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CN-117101557-B - Preparation method of ion thermosensitive composite gel for efficiently extracting nicotine

CN117101557BCN 117101557 BCN117101557 BCN 117101557BCN-117101557-B

Abstract

The invention discloses a preparation method of an ion thermosensitive composite gel for efficiently extracting nicotine. The method comprises the steps of physically mixing Boron Nitride (BN) with anhydrous citric acid, ball milling, washing, centrifuging and drying to obtain the boron nitride nanosheets. And reacting the boron nitride nano-sheet with the ionic liquid under nitrogen atmosphere for 24 h to obtain the ionic liquid-boron nitride nano-sheet (IL-BNNs). Dispersing IL-BNNs into monomer solution, adding cross-linking agent after colloid is formed, adding tetramethyl ethylenediamine and ammonium persulfate, and stirring under ice bath. And transferring the mixed system into a mould to react 12-24 h to obtain the ionic liquid thermosensitive composite gel. The invention utilizes the ionic liquid to form dense nicotine binding sites in the composite material, thereby enhancing the adsorption-desorption performance of the material on nicotine. Meanwhile, the desorption performance of the material is enhanced by utilizing the heat conductivity of the boron nitride and the phase change property of the gel, so that the nicotine extraction process is simplified, and the dosage of the eluent in the nicotine recovery process is reduced.

Inventors

  • ZHOU LIQIN
  • HE QINGQING
  • ZHANG YUANLIANG
  • ZHAO ZHONGXING
  • ZHAO ZHENXIA

Assignees

  • 广西大学

Dates

Publication Date
20260512
Application Date
20230809

Claims (10)

  1. 1. The preparation method of the ion thermosensitive composite gel for efficiently extracting nicotine is characterized by comprising the following steps of: (1) Mixing hexagonal boron nitride with anhydrous citric acid, ball milling, pouring the powder into a container filled with water after ball milling is finished, stirring, suction filtering and washing until the pH value of the washing solution is close to neutral, dispersing the obtained powder into water, centrifuging, taking an upper suspension, and centrifuging and drying for many times to obtain the boron nitride nanosheets; (2) Dispersing the boron nitride nano-sheets obtained in the step (1) in a certain amount of ionic liquid, stirring and reacting in nitrogen atmosphere, repeatedly washing and filtering, and then drying to obtain the ionic liquid-boron nitride nano-sheets; (3) The preparation of the ionic liquid thermosensitive gel comprises the steps of dispersing the ionic liquid-boron nitride nanosheets obtained in the step (2) into an aqueous solution containing a certain amount of isopropyl acrylamide monomer, stirring to form colloid, adding a cross-linking agent N, N-methylene bisacrylamide, continuing stirring until the cross-linking agent N, N-methylene bisacrylamide is fully dissolved, then adding tetramethyl ethylenediamine and stirring under an ice bath, finally adding an initiator ammonium persulfate, continuing stirring uniformly, transferring a mixed system into a die, and carrying out room temperature polymerization reaction for 10-12 h to obtain a white composite material, namely the ionic thermosensitive composite gel for efficiently extracting nicotine.
  2. 2. The method of claim 1, wherein the mass ratio of hexagonal boron nitride to anhydrous citric acid in the step (1) is 1:1-5.
  3. 3. The method of claim 1, wherein the ball-milling beads in the step (1) are made of zirconia, the ball-milling beads have a diameter of 0.5 cm, the ball-milling revolution is 220-250 r/min, and the ball-milling time is 10-12 h.
  4. 4. The method for preparing the ion-thermosensitive composite gel for efficiently extracting nicotine according to claim 1, wherein the molar ratio of the boron nitride nano-sheet to the ionic liquid in the step (2) is 1:3.
  5. 5. The method of claim 1, wherein the ionic liquid in the step (2) is any one of 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-propyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium tetrafluoroborate.
  6. 6. The method for preparing the ion-thermosensitive composite gel for efficiently extracting nicotine according to claim 1, wherein the boron nitride nano-sheets in the step (2) are dispersed into an ionic liquid, and the reaction is carried out for 24-48 hours under stirring in nitrogen atmosphere.
  7. 7. The method for preparing the ion-thermosensitive composite gel for efficiently extracting nicotine according to claim 1, wherein the mass ratio of the ionic liquid-boron nitride nanosheets to the isopropyl acrylamide monomers in the step (3) is 0.5-2:1.
  8. 8. The preparation method of the ion-thermosensitive composite gel for efficiently extracting nicotine according to claim 1, wherein the mass ratio of isopropyl acrylamide monomer, cross-linking agent N, N-methylene bisacrylamide and initiator ammonium persulfate in the step (3) is 100:1:10, and the mass ratio of isopropyl acrylamide monomer to tetramethyl ethylenediamine is 1g and 35-40 mu L.
  9. 9. The method for preparing an ion-thermosensitive composite gel for efficiently extracting nicotine according to claim 1, wherein in the step (3), the reaction is carried out by stirring under ice bath for 2-3 h.
  10. 10. The use of an ion-sensitive composite gel prepared by the method according to any one of claims 1 to 9 for extracting nicotine.

Description

Preparation method of ion thermosensitive composite gel for efficiently extracting nicotine Technical Field The invention belongs to the field of extraction and separation of tobacco alkaloids, and particularly relates to a preparation method of an ion thermosensitive composite gel for extracting nicotine. Background Nicotine has bioactivity and unique pharmacological action, and is widely used in medicine, agriculture and tobacco industry. Tobacco is the primary source of nicotine, and extraction of nicotine from tobacco is of great importance. However, the organic solvents used in large amounts by conventional solvent extraction methods pose a significant threat to human health and the environment. How to realize green, efficient and recyclable extraction of nicotine in tobacco extracts is one of the problems to be solved at present. The ionic liquid (Ionic liquid) is a compound salt which is composed of organic cations and organic anions or inorganic anions and is in a liquid state at room temperature or near room temperature. In the extraction separation application, compared with the traditional organic solvent, the ionic liquid has the advantages of non-volatilization, low toxicity, high selectivity and the like, and has wide application prospect in the fields of extraction separation of aromatic hydrocarbon, halogenated hydrocarbon compounds and metal ions through Van der Waals force, hydrogen bond and anion-cation electrostatic force formed between the ionic liquid and a target object. However, ionic liquids generally have high viscosity, are unfavorable for mass transfer processes of extraction, and are difficult to separate target objects from the ionic liquids. As an extractant, the ionic liquid is difficult to preserve for a long period of time, and there is also a problem of loss during recovery. Hydrogels are a new class of low toxicity, naturally degradable polymeric materials. The composite material has the characteristics of solid materials, can maintain a certain shape and size, has the fluidity of liquid, and can freely permeate small molecular solvents or solutes inside and outside. The thermosensitive hydrogel has phase change characteristic, and can generate hydrophobic-hydrophilic transition at a certain temperature, so that the adsorption-desorption performance of the gel material on different small molecular substances is changed. The thermosensitive hydrogel composite material has great contribution in the fields of extraction separation, drug delivery and the like. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a preparation method of ion thermosensitive composite gel with simple process and strong nicotine adsorption-desorption function. The ion liquid is utilized to form dense nicotine binding sites in the composite material, so that the adsorption-desorption performance of the material to nicotine is enhanced, and meanwhile, the desorption performance of the material is enhanced by utilizing the heat conductivity of boron nitride and the phase change property of gel, so that the nicotine extraction process is simplified, and the consumption of eluent in the nicotine recovery process is reduced. The aim of the invention is realized by the following technical scheme: A preparation method of ion thermosensitive composite gel for efficiently extracting nicotine comprises the following steps: Mixing hexagonal boron nitride with anhydrous citric acid, performing ball milling, pouring powder into a container filled with water after ball milling is finished, stirring, suction filtering, washing until the pH value of the washing solution is close to neutral, dispersing the obtained powder into water, centrifuging, taking an upper suspension, and centrifugally drying for many times to obtain boron nitride nanosheets (carboxyl functionalized boron nitride nanosheets BNNs); Dispersing the boron nitride nano-sheets obtained in the step (1) in a certain amount of ionic liquid, stirring and reacting in nitrogen atmosphere, repeatedly washing and filtering, and then drying to obtain the ionic liquid-boron nitride nano-sheets; The preparation of the ionic liquid thermosensitive gel comprises the steps of dispersing the ionic liquid-boron nitride nano-sheet obtained in the step (2) into an aqueous solution containing a certain amount of isopropyl acrylamide monomer (NIPAM), stirring to form colloid, adding a cross-linking agent N, N-methylene bisacrylamide, continuously stirring until the cross-linking agent N, N-methylene bisacrylamide is fully dissolved, then adding tetramethyl ethylenediamine and stirring under ice bath, finally adding an initiator ammonium persulfate, continuously stirring uniformly, transferring the mixed system into a die, and carrying out room-temperature polymerization reaction for 10-12 h to obtain a white composite material, namely the ionic thermosensitive composite gel for efficiently extracting nicotine. As a further pr