Preparation method of hydrophobic nano-microsphere composite super-hydrophobic hydrospinning membrane

Abstract

The invention discloses a preparation method of a hydrophobic nano-microsphere compounded super-hydrophobic electrospinning membrane, and belongs to the technical field of preparation and hydrophobic enhancement of electrospinning membranes. The preparation method comprises the following steps: preparing hydrophobic nano-microspheres, dissolving the hydrophobic nano-microspheres and hydrophobic polyvinyl butyral in ethanol to obtain an electrospinning precursor solution, and carrying out electrostatic spinning at the same time to obtain the hydrophobic nano-microsphere composite super-hydrophobic electrospinning membrane. As the hydrophobic nano-microspheres have strong hydrophobicity, hydrophobic nanoscale protrusion structures are formed on the surfaces of the hydrophobic fibers, the hydrophobicity of the electrospinning membrane is obviously improved, and the contact angle reaches 150 degrees or above.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation and enhancement of hydrophobic electrospun membranes, and particularly relates to a method for preparing a hydrophobic electrospun membrane composite with hydrophobic nanospheres. Background Art

[0002] Electrospinning is the most feasible method for preparing nanofibers with a high specific surface area. It can prepare one-dimensional wire materials, two-dimensional nanofiber membranes, and three-dimensional bulk materials, and electrospinning has great advantages in preparing nanomaterials. Currently, a large number of natural polymers and synthetic polymers can be used to prepare various functional nanomaterials through electrospinning technology, which are widely used in fields such as filtration materials, biomedical materials, tissue engineering scaffolds, and catalyst support materials. However, most electrospun nanomaterials are limited in some application fields that require highly hydrophobic electrospun membranes due to their lack of superhydrophobic properties, such as self-cleaning coatings, snow / ice-proof glass, and non-wetting coatings for transmission lines. Therefore, developing a superhydrophobic electrospun membrane is of great significance for broadening the application fields of electrospun nanomaterials.

[0003] The hydrophobicity of an electrospun membrane is a very important performance index. Generally, the hydrophobicity of an electrospun membrane is closely related to the spinning material used. Even if a hydrophobic material is selected, its contact angle is generally within 120°. Therefore, during the manufacturing process of an electrospun membrane, in addition to paying attention to the hydrophobicity of the material itself, more attention should be paid to improving the hydrophobicity of the micro-nano structure on the surface of the electrospun membrane.

[0004] There are a large number of reports on hydrophobic electrospun membranes at home and abroad. The research group of Jiang Lei from the Chinese Academy of Sciences (A Lotus-Leaf-like Superhydrophobic Surface: A Porous Microsphere / Nanofiber Composite Film Prepared by Electrohydrodynamics Angew, Chem. Int. Ed., 2004, 43: 4338–4341) prepared porous polystyrene microspheres and three-dimensional network fibers by electrospinning technology. The diameter of the porous polystyrene microspheres is larger than that of the fibers, and the fibers are combined into a film by bundling the styrene microspheres. The contact angle of this hydrophobic film surface is 160.4°; Yang Qingbiao et al. from Jilin University (Preparation of a durable superhydrophobic membrane by electrospinning poly (vinylidene fluoride) (PVDF) mixed with epoxy–siloxane modified SiO2 nanoparticles: A possible route to superhydrophobic surfaces with low water sliding angle and high water contact angle, Journal of Colloid and Interface Science, 2011, 359: 380–388) introduced epoxy-modified silicone oil-modified SiO2 nanoparticles into the PVDF electrospun fiber film and obtained good hydrophobicity. The contact angle of this hydrophobic film surface is 161.2°.

[0005] There is no report on the preparation of a hydrophobic electrospun membrane using hydrophobic nanospheres that can be both a part of the electrospun fiber composition and form hydrophobic micro-nano protrusion structures on the fiber surface. Summary of the Invention

[0006] In order to solve the problem of poor hydrophobicity of electrospun membranes, the present invention provides a method for preparing a superhydrophobic electrospun membrane composite with hydrophobic nanospheres that can be both a part of the electrospun fiber composition and form hydrophobic micro-nano protrusion structures on the fiber surface.

[0007] The so-called superhydrophobic means that the contact angle of the superhydrophobic electrospun membrane composite with hydrophobic nanospheres based on polyvinyl butyral as the main spinning raw material reaches more than 150°.

[0008] The preparation method of a superhydrophobic electrospun membrane composite with hydrophobic nano - microspheres of the present invention is as follows: (1) Prepare hydrophobic nano - microspheres a. Prepare a pre - emulsion solution Mix water, butyl acrylate copolymer monomer I, methyl methacrylate copolymer monomer II, emulsifier, initiator, dicyclopentenyl acrylate cross - linker, molecular weight regulator and pH buffer in a mass ratio of 100:70 - 80:10 - 20:8 - 10:0.2 - 0.5:0.3 - 0.7:0.02 - 0.06:0.2 - 0.5 evenly to obtain a pre - emulsion solution; b. Stir the pre - emulsion solution at 45 - 65 °C and introduce nitrogen into it. After the air in the system is evacuated, raise the temperature to 70 - 85 °C and react for 2 - 4 hours. After the polymerization reaction ends, obtain an emulsion of hydrophobic nano - microspheres. Dry the emulsion of hydrophobic nano - microspheres at 60 - 70 °C for 4 - 6 hours to obtain hydrophobic nano - microspheres; the copolymer monomers and cross - linker of the hydrophobic nano - microspheres have hydrophobicity, so the hydrophobic nano - microspheres have hydrophobic functions; (2) Prepare an electrospun membrane a. Prepare an electrospinning precursor solution Dissolve hydrophobic polymer polyvinyl butyral with a mass concentration of 10 - 25% and hydrophobic nano - microspheres with a mass concentration of 5 - 10% in an ethanol - aqueous solution with a mass concentration of 30 - 70% to obtain an electrospinning precursor solution; b. Draw the electrospinning precursor solution with a syringe and perform electrospinning at a voltage of 20 - 30 kV, a collection distance of 15 - 25 cm, and a feeding speed of 1 - 2 mL / h to obtain a superhydrophobic electrospun membrane composite with hydrophobic nano - microspheres.

[0009] The emulsifier is sodium dodecyl sulfonate or sodium lauryl sulfate; the initiator is potassium persulfate or ammonium persulfate; the molecular weight regulator is tert - dodecyl mercaptan; the pH buffer is sodium bicarbonate.

[0010] The thickness of the superhydrophobic electrospun membrane composite with hydrophobic nano - microspheres is 0.5 - 1 mm.

[0011] The syringe needle model used in (2) is 26 - 36G.

[0012] Beneficial effects: The superhydrophobic electrospun membrane composite with hydrophobic nanospheres prepared by the present invention is different from the existing hydrophobic electrospun membranes and electrospun membranes composite with nanospheres. This is due to the addition of hydrophobic nanospheres. The hydrophobic nanospheres have extremely strong hydrophobicity, a large specific surface area, and form micro-nano hydrophobic protrusions on the fiber surface, significantly improving the hydrophobicity of the electrospun membrane, with the contact angle reaching over 150°. The key technical problem of improving the hydrophobicity of the electrospun membrane - the increase in the contact angle - is solved to broaden the application fields of electrospun membranes. Detailed implementation manners Examples

[0013] (1) Preparation of hydrophobic nanospheres a. Preparation of pre-emulsion Mix water, butyl acrylate comonomer Ⅰ, methyl methacrylate comonomer Ⅱ, emulsifier, initiator, dicyclopentenyl acrylate crosslinking agent, molecular weight regulator, and pH buffer in a mass ratio of 100:70:10:8:0.2:0.3:0.02:0.2 evenly to obtain a pre-emulsion. b. Stir the pre-emulsion at 45 °C and introduce nitrogen into it. After the air in the system is exhausted, raise the temperature to 70 °C and react for 2 hours. After the polymerization reaction ends, obtain an emulsion of hydrophobic nanospheres. Dry the emulsion of hydrophobic nanospheres at 60 °C for 4 hours to obtain hydrophobic nanospheres; the comonomers and crosslinking agent of the hydrophobic nanospheres have hydrophobicity, so the hydrophobic nanospheres have hydrophobic functions. (2) Preparation of electrospun membrane a. Preparation of electrospinning precursor solution Dissolve hydrophobic polymer polyvinyl butyral with a mass concentration of 10% and hydrophobic nanospheres with a mass concentration of 5% in an ethanol aqueous solution with a mass concentration of 30% to obtain an electrospinning precursor solution. b. Draw the electrospinning precursor solution with a syringe and perform electrospinning at a voltage of 20 kV, a collection distance of 15 cm, and a feeding speed of 1 mL / h to obtain a superhydrophobic electrospun membrane composite with hydrophobic nanospheres.

[0014] Wherein the emulsifier is sodium dodecyl sulfonate or sodium lauryl sulfate; the initiator is potassium persulfate or ammonium persulfate; the molecular weight regulator is tert-dodecyl mercaptan; the pH buffer is sodium bicarbonate.

[0015] The thickness of the superhydrophobic electrospun membrane composite with hydrophobic nanospheres is 0.5 mm.

[0016] The syringe needle model used in (2) is 26G.

[0017] Method for measuring the particle size of hydrophobic nano - microspheres: The particle size of hydrophobic nano - microspheres was measured using a 90Plus particle size analyzer from Brookhaven Corporation. One drop of the emulsion of hydrophobic nano - microspheres was placed in the sample cell, diluted with deionized water, and then the test was started. After repeating the test 4 times, the average particle size was 41 nm.

[0018] Method for measuring the contact angle of electrospun membrane: It was measured using a DSA30 contact angle tester from KRÜSS GmbH, Germany.

[0019] 5 μL of water droplets were dropped onto the electrospun membrane, and then the test was started. After repeating the test 5 times, the average contact angle was 152°. Examples

[0020] (1) Preparation of hydrophobic nano - microspheres a. Preparation of pre - emulsion Water, butyl acrylate copolymer monomer Ⅰ, methyl methacrylate copolymer monomer Ⅱ, emulsifier, initiator, dicyclopentenyl acrylate cross - linker, molecular weight regulator, and pH buffer were mixed evenly according to the mass ratio of 100:75:15:9:0.3:0.5:0.04:0.3 to obtain the pre - emulsion. b. The pre - emulsion was stirred at 55 °C, and nitrogen was introduced into it. After the air in the system was exhausted, the temperature was raised to 80 °C, and the reaction was carried out for 3 hours. After the polymerization reaction ended, an emulsion of hydrophobic nano - microspheres was obtained. The emulsion of hydrophobic nano - microspheres was dried at 65 °C for 5 hours to obtain hydrophobic nano - microspheres; the copolymer monomers and cross - linker of the hydrophobic nano - microspheres have hydrophobicity, so the hydrophobic nano - microspheres have hydrophobic functions. (2) Preparation of electrospun membrane a. Preparation of electrospinning precursor solution A hydrophobic polymer polyvinyl butyral with a mass concentration of 20% and hydrophobic nano - microspheres with a mass concentration of 8% were dissolved in an ethanol aqueous solution with a mass concentration of 50% to obtain the electrospinning precursor solution. b. The electrospinning precursor solution was drawn into a syringe, and electrospinning was carried out at a voltage of 20 kV, a collection distance of 20 cm, and a feeding speed of 2 mL / h to obtain a super - hydrophobic electrospun membrane composite with hydrophobic nano - microspheres.

[0021] Among them, the emulsifier is sodium dodecyl sulfonate or sodium lauryl sulfate; the initiator is potassium persulfate or ammonium persulfate; the molecular weight regulator is tert - dodecyl mercaptan; the pH buffer is sodium bicarbonate.

[0022] The thickness of the super - hydrophobic electrospun membrane composite with hydrophobic nano - microspheres is 0.7 mm.

[0023] The syringe needle model used in (2) is 26G.

[0024] Using the measurement method of Example 1, the average particle size of the hydrophobic nanospheres in Example 2 was 43 nm.

[0025] Using the measurement method of Example 1, the average contact angle of the electrospun membrane in Example 2 was 155°. Example

[0026] (1) Preparation of hydrophobic nanospheres a. Preparation of pre-emulsion Water, butyl acrylate copolymer monomer I, methyl methacrylate copolymer monomer II, emulsifier, initiator, dicyclopentenyl acrylate crosslinker, molecular weight regulator, and pH buffer were mixed evenly according to the mass ratio of 100:80:20:10:0.5:0.7:0.06:0.5 to obtain a pre-emulsion. b. The pre-emulsion was stirred at 60 °C, and nitrogen was introduced into it. After the air in the system was exhausted, the temperature was raised to 80 °C and reacted for 3 hours. After the polymerization reaction, an emulsion of hydrophobic nanospheres was obtained. The emulsion of hydrophobic nanospheres was dried at 68 °C for 5 hours to obtain hydrophobic nanospheres; the copolymer monomers and crosslinker of the hydrophobic nanospheres are hydrophobic, so the hydrophobic nanospheres have hydrophobic functions. (2) Preparation of electrospun membrane a. Preparation of electrospinning precursor solution A hydrophobic polymer polyvinyl butyral with a mass concentration of 25% and hydrophobic nanospheres with a mass concentration of 10% were dissolved in an ethanol aqueous solution with a mass concentration of 70% to obtain an electrospinning precursor solution. b. The electrospinning precursor solution was drawn with a syringe, and electrospinning was carried out at a voltage of 30 kV, a collection distance of 20 cm, and a feeding speed of 1.5 mL / h to obtain a superhydrophobic electrospun membrane composite with hydrophobic nanospheres.

[0027] The emulsifier is sodium dodecyl sulfonate or sodium lauryl sulfate; the initiator is potassium persulfate or ammonium persulfate; the molecular weight regulator is tert-dodecyl mercaptan; the pH buffer is sodium bicarbonate.

[0028] The thickness of the superhydrophobic electrospun membrane composite with hydrophobic nanospheres is 0.8 mm.

[0029] The syringe needle model used in (2) is 36G.

[0030] Using the measurement method of Example 1, the average particle size of the hydrophobic nanospheres in Example 3 was 45 nm.

[0031] Using the measurement method of Example 1, the average contact angle of the electrospun membrane in Example 3 was 150°.

Claims

1. A method for preparing a super-hydrophobic electrospinning membrane composited with hydrophobic nano-microspheres, comprising the following steps: (1) Preparation of hydrophobic nanospheres a. Prepare pre-emulsion Mix water, butyl acrylate comonomer I, methyl methacrylate comonomer II, emulsifier, initiator, dicyclopentenyl acrylate crosslinker, molecular weight regulator and pH buffer in a mass ratio of 100:70-80:10-20:8-10:0.2-0.5:0.3-0.7:0.02-0.06:0.2-0.5 to obtain a pre-emulsion; b. Stirring the pre-emulsion at 45-65° C. and introducing nitrogen therein, after the air in the system is evacuated, heating to 70-85° C. and reacting for 2-4 hours. After the polymerization reaction is completed, an emulsion of hydrophobic nano-microspheres is obtained, and the emulsion of hydrophobic nano-microspheres is dried at 60-70° C. for 4-6 hours to obtain hydrophobic nano-microspheres; the comonomer and the cross-linking agent of the hydrophobic nano-microspheres are hydrophobic, so the hydrophobic nano-microspheres have a hydrophobic function; (2) Preparation of electrospun membrane a. Preparation of electrospinning precursor solution Dissolving a hydrophobic polymer polyvinyl butyral with a mass concentration of 10 to 25% and a hydrophobic nanosphere with a mass concentration of 5 to 10% in an ethanol aqueous solution with a mass concentration of 30 to 70% to obtain an electrospinning precursor solution; b. Use a syringe to extract the electrospinning precursor solution, and spin it at a voltage of 20 to 30 kV, a collection distance of 15 to 25 cm, and a propulsion speed of 1 to 2 mL / h to obtain a super-hydrophobic electrospun membrane composited with hydrophobic nano-microspheres.

2. The method for preparing a super-hydrophobic electrospinning membrane of a hydrophobic nano-microsphere composite as claimed in claim 1, characterized in that The emulsifier is sodium dodecyl sulfate or sodium lauryl sulfate; the initiator is potassium persulfate or ammonium persulfate; the molecular weight regulator is tert-dodecyl mercaptan; and the pH buffer is sodium bicarbonate.

3. The super-hydrophobic electrospinning membrane of a hydrophobic nano-microsphere composite according to claim 1, characterized in that: The thickness of the film is 0.5 to 1 mm.

4. The method for preparing a super-hydrophobic electrospinning membrane composited with hydrophobic nano-microspheres according to claim 1, characterized in that: The syringe needle used in (2) is of model 26-36G.