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CN-121972129-A - Flexible silica composite aerogel adsorption material without powder falling

CN121972129ACN 121972129 ACN121972129 ACN 121972129ACN-121972129-A

Abstract

The invention discloses a flexible silica composite aerogel adsorption material without powder falling, which is formed by in-situ compounding of SiO 2 aerogel and carbon aerogel materials and is used for a filter tip adsorption material, and can effectively adsorb harmful substances in cigarette smoke, wherein the mass ratio of the silica aerogel to the carbon aerogel is 1 (0.1-0.3). The invention is formed by carrying out in-situ doping composite drying on the silicon dioxide aerogel and the nitrogen-containing carbon aerogel with a high-porosity macroporous structure, combines the adsorption performance of the silicon dioxide aerogel and the carbon aerogel, has high porosity, rich pore channel structure and difficult powder falling compared with the traditional silicon dioxide aerogel, can fully adsorb and degrade harmful substances in smoke, such as aldehydes, carbon monoxide, tar and the like, has smaller inhalation resistance, and has the advantages of good adsorption capacity, lower cost, simple preparation process, easy operation and the like compared with the adsorbent commonly used in cigarettes in the prior art.

Inventors

  • LI HUI
  • WU SHAOQING
  • XU FAN
  • TAN CHONG
  • XIONG FENG
  • XIONG CHAO

Assignees

  • 中化学华陆新材料有限公司

Dates

Publication Date
20260505
Application Date
20260323

Claims (9)

  1. 1. The flexible silica composite aerogel adsorbing material is characterized by being formed by in-situ compounding of SiO 2 aerogel and carbon aerogel materials, and is used for adsorbing harmful substances in cigarette smoke through a filter tip adsorbing material, wherein the mass ratio of the silica aerogel to the carbon aerogel is 1 (0.1-0.3).
  2. 2. The composite aerogel adsorbing material of claim 1, wherein the carbon aerogel is prepared by: Mixing resorcinol, formaldehyde, a pore-enlarging agent and ethyl orthosilicate uniformly, adding an alkali catalyst to gel, adding an alcohol solvent to age the gel, drying and roasting to obtain silicon dioxide-carbon composite aerogel, putting the silicon dioxide-carbon composite aerogel into hydrofluoric acid or a strong alkali solution to etch, and drying to obtain the nitrogen-containing carbon aerogel with a high-porosity macroporous structure; The molar ratio of resorcinol to formaldehyde to pore-enlarging agent to ethyl orthosilicate is 1:2 (0.05-0.1) (0.1-0.2), the molar ratio of resorcinol to alkali catalyst is (300-1000) (1), the pore-enlarging agent is cetyl trimethyl ammonium bromide or cetyl trimethyl ammonium chloride, the alkali catalyst is one or two of ammonia water and tetramethyl ammonium hydroxide, the solvent is one of methanol, ethanol and propanol, the drying and roasting temperature is gradient drying, the specific drying parameters are 300 ℃ drying 0.5h,600 ℃ drying 0.5h,800 ℃ drying 1-2h,1000 ℃ drying 1-2h,1200 ℃ drying 1-2h, the etching solution is hydrofluoric acid or one of sodium hydroxide and potassium hydroxide, the concentration is 3-8 mol/L, the etching time is 2-10 h, and the etching temperature is 25-50 ℃.
  3. 3. The composite aerogel adsorbing material of claim 1, wherein the composite aerogel adsorbing material is prepared by: Step 1, uniformly mixing a silicon source, a solvent, a catalyst and a pore-expanding agent, and continuously stirring for 1-4 hours at 25-50 ℃ to prepare a sol, wherein the mass ratio of the silicon source to the solvent to the catalyst to the pore-expanding agent is1 (1.5-2.5) (0.4-0.7) (0.02-0.08); Step2, adding an alkali catalyst into the sol prepared in the step 1 to adjust the pH value to 7-8, then adding carbon aerogel powder, and then pouring the mixture into a mold to heat the gel to obtain a wet gel material, wherein the wet gel material is heated to 40-55 ℃; Step 3, putting the wet gel material prepared in the step 2 into an alcohol solution, adding an alkaline solution into the alcohol solution to adjust the pH value to 8-9, and aging for 10-24 hours at 55-75 ℃; Step 4, drying the wet gel aged in the step 3 by supercritical CO 2 to obtain the composite aerogel adsorption material; and 5, drying and deodorizing the composite aerogel adsorption material obtained in the step 4.
  4. 4. The composite aerogel adsorption material according to claim 3, wherein in the step 1, the pore expanding agent is cetyltrimethylammonium bromide or cetyltrimethylammonium chloride, the silicon source is a mixture of a silane compound and a silicate compound, the silane compound is one or two of methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane and dimethyldiethoxysilane, the silicate compound is one or two of tetraethoxysilane and tetramethylsilicate, the molar ratio of the silane compound to the silicate compound is 1 (0.05-0.2), and the catalyst is an aqueous solution of one or two of nitric acid, hydrochloric acid, acetic acid, sulfuric acid or phosphoric acid, and the concentration is 0.2 mol/L-1 mol/L.
  5. 5. The composite aerogel adsorbing material of claim 3, wherein in step 2, the base catalyst is one or both of ammonium carbonate, ammonium acetate buffer, or urea.
  6. 6. The composite aerogel adsorbing material of claim 3, wherein in step 3, the alcohol solution is one of methanol, ethanol or propanol, and the alkaline solution is one or two of sodium hydroxide, potassium hydroxide or ammonia water.
  7. 7. A composite aerogel adsorbing material as claimed in claim 3, wherein in step 4, supercritical CO 2 drying conditions are: The flow rate of CO 2 is 450L/h-600L/h, the drying temperature is 45-55 ℃, the drying pressure is 14.5-16.5 MPa, and the drying time is 3-8 h.
  8. 8. The composite aerogel adsorbing material of any of claims 1-7, wherein the composite aerogel adsorbing material has a resistance value of less than 1000 Pa and an adsorption mass of at least 20 times the mass of the material itself.
  9. 9. A filter tip, characterized in that the filter tip comprises the flexible silica composite aerogel adsorption material without powder falling according to any one of claims 1-8.

Description

Flexible silica composite aerogel adsorption material without powder falling Technical Field The invention relates to the technical field of aerogel adsorption filtration, in particular to a flexible silica composite aerogel adsorption material without powder falling, which is particularly used for a cigarette holder filtration adsorption material. Background The cigarette smoke contains thousands of chemical substances such as tar, aldehydes, carbon monoxide, nicotine and the like, wherein various components have obvious harm to the respiratory system, the cardiovascular system and the like of a human body, the risk of various diseases is increased after long-term smoking, and the second-hand smoke also has adverse effect on the health of non-smokers. On the premise of considering smoking experience, the method can effectively reduce harmful components in cigarette smoke, and is always the core scientific research direction of the global tobacco industry. At present, the most direct and widely applied mode for reducing the harmful substances in the smoke is to add an adsorption material into a cigarette filter. The traditional filter tip mainly adopts polymer materials such as cellulose diacetate, polypropylene fibers and the like, the problems of limited raw material sources, complex preparation process and high cost exist in the former, the adsorption capacity of the latter on harmful substances is weak, and the requirements of high-end cigarettes on reducing the harmful substances are difficult to meet, and the addition of conventional adsorbents such as activated carbon and the like can obviously increase the cigarette smoke resistance although a certain harmful substance adsorption can be realized, so that the smoking is unsmooth, and the smoking taste and the user experience are seriously influenced. Therefore, the development of the cigarette smoke filtering material with high filtering efficiency, low suction resistance, good stability and safe use is a technical key point to be broken through in the cigarette industry. Aerogel is a nano porous solid material with a three-dimensional network-shaped framework structure, is praised as the lightest solid material, and has huge application potential in the fields of sound insulation, heat insulation, catalytic carrier, filtration and adsorption and the like by virtue of ultrahigh porosity, large specific surface area and excellent adsorption performance, and particularly has natural high adsorption advantage on oily harmful substances in smoke. The silica aerogel is the most widely studied and industrialized aerogel product at present, but the pure silica aerogel has the defects of low inherent strength and high brittleness, so that the problems of cracking, crushing and powder falling easily occur in the actual use process of the cigarette holder filter, the adsorption performance is fast attenuated, the fallen powder enters a human body along with smoke, new health safety risks are brought, and the large-scale application of the silica aerogel in the field of cigarette filters is greatly limited. Patent CN114307953a discloses a preparation method of a silica/carbon composite aerogel material, by forming a carbon layer on a framework of silica aerogel and combining a two-stage heat treatment process, the structure and components of the material are optimized, and the adsorption and degradation effects of aldehydes and carbon monoxide in cigarette smoke are realized, but the preparation process of the material is complex and high in cost, and the adsorption effect of tar is not ideal, the resistance is large, and powder falling is easy. Patent CN113598411A adopts a mixture of macroporous silica gel, carbon aerogel and linoleic acid modified nano silicon-based oxide as a specific adsorption material, and through the structural design of a composite filter tip, a general adsorption section and a specific adsorption section are arranged in series, and the material has a good adsorption effect on crotonaldehyde, but has a poor effect on other adsorption materials in smoke, and is also easy to fall off powder. Patent CN113735556a discloses a silicon-containing aerogel composite material, and a preparation method and application thereof. The material is formed by compounding silicon-containing aerogel and fibers. The material has the advantages of no powder falling, but high resistance. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a flexible silica composite aerogel adsorption material without powder falling, so as to solve the problems that the filter effect is poor, powder falling is easy, the respiratory resistance is large and the three performances are difficult to optimize simultaneously when a silica aerogel material is adopted as an adsorption material in a filter tip in the prior art. In order to achieve the above purpose, in a first aspect, the invention provides a flexible silica composite aerogel adsorpti