CN107759809A - A kind of preparation method of stretchable organic/inorganic composite aquogel - Google Patents

Abstract

The invention discloses a kind of preparation method of stretchable organic/inorganic composite aquogel, it comprises the following steps：（1）At room temperature, water-soluble monomer, crosslinking agent are dissolved in deionized water, stir and ultrasonic disperse uniformly forms solution afterwards, it is standby；（2）Ammonium persulfate is added in above-mentioned solution, stirs and forms reaction system using ultrasonic wave is scattered；（3）Reducing agent is added in above-mentioned reaction system, continues to stir；（4）Treat step（3）Pyrrole monomer and oxidant are added when products therefrom starts to become viscous, after stirring, is rapidly added inorganic nano material dispersion liquid, continues to stir 5 10min；（5）Reaction is stood, by step（4）Obtained product cleaning and balance in distilled water, obtain stretchable organic/inorganic composite aquogel.

Description

A kind of preparation method of stretchable organic/inorganic composite hydrogel

technical field

The invention belongs to the technical field of polymer composite materials, and in particular relates to a preparation method of stretchable organic/inorganic composite hydrogel.

Background technique

Polymer hydrogels have become a research hotspot in recent years. Polymer hydrogel is a cross-linked 3D network structure that can absorb a large amount of water. It is soft in nature and has certain elasticity and mechanical strength. Hydrogel is a kind of hydrophilic polymer material. The hydrophilic group inside its 3D network can combine with water molecules to fix it inside the network structure. The long hydrophobic chain stretches when it encounters water, giving the hydrogel a good stretchability. The 3D network structure of hydrogel in water mainly exists in the form of bonded water, bound water, etc., and loses its fluidity. Therefore, hydrogel is an intermediate state between solid and liquid. As a new type of polymer functional material, hydrogel has unique excellent properties such as water absorption and retention, adsorption, bionics, intelligence and biocompatibility, and is widely used in artificial muscles, daily chemicals, construction engineering and environmental protection and other fields.

Due to the large amount of water inside the 3D network of polymer hydrogels, the gel strength will be reduced, which limits its wide application in many fields. In recent years, in order to improve the mechanical properties of polymer hydrogels, researchers have introduced nanoparticles into the 3D network of polymer hydrogels to prepare polymer nanocomposite hydrogels, whose mechanical properties can be determined by the content of nanoparticles. control adjustment. Moreover, the introduction of nanoparticles with different properties and morphologies will also endow hydrogels with new properties, such as electrical conductivity and environmental properties. Servant et al. introduced carbon nanotubes into the polymethacrylic acid hydrogel network to form a nanocomposite hydrogel, and the conductivity of the hydrogel was significantly enhanced (Servant A, Methven L, Williams RP, et al. Electroresponsive polymer-carbon nanotube hydrogel hybrids for pulsatiledrug delivery in vivo. Advanced Healthcare Materials, 2013, 2:806-811). Bai et al. introduced graphene oxide into the conductive polymer network to prepare graphene oxide/conductive polymer nanocomposite hydrogel. The prepared hydrogel showed good conductivity and electrochemical activity, which has potential in the field of biosensors. Application (Bai H, Li C, Zhang P, et al. Graphene oxide/conducting polymer composite hydrogels. Journal of Materials Chemistry, 2011, 21 (46): 18653-18658).

The successful preparation of flexible conductive composite hydrogels with good conductivity and electrochemical activity has laid a good foundation for them to be used as flexible energy storage electrode materials. Guang et al. (Guang P H, Felix H, Martin O.Stretchable and semitransparent conductive hybrid hydrogels for flexible supercapacitors. J. Am. Chem. Soc., 2014,8(7): 7138-7146) introduced polyaniline nanoparticles into polyacrylamide In the 3D network structure of hydrogel, the prepared composite hydrogel network has high conductivity, stretchability and transparency, and exhibits good cycle stability and rate characteristics, which has great development in the application of flexible electrodes. potential. Due to the insulating properties of the flexible composite hydrogel matrix polymer and its 3D network structure dominated by macropores, as a flexible electrode material, its electrical conductivity and mechanical properties still need to be improved urgently.

Contents of the invention

In order to solve the above problems, the purpose of the present invention is to successfully introduce conductive polypyrrole and inorganic nanomaterials into the 3D network structure of organic polymers. On the one hand, physical entanglement between conductive polypyrrole and organic polymer chains can be used to form conductive physical crosslinks. On the other hand, the introduction of one-dimensional or two-dimensional inorganic nanoparticles effectively regulates the 3D porous structure of organic polymers and endows hydrogels with good mechanical and conductive properties. This method has not been reported at home and abroad.

In order to realize above-mentioned purpose of the invention, the technical scheme that the present invention adopts is as follows:

A method for preparing a stretchable organic/inorganic composite hydrogel, comprising the steps of:

(1) Dissolve the water-soluble monomer and cross-linking agent in deionized water at room temperature, stir and disperse evenly by ultrasonic to form a solution, and set aside;

(2) Add ammonium persulfate to the above solution, stir and disperse with ultrasonic waves to form a reaction system;

(3) Add the reducing agent into the above reaction system and continue stirring;

(4) When the product obtained in step (3) starts to become viscous, add pyrrole monomer and oxidant, stir evenly, quickly add inorganic nanomaterial dispersion, and continue stirring for 5-10 minutes

(5) Static reaction, the product obtained in step (4) was purified and balanced in distilled water to obtain a stretchable organic/inorganic composite hydrogel.

Further, the water-soluble monomer in the step (1) is one of acrylamide and acrylic acid.

Further, the crosslinking agent in the step (1) is N, N'-methylenebisacrylamide.

Further, the concentration of the water-soluble monomer in the step (1) is 0.1 g/mL, and the mass ratio of the water-soluble monomer to the crosslinking agent is 2000:1-100:1.

Further, the mass ratio of the water-soluble monomer to ammonium persulfate in the step (2) is 500:1-10:1.

Further, the reducing agent in the step (3) is one of ferrous chloride, Na ₂ SO ₃ , Na ₂ S ₂ O ₃ , and NaHSO ₃ .

Further, the molar ratio of ammonium persulfate to reducing agent in the step (3) is 10:1-20:1.

Further, the oxidant in the step (4) is one of ammonium persulfate, potassium persulfate, anhydrous ferric chloride, and ferric nitrate nonahydrate.

Further, in the step (4), the mass ratio of the water-soluble monomer to the pyrrole monomer is 2:1-50:1, the molar ratio of the pyrrole monomer to the oxidizing agent is 1:1, and the concentration of the inorganic nanomaterial dispersion is 0.5-10mg/mL.

Further, the static reaction time in the step (5) is 12-24 hours, the purification equilibrium time is 24 hours, and the water is changed every 4 hours.

The invention uses an oxidation-reduction initiator to initiate the cross-linking polymerization of the organic polymer hydrogel at normal temperature, and introduces conductive polypyrrole and inorganic nanometer materials before reaching the gel point.

The beneficial effects of the present invention are as follows:

1. The present invention can be formed by reaction at room temperature, which is conducive to the orderly growth of conductive polypyrrole in the 3D network structure of the organic polymer hydrogel, and can effectively improve the conductivity and electrochemical activity of the composite hydrogel.

2. In the present invention, inorganic nanoparticles are introduced into the composite hydrogel, which can effectively control the stretchability and electrical conductivity of the hydrogel. The prepared stretchable conductive composite hydrogel has a good application prospect as a flexible energy storage electrode material.

3. The present invention carries out the polymerization reaction at normal temperature, and the equipment is simple, easy to operate, and easy to expand scale production.

Description of drawings

Fig. 1 is the elasticity test photo of the composite hydrogel prepared by the embodiment of the present invention 1;

Fig. 2 is the tensile test photo of the composite hydrogel prepared in Example 1 of the present invention;

Fig. 3 is a scanning electron micrograph of pure polyacrylic acid hydrogel (Fig. 3a) and the composite hydrogel (Fig. 3b) prepared in Example 1 of the present invention. Fig. 3a and 3b are both tested by Nova Nano SEM 450 scanning electron microscope Samples were plated with platinum prior to testing.

Detailed ways

The present invention will be further described in detail below through specific examples. However, it should not be understood that the content of the present invention is limited to the following examples.

Example 1

A method for preparing a stretchable organic/inorganic composite hydrogel, comprising the steps of:

(1) Dissolve 2g of acrylic acid (purchased from Chengdu Kelong Chemical Reagent Factory), 0.001g of N,N′-methylene bisacrylamide (purchased from Tianjin Kemiou Chemical Reagent Co., Ltd.) in 15mL of deionized water at room temperature , stir and ultrasonically disperse evenly to form a solution, and set aside;

(2) Add 0.2g (0.88mmol) ammonium persulfate (purchased from Sinopharm Chemical Reagent Co., Ltd.) to the above solution, stir and disperse with ultrasonic waves to form a reaction system;

(3) Add 0.009gNaHSO ₃ (0.088mmol) into the above reaction system and continue stirring;

(4) When the product obtained in step (3) starts to become viscous, add 0.134g (2mmol) of pyrrole monomer and 0.54g of potassium persulfate (2mmol) and stir evenly, then quickly add 5mL of 0.8mg/mL Mxene dispersion (Preparation For the method, see MRLukatskaya, Mashtalir O, Ren CE, et al.Cation intercalation and high volumetric capacitance of two-dimensional titanium carbide. Science, 2013,341: 1502-1505.), continue stirring for 5-10min

(5) Stand for reaction for 12 hours, purify and balance the obtained product in distilled water for 24 hours, and change the water every 4 hours. A stretchable organic/inorganic composite hydrogel was obtained.

Example 2

A kind of preparation method of stretchable organic/inorganic composite hydrogel, its difference with embodiment 1 is that 2g acrylic acid becomes 10g acrylamide, 15mL deionized water becomes 80mL deionized water, 0.001g N, N'- Methylenebisacrylamide becomes 0.1 g N, N′-methylenebisacrylamide, 0.2g (0.88mmol) ammonium persulfate becomes 0.02g (0.088mmol) ammonium persulfate, 0.009gNaHSO ₃ (0.088mmol) becomes 0.0007g Na ₂ S ₂ O ₃ (0.0044mmol), 0.134g (2mmol) pyrrole becomes 0.2g (3mmol) pyrrole, 0.54g potassium persulfate (2mmol) becomes 0.684g ammonium persulfate (3mmol), 5mL 0.8 The mg/mL Mxene dispersion changed to 20mL 50mg/mL acidified carbon nanotube dispersion (prepared by refluxing concentrated nitric acid at 80°C for 12h) dispersion, and the standing reaction for 12h became 24h.

Example 3

A kind of preparation method of stretchable organic/inorganic composite hydrogel, its difference with embodiment 1 is that 2g acrylic acid becomes 10g acrylic acid, 15mL deionized water becomes 80mL deionized water, 0.001g N, N'- Methylbisacrylamide becomes 0.01g N, N′-methylenebisacrylamide, 0.009gNaHSO ₃ (0.088mmol) becomes 0.0063g Na ₂ SO ₃ (0.005mmol), 0.134g (2mmol) pyrrole becomes 5g ( 74.6mmol), 0.54g potassium persulfate (2mmol) becomes 12.08g anhydrous ferric chloride (74.6mmol), 5mL 0.8mg/mL Mxene dispersion becomes 20mL 25mg/mL acidified carbon nanotube dispersion, The standing reaction changed from 12h to 24h.

Example 4

A kind of preparation method of stretchable organic/inorganic composite hydrogel, its difference with embodiment 1 is that 2g acrylic acid becomes 2g acrylamide, 0.001g N, N′-methylene bisacrylamide becomes 0.004 g N , N′-methylenebisacrylamide, 0.2g (0.88mmol) ammonium persulfate becomes 0.1g (0.44mmol) ammonium persulfate, 0.009gNaHSO ₃ (0.088mmol) becomes 0.005g FeCl ₂ (0.04mmol), 0.134 g (2mmol) pyrrole becomes 0.268g (4mmol), 0.54g potassium persulfate (2mmol) becomes 1.616g ferric nitrate nonahydrate (4mmol), 5mL 0.8mg/mL Mxene dispersion becomes 50mL 8mg/mL Mxene Dispersions.

Example 5

A preparation method of stretchable organic/inorganic composite hydrogel, which differs from Example 1 in that 0.001g N, N'-methylenebisacrylamide becomes 0.002 g N, N'-methylenebisacrylamide Amide, 0.2g (0.88mmol) ammonium persulfate becomes 0.13g (0.57mmol) ammonium persulfate, 0.009g NaHSO ₃ (0.088mmol) becomes 0.004g NaHSO ₃ (0.038mmol), 0.134g (2mmol) pyrrole becomes 0 .067g (1mmol), 0.27g potassium persulfate (1mmol) becomes 0.228g ammonium persulfate (1mmol), 5mL 0.8mg/mL Mxene dispersion becomes 50mL 4mg/mL Mxene dispersion.

The performance parameters of the composite hydrogel prepared in Example 1-5 are shown in Table 1.

Table 1

Example 1 2 3 4 5 Conductivity (S/cm) 2.2 4.2 5.5 8.2 7.6 Elongation δ (%)) 300 320 350 330 390 Energy density (Whkg ^-1 ) 32 35 37 42 40 Cycle 2000 cycle specific capacitance retention (%) 82 85 88 91 90

Elongation was calculated according to the following formula:

Among them, δ is the elongation rate, L is the maximum elongation length, and s is the original length

Fig. 1 is the photo of the elasticity test of the composite hydrogel prepared in Example 1 of the present invention, as can be seen from the figure, the composite hydrogel has good elasticity.

FIG. 2 is a tensile test photo of the composite hydrogel prepared in Example 1 of the present invention. It can be seen from the figure that the composite hydrogel exhibits good stretchability.

Figure 3 is a scanning electron micrograph of pure polyacrylic acid hydrogel (Figure 3a) and the composite hydrogel prepared in Example 1 of the present invention (Figure 3b). 3D porous structure. The pore size of the pure polyacrylic acid hydrogel is 1-5 μm, and the pore size of the composite hydrogel is reduced to 500 nm-2 μm after introducing the inorganic nanometer material.

The above embodiments have described the technical solutions of the present invention in detail. Obviously, the invention is not limited to the described embodiments. Based on the embodiments of the present invention, those skilled in the art can make various changes accordingly, but any changes that are equivalent or similar to the present invention fall within the protection scope of the present invention.

Claims (10)

1. a preparation method of stretchable organic/inorganic composite hydrogel, is characterized in that, comprises the steps: At room temperature, dissolve the water-soluble monomer and cross-linking agent in deionized water, stir and ultrasonically disperse evenly to form a solution, and set aside; Add ammonium persulfate to the above solution, stir and disperse with ultrasonic waves to form a reaction system; The reducing agent is added in the above-mentioned reaction system, continue to stir; When the product obtained in step (3) starts to become viscous, add pyrrole monomer and oxidant, stir evenly, quickly add inorganic nanomaterial dispersion, and continue stirring for 5-10 minutes; After static reaction, the product obtained in step (4) was purified and balanced in distilled water to obtain a stretchable organic/inorganic composite hydrogel. 2. The preparation method according to claim 1, characterized in that the water-soluble monomer in step (1) is acrylamide or acrylic acid. 3. The preparation method according to claim 1, characterized in that the crosslinking agent in step (1) is N, N'-methylenebisacrylamide. 4. The preparation method according to claim 1, wherein the concentration of the water-soluble monomer in step (1) is 0.1 g/mL, and the mass ratio of the water-soluble monomer to the crosslinking agent is It is 2000:1-100:1. 5. The preparation method according to claim 1, characterized in that the mass ratio of the water-soluble monomer to ammonium persulfate in step (2) is 500:1-10:1. 6 . The preparation method according to claim 1 , wherein the reducing agent in step (3) is one of ferrous chloride, Na ₂ SO ₃ , Na ₂ S ₂ O ₃ , and NaHSO ₃ . 7. The preparation method according to claim 1, characterized in that the molar ratio of ammonium persulfate to reducing agent in step (3) is 10:1-20:1. 8 . The preparation method according to claim 1 , wherein the oxidant in step (4) is one of ammonium persulfate, potassium persulfate, anhydrous ferric chloride, and ferric nitrate nonahydrate. 9. The preparation method according to claim 1, wherein the inorganic nanomaterial dispersion in step (4) is a Mxene dispersion or a carbon nanotube dispersion, and the water-soluble monomer in step (1) and pyrrole The mass ratio of the monomers is 2:1-50:1, the molar ratio of the pyrrole monomer to the oxidizing agent is 1:1, and the concentration of the inorganic nanomaterial dispersion is 0.5-10 mg/mL. 10. The preparation method according to claim 1, characterized in that the standing reaction time in step (5) is 12-24 hours, the purification equilibrium time is 24 hours, and the water is changed every 4 hours.