Heat-conducting water-retaining hydrogel, composite water-retaining adsorption material, preparation of heat-conducting water-retaining hydrogel and composite water-retaining adsorption material and application of heat-conducting water-retaining hydrogel

Abstract

The invention relates to the technical field of cigarette harm reduction, in particular to a preparation method of heat-conducting and water-retaining hydrogel, which comprises the following steps: compounding hydrogel and a hydrophilic modified heat-conducting carbon material, and then carrying out hydrogen bond decomposition treatment in atmosphere to obtain the heat-conducting and water-retaining hydrogel. The invention further discloses application of the heat-conducting water-retaining hydrogel in cigarette preparation. In order to solve the problem that water is easy to release difficultly in the use process of the water retention material for the cigarettes, hydrogel and a hydrophilic modified heat conduction carbon material are creatively compounded, and hydrogen bond decomposition treatment is carried out, so that synergy can be accidentally realized, the water release effect of the material can be improved, and the water retention effect of the material is improved. Even if the composite material is combined with a harm-reducing adsorption material, the composite material can still show an excellent moisture release effect, and moreover, the composite material also has a certain harm-reducing effect.

Description

Technical Field

[0001] The present invention belongs to the field of cigarette materials, and particularly relates to the technical field of cigarette filters. Background Art

[0002] In order to reduce the harm of smoking to health, many researchers are committed to researching and developing various filter materials in order to reduce the content of harmful substances in cigarette smoke. Among them, the cigarette filter technology for reducing harm and retaining moisture, as a new type of filter material, has received extensive attention.

[0003] Some prior art reports on solutions for reducing harm and retaining moisture in cigarette filters. For example, the Chinese patent document with the publication number CN103190701A discloses a preparation method of a cigarette filter rod with controllable adsorption performance. By uniformly dispersing activated carbon in triacetin, the effect of triacetin as a plasticizer is not changed, and the cigarette filter rod containing the activated carbon-containing triacetin has a strong adsorption function. However, this technology fails to solve the problem that the activated carbon filter rod is unfavorable to the taste of cigarettes, and there will be a dry feeling when smoking cigarettes using activated carbon.

[0004] Again, the Chinese patent document with the publication number CN114886154A discloses an additive for improving the dry feeling of ventilated cigarette filters and its preparation method. Specifically, an additive for improving the dry feeling of ventilated cigarette filters is disclosed. The additive comprises the following components in parts by weight: levulinic acid 5 - 20, lactic acid 5 - 20, pyruvic acid 5 - 30, water 20 - 60, and ethanol 30 - 60. Adding the additive to the tobacco shreds according to 1.0‰ - 1.5% of the weight of the tobacco shreds of the ventilated cigarette can improve the moist feeling of the cigarette smoke, enhance the aroma, improve the aftertaste, and significantly improve the dry feeling of the ventilated cigarette. However, this technology has no effect of reducing harmful components, and the adsorption performance of activated carbon can reduce harm.

[0005] The above two inventions respectively solve two single problems of reducing harmful components in cigarette smoke and the dry feeling of ventilated cigarettes. If the activated carbon and additives used in these two inventions are simply combined technically, it cannot solve the two problems of reducing harm and improving the dry feeling at the same time. Because the additive is added to the tobacco shreds to produce cigarette smoke with a more moist feeling. When the cigarette smoke flows through the filter containing activated carbon, the dry feeling will reappear. Activated carbon is easily oxidized by oxidants such as oxygen and nitric acid during the production process to generate surface functional groups, and there is a hydrophilic carboxyl group in the surface functional groups. The moisture supplemented from the tobacco shred end is limited and will be completely adsorbed by the activated carbon, and the effect of the additive to enhance the moist feeling is finally eliminated.

[0006] For another example, publication number CN113457641A discloses an activated carbon-sodium polyacrylate composite desiccant coating, which has the performance of high-efficiency adsorption and low-temperature desorption at 40-70°C, overcoming the shortcomings of traditional solid dehumidification air-conditioning systems in heating and dehumidification. However, this idea cannot achieve the desired effect when transplanted into cigarette filter rods as an adsorption and water-retention material. That is, simply mixing the adsorption material (activated carbon) and the water-retention material (sodium polyacrylate hydrogel) and adding them to the cigarette filter rod cannot simultaneously achieve the effects of reducing harmful components and improving the smoking taste. This is because the moisture in the hydrogel cannot be effectively desorbed and released under the smoking conditions of the cigarette. The smoke only comes into contact with the adsorption and water-retention material when flowing through the filter rod during the smoking process, and the contact time is short. Only by improving the energy transfer efficiency can a sufficient amount of moisture be released. Summary of the Invention

[0007] In response to the problems that the adsorption efficiency of harmful components added to existing filter tips is low and it is difficult to balance harm reduction and water retention, the present invention provides a thermally conductive and water-retaining hydrogel, its preparation, and its application in filter tip water retention, aiming to assist in improving the harm reduction and water retention effects.

[0008] The second object of the present invention is to provide a composite water-retaining adsorption material comprising a heat-conducting and water-retaining hydrogel and an adsorbent, and the preparation and application thereof.

[0009] A third object of the present invention is to provide a cigarette comprising the heat-conducting and water-retaining hydrogel.

[0010] To address the issues of harm reduction and moisture retention during cigarette smoking, one approach is to combine harm reduction adsorbent materials with water retention materials to achieve the dual effects of harm reduction and moisture retention. However, practice has shown that the effects of this type of solution are not ideal. The main reason is that combining water retention materials with adsorbent materials easily blocks adsorption channels, affecting the instantaneous adsorption effect of the composite material. Furthermore, the adsorbent material easily captures moisture, resulting in a moisture retention effect that is less than expected. To address this issue, the present invention provides the following technical solutions:

[0011] A method for preparing a heat-conducting and water-retaining hydrogel comprises compounding a hydrogel and a hydrophilic modified heat-conducting carbon material, and then performing a hydrogen bond decomposition treatment in an atmosphere to obtain the heat-conducting and water-retaining hydrogel.

[0012] In response to the problem that water-retaining materials for cigarettes are difficult to release water during use, the present invention innovatively compounds hydrogel and hydrophilically modified thermally conductive carbon material and performs hydrogen bond decomposition treatment. This unexpectedly achieves synergy and improves the water release effect of the material, so that it can still exhibit excellent water release effect even when used in combination with harm-reducing adsorption materials. Not only that, it also takes into account a certain harm-reduction effect.

[0013] In the present invention, the polymer in the hydrogel may be a conventional hydrophilic polymer, such as polyacrylic acid and its salts.

[0014] In the present invention, there is no particular requirement for the water absorption rate of the hydrogel, for example, it can be 4900% to 12400%.

[0015] In the present invention, the hydrogel is pre-modified with calcium carbonate, and the steps are as follows: calcium carbonate is dispersed in an aqueous solution, and then mixed with the polymer of the hydrogel to obtain the hydrogel.

[0016] Research in the present invention shows that innovatively using calcium carbonate to further modify the hydrogel helps to further improve the water release effect of the prepared material during the suction stage.

[0017] In the present invention, the weight ratio of the calcium carbonate to the polymer in the hydrogel is 1:24 to 1:123.

[0018] In the present invention, the thermally conductive carbon material is carbon nanotubes.

[0019] In the present invention, the surface of the thermally conductive carbon material is innovatively hydrophilically modified, and further combined with the hydrogel, so that the hydrogel network can be improved based on hydrogen bonds and chemical interactions, and further improve the water release effect of the composite material during the suction stage.

[0020] In the present invention, the thermally conductive carbon material is pre-treated with an organic solvent and then hydrophilically modified under blue light irradiation to obtain the hydrophilically modified thermally conductive carbon material. The present invention innovatively uses blue light irradiation to modify the carbon material, so that the adaptability of the prepared material to the cigarette application scenario can be further improved, and it helps to further improve the water release effect of the prepared material during the suction stage.

[0021] In the present invention, the wavelength range of the blue light is 435 - 450 nanometers;

[0022] Preferably, the time of blue light irradiation is more than 30 minutes, preferably 100 - 300 minutes.

[0023] In the present invention, the weight ratio of the polymer in the hydrogel to the hydrophilically modified thermally conductive carbon material is 1:1 to 5:1.

[0024] In the present invention, after the hydrogel and the hydrophilically modified thermally conductive carbon material are compounded, the pressure of the system is pre-controlled to be negative pressure, and then an atmosphere is introduced to maintain the pressure of the system above atmospheric pressure (such as 1 - 5 atm), and the atmosphere and pressure are maintained for de-hydrogen bond treatment. In the present invention, through the de-hydrogen bond treatment, it helps to reduce harm in cigarette use and regulate the water release effect of the material.

[0025] In the present invention, the pressure of the negative pressure is below 0.5 atm;

[0026] Preferably, the atmosphere is an oxygen-containing atmosphere, preferably oxygen with a purity of more than 95%;

[0027] Preferably, the time for hydrogen bond dissociation treatment is more than 2 h, preferably 3 - 10 h.

[0028] The present invention also provides a heat-conducting and water-retaining hydrogel prepared by the above-mentioned preparation method.

[0029] The present invention also provides an application of the heat-conducting and water-retaining hydrogel prepared by the above-mentioned preparation method. It is used as an additive for preparing cigarettes; preferably, it is used as an additive for preparing cigarette filters.

[0030] The present invention also provides a composite water-retaining and adsorbing material, which comprises an adsorbing material and the heat-conducting and water-retaining hydrogel of the present invention.

[0031] Research of the present invention shows that innovatively combining the adsorbing material and the heat-conducting and water-retaining hydrogel can solve the problems caused by the structural blockage of the adsorbing material by the water-retaining material and the difficulty in releasing water due to the water capture by the adsorbing material, etc. It can unexpectedly achieve synergy, enabling the composite material to have both excellent harm reduction and water release effects.

[0032] In the present invention, the adsorbing material can be a material known in the industry that has adsorption ability, such as activated carbon.

[0033] In the present invention, the weight ratio of the adsorbing material to the heat-conducting and water-retaining hydrogel can be adjusted as needed, for example, it can be 0.5 - 2.5:1, preferably 1 - 2:1; more preferably 1 - 1.5:1.

[0034] In the present invention, the adsorbing material and the heat-conducting and water-retaining hydrogel can be compounded based on known processes.

[0035] For example, the heat-conducting and water-retaining hydrogel and the adsorbing material are mechanically mixed evenly. The stirring time is 3 min - 30 min (for 0.1 kg - 1 kg of materials), and the stirring time should be extended by 3 min for every additional 100 g of dosage to ensure sufficient contact between the two component materials and form a water-retaining and adsorbing composite material embryo with good uniformity. <>

[0036] The present invention also provides an application of the above-mentioned composite water-retaining and adsorbing material. It is used as an additive for preparing cigarettes; preferably, it is used as an additive for preparing cigarette filters.

[0037] The present invention also provides a cigarette filter, which comprises the heat-conducting and water-retaining hydrogel of the present invention, and further comprises the composite water-retaining and adsorbing material of the present invention.

[0038] In the present invention, for the cigarette filter tip, except for containing the heat-conducting water-retaining hydrogel or the composite water-retaining adsorbent material of the present invention, other components and parts can be conventional.

[0039] In the present invention, the addition amount of the heat-conducting water-retaining hydrogel or the composite water-retaining adsorbent material in the cigarette filter tip can be adjusted as needed. For example, it can be 30-80 mg per cigarette, and further can be 50-70 mg per cigarette.

[0040] The present invention also provides a cigarette, which includes the cigarette filter tip of the present invention.

[0041] In the present invention, the preparation process of the cigarette filter tip can be conventional. For example, a blank containing a heat-conducting water-retaining material and an adsorbent material is put into an extruder or extruded using a sieve to obtain particles with a particle size of 0.5 mm - 1.5 mm, which are filled into a cigarette filter rod as a water-retaining adsorbent composite material. There are mainly two filling methods: filling into the cavity of the filter rod and adding it to the acetate fiber tow during the formation of the filter rod.

[0042] For the cigarette of the present invention, except that its filter tip contains the heat-conducting water-retaining hydrogel or the composite water-retaining adsorbent material of the present invention, other components and parts can be conventional.

[0043] Beneficial effects

[0044] (1) In the present invention, the hydrogel and the hydrophilic modified heat-conducting carbon material are innovatively compounded and subjected to de-hydrogen bond treatment, so that synergism can be unexpectedly achieved, the water release effect of the material can be improved, and it can still show an excellent water release effect even when used in combination with a harm reduction adsorbent material. The material prepared by the present invention can greatly reduce the dry feeling of the smoke formed by adsorbent materials such as activated carbon, and fully make up for the shortcoming that activated carbon as a harm reduction material will seriously affect the smoking flavor.

[0045] (2) By utilizing the absorption capacity of water in the water-retaining material for some harmful components, the advantage of the adsorbent material in harm reduction is expanded.

[0046] (3) The food-grade materials used are safe and non-toxic by themselves, and at the same time, the dual effects of improving the smoking flavor and enhancing harm reduction are achieved. The present invention is a new technical means that is easy to be applied to cigarette products. Description of the drawings

[0047] Figure 1 It is the water-retaining adsorbent composite material particles prepared in step (5) of Example 1;

[0048] Figure 2 It is the radar chart of the sensory evaluation results of Example 1 and Comparative Example 2; Detailed implementation manners

[0049] The high water retention material is a superabsorbent resin, specifically sodium polyacrylate. The water absorption rate of the high water retention material needs to be controlled between 4900% and 12400% (i.e., at most 2 parts of dry material and 98 parts of water, and at least 0.8 parts of dry material and 99.2 parts of water).

[0050] Water absorption rate is a physical quantity representing the degree of water absorption of an object under normal atmospheric pressure, expressed as a percentage. The formula for calculating the water absorption rate is W = (B - G) / G × 100%. In the formula, W is the water absorption rate, expressed as a percentage, G is the weight of the dry sample of the test specimen in grams, and B is the weight after the dry sample adsorbs a certain amount of water in grams.

[0051] The strong adsorption material is a safe and harmless porous material with a large specific surface area, specifically activated carbon. The size of the strong adsorption material needs to be controlled between 60 mesh and 200 mesh.

[0052] Example 1

[0053] Step (1): Modification of the water retention material

[0054] Add 1 part of calcium carbonate to 3 parts of water, continuously stir the suspension for more than 72 h until the pH no longer changes, dilute it by 1.5 times to obtain a solvent with a barrier effect, and dissolve the superabsorbent resin sodium polyacrylate (the total ratio of calcium carbonate to sodium polyacrylate is 1:30) to obtain a 0.8% wt hydrogel.

[0055] Step (2): Modification of the thermal conductive material

[0056] Place the carbon nanotubes in an anhydrous ethanol solution for 48 h. During this period, ultrasonic treatment should be applied intermittently 10 - 20 times, each time for 15 - 20 min to remove amorphous carbon and tube agglomeration. The carbon nanotubes are dried in an oven at a temperature of 100 °C for one hour and then cooled to ambient temperature in a desiccator. Treat with blue light (wavelength range of 435 - 450 nm) for 240 min to obtain superhydrophilic carbon nanotubes.

[0057] Step (3): Preparation of the thermally conductive hydrogel

[0058] Immediately load the water retention material after superhydrophilic treatment. Add the modified carbon nanotubes to the prepared hydrogel at a ratio of 100:0.4, mix well and perform ultrasonic treatment for 0.8 - 1.2 h to obtain a high thermal conductivity hydrogel. To prevent the temperature of the mixture from rising too high, ultrasonic treatment is performed every 90 s for 60 s each time. In addition, immerse the mixing beaker in an ice - water mixture to avoid temperature rise during ultrasonic treatment and keep it below 42 °C.

[0059] Step (4): Release of hydrogen bond constraints

[0060] The mixed system in Step 3 is evacuated in advance (pressure below -0.1 MPa), and then oxygen is introduced to make the pressure of the system normal pressure, and it is maintained in a high-purity oxygen atmosphere for 3 h.

[0061] Step (5): Preparation of composite material

[0062] The heat-conducting hydrogel and activated carbon powder are mechanically mixed evenly at a weight ratio of 1:1 to obtain 1 kg of material, and the stirring time is 30 min to make the two component materials contact sufficiently, forming a water-retaining adsorption composite embryo with good homogeneity. The embryo is put into an extruder or extruded using a sieve to obtain particles with a particle size of 0.5 mm to 1.5 mm.

[0063] Step (6): Preparation of filter rod and cigarette

[0064] The water-retaining adsorption composite material is filled into the cavity on a filter rod forming machine to obtain a water-retaining adsorption functional filter rod (YC / T 232.2-2007), and the filling amount is 60 ± 2 mg. The finished cigarette is made by using this filter rod for tipping and rolling. The prepared cigarette samples are used to determine the representative harmful components crotonaldehyde and moisture in the cigarette smoke according to "Determination of main carbonyl compounds in cigarette mainstream smoke - High performance liquid chromatography" (YC / T 254-2008) and "Determination of moisture in total particulate matter of cigarettes - Part 1: Gas chromatography" (GB / T 23203.1-2008).

[0065] Example 2

[0066] Compared with Example 1, the difference is only that the process of Step 1 is changed. The specific experimental groups are as follows:

[0067] Group A: The total amount ratio of calcium carbonate to sodium polyacrylate is 1:120;

[0068] Group B: Calcium carbonate is not added.

[0069] Group C: The concentration of sodium polyacrylate in the hydrogel in Step 1 is controlled to be 2 wt%.

[0070] Other operations and parameters are the same as those in Example 1.

[0071] Example 3

[0072] Compared with Example 1, the difference is only that the conditions of Step 2 are changed. Specifically:

[0073] A: Change the process of Step 2: Disperse the carbon nanotubes in 1 M nitric acid solution, stir and react at a temperature of 50 - 60 °C for 2 h to obtain modified carbon nanotubes;

[0074] Group B: The blue light irradiation time is reduced to 120 min, and other conditions are the same as those in Example 1.

[0075] Example 4

[0076] Compared with Example 1, the only difference is that in Step 3, the weight ratio of the hydrogel to the modified carbon nanotubes is controlled at 100:0.8, and other conditions are the same as those in Example 1.

[0077] Example 5:

[0078] Compared with Example 1, the only difference is that in Step 4, the mixed system is pre-evacuated (-0.15 MPa), and then oxygen is introduced to maintain the pressure of the system at 2 atm (2 atmospheric pressures) and maintained at this pressure for 10 h. Other conditions are the same as those in Example 1.

[0079] Example 6

[0080] Compared with Example 1, the only difference is that in Step 5, the heat-conducting hydrogel and the strong adsorption material are mechanically mixed evenly at a weight ratio of 1:2 to obtain 1 kg of material. Other conditions are the same as those in Example 1.

[0081] Example 7

[0082] Compared with Example 1, the only difference is that in Step 6, the water-retaining adsorption composite material is filled into the cavity or the tow on a filter rod forming machine to obtain a water-retaining adsorption functional filter rod (YC / T 232.2-2007), and the filling amount is 30 ± 2 mg, and finished cigarette sticks are rolled and connected using this filter rod. Other conditions are the same as those in Example 1.

[0083] Comparative Example 1

[0084] Compared with Example 1, the only difference is that in Step 6, the filling amount of the water-retaining adsorption composite material in the filter rod is 0. Comparative Example 1 is the reference sample.

[0085] Comparative Example 2

[0086] Compared with Example 1, the only difference is that in Step 6, activated carbon (the same as in Step 5 of Example 1) is filled into the cavity on a filter rod forming machine to obtain an adsorption functional filter rod (YC / T 232.2-2007), and the filling amount is 60 ± 2 mg, and finished cigarette sticks are rolled and connected using this filter rod. Although it can obtain a certain harm reduction effect, the water loss is relatively large and the overall smoking sensation is not ideal.

[0087] Comparative Example 3

[0088] Compared with Example 1, the only difference is that the condition of Step 2 is changed, and it is irradiated with blue light (wavelength range: 435 - 450 nm) for 0 min. Other conditions are the same as those in Example 1.

[0089] Comparative Example 4

[0090] Compared with Example 1, the only difference is that the conditions in Step 2 are changed, and the modified carbon nanotubes are added to the prepared hydrogel in a ratio of 100:0. Other conditions are the same as those in Example 1.

[0091] Comparative Example 5

[0092] Compared with Example 1, the only difference is that the treatment in Step 4 is not carried out. Other conditions are the same as those in Example 1.

[0093] The data of the changes in crotonaldehyde and water release of each example and comparative example compared with Comparative Example 1 are shown in Table 1:

[0094] Case Crotonaldehyde decline rate <![CDATA[Water content change (a) > Example 1 42％ +28％ Example 2A 40％ +29％ Example 2B 32％ +21％ Example 2C 41％ +23％ Example 3A 30％ +19％ Example 3B 40％ +27％ Example 4 43％ +31％ Example 5 44％ +32％ Example 6 46％ +22％ Example 7 30％ +20％ Comparative Example 2 48％ -11％ Comparative Example 3 39％ +11％ Comparative Example 4 38％ +5％ Comparative Example 5 32％ +14％

[0095] Note: In (a), the "+" indicates the percentage increase in water release compared with Comparative Example 1, and the "-" indicates the percentage decrease in water compared with Comparative Example 1.

[0096] In summary, the process of the present invention can improve the removal effect of crotonaldehyde. Moreover, it can avoid excessive adsorption of water, achieving both harm reduction and water retention. In addition, it can also improve the flavor absorption.

Claims

1. A preparation method of a heat-conducting and water-retaining hydrogel, characterized in that, The hydrogel and the hydrophilic modified thermally conductive carbon material are compounded, and then dehydroxylation treatment is carried out in an atmosphere to obtain the thermally conductive water-retaining hydrogel.

2. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 1, wherein, The polymer in the hydrogel is polyacrylic acid and its salts.

3. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 1, wherein The water absorption rate of the hydrogel is 4900% to 12400%.

4. The preparation method of the heat-conducting and water-retaining hydrogel according to any one of claims 1 to 3, characterized in that, The hydrogel is pre-modified with calcium carbonate, and the steps are as follows: calcium carbonate is dispersed in an aqueous solution, and then mixed with the polymer of the hydrogel to obtain the hydrogel.

5. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 4, wherein, The weight ratio of the calcium carbonate to the polymer in the hydrogel is 1:24 to 1:

123.

6. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 1, characterized in that, The thermally conductive carbon material is a carbon nanotube.

7. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 1 or 6, characterized in that, The thermally conductive carbon material is pre-treated with an organic solvent, and then hydrophilic modification is carried out under blue light irradiation to obtain the hydrophilic modified thermally conductive carbon material.

8. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 7, characterized in that, The wavelength range of the blue light is 435 - 450 nm; Preferably, the time of blue light irradiation is more than 30 min, preferably 100 - 300 min.

9. The preparation method of the heat-conducting water-retaining hydrogel according to claim 1, characterized in that, The weight ratio of the polymer in the hydrogel to the hydrophilic modified thermally conductive carbon material is 1:1 to 5:

1.

10. The preparation method of the heat-conducting and water-retaining hydrogel according to claim 1, wherein, After the hydrogel and the hydrophilic modified thermally conductive carbon material are compounded, the pressure of the system is pre-controlled to be negative pressure, and then an atmosphere is introduced to maintain the pressure of the system above atmospheric pressure, and the atmosphere and pressure are maintained for dehydroxylation treatment.

11. The preparation method of the heat-conducting water-retaining hydrogel according to claim 10, characterized in that, The pressure of the negative pressure is below 0.5 atm; Preferably, the atmosphere is an oxygen-containing atmosphere, preferably oxygen with a purity of more than 95%; Preferably, the time of dehydroxylation treatment is more than 2 h, preferably 3 - 10 h.

12. A thermally conductive water-retaining hydrogel prepared by the preparation method according to any one of claims 1 to 11.

13. Use of the thermally conductive water-retaining hydrogel prepared by the preparation method according to any one of claims 1 to 11, characterized in that, Using it as an additive for preparing cigarettes; Preferably, using it as an additive for preparing the filter tip of cigarettes.

14. A composite water retention and adsorption material, characterized in that, Comprising an adsorbent material and a thermally conductive water-retaining hydrogel prepared by the preparation method according to any one of claims 1 to 11.

15. The composite water-retaining and adsorbing material according to claim 14, wherein The weight ratio of the adsorbent material to the thermally conductive water-retaining hydrogel is 0.5 - 2.5:1, preferably 1 - 2:1; more preferably 1 - 1.5:

1.

16. Use of the composite water-retaining and adsorbing material according to any one of claims 14 to 15, characterized in that, Using it as an additive for preparing cigarettes; Preferably, using it as an additive for preparing the filter tip of cigarettes.

17. A cigarette filter, characterized in that, Including a thermally conductive water-retaining hydrogel prepared by the preparation method according to any one of claims 1 to 11.

18. The cigarette filter according to claim 17, wherein, Including the composite water-retaining adsorbent material according to any one of claims 14 to 15.

19. A cigarette, characterized in that, Comprising a cigarette filter tip according to any one of claims 17 to 18.

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