Silica gel capable of rapidly absorbing water as well as preparation method and application of silica gel

Abstract

The invention belongs to the technical field of silica gel, and particularly relates to silica gel capable of rapidly absorbing water as well as a preparation method and application thereof. The silica gel capable of rapidly absorbing water is prepared by carrying out a thiol-ene click reaction on silochrom loaded with a polyhydroxy compound and silochrom loaded with polydopamine. The silica gel provided by the invention has relatively high water absorption rate while rapidly absorbing water, and also has good regeneration performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of silica gel, and particularly relates to a silica gel with rapid water absorption, a preparation method thereof, and an application thereof. Background Art

[0002] Silica gel is an amorphous inorganic polymer material that can absorb moisture in the air. Due to its non-toxic, odorless, non-corrosive, and pollution-free properties, it is widely used in food and drug desiccants, moisture-proof protection of electronic devices, and control of air humidity. However, the problems of low water absorption rate and slow adsorption speed of ordinary silica gel limit its application in high-humidity environments.

[0003] In order to improve the water absorption rate of silica gel, Chinese Patent with the authorized publication number CN 118437280 B discloses a composite desiccant and a preparation method thereof. The composite desiccant includes modified silica gel and activated carbon with a mass ratio of (7-15):(1-5). The modified silica gel prepared by this technical solution has an excellent microporous structure. After being treated with an organic acid solution, it can play a certain role in cleaning and expanding the micropores, thereby having a high specific surface area, being able to load more activated carbon, and having a more excellent adsorption effect through synergistic action. At the same time, the modified silica gel of this technical solution has a larger number of hydroxyl groups and high internal structural stability, which can not only significantly improve its adsorption performance, but also is not easy to deform, deteriorate, or penetrate out of the packaging bag after water absorption, thus not affecting the product. Moreover, the recycling process is simple. However, the moisture absorption amount of the composite desiccant prepared by this technical solution can only reach about 33 after being placed for 48 h at 90% humidity, and its adsorption speed is relatively slow.

[0004] In order to improve the adsorption speed of silica gel, Chinese Patent with the publication number CN 119236889 A discloses a fast-adsorbing medicinal silica gel desiccant and a preparation method thereof. The fast-adsorbing medicinal silica gel desiccant is composed of the following components in parts by weight: 50-65 parts of silica gel, 4-8 parts of calcium chloride, 3-6 parts of magnesium sulfate, 3-7 parts of iron(III) oxide, 1-4 parts of antibacterial compound, 5-10 parts of modified surfactant, 1-2 parts of potassium hydroxide, 10-30 parts of ice water, 2-4 parts of acrylic acid, 2-4 parts of acrylamide, 0.4-0.8 part of sodium carboxymethyl starch, 0.2-0.3 part of dimethoxybenzyl benzoate, 0.005-0.015 part of polyethylene glycol diacrylate, and 1-2 parts of methanol. The silica gel desiccant prepared by this method has excellent antibacterial properties, adsorption rate, and adsorption capacity. However, the moisture absorption rate of this technical solution is about 53%, and the water absorption rate still needs to be improved.

[0005] In addition, none of the above-mentioned prior arts pays attention to the regeneration performance of their products. Summary of the Invention

[0006] The object of the present invention is to overcome the problems of low water absorption rate and water absorption capacity of silica gel in the prior art, and to provide a silica gel with rapid water absorption, which is prepared by a thiol-ene click reaction of macroporous silica gel loaded with polyhydroxy compounds and macroporous silica gel loaded with polydopamine, so that the silica gel has a high water absorption rate while rapidly absorbing water. In addition, it also has good regeneration performance.

[0007] Another object of the present invention is to provide a preparation method of a silica gel with rapid water absorption.

[0008] Another object of the present invention is to provide an application of a silica gel with rapid water absorption in a desiccant.

[0009] Another object of the present invention is to provide a desiccant.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] On the one hand, the present invention provides a silica gel with rapid water absorption, which is formed by a thiol-ene click reaction of macroporous silica gel loaded with polyhydroxy compounds and macroporous silica gel loaded with polydopamine.

[0012] The pore volume of the macroporous silica gel of the present invention is preferably 0.6-1 mL / g, more preferably 0.6-0.8 mL / g, and even more preferably 0.65 mL / g-0.78 mL / g.

[0013] The polyhydroxy compounds of the present invention include at least one of glyceroglucoside and konjac glucomannan.

[0014] Further, the polyhydroxy compounds are a mixture of glyceroglucoside and konjac glucomannan with a mass ratio of 3-8:2-4.

[0015] Further, the polyhydroxy compounds are a mixture of glyceroglucoside and konjac glucomannan with a mass ratio of 5:3.

[0016] The macroporous silica gel loaded with polyhydroxy compounds of the present invention is preferably loaded with polyhydroxy compounds inside the macroporous silica gel.

[0017] Further, the preparation method of the macroporous silica gel loaded with polyhydroxy compounds includes the following steps: stirring and dispersing an aqueous solution of polyhydroxy compounds and macroporous silica gel evenly, placing them in a sealed container, evacuating, releasing the vacuum, repeating 3-5 times, and drying to obtain intermediate A; mixing intermediate A, a thiol silane coupling agent and an aqueous ethanol solution, stirring and reacting, filtering, washing, and drying to obtain.

[0018] Further, the mass concentration of the aqueous solution of polyhydroxy compounds is 2-5%.

[0019] Further, the mass ratio of the polyhydroxy compound to the macroporous silica gel is 0.3 - 0.8:1.

[0020] Further, the mass ratio of the intermediate A to the mercapto silane coupling agent is 1:2 - 4.

[0021] Further, the ratio of the intermediate A to the ethanol aqueous solution is 1 g:30 - 50 mL.

[0022] Further, the mass ratio of ethanol to water in the ethanol aqueous solution is 1 - 3:97 - 99.

[0023] Further, the mercapto silane coupling agent is selected from at least one of γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane or γ-mercaptopropyltriethoxysilane, and is further preferably γ-mercaptopropyltrimethoxysilane.

[0024] Further, the method for preparing the macroporous silica gel loaded with the polyhydroxy compound includes the following steps: stirring and dispersing the polyhydroxy compound aqueous solution and the macroporous silica gel evenly, placing them in a sealed container, evacuating to 0.1 - 0.3 atm, releasing the vacuum, repeating 3 - 5 times, and drying to obtain the intermediate A; mixing the intermediate A, the mercapto silane coupling agent and the ethanol aqueous solution, stirring and reacting at 60 - 80 °C for 3 - 5 h, filtering, washing, and drying to obtain the product.

[0025] The macroporous silica gel loaded with polydopamine of the present invention is preferably polydopamine loaded on the surface of the macroporous silica gel.

[0026] Further, the method for preparing the macroporous silica gel loaded with polydopamine includes the following steps: dispersing the macroporous silica gel in a Tris (tris(hydroxymethyl)aminomethane hydrochloride) buffer solution, adding an aqueous dopamine hydrochloride solution, stirring, filtering, washing, and drying to obtain the intermediate B, mixing the intermediate B, the vinyl silane coupling agent and the ethanol aqueous solution, filtering, washing, and drying to obtain the product.

[0027] Further, the mass concentration of the Tris buffer solution is 0.5 - 1%.

[0028] Further, the mass concentration of the aqueous dopamine hydrochloride solution is 0.5 - 1%.

[0029] Further, the mass-to-volume ratio of the macroporous silica gel to the Tris buffer solution is 5 - 10 mg:1 mL.

[0030] Further, the volume ratio of the Tris buffer solution to the aqueous dopamine hydrochloride solution is 1 - 1.5:1.

[0031] Further, the mass ratio of the intermediate B to the vinyl silane coupling agent is 1:3 - 5.

[0032] Further, the ratio of the intermediate B to the aqueous ethanol solution is 1 g: 30 - 50 mL.

[0033] Further, the vinyl silane coupling agent is selected from at least one of vinyltriethoxysilane, γ - methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyl - tris(2 - methoxyethoxy)silane, and is preferably vinyltrimethoxysilane.

[0034] Further, the method for preparing the macroporous silica gel loaded with polydopamine includes the following steps: dispersing the macroporous silica gel in a Tris (tris - hydroxymethylaminomethane hydrochloride) buffer solution, adding an aqueous solution of dopamine hydrochloride, stirring at 300 - 500 rpm for 20 - 24 h, centrifuging, filtering, washing, and drying to obtain the intermediate B. Mixing the intermediate B, the vinyl silane coupling agent, and the aqueous ethanol solution, and stirring and reacting at 60 - 80 °C for 3 - 5 h, filtering, washing, and drying to obtain the product.

[0035] The present invention creatively cross - links the macroporous silica gel loaded with polyhydroxy compounds and the macroporous silica gel loaded with polydopamine through a thiol - ene click reaction to form a stable silica gel. Among them, the polyhydroxy compounds are loaded inside the macroporous silica gel, and the polydopamine is loaded on the outer surface of the macroporous silica gel. The two work together to achieve rapid water absorption and have a high water absorption rate. In addition, the regeneration rate is improved due to the presence of the thiol - ene cross - linked network.

[0036] During this process, the inventors found that: (1) when the polyhydroxy compounds include gluconic acid glycerol ester and konjac glucomannan, the hygroscopic rate, hygroscopic rate, and regeneration rate of the obtained silica gel are better than those using the same mass of a single polyhydroxy compound. It is speculated that this is because the hydroxyl groups of gluconic acid glycerol ester and konjac glucomannan accelerate capillary penetration, and at the same time enhance the multilayer adsorption of water molecules through a hydrogen bond network, showing a synergistic effect; (2) when the polyhydroxy compounds are loaded on the surface of the macroporous silica gel, the hygroscopic rate, hygroscopic rate, and regeneration rate of the obtained silica gel are poor, probably because the pore utilization rate of the macroporous silica gel is low and the structural stability of the macroporous silica gel is poor; (3) when preparing the macroporous silica gel loaded with polyhydroxy compounds, using other thiol compounds to react with the macroporous silica gel loaded with polydopamine may result in poor hygroscopic rate, hygroscopic rate, and regeneration rate of the obtained silica gel due to insufficient cross - linking density.

[0037] On the other hand, the present invention also provides a method for preparing the above - mentioned silica gel with rapid water absorption, including the following steps: dispersing the macroporous silica gel loaded with polyhydroxy compounds in dimethylformamide, adding the macroporous silica gel loaded with polydopamine and an initiator, reacting under ultraviolet light, filtering, washing, and drying to obtain the product.

[0038] Further, the initiator is selected from at least one of benzoin dimethyl ether or 2-hydroxy-2-methyl-1-phenyl-1-propanone, preferably benzoin dimethyl ether.

[0039] Further, the ratio of the macroporous silica gel loaded with polyhydroxy compound, the macroporous silica gel loaded with polydopamine, the initiator and dimethylformamide is 2-3 g: 1 g: 0.2-0.3 g: 30-50 mL.

[0040] Further, the preparation method of the silica gel with rapid water absorption includes the following steps: the macroporous silica gel loaded with polyhydroxy compound is dispersed in dimethylformamide, the macroporous silica gel loaded with polydopamine and the initiator are added, and the reaction is carried out under ultraviolet light (wavelength 365 nm) for 1-2 h, filtered, washed, and dried to obtain.

[0041] Another aspect of the present invention also provides the application of the above-mentioned silica gel with rapid water absorption in desiccants.

[0042] Another aspect of the present invention also provides a desiccant, including the above-mentioned silica gel with rapid water absorption.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The present invention creatively crosslinks the macroporous silica gel loaded with polyhydroxy compound and the macroporous silica gel loaded with polydopamine through thiol-ene click reaction to form a stable silica gel. The two act together to achieve rapid water absorption while having a high water absorption rate and regeneration rate.

[0045] 2. When the polyhydroxy compound includes glycerol glucoside and konjac glucomannan in the present invention, the moisture absorption rate, moisture absorption rate and regeneration rate of the silica gel are improved.

[0046] 3. The present invention uses a specific thiol compound to react with the macroporous silica gel loaded with polydopamine, improving the moisture absorption rate, moisture absorption rate and regeneration rate of the silica gel. Detailed Embodiments

[0047] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods are described in detail below.

[0048] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each implementation manner of the present invention can be combined with each other as long as they do not conflict with each other.

[0049] In the following examples and comparative examples, unless otherwise specified, the raw materials used are all commercially available or prepared by conventional methods in the art.

[0050] The pore volume of the macroporous silica gel is 0.78 mL / g, purchased from Qingdao Century Marine Environmental Protection New Materials Co., Ltd., type C-1, first-class product.

[0051] Example 1 A silica gel with rapid water absorption

[0052] Step 1: Prepare macroporous silica gel loaded with glycerol glucoside:

[0053] The glycerol glucoside aqueous solution and the macroporous silica gel were stirred and dispersed evenly, placed in a sealed container, evacuated to 0.2 atm, the vacuum was released, and the process was repeated 4 times, then dried to obtain intermediate A; Intermediate A, γ-mercaptopropyltrimethoxysilane and an ethanol aqueous solution were mixed, and stirred and reacted at 70 °C for 4 h, filtered, washed, and dried to obtain the product.

[0054] The mass concentration of the glycerol glucoside aqueous solution is 4%.

[0055] The mass ratio of the glycerol glucoside to the macroporous silica gel is 0.5:1.

[0056] The mass ratio of the intermediate A to γ-mercaptopropyltrimethoxysilane is 1:3.

[0057] The ratio of the intermediate A to the ethanol aqueous solution is 1 g:40 mL.

[0058] The mass ratio of ethanol to water in the ethanol aqueous solution is 3:97.

[0059] Step 2: Prepare macroporous silica gel loaded with polydopamine:

[0060] The macroporous silica gel was dispersed in Tris buffer solution, hydrochloric acid dopamine aqueous solution was added, and stirred at 400 rpm for 24 h, centrifuged, filtered, washed, and dried to obtain intermediate B. Intermediate B, vinyltrimethoxysilane and an ethanol aqueous solution were mixed, and stirred and reacted at 70 °C for 4 h, filtered, washed, and dried to obtain the product.

[0061] The mass concentration of the Tris buffer solution is 0.5%.

[0062] The mass concentration of the hydrochloric acid dopamine aqueous solution is 0.5%.

[0063] The mass-volume ratio of the macroporous silica gel to the Tris buffer solution is 8 mg:1 mL.

[0064] The volume ratio of the Tris buffer solution to the hydrochloric acid dopamine aqueous solution is 1:1.

[0065] The mass ratio of the intermediate B to vinyltrimethoxysilane is 1:4.

[0066] The ratio of the intermediate B to the aqueous ethanol solution is 1 g: 40 mL.

[0067] Step 3: Prepare the silica gel with rapid water absorption:

[0068] The macroporous silica gel loaded with glycerol glucoside is dispersed in dimethylformamide, the macroporous silica gel loaded with polydopamine and benzoin dimethyl ether are added, and the reaction is carried out under ultraviolet light (wavelength 365 nm) for 1.5 h, followed by filtration, washing, and drying to obtain the product.

[0069] The ratio of the macroporous silica gel loaded with glycerol glucoside, the macroporous silica gel loaded with polydopamine, benzoin dimethyl ether and dimethylformamide is 2 g: 1 g: 0.2 g: 40 mL.

[0070] Example 2 A silica gel with rapid water absorption

[0071] Step 1: Prepare the macroporous silica gel loaded with konjac glucomannan:

[0072] The aqueous solution of konjac glucomannan and the macroporous silica gel are stirred and dispersed evenly, placed in a sealed container, evacuated to 0.2 atm, the vacuum is released, and the process is repeated 4 times, followed by drying to obtain intermediate A; Intermediate A, γ-mercaptopropyltrimethoxysilane and the aqueous ethanol solution are mixed, and the reaction is carried out with stirring at 70 °C for 4 h, followed by filtration, washing, and drying to obtain the product.

[0073] The mass concentration of the aqueous solution of konjac glucomannan is 4%.

[0074] The mass ratio of konjac glucomannan to the macroporous silica gel is 0.5:1.

[0075] The mass ratio of intermediate A to γ-mercaptopropyltrimethoxysilane is 1:3.

[0076] The ratio of intermediate A to the aqueous ethanol solution is 1 g: 40 mL.

[0077] The mass ratio of ethanol to water in the aqueous ethanol solution is 3:97.

[0078] Step 2: Prepare the macroporous silica gel loaded with polydopamine: The same as step 2 of Example 1.

[0079] Step 3: Prepare the silica gel with rapid water absorption:

[0080] The macroporous silica gel loaded with konjac glucomannan is dispersed in dimethylformamide, the macroporous silica gel loaded with polydopamine and benzoin dimethyl ether are added, and the reaction is carried out under ultraviolet light (wavelength 365 nm) for 1.5 h, followed by filtration, washing, and drying to obtain the product.

[0081] The ratio of the macroporous silica gel loaded with konjac glucomannan, the macroporous silica gel loaded with polydopamine, benzoin dimethyl ether and dimethylformamide is 2 g: 1 g: 0.2 g: 40 mL.

[0082] Example 3 A kind of silica gel with rapid water absorption

[0083] Step 1: Prepare macroporous silica gel loaded with glyceroglucoside and konjac glucomannan:

[0084] Stir and disperse the aqueous solution of polyhydroxy compound and macroporous silica gel evenly, place it in a sealed container, evacuate to 0.2 atm, release the vacuum, repeat 4 times, and dry to obtain intermediate A; mix intermediate A, γ-mercaptopropyltrimethoxysilane and aqueous ethanol solution, stir and react at 70 °C for 4 h, filter, wash, and dry to obtain.

[0085] The polyhydroxy compound is a mixture of glyceroglucoside and konjac glucomannan with a mass ratio of 5:3.

[0086] The mass concentration of the aqueous solution of the polyhydroxy compound is 4%.

[0087] The mass ratio of the polyhydroxy compound to the macroporous silica gel is 0.5:1.

[0088] The mass ratio of intermediate A to γ-mercaptopropyltrimethoxysilane is 1:3.

[0089] The ratio of intermediate A to the aqueous ethanol solution is 1 g: 40 mL.

[0090] The mass ratio of ethanol to water in the aqueous ethanol solution is 3:97.

[0091] Step 2: Prepare macroporous silica gel loaded with polydopamine: The same as step 2 of Example 1.

[0092] Step 3: Prepare silica gel with rapid water absorption:

[0093] Disperse the macroporous silica gel loaded with glyceroglucoside and konjac glucomannan in dimethylformamide, add the macroporous silica gel loaded with polydopamine and benzoin dimethyl ether, and react under ultraviolet light (wavelength 365 nm) for 1.5 h, filter, wash, and dry to obtain.

[0094] The ratio of the macroporous silica gel loaded with glyceroglucoside and konjac glucomannan, the macroporous silica gel loaded with polydopamine, benzoin dimethyl ether and dimethylformamide is 2 g: 1 g: 0.2 g: 40 mL.

[0095] Comparative Example 1 A kind of silica gel with rapid water absorption

[0096] Step 1: Prepare macroporous silica gel:

[0097] Mix macroporous silica gel, γ-mercaptopropyltrimethoxysilane and an ethanol aqueous solution, stir and react at 70 °C for 4 h, filter, wash, and dry to obtain the product.

[0098] The mass ratio of the macroporous silica gel to γ-mercaptopropyltrimethoxysilane is 1:3.

[0099] The ratio of the macroporous silica gel to the ethanol aqueous solution is 1 g:40 mL.

[0100] The mass ratio of ethanol to water in the ethanol aqueous solution is 3:97.

[0101] Step 2: Prepare macroporous silica gel loaded with polydopamine: same as step 2 of Example 3.

[0102] Step 3: Prepare silica gel with rapid water absorption:

[0103] Disperse the macroporous silica gel in dimethylformamide, add the macroporous silica gel loaded with polydopamine and benzoin dimethyl ether, and react under ultraviolet light (wavelength 365 nm) for 1.5 h, filter, wash, and dry to obtain the product.

[0104] The ratio of the macroporous silica gel loaded with glyceroglucoside and konjac glucomannan, the macroporous silica gel loaded with polydopamine, benzoin dimethyl ether and dimethylformamide is 2 g:1 g:0.2 g:40 mL.

[0105] Comparative Example 2 A kind of silica gel with rapid water absorption

[0106] Step 1: Prepare macroporous silica gel loaded with glyceroglucoside and konjac glucomannan:

[0107] Mix an aqueous solution of polyhydroxy compound and macroporous silica gel, stir at 400 rpm for 5 h to obtain intermediate A; mix intermediate A, γ-mercaptopropyltrimethoxysilane and an ethanol aqueous solution, stir and react at 70 °C for 4 h, filter, wash, and dry to obtain the product.

[0108] The polyhydroxy compound is a mixture of glyceroglucoside and konjac glucomannan with a mass ratio of 5:3.

[0109] The mass concentration of the aqueous solution of the polyhydroxy compound is 4%.

[0110] The mass ratio of the polyhydroxy compound to the macroporous silica gel is 0.5:1.

[0111] The mass ratio of intermediate A to γ-mercaptopropyltrimethoxysilane is 1:3.

[0112] The ratio of intermediate A to the ethanol aqueous solution is 1 g:40 mL.

[0113] The mass ratio of ethanol to water in the ethanol aqueous solution is 3:97.

[0114] Step 2: Prepare macroporous silica gel loaded with polydopamine: same as Step 2 of Example 3.

[0115] Step 3: Prepare silica gel with rapid water absorption: same as Step 3 of Example 3.

[0116] Comparative Example 3 A silica gel with rapid water absorption

[0117] Step 1: same as Step 1 of Example 3;

[0118] Step 2: Prepare macroporous silica gel:

[0119] Mix macroporous silica gel, vinyltrimethoxysilane and ethanol aqueous solution, stir and react at 70 °C for 4 h, filter, wash and dry to obtain.

[0120] The mass ratio of the intermediate B to vinyltrimethoxysilane is 1:4.

[0121] The ratio of the intermediate B to the ethanol aqueous solution is 1 g:40 mL.

[0122] The mass ratio of ethanol to water in the ethanol aqueous solution is 3:97.

[0123] Step 3: Prepare silica gel with rapid water absorption: same as Step 3 of Example 3.

[0124] Comparative Example 4 A silica gel with rapid water absorption

[0125] Step 1: Prepare macroporous silica gel loaded with glyceroglucoside and konjac glucomannan:

[0126] Stir and disperse the polyhydroxy compound aqueous solution and macroporous silica gel evenly, place them in a sealed container, evacuate to 0.2 atm, release the vacuum, repeat 4 times, and dry to obtain intermediate A; mix intermediate A, β-mercaptoethylamine and ethanol aqueous solution, stir and react at 70 °C for 4 h, filter, wash and dry to obtain.

[0127] The polyhydroxy compound is a mixture of glyceroglucoside and konjac glucomannan with a mass ratio of 5:3.

[0128] The mass concentration of the polyhydroxy compound aqueous solution is 4%.

[0129] The mass ratio of the polyhydroxy compound to macroporous silica gel is 0.5:1.

[0130] The mass ratio of the intermediate A to β-mercaptoethylamine is 1:3.

[0131] The ratio of the intermediate A to the ethanol aqueous solution is 1 g:40 mL.

[0132] The mass ratio of ethanol to water in the aqueous ethanol solution is 3:97.

[0133] Step 2: Prepare the macroporous silica gel loaded with polydopamine: same as step 2 of Example 3.

[0134] Step 3: Prepare the silica gel with rapid water absorption: same as step 3 of Example 3.

[0135] Comparative Example 5 A silica gel with rapid water absorption

[0136] Stir and disperse the aqueous solution of polyhydroxy compound and the macroporous silica gel evenly, place them in a sealed container, evacuate to 0.2 atm, release the vacuum, repeat 4 times, and dry to obtain.

[0137] The polyhydroxy compound is a mixture of glucomannan and konjac glucomannan with a mass ratio of 5:3.

[0138] The mass concentration of the aqueous solution of the polyhydroxy compound is 4%.

[0139] The mass ratio of the polyhydroxy compound to the macroporous silica gel is 0.5:1.

[0140] Comparative Example 6 A silica gel with rapid water absorption

[0141] Disperse the macroporous silica gel in Tris buffer solution, add aqueous dopamine hydrochloride solution, stir at 400 rpm for 24 h, centrifuge, filter, wash, and dry to obtain.

[0142] The mass concentration of the Tris buffer solution is 0.5%.

[0143] The mass concentration of the aqueous dopamine hydrochloride solution is 0.5%.

[0144] The mass-to-volume ratio of the macroporous silica gel to the Tris buffer solution is 8 mg:1 mL.

[0145] The volume ratio of the Tris buffer solution to the aqueous dopamine hydrochloride solution is 1:1.

[0146] Test Example

[0147] Test the performance of the silica gels with rapid water absorption (10 g) prepared in Examples 1-3 and Comparative Examples 1-6:

[0148] (1) At 25 °C, 90% humidity, and an adsorption time of 24 h, test its moisture absorption rate: Moisture absorption rate = (mass after water absorption - mass before water absorption) / mass before water absorption × 100%;

[0149] (2) Under the conditions of 25 °C, 90% humidity, and an adsorption time of 10 min, its moisture absorption rate was tested: Moisture absorption rate = (mass after water absorption - mass before water absorption) / time;

[0150] (3) First, under the conditions of 25 °C, 90% humidity, and an adsorption time of 1 h, and then heated at 100 °C for 4 h to remove water. Taking this as one cycle, its regeneration rate was tested: Regeneration rate = water absorption amount after 30 cycles / water absorption amount after the first cycle × 100%.

[0151] Test results:

[0152] Table 1

[0153] Moisture absorption rate (%) <![CDATA[Moisture absorption rate (g·g -1 ·min -1 )]]> Regeneration rate (%) Example 1 53 3.6 98.8 Example 2 48 3.2 98.2 Example 3 55 4.4 99.4 Comparative Example 1 35 2.3 96.4 Comparative Example 2 40 2.5 89.3 Comparative Example 3 31 2.2 87.1 Comparative Example 4 43 2.8 90.2 Comparative Example 5 30 2.2 85.7 Comparative Example 6 39 1.9 90.6

[0154] Result analysis:

[0155] Comparing Examples 1 - 3, it can be seen that when the polyhydroxy compound is a mixture of glycerol glucoside and konjac glucomannan, the moisture absorption rate, moisture absorption rate, and regeneration rate of the silica gel prepared are all improved compared to the silica gel prepared from a single polyhydroxy compound.

[0156] Comparing Example 3 and Comparative Example 1, it can be seen that when there is no polyhydroxy compound loaded inside the macroporous silica gel, the moisture absorption rate and moisture absorption rate of the prepared silica gel decrease significantly.

[0157] Comparing Example 3, Comparative Example 1, and Comparative Example 2, it can be seen that when the macroporous silica gel surface is loaded with polyhydroxy compounds, compared with when there is no polyhydroxy compound loaded, the moisture absorption rate and moisture absorption rate of the prepared silica gel are improved, but the regeneration rate decreases; compared with when the macroporous silica gel is loaded with polyhydroxy compounds, the moisture absorption rate, moisture absorption rate, and regeneration rate of the prepared silica gel all decrease significantly.

[0158] Comparing Example 3 and Comparative Example 3, it can be seen that when there is no polydopamine loaded on the surface of the macroporous silica gel, the moisture absorption rate, moisture absorption rate, and regeneration rate of the prepared silica gel all decrease significantly.

[0159] Comparing Example 3, Comparative Examples 1 - 2, and Comparative Example 4, it can be seen that when preparing macroporous silica gel loaded with glycerol glucoside and konjac glucomannan and replacing the mercapto silane coupling agent with β-mercaptoethylamine, the moisture absorption rate, moisture absorption rate, and regeneration rate of the obtained silica gel are better than those of Comparative Examples 1 - 2, but not as good as Example 3.

[0160] Comparing Example 3, Comparative Example 5, and Comparative Example 6, it can be seen that the moisture absorption rate, moisture absorption rate, and regeneration rate of the macroporous silica gel loaded only with glycerol glucoside and konjac glucomannan or only with polydopamine are far less than those of Example 3.

[0161] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than limiting the protection scope of the present invention. Any simple modification or equivalent replacement made by those of ordinary skill in the art to the technical solution of the present invention shall not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A quick water-absorbing silica gel, characterized in that: The fast water-absorbing silica gel is prepared by a thiol-ene click reaction between a macroporous silica gel loaded with a polyhydroxy compound and a macroporous silica gel loaded with polydopamine.

2. The quick water-absorbing silica gel according to claim 1, characterized in that: The polyol comprises at least one of glycerol glucoside and konjac glucomannan.

3. The quick water-absorbing silica gel according to claim 2, characterized in that: The polyhydroxy compound is a mixture of glycerol glucoside and konjac glucomannan in a mass ratio of 3-8:2-4.

4. The quick water-absorbing silica gel according to claim 3, characterized in that: The coarse-porous silica gel loaded with polyhydroxy compounds is a coarse-porous silica gel with polyhydroxy compounds loaded inside; the coarse-porous silica gel loaded with polydopamine is a coarse-porous silica gel with polydopamine loaded on the surface.

5. The quick water-absorbing silica gel according to claim 4, characterized in that: The preparation method of the macroporous silica gel loaded with polyhydroxy compounds, The method comprises the following steps: uniformly dispersing a polyhydroxy compound aqueous solution and coarse-porous silica gel by stirring, placing in a sealed container, evacuating, releasing the vacuum, repeating 3-5 times, and drying to obtain an intermediate A; and mixing the intermediate A, a mercaptosilane coupling agent and an ethanol aqueous solution, stirring for reaction, filtering, washing, and drying to obtain the intermediate A.

6. The quick water-absorbing silica gel according to claim 5, characterized in that: The preparation method of the coarse-porous silica gel loaded with polydopamine comprises the following steps: dispersing the coarse-porous silica gel in a Tris buffer solution, adding a dopamine hydrochloride aqueous solution, stirring, filtering, washing, and drying to obtain an intermediate B; and mixing the intermediate B, a vinyl silane coupling agent, and an ethanol aqueous solution, filtering, washing, and drying to obtain the intermediate B.

7. The quick water-absorbing silica gel according to claim 6, characterized in that: The vinyl silane coupling agent is selected from at least one of vinyl triethoxy silane, γ-methacryloxypropyl trimethoxy silane, vinyl trimethoxy silane, and vinyl-tri(2-methoxyethoxy) silane.

8. The method for preparing the quick water-absorbing silica gel according to any one of claims 1 to 7, characterized in that: The following steps are involved: The macroporous silica gel loaded with polyhydroxy compounds is dispersed in dimethylformamide, and the macroporous silica gel loaded with polydopamine and an initiator are added, reacted under ultraviolet light, filtered, washed and dried to obtain the product.

9. Use of the quick water-absorbing silica gel according to any one of claims 1 to 7 in a desiccant.

10. A desiccant, characterized in that: The invention relates to a silica gel having a rapid water absorption property comprising the silica gel according to any one of claims 1 to 7.