An oil-absorbing hydrogel, its preparation method and application

Abstract

The present invention discloses a hydrogel for absorbing oil, its preparation method and application. After mixing a polysaccharide gum with water, wet ultrafine grinding is carried out to obtain an ultrafine polysaccharide gum aqueous solution. High-shear mixing is adopted to uniformly infiltrate the polysaccharide gum into the interior of cellulose or its derivatives to form micelles. Microwave vacuum drying is used to promote the formation of a honeycomb structure in the micelles. Finally, ultrapure water subjected to high-pressure atomization is sprayed onto the honeycombed micelles and dried to obtain the oil-absorbing hydrogel. The prepared hydrogel has a water absorption multiple of more than 100 times, a storage modulus of more than 1350 Pa, and can efficiently absorb oil, and has broad development prospects in the field of weight loss drugs or foods.

Description

Technical Field

[0001] The present invention belongs to the field of high molecular compounds, relates to a composition of high molecular compounds, and particularly relates to an oil-absorbing hydrogel, a preparation method thereof and an application thereof. Background Art

[0002] The basic principle of weight loss is that the calories ingested are less than the calories consumed. As a low-calorie solution, meal replacement foods are popular in the weight loss circle and are characterized by low calories. They are available in the forms of granule powders, cakes and solid bars, etc. The common point of meal replacement foods is that their taste is not very good. At the same time, if a person only eats meal replacement foods, they are not only easy to get hungry, but also cannot enjoy delicious meals, making it difficult to stick to. Therefore, an ultra-high water absorption multiple weight control product that has no (or contains extremely low) calories itself and can increase the satiety of eaters and reduce food intake is an ideal choice for weight loss.

[0003] Chinese Patent CN111772180A discloses a weight control product with a high expansion coefficient. The raw materials are konjac glucomannan, pectin, bran, and proanthocyanidins. These raw materials are combined through hydrogen bonds between molecules to form a three-dimensional network structure. After ingestion, it rapidly swells by absorbing water in the stomach, increasing the satiety of the eater and reducing food intake, thereby achieving the purpose of weight loss or weight control. The water absorption multiple of this weight control product is relatively low, only about 10 - 15 times. To achieve satiety, more food needs to be eaten. However, bran itself has a relatively high calorie content (282 kcal / 100 g), so it is not suitable to eat too much. Chinese Patent CN115154407A discloses a chitosan flaxseed gum cross-linked hydrogel. The raw materials include chitosan, flaxseed gum, and calcium salt. The carboxyl groups contained in flaxseed gum can undergo electrostatic interaction with the ammonium ions generated when chitosan is dissolved in an acidic solution, thereby forming physical cross-linking sites. At the same time, the galacturonic acid contained in flaxseed gum is located on the main chain of the molecule and can come into contact with calcium ions to undergo bridging, which helps to form a three-dimensional network of the hydrogel. When this chitosan flaxseed gum cross-linked hydrogel is used as a gastric filler, it can achieve a certain swelling ratio in acidic gastric juice. After entering the alkaline colonic environment, the hydrogel can disintegrate, having pH sensitivity and providing satiety. However, the swelling ratio of this chitosan flaxseed gum cross-linked hydrogel in the stomach is relatively low, and the satiety provided is limited. Chinese Patent CN113854567A discloses an edible hydrogel and its preparation method. A dibasic acid and a polysaccharide or a polysaccharide derivative are dissolved in water, and chemical cross-linking is carried out through esterification reaction by drying at a relatively high temperature to prepare the edible hydrogel. The edible hydrogel prepared by this method is a chemically cross-linked high-molecular compound, and since the amount of water added is several times to dozens of times the amount of solid solute added, the energy consumption required for drying is high, and the production capacity and efficiency are low. Chinese Patent CN17179281A discloses a composite gel. This composite gel is prepared by physically cross-linking pectin and cellulose or its derivatives after dissolving them in a large amount of water by high-temperature drying. Since pectin is a dietary fiber that is poorly soluble in water and has poor solubility, a large amount of pectin needs to be added to water to increase the contact area and entanglement efficiency between pectin and cellulose or its derivatives to a certain extent. Moreover, the physical cross-linking is uneven, so the formed gel has poor water absorption performance and uneven storage modulus. The increase in oil content is one of the important reasons for the increase in human body weight. All of the above hydrogel products have obvious deficiencies in oil adsorption ability. To effectively control weight, it is urgent to develop a hydrogel product that can efficiently adsorb oil, has high safety, and strong water absorption ability. Summary of the Invention

[0004] To overcome the above-mentioned deficiencies of the existing technologies, the objective of the present invention is to provide a grease-absorbing hydrogel, its preparation method and application. After mixing the polysaccharide gum with water, wet ultrafine grinding is carried out, and high-shear mixing is used to uniformly infiltrate the polysaccharide gum into the interior of cellulose or its derivatives to form micelles. Microwave vacuum drying is used to promote the formation of a honeycomb structure in the micelles, and finally ultrapure water is sprayed and dried, thereby enhancing the water absorption performance and grease absorption capacity of the hydrogel, increasing the bulk density, significantly reducing the production energy consumption, and improving the production efficiency.

[0005] The objective of the present invention is achieved by at least one of the following technical solutions.

[0006] The first aspect of the present invention provides a preparation method of a grease-absorbing hydrogel, comprising the following steps:

[0007] (1) Mix the polysaccharide gum with water to obtain a mixed solution, and carry out wet ultrafine grinding on the mixed solution to form an ultrafine polysaccharide gum aqueous solution; the polysaccharide gum is high-ester pectin or a mixture of high-ester pectin and xanthan gum; the molecular weight of the high-ester pectin is 20,000 - 200,000, and the esterification degree of the high-ester pectin is 58% - 62%; the molecular weight of the xanthan gum is 1,000,000 - 2,000,000; the particle size of the polysaccharide gum in the ultrafine polysaccharide gum aqueous solution is less than 10 μm;

[0008] (2) High-pressure atomize and spray the ultrafine polysaccharide gum aqueous solution on the surface of cellulose or its derivatives, and use high-shear mixing to infiltrate the ultrafine polysaccharide gum aqueous solution into the interior of cellulose or its derivatives and bond to form micelles; the cellulose or its derivatives is sodium carboxymethyl cellulose or a mixture of sodium carboxymethyl cellulose and hydroxyethyl cellulose; the molecular weight of the sodium carboxymethyl cellulose is 20,000 - 80,000, and the substitution degree of the sodium carboxymethyl cellulose is 0.7 - 0.9; the molecular weight of the hydroxyethyl cellulose is 100,000 - 200,000, and the substitution degree is 1.3 - 1.5; the size of the micelles is 0.1 - 1 mm;

[0009] (3) Microwave vacuum dry the micelles to form honeycomb-like micelles;

[0010] (4) Adopt the spray fluidized bed granulation technology, high-pressure atomize and spray water on the surface of the honeycomb-like micelles, and dry to obtain the grease-absorbing hydrogel; the process parameters of the spray fluidized bed granulation technology are an inlet air temperature of 10 - 30 °C, a fan frequency of 20 - 50 Hz, and an atomized water flow rate of 10 - 20 g / min.

[0011] Further, in step (1), the water is ultrapure water, which can avoid the influence of other ions and substances, and is beneficial to the formation of the physical cross-linking network of the hydrogel.

[0012] Further, in step (1), the concentration of the polysaccharide gum in the ultrafine polysaccharide gum aqueous solution is 0.01 kg / L - 0.1 kg / L.

[0013] Further, in step (1), the mass ratio of the high-ester pectin to xanthan gum is greater than or equal to 3:1.

[0014] Furthermore, in step (1), the mass ratio of the high-ester pectin to xanthan gum is 3:1 or 4:1.

[0015] Further, in step (1), the rotation speed of the wet ultrafine grinding is 1000 - 1500 rpm, and the time of the wet ultrafine grinding is 30 - 60 min.

[0016] Furthermore, in step (1), the equipment used for the wet ultrafine grinding is a sand mill.

[0017] Further, in step (2), the mass ratio of the sodium carboxymethyl cellulose to hydroxyethyl cellulose is 10 - 15:4.98 - 9.98.

[0018] Furthermore, in step (2), the mass ratio of the sodium carboxymethyl cellulose to hydroxyethyl cellulose is 15:4.98 or 10:9.98.

[0019] Further, in step (2), the rotation speed of the high-shear mixing is 1000 - 1500 rpm, and the time of the high-shear mixing is 5 - 10 min.

[0020] Furthermore, in step (2), the equipment used for the high-shear mixing is a high-speed shear mixer.

[0021] Further, in step (2), the mass ratio of the polysaccharide gum in the ultrafine polysaccharide glue aqueous solution to the mass of cellulose or its derivative is 0.01 - 0.1:9.9 - 9.99.

[0022] Furthermore, in step (2), the mass ratio of the polysaccharide gum in the ultrafine polysaccharide glue aqueous solution to the mass of cellulose or its derivative is 0.02:19.98 or 0.2:19.8.

[0023] Further, in step (3), the vacuum degree of the microwave vacuum drying is -98.0 kPa to -100.0 kPa, the temperature of the microwave vacuum drying is 28 - 44 °C, and the time of the microwave vacuum drying is 0.5 - 1 h.

[0024] Further, in step (4), the drying is fluidized bed drying, and the drying time is 0.5 - 1 h.

[0025] Further, in step (4), the water used for the high-pressure atomizing spray is ultrapure water.

[0026] Furthermore, the bulk density of the oil-absorbing hydrogel is 0.5 - 0.7 g / ml.

[0027] The second aspect of the present invention provides an oil-absorbing hydrogel prepared by the preparation method described in any one of the above, and the oil-absorbing hydrogel has a honeycomb structure.

[0028] Even further, the bulk density of the oil-absorbing hydrogel is 0.5 - 0.7 g / ml.

[0029] The third aspect of the present invention provides the use of an oil-absorbing hydrogel prepared by the preparation method described in any one of the first aspect of the present invention or the oil-absorbing hydrogel provided by the second aspect of the present invention in the preparation of foods, drugs or health products having the functions of controlling diet, inducing satiety and losing weight.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] (1) In the preparation method of the present invention, a specific low-molecular-weight polysaccharide gum is mixed with water and then subjected to wet ultrafine grinding. Compared with conventional polysaccharide gums, the solubility is greatly improved, the particle size of the polysaccharide gum is significantly reduced, the contact area, collision probability and mixing uniformity between the polysaccharide gum and cellulose or its derivatives can be increased, the usage amount of the polysaccharide gum can be reduced, the production cost can be lowered, and the physical cross-linking efficiency can be improved; at the same time, the collision probability and contact area between the polysaccharide gum and oil in the hydrogel can be increased, and the oil absorption capacity of the hydrogel can be improved.

[0032] (2) In the preparation method of the present invention, an ultrafine polysaccharide gum aqueous solution is sprayed onto the surface of cellulose or its derivatives, and high-shear mixing is used to uniformly infiltrate the polysaccharide gum with a very small particle size (<10 μm) into the interior of cellulose or its derivatives. And because there is a certain amount of moisture on the surface of the polysaccharide gum, it is beneficial for the polysaccharide gum to adhere to form micelles inside cellulose or its derivatives; the micelles formed by the polysaccharide gum and cellulose or its derivatives are subjected to microwave vacuum drying. Compared with hot air drying, the interior of the micelles is uniformly heated and expands to form a honeycomb structure under vacuum treatment. The honeycomb structure and the polysaccharide gum with a very small particle size cooperate with each other, significantly enhancing the adsorption capacity of the hydrogel for water and oil. At the same time, microwave vacuum drying significantly reduces the drying time and reduces the process energy consumption.

[0033] (3) In the preparation method of the present invention, spraying ultrapure water on the honeycomb-like micelles using a fluidized bed and drying can reduce the pore size of the honeycomb structure, improve the bulk density and physical cross-linking strength of the hydrogel. Compared with not spraying ultrapure water, the volume of the hydrogel with the same mass is smaller (the bulk density is larger), and it is easier for the user to swallow.

[0034] (4)The hydrogel provided by the present invention uses safe raw materials, does not undergo chemical reactions during the preparation process, and no new substances are formed. Therefore, it has no potential toxicity and can be applied to the preparation of weight loss drugs, foods or health products.

[0035] (5)The unit adsorption capacity of the hydrogel provided by the present invention for grease reaches more than 16 ml / g, which can effectively reduce the absorption of grease by the body and achieve the weight loss effect. Description of the Drawings

[0036] Figure 1 It is the scanning electron microscope microscopic image of the composite gel 1 prepared in Example 1. Detailed Embodiments

[0037] The following non-limiting examples can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way. The following content is only an exemplary illustration of the scope claimed by the present invention. Those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and it should also fall within the scope claimed by the present invention.

[0038] When the examples give numerical ranges, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0039] The grease-absorbing hydrogel of the present invention is a composition of polysaccharides and their derivatives.

[0040] In the present invention, a preparation method of a grease-absorbing hydrogel includes the following steps:

[0041] (1)Mix the polysaccharide gum with water to obtain a mixed solution, and wet ultrafine grind the mixed solution to form an ultrafine polysaccharide gum aqueous solution; the polysaccharide gum is high-ester pectin or a mixture of high-ester pectin and xanthan gum; the molecular weight of the high-ester pectin is 20,000 - 200,000, and the esterification degree of the high-ester pectin is 58% - 62%; the molecular weight of the xanthan gum is 1 million - 2 million; the particle size of the polysaccharide gum in the ultrafine polysaccharide gum aqueous solution is less than 10 μm;

[0042] (2) High-pressure atomize and spray the ultramicro polysaccharide glue aqueous solution on the surface of cellulose or its derivatives, and use high-shear mixing to make the ultramicro polysaccharide glue aqueous solution penetrate into the interior of cellulose or its derivatives and bond to form microaggregates; the cellulose or its derivatives are sodium carboxymethyl cellulose or a mixture of sodium carboxymethyl cellulose and hydroxyethyl cellulose; the molecular weight of the sodium carboxymethyl cellulose is 20,000 - 80,000, and the degree of substitution of the sodium carboxymethyl cellulose is 0.7 - 0.9; the molecular weight of the hydroxyethyl cellulose is 100,000 - 200,000, and the degree of substitution is 1.3 - 1.5; the size of the microaggregates is 0.1 - 1 mm;

[0043] (3) Microwave vacuum dry the microaggregates to form honeycombed microaggregates;

[0044] (4) Adopt the spray fluidized bed granulation technology, high-pressure atomize and spray water on the surface of the honeycombed microaggregates, and dry to obtain a hydrogel for absorbing oil; the process parameters of the spray fluidized bed granulation technology are inlet air temperature 10 - 30 °C, fan frequency 20 - 50 Hz, and atomized water flow rate 10 - 20 g / min.

[0045] After the polysaccharide glue is mixed with water and undergoes wet ultrafine grinding by a sand mill, the size of the polysaccharide glue is less than 10 microns, and the specific surface area is larger. Therefore, more surface groups will be exposed, such as -OH, -COOH, -COO-, -O-, -NH2, -NH-, -COOR, etc. groups. Through high-shear mixing, the ultramicro polysaccharide glue aqueous solution can quickly and uniformly penetrate into the interior of cellulose or its derivatives and bond into microaggregates. Under high vacuum and relatively low temperature, the interior of the microaggregates can be expanded to form a honeycomb structure by microwave heating. Spraying ultrapure water on the honeycombed microaggregates by a fluidized bed and boiling and drying for granulation can cause the honeycomb structure in the microaggregates to re-bind water and then lose water again, thereby reducing the size of the honeycomb structure and increasing the entanglement strength of the polysaccharide glue molecular chain and the cellulose or its derivative molecular chain. The groups on the surface of the polysaccharide glue and the -OH or -COONa groups in the cellulose or its derivatives form a three-dimensional network structure through hydrogen bonds, combined with a dense honeycomb structure, which has stronger water absorption ability and faster water absorption speed. After consumption, it can greatly improve the satiety. And due to the existence of the honeycomb structure and the ultramicro high-ester pectin, the oil adsorption capacity of the hydrogel is increased by more than 10 times, and the absorption of oil in the body can be greatly reduced after consumption.

[0046] The change in the degree of esterification will affect the physicochemical properties and structure of pectin, and thus affect its functional properties. The degree of esterification of the high-ester pectin selected in the present invention is 58% - 62%. An increase or decrease in the degree of esterification will cause a conformational transformation of the pectin molecule, affect the formation of physical cross-linking sites, and ultimately affect the performance of the hydrogel.

[0047] In some embodiments of the present invention, in step (1), the water is ultrapure water, which can avoid the influence of other substances such as ions and is beneficial to the formation of the physical crosslinking network of the hydrogel.

[0048] In some embodiments of the present invention, in step (1), the concentration of the polysaccharide gum in the ultramicro polysaccharide gum aqueous solution is 0.01 kg / L to 0.1 kg / L.

[0049] The degree of substitution of sodium carboxymethylcellulose affects its stability and rheological properties. In the present invention, sodium carboxymethylcellulose with a degree of substitution of 0.7 to 0.9 and hydroxyethyl cellulose with a degree of substitution of 1.3 to 1.5 are selected. An increase or decrease in the degree of esterification will change the number of hydrophilic groups on its molecular chain and affect the formation of the physical crosslinking network.

[0050] In some embodiments of the present invention, in step (1), the mass ratio of the high-ester pectin to xanthan gum is greater than or equal to 3:1.

[0051] In some embodiments of the present invention, in step (1), the rotation speed of the wet ultrafine grinding is 1000 to 1500 rpm, and the time of the wet ultrafine grinding is 30 to 60 min. Preferably, the equipment used for the wet ultrafine grinding in the present invention is a sand mill.

[0052] In some embodiments of the present invention, in step (2), the mass ratio of the sodium carboxymethylcellulose to the hydroxyethyl cellulose is 10 to 15:4.98 to 9.98. Preferably, the mass ratio of the sodium carboxymethylcellulose to the hydroxyethyl cellulose in the present invention is 15:4.98 or 10:9.98.

[0053] In some embodiments of the present invention, in step (2), the rotation speed of the high-shear mixing is 1000 to 1500 rpm, the time of the high-shear mixing is 5 to 10 min, and finally, microaggregates with a size of 0.1 to 1 mm are formed. Preferably, the equipment used for the high-shear mixing in the present invention is a high-speed shear mixer.

[0054] In some embodiments of the present invention, in step (2), the mass ratio of the polysaccharide gum in the ultramicro polysaccharide gum aqueous solution to the mass of the cellulose or its derivative is 0.01 to 0.1:9.9 to 9.99. Preferably, the mass ratio of the polysaccharide gum in the ultramicro polysaccharide gum aqueous solution to the mass of the cellulose or its derivative in the present invention is 0.02:19.98 or 0.2:19.8.

[0055] In some embodiments of the present invention, in step (3), the vacuum degree of the microwave vacuum drying is -98.0 kPa to -100.0 kPa, the temperature of the microwave vacuum drying is 28 to 44 °C, and the time of the microwave vacuum drying is 0.5 to 1 h.

[0056] In some embodiments of the present invention, in step (4), the water used in the high-pressure atomizing spray is ultrapure water.

[0057] In some embodiments of the present invention, in step (4), the drying is fluidized bed drying, and the drying time is 0.5 - 1 h.

[0058] In some embodiments of the present invention, the bulk density of the prepared hydrogel for absorbing oil is 0.5 - 0.7 g / ml.

[0059] The present invention also provides a hydrogel for absorbing oil prepared by the preparation method described in any one of the above, and the hydrogel for absorbing oil has a honeycomb structure. Preferably, the bulk density of the hydrogel for absorbing oil is 0.5 - 0.7 g / ml, and the hydrogel has a smaller unit volume, which is more conducive to the user's swallowing.

[0060] The present invention also provides an application of the hydrogel for absorbing oil prepared by the preparation method described in any one of the above or the hydrogel for absorbing oil described above in the preparation of foods, drugs or health products having the functions of controlling diet, inducing satiety and losing weight.

[0061] The present invention will be further described below by way of specific examples. All chemical reagents used in the examples of the present invention are obtained through conventional commercial channels unless otherwise specified.

[0062] In the present invention, the test method for the micelle size is as follows: The micelles after high-shear mixing are placed on a sieve and sieved. If there are micelles remaining on the sieve, a sieve with a smaller mesh number is replaced, and the pore size corresponding to the sieve interval where the micelles are located is the micelle size range.

[0063] Table 1 Comparison of sieve mesh number and pore diameter

[0064]

[0065] In the examples and the control group, xanthan gums with different molecular weights are self-made materials. Using the Ziboxan® KF type xanthan gum (viscosity: 600 - 1800 cps) produced by Ordos Zhongxuan Biochemical Co., Ltd. as the raw material, xanthan gums with different molecular weights are prepared.

[0066] The specific preparation method is as follows:

[0067] Put 200 g of the Ziboxan® KF type xanthan gum sample into 20 kg of water, after ultrasonic treatment at 40 kHz for 60, 90, 120, 150 or 160 min, pour it into a tray and dry it in a blast drying oven at 80 °C for 24 h, and then pulverize it to obtain xanthan gums with molecular weights of 2.5 million, 2 million, 1.6 million, 1 million or 0.8 million.

[0068] Table 2 Other raw material manufacturers and product numbers

[0069]

[0070] The molecular weight test methods for xanthan gum, sodium carboxymethyl cellulose, hydroxyethyl cellulose, high-ester pectin and low-ester pectin refer to "Chinese Pharmacopoeia 0514 Molecular Exclusion Chromatography":

[0071] Liquid chromatography parameters: TSK-GMPWxl chromatographic column (7.8mm×30.0cm), column temperature 50°C, mobile phase is 0.05mol / L sodium sulfate solution, flow rate is 0.5ml / min, injection volume is 20μL, detector: differential refractive index detector.

[0072] Drawing of molecular weight calibration curve: Weigh 1.5g of polyglucose standard samples with known molecular weights (DXT 500, DXT 3K, DXT 20K, DXT 200K, DXT 1185K, DXT 5900K, whose weight-average molecular weights are 505, 3650, 20100, 207200, 1185000, 5900000) respectively and dissolve them in 0.05mol / L sodium sulfate solution, make up the volume to 1L, filter through a 0.45μm filter paper, and respectively absorb 20μL for injection to obtain the standard curve;

[0073] Sample treatment: Weigh 1.5g of the sample, dissolve it with 0.05mol / L sodium sulfate solution and make up the volume to 1L, filter through a 0.45μm filter paper, absorb 20μL for injection, and test to obtain its molecular weight.

[0074] The substitution degree test method for hydroxyethyl cellulose refers to "ASTM D4794-94 Standard Test Method for Determining Ethoxy or Hydroxyethoxy Substitution in Cellulose Ether Products by Gas Chromatography":

[0075] Gas chromatography conditions: Column WAX, column temperature 100°C, detector is hydrogen flame detector, temperature is 250°C, vaporization chamber temperature 200°C, injection volume: 1.0μL.

[0076] Drawing of standard curve: Preparation of standard solution: 30μL (iodoethane) / 10mL (toluene), 40μL (iodoethane) / 10mL (toluene), 50μL (iodoethane) / 10mL (toluene), 60μL (iodoethane) / 10mL (toluene), 70μL (iodoethane) / 10mL (toluene). After preparation, inject the sample to obtain the standard curve.

[0077] Sample preparation: Weigh 0.0711 g of the dried sample and place it into a 15 mL reactor. Add 10 mL of hydroiodic acid solution. Place the reactor in an oven at 180 °C and react for 2 h. After the reaction, extract twice with 10 mL of toluene each time. Retain the extraction solution for gas chromatography testing, and obtain the molar substitution degree of the sample after testing.

[0078] The substitution degree of sodium carboxymethylcellulose is determined according to the method in Appendix A.5 of "GB 1886.232-2016 National Food Safety Standard Food Additive Sodium Carboxymethylcellulose".

[0079] Testing method for the esterification degree of high-ester pectin and low-ester pectin: The esterification degree of pectin is determined by Fourier transform infrared spectroscopy (FT-IR). Among them, the COOCH; and COOH groups have strong absorptions at 1740 cm -1 -- and ~1630 cm -1 respectively. Use Qmnic 9.2 software to correct the spectral baseline and perform quantitative analysis. The calculation formula for the esterification degree (DE) is DE = A1740 / (A1740 + A1630), where A1740 and A1630 represent the peak areas at 1740 cm -1 and 1630 cm -1 - respectively.

[0080] Example 1

[0081] Take 0.2 kg of high-ester pectin (molecular weight 20000, esterification degree 62%) and place it in 2 L of ultrapure water. Use a sand mill to wet-mill and dissolve it for 30 min until the particle size of the high-ester pectin is less than 10 μm. The rotation speed of the sand mill is 1500 rpm. Take 19.8 kg of sodium carboxymethylcellulose (molecular weight 20000, substitution degree 0.72) and place it in a high-speed shear mixer. While high-pressure atomizing and spraying the high-ester pectin solution onto the surface of sodium carboxymethylcellulose, perform high-shear mixing at a rotation speed of 1500 rpm for 5 min to form microgels with a size of 0.1 - 0.5 mm. Place the formed microgels in a microwave vacuum drying oven, set the vacuum degree to -98.0 kPa, the temperature to 44 °C, dry for 0.5 h, then take it out and place it in a fluidized bed. Set the inlet air temperature to 10 °C, the fan frequency to 50 Hz, and the atomized water flow rate to 10 g / min. After high-pressure atomizing and spraying the ultrapure water and boiling and drying for 1 h, take it out to obtain composite gel 1.

[0082] Example 2

[0083] The preparation method is the same as that of Example 1, except that the molecular weight of the high-ester pectin is 80000 and the esterification degree is 58%, to obtain composite gel 2.

[0084] Example 3

[0085] The preparation method was the same as that of Example 1, except that the molecular weight of high-ester pectin was 200,000 and the degree of esterification was 62%, to obtain Composite Gel 3.

[0086] Example 4

[0087] The preparation method was the same as that of Example 1, except that the molecular weight of sodium carboxymethyl cellulose was 50,000 and the degree of substitution was 0.75, to obtain Composite Gel 4.

[0088] Example 5

[0089] The preparation method was the same as that of Example 1, except that the molecular weight of sodium carboxymethyl cellulose was 80,000 and the degree of substitution was 0.89, to obtain Composite Gel 5.

[0090] Example 6

[0091] The preparation method was the same as that of Example 1, except that the rotation speed of the sand mill was replaced with 1000 rpm, the grinding duration was 60 min, the rotation speed of the high-speed shear mixer was replaced with 1000 rpm, and the mixing time was 10 min to form 0.3 - 1 mm microaggregates, to obtain Composite Gel 6.

[0092] The grinding time and the mixing time were longer, and the formed microaggregates were also larger.

[0093] Example 7

[0094] The preparation method was the same as that of Example 6, except that the rotation speed of the sand mill was replaced with 1100 rpm, the grinding duration was 55 min, the rotation speed of the high-speed shear mixer was replaced with 1300 rpm, and the mixing time was 7 min to form 0.3 - 0.9 mm microaggregates, to obtain Composite Gel 7.

[0095] Example 8

[0096] The preparation method was the same as that of Example 1, except that the addition amount of high-ester pectin was replaced with 0.02 kg and the addition amount of sodium carboxymethyl cellulose was replaced with 19.98 kg, to obtain Composite Gel 8.

[0097] Example 9

[0098] The preparation method was the same as that of Example 1, except that the addition amount of high-ester pectin was replaced with 0.1 kg and the addition amount of sodium carboxymethyl cellulose was replaced with 19.9 kg, to obtain Composite Gel 9.

[0099] Example 10

[0100] The preparation method was the same as that of Example 1, except that the vacuum degree of the microwave vacuum drying oven was set to -100.0 kPa and the temperature was 28 °C, to obtain Composite Gel 10.

[0101] Example 11

[0102] The preparation method was the same as that of Example 1, except that the inlet air temperature of the fluidized bed was replaced with 30 °C, the fan frequency was 50 Hz, and the atomized water flow rate was 20 g / min, to obtain Composite Gel 11.

[0103] Example 12

[0104] The preparation method was the same as that of Example 8, except that the polysaccharide gum was replaced with 0.015 kg of high-ester pectin and 0.005 kg of xanthan gum (molecular weight of 1 million), to obtain Composite Gel 12.

[0105] Example 13

[0106] The preparation method was the same as that of Example 8, except that the polysaccharide gum was replaced with 0.015 kg of high-ester pectin and 0.005 kg of xanthan gum (molecular weight of 2 million), to obtain Composite Gel 13.

[0107] Example 14

[0108] The preparation method was the same as that of Example 8, except that the polysaccharide gum was replaced with 0.015 kg of high-ester pectin and 0.005 kg of xanthan gum (molecular weight of 1.6 million), to obtain Composite Gel 14.

[0109] Example 15

[0110] The preparation method was the same as that of Example 8, except that the polysaccharide gum was replaced with 0.016 kg of high-ester pectin and 0.004 kg of xanthan gum (molecular weight of 1.6 million), to obtain Composite Gel 15.

[0111] Example 16

[0112] The preparation method was the same as that of Example 8, except that the addition amount of carboxymethyl cellulose was replaced with 15 kg of sodium carboxymethyl cellulose (molecular weight of 20,000, degree of substitution of 0.72) and 4.98 kg of hydroxyethyl cellulose (molecular weight of 100,000, degree of substitution of 1.5), to obtain Composite Gel 16.

[0113] Example 17

[0114] The preparation method was the same as that of Example 8, except that the addition amount of carboxymethyl cellulose was replaced with 15 kg of sodium carboxymethyl cellulose (molecular weight of 20,000, degree of substitution of 0.72) and 4.98 kg of hydroxyethyl cellulose (molecular weight of 200,000, degree of substitution of 1.3), to obtain Composite Gel 17.

[0115] Example 18

[0116] The preparation method was the same as that of Example 8, except that the addition amount of sodium carboxymethyl cellulose was replaced with 10 kg of sodium carboxymethyl cellulose (molecular weight of 20,000, degree of substitution of 0.72) and 9.98 kg of hydroxyethyl cellulose (molecular weight of 160,000, degree of substitution of 1.3), to obtain Composite Gel 18.

[0117] Control Group 1

[0118] The preparation method was the same as that of Example 1, except that the molecular weight of high-ester pectin was increased to 250,000 to obtain Comparative Gel 1.

[0119] Control Group 2

[0120] The preparation method was the same as that of Example 1, except that the degree of esterification of high-ester pectin was reduced to 56% to obtain Comparative Gel 2.

[0121] Control Group 3

[0122] The preparation method was the same as that of Example 1, except that the degree of esterification of high-ester pectin was increased to 63% to obtain Comparative Gel 3.

[0123] Control Group 4

[0124] The preparation method was the same as that of Example 1, except that high-ester pectin was replaced with low-ester pectin with a molecular weight of 50,000 and a degree of esterification of 44% to obtain Comparative Gel 4.

[0125] Control Group 5

[0126] The preparation method was the same as that of Example 1, except that the molecular weight of sodium carboxymethyl cellulose was increased to 100,000 and the degree of substitution was 0.75 to obtain Comparative Gel 5.

[0127] Control Group 6

[0128] The preparation method was the same as that of Example 1, except that the degree of substitution of sodium carboxymethyl cellulose was reduced to 0.66 to obtain Comparative Gel 6.

[0129] Control Group 7

[0130] The preparation method was the same as that of Example 1, except that the degree of substitution of sodium carboxymethyl cellulose was increased to 0.95 to obtain Comparative Gel 7.

[0131] Control Group 8

[0132] The preparation method was the same as that of Example 1, except that the molecular weight of sodium carboxymethyl cellulose was reduced to 10,000 to obtain Comparative Gel 8.

[0133] Control Group 9

[0134] The preparation method was the same as that of Example 12, except that the polysaccharide gum was replaced with 0.01 kg of high-ester pectin and 0.01 kg of xanthan gum (molecular weight of 1 million) to obtain Comparative Gel 9.

[0135] Control Group 10

[0136] The preparation method was the same as that of Example 12, except that the polysaccharide gum was replaced with 0.005 kg of high-ester pectin and 0.015 kg of xanthan gum (molecular weight of 1 million), and Comparative Gel 10 was obtained.

[0137] Control Group 11

[0138] The preparation method was the same as that of Example 12, except that the molecular weight of xanthan gum was reduced to 800,000, and Comparative Gel 11 was obtained.

[0139] Control Group 12

[0140] The preparation method was the same as that of Example 12, except that the molecular weight of xanthan gum was increased to 2.5 million, and Comparative Gel 12 was obtained.

[0141] Control Group 13

[0142] The preparation method was the same as that of Example 17, except that the molecular weight of hydroxyethyl cellulose was reduced to 80,000 and the degree of substitution was 1.5, and Comparative Gel 13 was obtained.

[0143] Control Group 14

[0144] The preparation method was the same as that of Example 17, except that the molecular weight of hydroxyethyl cellulose was increased to 250,000 and the degree of substitution was 1.5, and Comparative Gel 14 was obtained.

[0145] Control Group 15

[0146] The preparation method was the same as that of Example 17, except that the degree of substitution of hydroxyethyl cellulose was reduced to 1.1, and Comparative Gel 15 was obtained.

[0147] Control Group 16

[0148] The preparation method was the same as that of Example 17, except that the degree of substitution of hydroxyethyl cellulose was increased to 1.8, and Comparative Gel 16 was obtained.

[0149] Control Group 17

[0150] Take 0.2 kg of high-ester pectin (molecular weight of 20,000 and esterification degree of 62%) and place it in 2 L of ultrapure water, stir and dissolve for 30 min. Take 19.8 kg of sodium carboxymethyl cellulose (molecular weight of 20,000 and degree of substitution of 0.72) and place it in a high-speed shear mixer. Pour the high-ester pectin solution onto the surface of sodium carboxymethyl cellulose and perform high-shear mixing at a rotation speed of 1500 rpm for 5 min to form 0.1 - 2.0 mm micelles. Place the formed micelles in a microwave vacuum drying oven, set the vacuum degree to -98.0 kPa and the temperature to 44 °C. After drying for 0.5 h, take it out and place it in a fluidized bed. Set the inlet air temperature to 10 °C, the fan frequency to 50 Hz, and the atomized water flow rate to 10 g / min. After the ultrapure water is atomized and sprayed under high pressure and dried by boiling for 1 h, it forms agglomerates, and Comparative Gel 17 is obtained.

[0151] In this comparative example, wet ultrafine grinding is not carried out using a sand mill. Most of the high-ester pectin cannot be dissolved and sinks to the bottom. The particle size reaches more than 100 μm, and even reaches the millimeter level. It cannot be atomized and sprayed under high pressure, and it is easy to block the nozzle, so only pouring can be used. Due to uneven pouring, the size of the formed micro-masses is relatively large, it is not easy to boil, and it is easy to agglomerate.

[0152] Control group 18

[0153] The preparation method is the same as that of Example 1, only the rotation speed of the sand mill is adjusted to 900 rpm and the grinding time is increased to 5 hours to obtain Comparative Gel 18.

[0154] In this comparative example, the rotation speed of the sand mill is too low. Even if the grinding time is increased to 5 hours, the particle size of the high-ester pectin is still greater than 10 μm.

[0155] Control group 19

[0156] The preparation method is the same as that of Example 1, but a high-speed shear mixer is not used to perform high-shear mixing on the sodium carboxymethyl cellulose of the sprayed ultrafine polysaccharide glue solution. The agglomeration is uneven, there are large agglomerates and dry powder that cannot form agglomerates. The large agglomerates cannot boil in the fluidized bed, and after drying, the large agglomerates are crushed to obtain Comparative Gel 19.

[0157] Control group 20

[0158] The preparation method is the same as that of Example 1, only the rotation speed of the high-speed shear mixer is adjusted to 900 rpm, and the particle size of the obtained micro-masses is 0.5 - 5 mm. The large-particle-size micro-masses cannot boil in the fluidized bed, and after drying, the large-particle-size micro-masses are crushed to obtain Comparative Gel 20.

[0159] Control group 21

[0160] The preparation method is the same as that of Example 1, but instead of using a microwave vacuum drying oven to vacuum-dry the micro-masses, an ordinary blast drying oven is used for drying, and finally Comparative Gel 21 is obtained.

[0161] Drying with an ordinary drying oven cannot form a honeycomb structure.

[0162] Control group 22

[0163] The preparation method is the same as that of Example 1, only the inlet air temperature of the fluidized bed is adjusted to 8 °C, and the target gel cannot be obtained.

[0164] The inlet air temperature of the fluidized bed is too low, and the moisture cannot evaporate quickly, resulting in caking and unable to form a dry gel.

[0165] Control group 23

[0166] The preparation method is the same as that of Example 1, only the fan frequency is reduced to 15 Hz, and the target gel cannot be obtained.

[0167] The fluidized bed fan frequency is too low, the micro-clusters cannot boil, and the water cannot evaporate quickly, resulting in agglomeration and the inability to form a dry gel.

[0168] Control group 24

[0169] The preparation method was consistent with that in Example 1, except that the atomized water flow rate was increased to 22 g / min, and the target gel could not be obtained.

[0170] The sprayed atomized water cannot evaporate quickly, resulting in gradual agglomeration and failure to obtain a dry gel.

[0171] Control group 25

[0172] The preparation method was consistent with that of Example 1, but high-pressure atomization spraying of ultrapure water was not performed during boiling drying, and comparative gel 25 was obtained.

[0173] Ultrapure water was not sprayed during boiling drying, so the pore size of the honeycomb structure could not be miniaturized, the packing density was low, and because the honeycomb structure was too loose, the modulus after water absorption was low.

[0174] Control group 26: only sodium carboxymethylcellulose was used without adding polysaccharide gum

[0175] Take 20kg of sodium carboxymethyl cellulose (molecular weight of 20,000, degree of substitution of 0.72) and place it in a high-speed shear mixer. Spray ultrapure water on the surface of the sodium carboxymethyl cellulose by high-pressure atomization, and perform high-speed shearing at a rotation speed of 1500rpm and a mixing time of 5min to form 0.1~0.5mm micelles. Place the formed micelles in a microwave vacuum drying oven, set the vacuum degree to -98.0kPa, the temperature to 44°C, dry for 0.5h, take out and place in a fluidized bed, set the inlet temperature to 10°C, the fan frequency to 50Hz, and the atomized water flow rate to 10g / min. Ultrapure water is sprayed by high-pressure atomization and boiled for 1h before taking out to obtain comparison gel 26.

[0176] Sodium carboxymethyl cellulose alone cannot form a three-dimensional network structure, so it will clump when it comes into contact with water, making it impossible to test the modulus and unable to absorb oil.

[0177] Control group 27

[0178] The sample was prepared according to the method of Example 1 of patent CN17179281A, i.e., 3 g of high-ester pectin was placed in 3.33 L of ultrapure water and stirred to dissolve, 200 g of sodium carboxymethyl cellulose was added to the high-ester pectin solution and stirred for 2 h, then placed in a forced air drying oven at 110°C for 8 h, and then crushed into particles of 20-50 mesh after drying to obtain comparison gel 27.

[0179] 1. Water absorption test method:

[0180] Take 1 g of the composite gel or the control gel and place it in a medium with an artificial gastric juice to water ratio of 1:8. Place it in an incubator at 37 °C for 30 minutes. After filtering off the water with a stainless steel sieve and weighing, the weight of the hydrogel after water absorption is m1. The water absorption multiple = (m1 - 1) / 1. The artificial gastric juice is prepared according to the method in the Chinese Pharmacopoeia.

[0181] 2. Storage modulus test method:

[0182] Wipe the surface moisture of the sample obtained from the above water absorption multiple test, place it between the parallel plates (25 mm) of a rotational rheometer, fix the tension at 0.5%, fix the frequency range at 1 - 50 rad / s, and take the storage modulus value corresponding to a frequency of 10 rad / s as the storage modulus G of the sample.

[0183] 3. Water absorption rate test method:

[0184] Respectively take 1 g of the composite gel or the control gel and place it in a medium with an artificial gastric juice to water ratio of 1:8. Take it out after placing it in an incubator at 37 °C for 10 s, 30 s, 60 s, and 120 s. After filtering off the water with a stainless steel sieve and weighing, the weight of the hydrogel after water absorption is m2. The water absorption multiple = (m2 - 1) / 1. The artificial gastric juice is prepared according to the method in the Chinese Pharmacopoeia.

[0185] 4. Oil absorption capacity test method:

[0186] Take 1 g of the composite gel or the control gel and place it in a medium with 200 ml of vegetable oil to water ratio of 1:1. Place it in an incubator at 37 °C and stir for 30 minutes. Filter off the mixture of oil and water with a stainless steel sieve, separate the oil and water in the filtrate with a separating funnel, measure the volume of the vegetable oil as V1, and the volume of the vegetable oil absorbed by 1 g of the composite gel or the control gel = 100 ml - V1.

[0187] 5. Bulk density test method:

[0188] Take 1 g of the composite gel or the control gel and place it in a 5 ml graduated cylinder. Visually estimate the volume V2, and the bulk density = 1 / V2.

[0189] Analysis and conclusion

[0190] Table 3 Water absorption multiple, storage modulus, oil absorption volume, and bulk density of the samples in the examples and the control group

[0191]

[0192]

[0193] Table 4 Water absorption rate of the samples in the examples and the control group

[0194]

[0195]

[0196] Table 5 Amounts of polysaccharide gum used, solvent used, drying time, and energy consumption for Examples 1-18 and Control Group 27 in preparing the same sample amount (20 kg)

[0197]

[0198] Note: The power of the microwave drying oven with the same production capacity is 36 kw, the power of the blast drying oven is 36 kw, and the combined power of the fluidized bed fan and peristaltic pump is 6 kw.

[0199] Control Groups 1-16 showed that the selection and ratio of raw materials had a great impact on the comprehensive properties of the prepared hydrogel. It was necessary to consider factors such as the molecular weight and degree of esterification of high-ester pectin, the molecular weight of xanthan gum, the ratio of high-ester pectin to xanthan gum, the molecular weight and degree of substitution of sodium carboxymethyl cellulose, and the molecular weight and degree of substitution of hydroxyethyl cellulose. By synergistically adjusting the ratios of various raw materials and the characteristics of the raw materials, the prepared hydrogel could have excellent oil absorption ability while also having a high water absorption multiple, a large storage modulus, and a fast water absorption rate.

[0200] In Control Group 17, since wet ultrafine grinding with a sand mill was not carried out and spraying was not possible, only pouring could be done, so the materials quickly agglomerated, resulting in the formation of lumps. The inside of the lumps was un-wetted sodium carboxymethyl cellulose, and the overall dispersion was extremely uneven. Therefore, the prepared Comparative Gel 1 had a low water absorption multiple, uneven modulus, and weak oil absorption ability.

[0201] In Control Group 18, the low speed of the sand mill led to a relatively large particle size of pectin, low physical cross-linking efficiency and uneven cross-linking, resulting in weak water and oil absorption ability of the hydrogel.

[0202] In Control Group 19, a high-speed shear mixer was not used to perform high-shear mixing on sodium carboxymethyl cellulose in the sprayed ultrafine polysaccharide gum aqueous solution. The agglomeration was uneven, with large lumps and dry powder that could not form lumps. The large lumps could not boil in the fluidized bed, and the obtained gel had weak water and oil absorption ability.

[0203] In Control Group 20, due to the slow speed of the high-speed shear mixer, the obtained micro-lump particle size was relatively large and could not boil in the fluidized bed. Therefore, the materials were also prone to agglomerating to form lumps, with uneven dispersion, low water absorption multiple, and uneven modulus.

[0204] In Control Group 21, since a microwave vacuum drying oven was not used for vacuum drying, a honeycomb structure could not be formed, so the water absorption multiple was relatively low.

[0205] In Control Group 22, the inlet air temperature of the fluidized bed was too low, and the water could not evaporate quickly, resulting in caking and the inability to form a dry gel.

[0206] In Control Group 23, the frequency of the fluidized bed fan was too low, the microclusters could not boil, and the moisture could not evaporate quickly, resulting in caking and preventing the formation of dry gel.

[0207] In Control Group 24, the atomized water sprayed had too high a flow rate and could not evaporate quickly, resulting in gradual caking and preventing the obtaining of dry gel.

[0208] In Control Group 25, atomized water was not sprayed during fluidized bed drying, which could not cause the pore size of the honeycomb structure to shrink, the bulk density was low, and due to the overly loose honeycomb structure, the modulus was low after water absorption.

[0209] In Control Group 26, since sodium carboxymethyl cellulose alone could not form a three-dimensional network structure, it would agglomerate when encountering water, making it impossible to test the modulus and absorb oil.

[0210] In Examples 1 - 18, the process of the present invention was adopted. The water absorption performance was improved by more than 50% compared with Control Group 27, the water absorption speed was increased by about 1 time, and the oil absorption capacity was increased by more than 13 times. Pectin has certain lipophilic properties. After wet ultrafine grinding by a sand mill, the contact area with oil was greatly increased. Combined with the honeycomb structure, its oil absorption capacity was greatly enhanced. When preparing composite gels with the same sample amount, the amount of high-ester pectin and solvent water used in Examples 1 - 18 was less, which could save raw material costs (the price of high-ester pectin was more than 5 times that of sodium carboxymethyl cellulose, and the water consumption was reduced by more than 99%); the drying time was shortened by more than 75%, and the energy consumption was reduced by more than 85.41%.

[0211] Figure 1 It is the scanning electron microscope microscopic image of composite gel 1 prepared in Example 1. The composite gel 1 sample was subjected to surface gold spraying treatment, and the surface of the sample was analyzed using a scanning electron microscope. The parameters were 15.0 kV and 500×. The surface microstructure of composite gel 1 showed a honeycomb-like porous structure.

[0212] The above examples are only the preferred embodiments of the present invention, which are only used to explain the present invention and not to limit the present invention. Any changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit and essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a hydrogel for absorbing oil, characterized in that: The following steps are involved: (1) mixing polysaccharide gum and water to obtain a mixed solution, and wet-milling the mixed solution to form an ultrafine polysaccharide gum aqueous solution; The polysaccharide gum is high-ester pectin or a mixture of high-ester pectin and xanthan gum; the molecular weight of the high-ester pectin is 20,000-200,000, and the degree of esterification of the high-ester pectin is 58%-62%; the molecular weight of the xanthan gum is 1 million-2 million; the particle size of the polysaccharide gum in the ultrafine polysaccharide gum aqueous solution is less than 10 μm; the rotation speed of the wet ultrafine grinding is 1000-1500 rpm, and the time of the wet ultrafine grinding is 30-60 minutes; the mass ratio of the high-ester pectin to the xanthan gum is greater than or equal to 3:1; (2) spraying the ultrafine polysaccharide glue solution on the surface of cellulose or its derivatives by high-pressure atomization, and high-shear mixing to make the ultrafine polysaccharide glue solution penetrate into the interior of cellulose or its derivatives and bond to form micelles; the cellulose or its derivatives are sodium carboxymethyl cellulose or a mixture of sodium carboxymethyl cellulose and hydroxyethyl cellulose; the molecular weight of the sodium carboxymethyl cellulose is 20,000-80,000, and the degree of substitution of the sodium carboxymethyl cellulose is 0.7-0.9; the molecular weight of the hydroxyethyl cellulose is 100,000-200,000, and the degree of substitution is 1.3-1.5; the size of the micelle is 0.1-1 mm; the rotation speed of the high-shear mixing is 1000-1500 rpm, and the high-shear mixing time is 5-10 min; the mass ratio of sodium carboxymethyl cellulose to hydroxyethyl cellulose is 10-15:4.98-9.98; the mass ratio of the polysaccharide glue in the ultrafine polysaccharide glue solution to the mass of cellulose or its derivatives is 0.01-0.1:9.9-9.99; (3) drying the micelles by microwave vacuum drying to form honeycombed micelles; the vacuum degree of the microwave vacuum drying is -98.0 kPa to -100.0 kPa, the temperature of the microwave vacuum drying is 28 to 44° C., and the time of the microwave vacuum drying is 0.5 to 1 h; (4) Using a spray fluidized bed granulation technology, water is sprayed on the surface of the honeycomb micro-clusters at high pressure and dried to obtain a hydrogel that absorbs oil; the process parameters of the spray fluidized bed granulation technology are an air inlet temperature of 10-30°C, a fan frequency of 20-50Hz, and an atomized water flow rate of 10-20g / min; the hydrogel that absorbs oil has a honeycomb structure; and the bulk density of the hydrogel that absorbs oil is 0.5-0.7g / ml.

2. The preparation method according to claim 1, characterized in that: In step (1), the concentration of the polysaccharide glue in the ultrafine polysaccharide glue aqueous solution is 0.01kg / L~0.1kg / L.

3. The preparation method according to claim 1, characterized in that: In step (4), the drying is performed by boiling in a fluidized bed, and the drying time is 0.5 to 1 hour.

4. The oil-absorbing hydrogel prepared by the preparation method according to any one of claims 1 to 3, characterized in that: The oil-absorbing hydrogel has a honeycomb structure.

5. Use of a fat-absorbing hydrogel prepared by the preparation method according to any one of claims 1 to 3 or a fat-absorbing hydrogel according to claim 4 in preparing food, medicine or health care products with the effects of controlling diet, inducing satiety and losing weight.

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