background Technology

[0002] Humidity, due to its unique properties, plays a vital role in people's daily lives and production. Both excessively high and low humidity levels can cause adverse effects. Fields such as agriculture and medicine require humidity sensors that can respond quickly and in real-time to environmental changes. Therefore, there is a need to develop a humidity sensing material with high linearity, low hysteresis, fast response, and long-term stability for use in humidity sensors to monitor humidity in real-time during production and daily life.

[0003] Based on different conduction principles, humidity sensors can be classified into resistive humidity sensors, capacitive humidity sensors, quartz crystal microbalance humidity sensors, and optical humidity sensors. Among them, resistive humidity sensors operate based on the difference between the resistance generated by the interaction between the humidity-sensitive material and water molecules and the ambient humidity. Therefore, selecting a suitable humidity-sensitive material is crucial for the fabrication of resistive humidity sensors.

[0004] In recent years, porous organic polymers have attracted widespread attention from researchers due to their high specific surface area, stable porosity, and ease of modification. They have already been applied in gas adsorption, catalysts, adsorption, and supercapacitors. Researchers have discovered that polyhedral oligomeric silsesquioxanes (POSS), containing both organic and inorganic components, possess high thermal and mechanical stability, making them ideal substrates for constructing organic-inorganic hybrid porous organic materials. Many methods exist for synthesizing organosilicon porous polymers, such as hydrosilylation, Sonogashira reaction, and Heck reaction; however, most of these reactions require noble metal catalysts, and the reaction steps are complex and the conditions are harsh. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing organosilicon porous polymers and their derivatives, their applications, and a humidity sensor and its preparation method. This invention uses the Friedel-Craft reaction to prepare a series of organosilicon porous polymers and their derivatives, which has the advantages of simple operation and low cost.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for preparing a porous organosilicon polymer, comprising the following steps:

[0008] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer.

[0009] This invention provides a method for preparing hydroxyl-functionalized organosilicon porous polymers, comprising the following steps:

[0010] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer;

[0011] The organosilicon porous polymer was mixed with an alkaline alcohol solution and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized organosilicon porous polymer.

[0012] This invention provides a method for preparing a sulfonic acid group-functionalized organosilicon porous polymer, comprising the following steps:

[0013] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer;

[0014] The organosilicon porous polymer, solvent, and 1,3-propanesulfonic acid lactone were mixed and subjected to a first bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-functionalized organosilicon porous polymer.

[0015] This invention provides a method for preparing a sulfonic acid group-hydroxyl functionalized organosilicon porous polymer, comprising the following steps:

[0016] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer;

[0017] The organosilicon porous polymer and an alkaline alcohol solution are mixed and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized organosilicon porous polymer.

[0018] The hydroxyl-functionalized organosilicon porous polymer, solvent, and 1,3-propanesulfonic acid lactone were mixed and subjected to a second bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-hydroxyl-functionalized organosilicon porous polymer.

[0019] This invention provides the application of one or more of the following in humidity sensors: the organosilicon porous polymer prepared by the preparation method described above; the hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described above; the sulfonic acid group-functionalized organosilicon porous polymer prepared by the preparation method described above; and the sulfonic acid group-hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described above.

[0020] This invention provides a humidity sensor, comprising a ceramic substrate and a plurality of interdigitated electrodes disposed on the surface of the ceramic substrate; a sensing layer is disposed on the surface of the interdigitated electrodes; the raw materials for preparing the sensing layer include one or more of the following: organosilicon porous polymer prepared by the preparation method described in the above technical solution, hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described in the above technical solution, sulfonic acid-functionalized organosilicon porous polymer prepared by the preparation method described in the above technical solution, and sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described in the above technical solution.

[0021] Preferably, the interdigitated electrode is an Ag-Pd interdigitated electrode; the width of the interdigitated electrode is 150-200 μm.

[0022] Preferably, there are five groups of interdigital electrodes; the distance between two adjacent groups of interdigital electrodes is 150-200 μm.

[0023] Preferably, the thickness of the sensing layer is 40–80 μm.

[0024] This invention provides a method for preparing the humidity sensor described in the above technical solution, comprising the following steps:

[0025] One or more of the following prepared by the above-described technical solution method, the hydroxyl-functionalized organosilicon porous polymer prepared by the above-described technical solution method, the sulfonic acid-functionalized organosilicon porous polymer prepared by the above-described technical solution method, and the sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the above-described technical solution method, are mixed with an organic solvent to obtain a dispersion.

[0026] The dispersion was coated onto the surface of the interdigitated electrode on a ceramic substrate, and then dried and aged sequentially to obtain a humidity sensor.

[0027] This invention provides methods for preparing organosilicon porous polymers, hydroxyl-functionalized organosilicon porous polymers, sulfonic acid-functionalized organosilicon porous polymers, and sulfonic acid-hydroxyl-functionalized organosilicon porous polymers. This invention prepares a series of organic-inorganic hybrid porous materials based on octaphenylcyclotetrasiloxane (OPCTS) via Friedel-Craft reaction. By introducing three functional hydrophilic groups—-NH2, -OH, and -SO3—into the pores of the porous polymer through chemical reaction, it achieves a wide response range (11%RH-97%RH, 6 orders of magnitude) and rapid response (0.6s) in humidity sensors, while maintaining good long-term stability at both 11%RH and 97%RH. Attached Figure Description

[0028] Figure 1 Infrared spectra of HCP-A, HCP-A-SO3, HCP-B, and HCP-B-SO3;

[0029] Figure 2 XPS characterization images of HCP-A, HCP-A-SO3, HCP-B, and HCP-B-SO3;

[0030] Figure 3 The graph shows the relationship between impedance and relative humidity for HCP-A, HCP-A-SO3, HCP-B, and HCP-B-SO3 humidity sensors at 100Hz.

[0031] Figure 4 (a) Response-recovery curves of HCP-B-SO3 for 10 cycles between 11%RH and 97%RH at 100Hz, and (b) locally magnified response-recovery curves in a linear coordinate system.

[0032] Figure 5 The long-term stability of HCP-B-SO3 at 100Hz for 30 days at 11%RH and 97%RH was measured. Detailed Implementation

[0033] This invention provides a method for preparing a porous organosilicon polymer, comprising the following steps:

[0034] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer.

[0035] In this invention, the mass ratio of octaphenylcyclotetrasiloxane to benzylamine is preferably 1.5–2:1, more preferably 1.85:1. In this invention, the mass ratio of octaphenylcyclotetrasiloxane to organic solvent is preferably 1:9–10, more preferably 1:9.5; the organic solvent preferably includes 1,2-dichloroethane or dichloromethane. In this invention, the mass ratio of octaphenylcyclotetrasiloxane to crosslinking agent is preferably 1:2–3, more preferably 1:2.5; the crosslinking agent preferably includes dimethoxymethane. In this invention, the mass ratio of octaphenylcyclotetrasiloxane to catalyst is preferably 1:2–3, more preferably 1:2.5; the catalyst preferably includes anhydrous ferric chloride or anhydrous aluminum chloride.

[0036] In this invention, the mixing of octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst preferably includes: dispersing octaphenylcyclotetrasiloxane and benzylamine in an organic solvent, and adding a crosslinking agent and catalyst.

[0037] In this invention, the polymerization reaction temperature is preferably 40-80°C, more preferably 40-5 hours after prepolymerization at 40°C, followed by heating to 80°C and continuing the reaction for 20-30 hours.

[0038] Preferably, after the polymerization reaction, the product is washed with ethanol, filtered, and dried to obtain an organosilicon porous polymer.

[0039] In this invention, the average pore size of the organosilicon porous polymer is preferably 14.9–15.9 nm, and the total pore volume is preferably 0.082–0.084 cm³. 3 ·g -1 The specific surface area of ​​BET is 19–22 m². 2 ·g -1 .

[0040] This invention provides a method for preparing hydroxyl-functionalized organosilicon porous polymers, comprising the following steps:

[0041] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer;

[0042] The organosilicon porous polymer was mixed with an alkaline alcohol solution and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized organosilicon porous polymer.

[0043] This invention involves mixing octaphenylcyclotetrasiloxane, benzylamine, an organic solvent, a crosslinking agent, and a catalyst to perform a polymerization reaction, thereby obtaining a porous organosilicon polymer. In this invention, the preparation method of the porous organosilicon polymer is consistent with that described above and will not be repeated here.

[0044] After obtaining the organosilicon porous polymer, the present invention mixes the organosilicon porous polymer with an alkaline alcohol solution and performs a hydrolysis reaction to obtain a hydroxyl-functionalized organosilicon porous polymer. In the present invention, the alkaline alcohol solution specifically includes a sodium hydroxide alcohol solution; the preferred mass concentration of the alkaline alcohol solution is 0.5–2 mol·L⁻¹. -1 More preferably 1 mol·L -1 In this invention, the amount of alkaline alcohol solution used is preferably sufficient to immerse the organosilicon porous polymer.

[0045] In this invention, the temperature of the hydrolysis reaction is preferably 60-80°C, more preferably 70-75°C; the time of the hydrolysis reaction is preferably 24-36 hours, more preferably 24 hours.

[0046] Preferably, after the hydrolysis reaction, the obtained product is washed, filtered, and dried to obtain a hydroxyl-functionalized organosilicon porous polymer. In this invention, the washing and filtration preferably includes washing with water followed by washing with ethanol.

[0047] In this invention, the average pore size of the hydroxyl-functionalized organosilicon porous polymer is preferably 6.0–6.6 nm, and the total pore volume is preferably 0.073–0.076 cm³. 3 ·g -1 The preferred specific surface area of ​​BET is 44–47 m². 2 ·g -1 .

[0048] This invention provides a method for preparing a sulfonic acid group-functionalized organosilicon porous polymer, comprising the following steps:

[0049] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer;

[0050] The organosilicon porous polymer, solvent, and 1,3-propanesulfonic acid lactone were mixed and subjected to a first bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-functionalized organosilicon porous polymer.

[0051] This invention involves mixing octaphenylcyclotetrasiloxane, benzylamine, an organic solvent, a crosslinking agent, and a catalyst to perform a polymerization reaction, thereby obtaining a porous organosilicon polymer. In this invention, the preparation method of the porous organosilicon polymer is consistent with that described above and will not be repeated here.

[0052] After obtaining the organosilicon porous polymer, the present invention mixes the organosilicon porous polymer with a solvent and 1,3-propanesulfonate lactone, and performs a first bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-functionalized organosilicon porous polymer. In the present invention, the solvent preferably includes dichloromethane or trichloromethane. In the present invention, the amount of solvent used is preferably sufficient to submerge the solid matter in the system. In the present invention, the mass ratio of the organosilicon porous polymer to 1,3-propanesulfonate lactone is preferably 1:3 to 8, more preferably 1:5.

[0053] In this invention, the mixing of the organosilicon porous polymer, the solvent, and 1,3-propanesulfonate lactone preferably includes: dispersing the organosilicon porous polymer in the solvent and adding 1,3-propanesulfonate lactone.

[0054] In this invention, the first bimolecular nucleophilic substitution reaction (S N 2) The preferred temperature is 40–60 °C; the first bimolecular nucleophilic substitution reaction (S N 2) The preferred time is 4 to 6 hours.

[0055] The present invention preferably involves the first bimolecular nucleophilic substitution reaction (S N2) Subsequently, the obtained product is washed, filtered, and dried to obtain a sulfonic acid group-functionalized organosilicon porous polymer. In this invention, the washing and filtration preferably includes washing with deionized water followed by washing with ethanol.

[0056] In this invention, the average pore size of the sulfonic acid group-functionalized organosilicon porous polymer is preferably 6.2–8.9 nm, and the total pore volume is preferably 0.193–0.197 cm³. 3 ·g -1 The preferred specific surface area of ​​BET is 83–88 m². 2 ·g -1 .

[0057] This invention provides a method for preparing a sulfonic acid group-hydroxyl functionalized organosilicon porous polymer, comprising the following steps:

[0058] Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer;

[0059] The organosilicon porous polymer and an alkaline alcohol solution are mixed and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized organosilicon porous polymer.

[0060] The hydroxyl-functionalized organosilicon porous polymer, solvent, and 1,3-propanesulfonic acid lactone were mixed and subjected to a second bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-hydroxyl-functionalized organosilicon porous polymer.

[0061] This invention involves mixing octaphenylcyclotetrasiloxane, benzylamine, an organic solvent, a crosslinking agent, and a catalyst to perform a polymerization reaction, yielding an organosilicon porous polymer. The organosilicon porous polymer is then mixed with an alkaline alcohol solution and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized organosilicon porous polymer. In this invention, the preparation method of the hydroxyl-functionalized organosilicon porous polymer is consistent with that described above and will not be repeated here.

[0062] After obtaining the hydroxyl-functionalized organosilicon porous polymer, the present invention mixes the hydroxyl-functionalized organosilicon porous polymer with a solvent and 1,3-propanesulfonate lactone, and performs a second bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-hydroxyl-functionalized organosilicon porous polymer. In the present invention, the solvent preferably includes dichloromethane or trichloromethane. In the present invention, the amount of solvent used is preferably sufficient to submerge the solid matter in the system. In the present invention, the mass ratio of the hydroxyl-functionalized organosilicon porous polymer to 1,3-propanesulfonate lactone is preferably 1:3 to 8, more preferably 1:5.

[0063] In this invention, the mixture of the hydroxyl-functionalized organosilicon porous polymer, the solvent, and 1,3-propanesulfonate lactone preferably comprises: dispersing the hydroxyl-functionalized organosilicon porous polymer in the solvent and adding 1,3-propanesulfonate lactone.

[0064] In this invention, the second bimolecular nucleophilic substitution reaction (S N 2) The preferred temperature is 40–60 °C; the second bimolecular nucleophilic substitution reaction (S N 2) The preferred time is 4 to 6 hours.

[0065] The present invention preferably involves the second bimolecular nucleophilic substitution reaction (S N 2) Subsequently, the obtained product is washed, filtered, and dried to obtain a sulfonic acid group-hydroxyl functionalized organosilicon porous polymer. In this invention, the washing and filtration preferably includes washing with deionized water followed by washing with ethanol.

[0066] In this invention, the average pore size of the sulfonic acid group-hydroxyl functionalized organosilicon porous polymer is preferably 4.9–5.4 nm, and the total pore volume is preferably 0.080–0.086 cm³. 3 ·g -1 The preferred specific surface area of ​​BET is 59–62 m². 2 ·g -1 .

[0067] This invention provides the application of one or more of the following in humidity sensors: the organosilicon porous polymer prepared by the preparation method described above; the hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described above; the sulfonic acid group-functionalized organosilicon porous polymer prepared by the preparation method described above; and the sulfonic acid group-hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described above.

[0068] This invention provides a humidity sensor, comprising a ceramic substrate and a plurality of interdigitated electrodes disposed on the surface of the ceramic substrate; a sensing layer is disposed on the surface of the interdigitated electrodes; the raw materials for preparing the sensing layer include one or more of the following: organosilicon porous polymer prepared by the preparation method described in the above technical solution, hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described in the above technical solution, sulfonic acid-functionalized organosilicon porous polymer prepared by the preparation method described in the above technical solution, and sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method described in the above technical solution.

[0069] In this invention, the interdigitated electrode is etched onto a ceramic substrate. Preferably, the interdigitated electrode is an Ag-Pd interdigitated electrode; the width of the interdigitated electrode is preferably 150–200 μm, more preferably 200 μm. The dimensions of the interdigitated electrode are preferably 7.5 mm × 3.5 mm (length × width).

[0070] In this invention, the interdigitated electrodes are preferably in five groups; the spacing between two adjacent groups of interdigitated electrodes is preferably 150-200 μm, more preferably 200 μm.

[0071] In this invention, the thickness of the sensing layer is preferably 40-80 μm, more preferably 50-60 μm.

[0072] This invention provides a method for preparing the humidity sensor described in the above technical solution, comprising the following steps:

[0073] One or more of the following prepared by the above-described technical solution method, the hydroxyl-functionalized organosilicon porous polymer prepared by the above-described technical solution method, the sulfonic acid-functionalized organosilicon porous polymer prepared by the above-described technical solution method, and the sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the above-described technical solution method, are mixed with an organic solvent to obtain a dispersion.

[0074] The dispersion was coated onto the surface of the interdigitated electrode and then subjected to drying and aging treatments to obtain a humidity sensor.

[0075] This invention involves mixing one or more of the following: the porous organosilicon polymer prepared by the method described above; the hydroxyl-functionalized porous organosilicon polymer prepared by the method described above; the sulfonic acid-functionalized porous organosilicon polymer prepared by the method described above; and the sulfonic acid-hydroxyl-functionalized porous organosilicon polymer prepared by the method described above; with an organic solvent to obtain a dispersion. In this invention, the organic solvent preferably includes chloroform or dichloromethane. In this invention, the concentration of the polymer in the dispersion is preferably 0.05–0.2 g / mL, more preferably 0.1 g / mL. In this invention, the mixing is preferably carried out under ultrasonic conditions.

[0076] This invention involves coating the dispersion onto the surface of interdigitated electrodes on a ceramic substrate, followed by sequential drying and aging treatments to obtain a humidity sensor. Preferably, the coating method is brush coating. Before fabricating the humidity sensor, it is preferable to sequentially clean and dry the ceramic substrate and the several sets of interdigitated electrodes disposed on the surface of the ceramic substrate. Preferably, the cleaning includes sequential washing with anhydrous ethanol and distilled water; the cleaning is preferably ultrasonic cleaning; and the washing time for both the anhydrous ethanol and distilled water washing is preferably 15 minutes.

[0077] In this invention, the drying temperature is preferably 60°C, and the drying time is preferably 10-15 min. In this invention, the aging treatment temperature is preferably 20-25°C, the relative humidity is preferably 85-97% RH, more preferably 97%; and the aging treatment time is preferably 12-24 h.

[0078] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0079] Example 1

[0080] 4.0 g of octaphenylcyclotetrasiloxane and 2.0 g of benzylamine were dispersed in 30 mL of 1,2-dichloroethane solvent. 9.0 g of crosslinking agent dimethoxymethane and 9.7 g of catalyst anhydrous ferric chloride were added. After prepolymerization at 40 °C for 4 hours, the temperature was raised to 80 °C and the reaction continued for 24 hours. The product was washed with ethanol, filtered, and dried to obtain a brown powder organosilicon porous polymer, denoted as HCP-A.

[0081] Example 2

[0082] 1g of HCP-A prepared in Example 1 was added to 40mL of 1mol·L⁻¹ solution. -1 Hydrolyzed in sodium hydroxide alcohol solution at 75°C for 24 hours, the product was washed with deionized water and ethanol solution, and dried to obtain a brown powder product, hydroxyl-functionalized organosilicon porous polymer, denoted as HCP-B.

[0083] Example 3

[0084] 0.5g of HCP-A prepared in Example 1 was dispersed in 30mL of chloroform, and 2.5g of 1,3-propanesulfonic acid lactone was added. The mixture was reacted at 40°C for 6 hours. The product was washed with deionized water and ethanol in sequence and then dried to obtain a sulfonic acid functionalized organosilicon porous polymer, denoted as HCP-A-SO3.

[0085] Example 4

[0086] 0.5g of HCP-B prepared in Example 2 was dispersed in 30mL of chloroform, and 2.5g of 1,3-propanesulfonic acid lactone was added. The mixture was reacted at 40°C for 6 hours. The product was washed with deionized water and ethanol in sequence and then dried to obtain a sulfonic acid group-hydroxyl functionalized organosilicon porous polymer, denoted as HCP-B-SO3.

[0087] Test Example 1

[0088] The infrared spectra of the polymers prepared in Examples 1-4 are as follows: Figure 1 As shown. HCP-A and HCP-B at 3052cm -1 The CH stretching vibration of the aromatic ring was significantly weakened and the 2960–2850 cm⁻¹ was also reduced. -1 The appearance of the methylene bridge absorption peak confirms the formation of the cross-linked network. Compared with HCP-A, HCP-B, after alkali treatment, exhibits a Si-O-Si infrared characteristic absorption peak (1134 cm⁻¹). -1 The absorption peak weakens, while the Si-OH absorption peak (3430 cm⁻¹) weakens. -1 The enhancement indicates the breaking of Si-O-Si bonds and the formation of Si-OH during the synthesis process. After the introduction of sulfonyl lactone, HCP-A-SO3 and HCP-B-SO3 showed improved performance at 1600 cm⁻¹ compared to HCP-A and HCP-B. -1 The absorption peak of NH decreases at 1190 cm⁻¹ -1 and 1068cm -1 Left and right - SO3 2- The absorption peaks were enhanced. These all prove that the polymer was successfully synthesized.

[0089] XPS spectra of the polymers prepared in Examples 1-4 are as follows Figure 2 As shown, the nitrogen (N) content in HCP-A and HCP-B is 4%, and the sulfur (S) content is 0%. After the addition of sulfonyl lactone, the sulfur (S) content in HCP-A-SO3 and HCP-B-SO3 is 3%, and the nitrogen (N) content is 1%. This demonstrates that sulfonyl lactone was successfully introduced into the system.

[0090] Test Example 2

[0091] The pore structure characterization results of the polymers prepared in Examples 1-4 are shown in Table 1.

[0092] Table 1. Pore structures of polymers prepared in Examples 1-4

[0093]

[0094] Application examples

[0095] (1) The interdigitated electrodes used in this application example are Ag-Pd interdigitated electrodes with a ceramic substrate and a size of 3.5mm × 7.5mm. There are five groups of interdigitated electrodes, and the width and spacing of the interdigitated electrodes are both 200μm. Before fabricating the humidity sensor, the electrodes are dried by ultrasonication for 15min in anhydrous ethanol and distilled water, respectively.

[0096] (2) Mix 0.1g of HCP-A with 1mL of chloroform and ultrasonically disperse it evenly; brush the dispersion evenly onto the surface of the interdigital electrode and dry it in an oven at 60℃ for later use, forming a 60μm sensing layer on the surface of the interdigital electrode.

[0097] (3) Mix 0.1g of HCP-A-SO3 with 1mL of chloroform and disperse it evenly by ultrasonication; brush the dispersion evenly onto the surface of the interdigital electrode and dry it in an oven at 60℃ for later use, forming a 60μm sensing layer on the surface of the interdigital electrode.

[0098] (4) Mix 0.1g of HCP-B with 1mL of chloroform and disperse evenly by ultrasonication; brush the dispersion evenly onto the surface of the interdigital electrode and dry it in an oven at 60℃ for later use, forming a 60μm sensing layer on the surface of the interdigital electrode.

[0099] (5) Mix 0.1g of HCP-B-SO3 with 1mL of chloroform and disperse it evenly by ultrasonication; brush the dispersion evenly onto the surface of the interdigital electrode and dry it in an oven at 60℃ for later use, forming a 60μm sensing layer on the surface of the interdigital electrode.

[0100] (6) The humidity sensors from steps (2), (3), (4), and (5) are subjected to aging treatment at 97% relative humidity and 25°C for 24 hours to obtain a humidity sensor based on functional organosilicon porous polymer.

[0101] Test Example 3

[0102] To investigate the humidity sensing characteristics of the humidity sensor, the humidity sensor prepared for the application example was tested under different relative humidity conditions. The relative humidity environment was provided by saturated salt solutions with different saturated vapor pressures. The humidity response of the humidity sensor under different humidity conditions was tested using the CHS-1 intelligent humidity-sensitive analysis system manufactured by Beijing Elite Technology Co., Ltd.

[0103] The humidity sensor based on a functional organosilicon porous polymer, fabricated as an application example, exhibits the following humidity sensing characteristic curve at 100 Hz: Figure 3As shown in the figure, the humidity sensor based on HCP-B-SO3 has the highest sensitivity (0.08646) and the largest impedance value change (7 orders of magnitude) within the range of 11%RH to 97%RH. Considering the comprehensive evaluation of humidity sensing performance, including sensitivity and linearity, the humidity sensor based on HCP-B-SO3 exhibits the best humidity sensing performance among the four humidity sensors.

[0104] The response-recovery curve of the humidity sensor based on functional organosilicon porous polymer prepared in the application example at 100 Hz is shown below. Figure 4 As shown in the figure, response / recovery time is one of the important indicators for evaluating humidity sensors. Here, the response / recovery time is defined as the time when the impedance value reaches 90% of the total impedance change when the humidity sensor is repeatedly transferred between 11%RH and 97%RH environments. A segment is taken from the response-recovery curves of the HCP-B-SO3-based humidity sensor over 10 cycles between 11%RH and 97%RH. When the HCP-B-SO3-based humidity sensor is rapidly transferred from 11%RH to 97%RH, the adsorption process reaches equilibrium in 0.6 s. When it is rapidly transferred from 97%RH to 11%RH, the desorption process reaches equilibrium in 141 s. After 10 cycles, the HCP-B-SO3-based humidity sensor still recovers to its initial level, indicating that the impedance response of the HCP-B-SO3-based humidity sensor has high reproducibility.

[0105] The long-term stability of the HCP-B-SO3-based humidity sensor in environments of 100Hz, 11%RH, and 97%RH is as follows: Figure 5 As shown. Long-term stability is one of the key parameters for evaluating the overall performance of a humidity sensor, and it is also an important indicator determining the practical application value of a humidity sensor. Figure 5 As shown, the humidity sensor prepared by this invention exhibits excellent long-term stability at both 11% RH and 97% RH.

[0106] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing an organosilicon porous polymer, comprising the following steps: Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer; The mass ratio of the octaphenylcyclotetrasiloxane to benzylamine is 1.5~2:1; The crosslinking agent is dimethoxymethane; The catalyst is anhydrous ferric chloride or anhydrous aluminum chloride.

2. A method for preparing a hydroxyl-functionalized organosilicon porous polymer, comprising the following steps: Octaphenylcyclotetrasiloxane, benzylamine, an organic solvent, a crosslinking agent, and a catalyst are mixed and polymerized to obtain a porous organosilicon polymer; the mass ratio of octaphenylcyclotetrasiloxane to benzylamine is 1.5~2:1; the crosslinking agent is dimethoxymethane; and the catalyst is anhydrous ferric chloride or anhydrous aluminum chloride. The porous organosilicon polymer was mixed with an alkaline alcohol solution and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized porous organosilicon polymer; the mass concentration of the alkaline alcohol solution was 0.5~2 mol·L⁻¹. -1 .

3. A method for preparing a sulfonic acid group-functionalized organosilicon porous polymer, comprising the following steps: Octaphenylcyclotetrasiloxane, benzylamine, organic solvent, crosslinking agent and catalyst are mixed and polymerized to obtain organosilicon porous polymer; The organosilicon porous polymer, solvent, and 1,3-propanesulfonic acid lactone were mixed and subjected to a first bimolecular nucleophilic substitution reaction to obtain a sulfonic acid functionalized organosilicon porous polymer. The mass ratio of the octaphenylcyclotetrasiloxane to benzylamine is 1.5~2:1; The crosslinking agent is dimethoxymethane; the catalyst is anhydrous ferric chloride or anhydrous aluminum chloride. The mass ratio of the organosilicon porous polymer to 1,3-propanesulfonic acid lactone is 1:3~8.

4. A method for preparing a sulfonic acid group-hydroxyl functionalized organosilicon porous polymer, comprising the following steps: Octaphenylcyclotetrasiloxane, benzylamine, an organic solvent, a crosslinking agent, and a catalyst are mixed and polymerized to obtain a porous organosilicon polymer; the mass ratio of octaphenylcyclotetrasiloxane to benzylamine is 1.5~2:1; the crosslinking agent is dimethoxymethane; and the catalyst is anhydrous ferric chloride or anhydrous aluminum chloride. The porous organosilicon polymer was mixed with an alkaline alcohol solution and subjected to a hydrolysis reaction to obtain a hydroxyl-functionalized porous organosilicon polymer; the mass concentration of the alkaline alcohol solution was 0.5~2 mol·L⁻¹. -1 ; The hydroxyl-functionalized organosilicon porous polymer was mixed with a solvent and 1,3-propanesulfonic acid lactone and subjected to a second bimolecular nucleophilic substitution reaction to obtain a sulfonic acid group-hydroxyl-functionalized organosilicon porous polymer. The mass ratio of the organosilicon porous polymer to 1,3-propanesulfonic acid lactone is 1:3~8.

5. The application of one or more of the following in a humidity sensor: the organosilicon porous polymer prepared by the preparation method of claim 1, the hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method of claim 2, the sulfonic acid-functionalized organosilicon porous polymer prepared by the preparation method of claim 3, and the sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method of claim 4.

6. A humidity sensor, characterized in that, The invention includes a ceramic substrate and a plurality of interdigitated electrodes disposed on the surface of the ceramic substrate; a sensing layer is disposed on the surface of the interdigitated electrodes; the raw materials for preparing the sensing layer include one or more of the following: the organosilicon porous polymer prepared by the preparation method of claim 1, the hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method of claim 2, the sulfonic acid-functionalized organosilicon porous polymer prepared by the preparation method of claim 3, and the sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the preparation method of claim 4.

7. The humidity sensor according to claim 6, characterized in that, The interdigitated electrode is an Ag-Pd interdigitated electrode; the width of the interdigitated electrode is 150~200μm.

8. The humidity sensor according to claim 6, characterized in that, The interdigitated electrodes are in five groups; the distance between two adjacent groups of interdigitated electrodes is 150~200μm.

9. The humidity sensor according to claim 6, characterized in that, The thickness of the sensing layer is 40~80μm.

10. A method for preparing the humidity sensor according to any one of claims 6 to 9, comprising the following steps: One or more of the following polymers prepared by the method of claim 1, the hydroxyl-functionalized organosilicon porous polymer prepared by the method of claim 2, the sulfonic acid-functionalized organosilicon porous polymer prepared by the method of claim 3, and the sulfonic acid-hydroxyl-functionalized organosilicon porous polymer prepared by the method of claim 4 are mixed with an organic solvent to obtain a dispersion. The dispersion was coated onto the surface of the interdigitated electrode on a ceramic substrate, and then dried and aged sequentially to obtain a humidity sensor.

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