CN103736634B - Method for assembling polyelectrolyte/inorganic nano-particle multilayer films on surfaces of wood materials layer by layer - Google Patents

Abstract

A method for assembling a polyelectrolyte/inorganic nanoparticle multilayer film on the surface of a wood material, the invention relates to a method for assembling a multilayer film on the surface of a wood material. The present invention aims to solve the problems of high cost, large-scale equipment required, certain environmental pollution, certain damage to the physical and chemical properties of wooden materials and relatively long processing period in the existing wood material functional improvement technology. Method: pretreatment and drying treatment first, followed by preparation of polycation electrolyte film-making solution, polyanion electrolyte film-making solution and inorganic nanoparticle film-making solution, and then alternately soaking polyelectrolyte film-making solution to form a polyelectrolyte multilayer film, and finally Alternately immersing the polyelectrolyte film-forming solution and the inorganic nanoparticle film-forming solution to obtain a woody material with a polyelectrolyte/inorganic nanoparticle multilayer film formed on the surface. The invention is used for layer-by-layer assembly of polyelectrolyte/inorganic nano particle multilayer film on the surface of wooden materials.

Description

Method for assembling polyelectrolyte/inorganic nanoparticle multilayer films on the surface of wood materials

technical field

The invention relates to a method for assembling a multilayer film layer by layer on the surface of a wooden material.

Background technique

The introduction of nanotechnology into the field of wood functional improvement research has been a research hotspot in recent years. Using the properties of nanomaterials such as particle volume effect and surface effect, the rigidity, dimensional stability and thermal stability of inorganic substances are related to the toughness and toughness of wood. Workability, dielectric properties, and unique environmental properties combine to give wood new functions. Layer by layer self-assembly (LbL) is an important thin film preparation technology, which has the advantages of a wide range of assembled molecules, simple operation, and mild conditions. Therefore, the combination of the two technologies for the functional improvement of wood has strong development prospects.

As early as 1966, Iler first proposed the method of using oppositely charged inorganic nanoparticles to be deposited on a solid substrate through electrostatic interaction to form a multilayer film, but this method has not attracted people's attention. Until 1991, French scientist Decher used self-assembly method to prepare oppositely charged polyelectrolyte multilayer composite membranes, permeable membranes, conductive membranes, surface modification and antistatic coatings, etc.

Inorganic nanoparticles, nano-ZnO, nano-TiO ₂ , nano-Al ₂ O ₃ , nano-SiO ₂ and nano-Ag are all due to their unique surface effects, small size effects and macroscopic quantum tunneling effects, etc. , Flame retardant and so on have great applications. In recent years, it has been widely used in the functional improvement of wood materials.

However, in the existing technologies for functional improvement of wood materials, there are still some technical costs that are relatively high, require large-scale devices, cause certain environmental pollution, and the physical and chemical properties of the improved wood materials themselves are damaged to a certain extent, and the treatment period is relatively long. question.

Contents of the invention

The purpose of the present invention is to solve the problems of high cost, large-scale equipment, certain environmental pollution, certain damage to the physical and chemical properties of the wood material itself, and relatively long processing period in the existing wood material functional improvement technology. A method for assembling polyelectrolyte/inorganic nanometer particle multilayer films on the surface of wood materials is provided.

The method for assembling the polyelectrolyte/inorganic nanoparticle multilayer film on the surface of the wooden material is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: Clean the wooden material with distilled water or immerse the wooden material in 0.01mol/L～0.1mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 1min～5min, and then soak the wooden material The material is dried to obtain a woody material with a negatively charged surface;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

2. Preparation of polycation electrolyte film-making solution: dissolve polycation electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polycation electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

3. Preparation of polyanion electrolyte film-making solution: dissolve polyanion electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polyanion electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wooden material on the surface into the polycation electrolyte film-making solution for 5 minutes to 60 minutes, then wash and dry to obtain wooden material A, and then impregnate wooden material A Into the polyanion electrolyte film-making solution, soak for 5min to 60min, then wash and dry; ②, take step 4 ① as a cycle, and step 4 ① cycle for 1 cycle to 20 cycles, that is, the polyelectrolyte polyelectrolyte formed on the surface is obtained. the wood material of the film;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

5. Preparation of positively charged inorganic nanoparticles film-forming solution: under ultrasonic and stirring conditions, disperse the inorganic nanoparticles in water, and use HCl with a concentration of 0.1mol/L and NaOH solution with a concentration of 0.1mol/L to adjust The pH is lower than the isoelectric point to positively charge the inorganic nanoparticles to obtain a positively charged inorganic nanoparticle film-forming solution with a mass fraction of 1% to 5%;

6. Immerse the inorganic nanoparticle film-making solution: immerse the woody material with polyelectrolyte multilayer film on the surface prepared in step 4 into the positively charged inorganic nanoparticle film-making solution for 5 minutes to 60 minutes, then wash and dry. Obtain wooden material B;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

7. Alternately impregnating the polyelectrolyte film-making solution and the inorganic nanoparticle film-making solution: ①. Immerse the wooden material B into the polyanion electrolyte film-making solution for 5 minutes to 60 minutes, then wash and dry to obtain the wooden material C, and then Immerse the woody material C into the positively charged inorganic nanoparticle film-making solution for 5 minutes to 60 minutes, then wash and dry; ②, take step 7 ① as a cycle, and step 7 ① cycle for 1 cycle to 20 cycle, that is, to obtain a woody material with a polyelectrolyte/inorganic nanoparticle multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. to 105° C. or N ₂ airflow drying.

The method for assembling the polyelectrolyte/inorganic nanoparticle multilayer film on the surface of the wooden material is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: Clean the wooden material with distilled water or immerse the wooden material in 0.01mol/L～0.1mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 1min～5min, and then soak the wooden material The material is dried to obtain a woody material with a negatively charged surface;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

2. Preparation of polycation electrolyte film-making solution: dissolve polycation electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polycation electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

3. Preparation of polyanion electrolyte film-making solution: dissolve polyanion electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polyanion electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wooden material on the surface into the polycation electrolyte film-making solution for 5 minutes to 60 minutes, then wash and dry to obtain wooden material A, and then impregnate wooden material A Into the polyanion electrolyte film-making solution, soak for 5min to 60min, then wash and dry; ②, take step 4 ① as a cycle, and step 4 ① cycle for 1 cycle to 20 cycles, that is, the polyelectrolyte polyelectrolyte formed on the surface is obtained. the wood material of the film;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

5. Preparation of negatively charged inorganic nanoparticles film-forming solution: under ultrasonic and stirring conditions, disperse the inorganic nanoparticles in water, and use HCl with a concentration of 0.1mol/L and NaOH solution with a concentration of 0.1mol/L to adjust the pH Negatively charge the inorganic nanoparticles above the isoelectric point to obtain a negatively charged inorganic nanoparticle film-forming solution with a mass fraction of 1% to 5%;

6. Alternately immerse the polyelectrolyte film-making solution and the inorganic nanoparticle film-making solution: ①. Immerse the woody material with polyelectrolyte multilayer film on the surface prepared in step 4 into the polycation electrolyte film-making solution for 5 minutes to 60 minutes, and then Carry out water washing and drying to obtain woody material B, then immerse woody material B into negatively charged inorganic nanoparticle film-forming solution for 5min to 60min, then wash with water and dry; ②, take step 6 ① as a cycle , Step 6 ① cyclically carry out 1 cycle to 20 cycles to obtain a woody material with polyelectrolyte/inorganic nanoparticle multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. to 105° C. or N ₂ airflow drying.

Beneficial effects of the present invention: 1. The present invention does not require large-scale devices, is simple and convenient to operate, and the membrane-forming liquid can be reused, and can be completed at room temperature and normal pressure. The cost is low, energy is saved, and production efficiency is improved. It is suitable for large-scale Large-scale production; 2. The raw materials such as the film-making liquid used are non-toxic and pollution-free, and are environmentally friendly; 3. The present invention uses inorganic nanoparticles to modify the wood material so as to improve its performance without changing the original properties and characteristics of the wood material. The performance of wood materials, giving wood materials a variety of new properties at the same time.

The invention is used for a method for assembling polyelectrolyte/inorganic nanometer particle multilayer films on the surface of wooden materials layer by layer.

Description of drawings

Fig. 1 is that the surface that embodiment one prepares forms polyelectrolyte/nanometer TiO ₂ multilayer film wood magnifies 500 times SEM electron microscope figure;

Fig. 2 is that the surface that embodiment one prepares forms polyelectrolyte/nano-TiO ₂ the timber magnification 20000 times SEM electron microscope picture of multilayer film;

Fig. 3 is that the surface that embodiment one prepares forms polyelectrolyte/nanometer TiO ₂ multilayer film wood energy spectrogram;

Fig. 4 is that the surface that embodiment two prepares forms polyelectrolyte/nanometer Al ₂ O ₃ wood magnified 500 times SEM electron microscope picture of multilayer film;

Fig. 5 is that the surface that embodiment two prepares forms polyelectrolyte/nanometer Al ₂ O ₃ wood magnified 10000 times SEM electron microscope picture of multilayer film;

Fig. 6 is that the surface that embodiment two prepares forms polyelectrolyte/nanometer Al ₂ O ₃ wood energy spectrograms of multilayer film;

Fig. 7 is that the surface that embodiment three prepares forms polyelectrolyte/nano-SiO ₂ the timber of multilayer film enlarges 500 times SEM electron microscope figure;

Fig. 8 is that the surface that embodiment three prepares forms polyelectrolyte/nano-SiO ₂ multilayer film wood magnifies 20000 times SEM electron micrograph;

Fig. 9 is the wood energy spectrogram of the polyelectrolyte/nanometer SiO ₂ multilayer film formed on the surface prepared in Example 3.

Detailed ways

Embodiment 1: The method for assembling the polyelectrolyte/inorganic nanoparticle multilayer film on the surface of the wooden material described in this embodiment is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: Clean the wooden material with distilled water or immerse the wooden material in 0.01mol/L～0.1mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 1min～5min, and then soak the wooden material The material is dried to obtain a woody material with a negatively charged surface;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

2. Preparation of polycation electrolyte film-making solution: dissolve polycation electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polycation electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

3. Preparation of polyanion electrolyte film-making solution: dissolve polyanion electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polyanion electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wooden material on the surface into the polycation electrolyte film-making solution for 5 minutes to 60 minutes, then wash and dry to obtain wooden material A, and then impregnate wooden material A Into the polyanion electrolyte film-making solution, soak for 5min to 60min, then wash and dry; ②, take step 4 ① as a cycle, and step 4 ① cycle for 1 cycle to 20 cycles, that is, the polyelectrolyte polyelectrolyte formed on the surface is obtained. the wood material of the film;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

5. Preparation of positively charged inorganic nanoparticles film-forming solution: under ultrasonic and stirring conditions, disperse the inorganic nanoparticles in water, and use HCl with a concentration of 0.1mol/L and NaOH solution with a concentration of 0.1mol/L to adjust The pH is lower than the isoelectric point to positively charge the inorganic nanoparticles to obtain a positively charged inorganic nanoparticle film-forming solution with a mass fraction of 1% to 5%;

6. Immerse the inorganic nanoparticle film-making solution: immerse the woody material with polyelectrolyte multilayer film on the surface prepared in step 4 into the positively charged inorganic nanoparticle film-making solution for 5 minutes to 60 minutes, then wash and dry. Obtain wooden material B;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

7. Alternately impregnating the polyelectrolyte film-making solution and the inorganic nanoparticle film-making solution: ①. Immerse the wooden material B into the polyanion electrolyte film-making solution for 5 minutes to 60 minutes, then wash and dry to obtain the wooden material C, and then Immerse the woody material C into the positively charged inorganic nanoparticle film-making solution for 5 minutes to 60 minutes, then wash and dry; ②, take step 7 ① as a cycle, and step 7 ① cycle for 1 cycle to 20 cycle, that is, to obtain a woody material with a polyelectrolyte/inorganic nanoparticle multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. to 105° C. or N ₂ airflow drying.

In this specific embodiment, polyelectrolyte/inorganic nanoparticle multilayer films are assembled layer by layer on the surface of wood materials by using oppositely charged polyelectrolyte and inorganic nanoparticle under the action of electrostatic force. The key to obtain polyelectrolyte/inorganic nanoparticle multilayer film on the surface of wood materials lies in the control of pH and the size control of inorganic nanoparticles. Different types of polyelectrolytes have different charge intensities under different pH conditions, and the charge density can be maximized by adjusting the pH, which is conducive to the alternate assembly. Different types of inorganic nanoparticles have different isoelectric points, which are negatively charged if they are greater than the isoelectric point, and positively charged if they are smaller than the isoelectric point.

Due to their small size, inorganic nanoparticles are prone to agglomeration. Therefore, the agglomeration is opened by ultrasonic method, and then the agglomeration is suppressed by continuous mechanical stirring.

Because the main component of wood materials, cellulose, is negatively charged in aqueous solution, compared with glass sheets and polymer substrates widely used in layer-by-layer self-assembly technology, wood materials do not require pretreatment or only need simple pretreatment The surface can be negatively charged, which is beneficial to the application of layer-by-layer self-assembly technology in the functional improvement of wood materials.

During the processing, since the cellulose in the wood material is negatively charged, polycation electrolytes are initially used to form a polycation electrolyte layer on the surface of the wood material to prepare for the next step of assembling an oppositely charged polyanion electrolyte layer. After the polyanion electrolyte layer is assembled, a positively charged inorganic nanoparticle layer is further assembled on its surface. Finally, repeat the alternate assembly of polyanionic electrolytes and inorganic nanoparticles for 1 cycle to 20 cycles to obtain a wood material/polyelectrolyte/inorganic nanoparticle multilayer film.

The beneficial effects of this embodiment are: 1. This embodiment does not require large-scale devices, the operation is simple and convenient, the film-forming solution can be reused, and can be completed at room temperature and normal pressure, the cost is low, energy is saved, and production efficiency is improved. It is suitable for large-scale production; 2. The raw materials such as the film-making liquid used are non-toxic and pollution-free, and are green and environmentally friendly; 3. In this embodiment, the inorganic nanoparticles are used to treat the wood material without changing the original performance and characteristics of the wood material. Improvement to improve the performance of wood materials, and give wood materials a variety of new properties at the same time.

Embodiment 2: This embodiment is different from Embodiment 1 in that: the wooden material described in step 1 is wood, bamboo, rattan or wood fiber. Others are the same as in the first embodiment.

Specific embodiment three: the difference between this embodiment and specific embodiment one or two is that the polycation electrolyte described in step two is polyacrylamine hydrochloride, polyacrylamide or polydimethyldiallyl ammonium chloride. Others are the same as in the first or second embodiment.

Embodiment 4: The difference between this embodiment and one of Embodiments 1 to 3 is that the polyanion electrolyte described in step 3 is sodium polystyrene sulfonate, polyacrylic acid, polymethacrylic acid or polyvinyl phosphoric acid. Others are the same as those in Embodiments 1 to 3.

Embodiment 5: This embodiment differs from Embodiment 1 to Embodiment 4 in that the inorganic nanoparticles described in Step 5 are nano-TiO ₂ , nano-ZnO, nano-Al ₂ O ₃ , nano-SiO ₂ , and nano-WO ₃ , nanometer SnO ₂ , nanometer MnO ₂ , nanometer CeO ₂ , nanometer Fe ₃ O ₄ , nanometer Fe ₂ O ₃ , nanometer Y ₂ O ₃ , nanometer La ₂ O ₃ , nanometer SiC or nanometer Si ₃ N ₄ . Others are the same as the specific embodiments 1 to 4.

Specific embodiment six: The method for assembling the polyelectrolyte/inorganic nanoparticle multilayer film on the surface of the wooden material described in this embodiment is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: Clean the wooden material with distilled water or immerse the wooden material in 0.01mol/L～0.1mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 1min～5min, and then soak the wooden material The material is dried to obtain a woody material with a negatively charged surface;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

2. Preparation of polycation electrolyte film-making solution: dissolve polycation electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polycation electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

3. Preparation of polyanion electrolyte film-making solution: dissolve polyanion electrolyte in water, adjust pH to 2-9, stir evenly, and then perform ultrasonic degassing to obtain polyanion electrolyte film-making solution with a mass fraction of 0.5% to 5%. ;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wooden material on the surface into the polycation electrolyte film-making solution for 5 minutes to 60 minutes, then wash and dry to obtain wooden material A, and then impregnate wooden material A Into the polyanion electrolyte film-making solution, soak for 5min to 60min, then wash and dry; ②, take step 4 ① as a cycle, and step 4 ① cycle for 1 cycle to 20 cycles, that is, the polyelectrolyte polyelectrolyte formed on the surface is obtained. the wood material of the film;

The drying is drying at a temperature of 60°C to 105°C or _N2 airflow drying;

5. Preparation of negatively charged inorganic nanoparticles film-forming solution: under ultrasonic and stirring conditions, disperse the inorganic nanoparticles in water, and use HCl with a concentration of 0.1mol/L and NaOH solution with a concentration of 0.1mol/L to adjust the pH Negatively charge the inorganic nanoparticles above the isoelectric point to obtain a negatively charged inorganic nanoparticle film-forming solution with a mass fraction of 1% to 5%;

6. Alternately immerse the polyelectrolyte film-making solution and the inorganic nanoparticle film-making solution: ①. Immerse the woody material with polyelectrolyte multilayer film on the surface prepared in step 4 into the polycation electrolyte film-making solution for 5 minutes to 60 minutes, and then Carry out water washing and drying to obtain woody material B, then immerse woody material B into negatively charged inorganic nanoparticle film-forming solution for 5min to 60min, then wash with water and dry; ②, take step 6 ① as a cycle , Step 6 ① cyclically carry out 1 cycle to 20 cycles to obtain a woody material with polyelectrolyte/inorganic nanoparticle multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. to 105° C. or N ₂ airflow drying.

Embodiment 7: This embodiment is different from Embodiment 6 in that the wooden material described in step 1 is wood, bamboo, rattan or wood fiber. Others are the same as the sixth embodiment.

Embodiment 8: The difference between this embodiment and Embodiment 6 or 7 is that the polycation electrolyte described in step 2 is polyacrylamine hydrochloride, polyacrylamide or polydimethyldiallyl ammonium chloride. Others are the same as in Embodiment 6 or 7.

Embodiment 9: This embodiment differs from Embodiment 6 to Embodiment 8 in that the polyanion electrolyte described in step 3 is sodium polystyrene sulfonate, polyacrylic acid, polymethacrylic acid or polyvinyl phosphoric acid. Others are the same as the sixth to eighth specific embodiments.

Embodiment 10: This embodiment differs from Embodiment 6 to Embodiment 9 in that the inorganic nanoparticles described in Step 5 are nano-TiO ₂ , nano-ZnO, nano-Al ₂ O ₃ , nano-SiO ₂ , nano-WO _3. Nano SnO ₂ , nano MnO ₂ , nano CeO ₂ , nano Fe ₃ O ₄ , nano Fe ₂ O ₃ , nano Y ₂ O ₃ , nano La ₂ O ₃ , nano SiC or nano Si ₃ N ₄ . Others are the same as the sixth to ninth embodiments.

Adopt the following examples to verify the beneficial effects of the present invention:

Embodiment one:

The wood surface described in the present embodiment assembles polyelectrolyte/nanometer TiO layer _{by layer} The method for the multilayer film is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: immerse the wood in 0.05mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 2min, and then dry the impregnated wood to obtain wood with negatively charged surface;

The drying is drying at a temperature of 60° C. for 60 minutes;

2. Preparation of polycation electrolyte film-making solution: dissolve polyacrylamine hydrochloride in water, adjust the pH to 2, stir evenly, and then perform ultrasonic degassing to obtain 150 mL of polycation electrolyte film-making solution with a mass fraction of 2%.

The molecular weight of the polyallylamine hydrochloride is 8000Da～10000Da;

3. Preparation of polyanion electrolyte film-making solution: dissolve sodium polystyrene sulfonate in water, adjust the pH to 2, stir evenly, and then perform ultrasonic degassing to obtain 150 mL of polyanion electrolyte film-making solution with a mass fraction of 2%;

Described sodium polystyrene sulfonate molecular weight is 70000Da;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wood on the surface into the polycation electrolyte film-making solution for 10 minutes, then wash and dry to obtain wood A, and then impregnate wood A into the polyanion electrolyte film-making solution. Immerse in the film liquid for 10 minutes, then wash and dry; ②, take step 4 ① as a cycle, step 4 ① cycle for 1 cycle, and obtain wood with a polyelectrolyte multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. for 60 minutes;

5. Preparation of positively charged inorganic nanoparticle film-forming solution: under ultrasonic and stirring conditions, disperse inorganic nanoparticle _TiO2 in water, and use HCl solution with a concentration of 0.1mol/L to adjust the pH to be less than the isoelectric point. 2 makes the inorganic nanoparticles positively charged to obtain a positively charged inorganic nanoparticle film-forming solution with a mass fraction of 2%;

6. Immerse the inorganic nanoparticle film-making solution: immerse the wood with the polyelectrolyte multilayer film on the surface prepared in step 4 into the positively charged inorganic nanoparticle film-making solution for 10 minutes, then wash with water and dry to obtain wood B ;

The drying is drying at a temperature of 60° C. for 60 minutes;

7. Alternately impregnating polyelectrolyte film-making solution and inorganic nanoparticle film-making solution: ①. Immerse wood B into polyanion electrolyte film-making solution for 10 minutes, then wash and dry to obtain wood C, and then impregnate wood C Into the positively charged inorganic nanoparticle film-making solution, soak for 10 minutes, then wash and dry; ②, take step 7 ① as one cycle, and step 7 ① cycle for 5 cycles, that is, the surface formed polyelectrolyte/inorganic Nanoparticle multilayered wood;

The drying is drying at a temperature of 60° C. for 60 minutes.

The surface of the polyelectrolyte/nano _TiO2 multilayer film prepared by the present embodiment is magnified by 500 times SEM electron microscope picture as shown in Figure 1, as can be seen from the figure under the low power electron microscope, the overall microstructure of the wood surface is still clearly visible, the surface Covered with a uniform film-like structure.

The surface of the preparation of the present embodiment forms polyelectrolyte/nano TiO ₂ multilayer film wood magnification 20000 times SEM electron microscope figure as shown in Figure 2, as can be seen from the figure under the high power electron microscope, the film-like structure on the wood surface is composed of many nanoparticles Composition, no agglomeration and uniform distribution.

The surface that present embodiment prepares forms polyelectrolyte/nanometer _{TiO2Multilayer} film wood energy spectrogram as shown in Figure 3, the surface forms polyelectrolyte/ _{NanoTiO2Multilayer} filmThe wood surface element mass percentage and atomic percentage of multilayer film are as table 1 It can be seen from Figure 3 and Table 1 that in addition to the original C and O elements on the wood surface, Ti elements have also been added, indicating that the film-like structure on the wood surface is composed of nano-TiO ₂ .

Table 1: Mass percentage and atomic percentage of wood surface elements forming polyelectrolyte/nano- _TiO2 multilayer film on the surface

element mass percentage atomic percentage CK 55.14 65.44 OK 35.74 31.85 TiK 09.11 02.71

Embodiment two:

Wood surface layer-by-layer assembly polyelectrolyte/nanometer Al ₂ O The method for _multilayer film described in the present embodiment is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: immerse the wood in 0.05mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 2min, and then dry the impregnated wood to obtain wood with negatively charged surface;

The drying is drying at a temperature of 60° C. for 60 minutes;

2. Preparation of polycation electrolyte film-making solution: dissolve polyacrylamine hydrochloride in water, adjust the pH to 2 and stir evenly, then perform ultrasonic degassing to obtain 150 mL of polycation electrolyte film-making solution with a mass fraction of 2%;

The molecular weight of the polyallylamine hydrochloride is 8000Da～10000Da;

3. Preparation of polyanion electrolyte film-making solution: dissolve sodium polystyrene sulfonate in water, adjust the pH to 2 and stir evenly, then perform ultrasonic degassing to obtain 150 mL of polyanion electrolyte film-making solution with a mass fraction of 2%;

Described sodium polystyrene sulfonate molecular weight is 70000Da;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wood on the surface into the polycation electrolyte film-making solution for 10 minutes, then wash and dry to obtain wood A, and then impregnate wood A into the polyanion electrolyte film-making solution. Immerse in the film liquid for 10 minutes, then wash and dry; ②, take step 4 ① as a cycle, step 4 ① cycle for 1 cycle, and obtain wood with a polyelectrolyte multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. for 60 minutes;

5. Preparation of positively charged inorganic nanoparticles film-making solution: under ultrasonic and stirring conditions, disperse inorganic nanoparticles Al ₂ O ₃ in water, and use HCl solution with a concentration of 0.1mol/L to adjust the pH to be lower than the isoelectric point , the pH is 2 to make the inorganic nanoparticles positively charged to obtain a positively charged inorganic nanoparticle film-forming solution with a mass fraction of 2%;

6. Immerse the inorganic nanoparticle film-making solution: immerse the wood with the polyelectrolyte multilayer film on the surface prepared in step 4 into the positively charged inorganic nanoparticle film-making solution for 10 minutes, then wash with water and dry to obtain wood B ;

The drying is drying at a temperature of 60° C. for 60 minutes;

7. Alternately impregnating polyelectrolyte film-making solution and inorganic nanoparticle film-making solution: ①. Immerse wood B into polyanion electrolyte film-making solution for 10 minutes, then wash and dry to obtain wood C, and then impregnate wood C Into the positively charged inorganic nanoparticle film-making solution, soak for 10 minutes, then wash and dry; ②, take step 7 ① as one cycle, and step 7 ① cycle for 5 cycles, that is, the surface formed polyelectrolyte/inorganic Nanoparticle multilayered wood;

The drying is drying at a temperature of 60° C. for 60 minutes.

The polyelectrolyte/nano Al ₂ O ₃ multilayer film on the surface of the wood prepared in this example is magnified 500 times. The SEM electron microscope picture is shown in Figure 4. It can be seen from the figure that the overall microstructure of the wood surface is still clearly visible under the low magnification electron microscope , the surface is covered with a uniform film-like structure.

The surface of the prepared polyelectrolyte/nanometer Al ₂ O ₃ wood multilayer film magnified 10000 times SEM electron microscope picture is shown in Figure 5, as can be seen from the figure under the high power electron microscope, the film-like structure on the wood surface is composed of many Composed of nanoparticles, there is no agglomeration phenomenon and the distribution is uniform.

The wood energy spectrogram of polyelectrolyte/nano _{-Al2O3 multilayer} film formed on the surface prepared by this embodiment is shown in Figure 6, and the wood surface element mass percentage and atom of polyelectrolyte/nano _{-Al2O3 multilayer} film are formed on the surface The percentages are shown in Table 2. From Figure 6 and Table 2, it can be seen that in addition to the original C and O elements on the wood surface, Al elements have also been added, indicating that the film-like structure on the wood surface is composed of nano-Al ₂ O ₃ .

Table 2: Mass percentage and atomic percentage of wood surface elements forming polyelectrolyte/nano Al ₂ O ₃ multilayer film on the surface

element mass percentage atomic percentage CK 51.09 61.94 OK 31.50 28.67 K 17.40 0.939

Embodiment three:

The wood surface described in the present embodiment assembles polyelectrolyte/nanometer SiO layer _by layer The method for the multilayer film is specifically carried out according to the following steps:

1. Pretreatment and drying treatment: immerse the wood in 0.05mol/L dilute hydrochloric acid for surface activation treatment, the immersion time is 2min, and then dry the impregnated wood to obtain wood with negatively charged surface;

The drying is drying at a temperature of 60° C. for 60 minutes;

2. Preparation of polycation electrolyte film-making solution: dissolve polydiallyldimethylammonium chloride in water, adjust the pH to 7 and stir evenly, and then perform ultrasonic degassing to obtain 150mL of polycation electrolyte with a mass fraction of 2%. Membrane solution;

The molecular weight of the polydiallyldimethylammonium chloride is 200000Da～350000Da;

3. Preparation of polyanion electrolyte film-making solution: dissolve sodium polystyrene sulfonate in water, adjust the pH to 7 and stir evenly, then perform ultrasonic degassing to obtain 150 mL of polyanion electrolyte film-making solution with a mass fraction of 2%;

Described sodium polystyrene sulfonate molecular weight is 70000Da;

4. Immersion polyelectrolyte film-making solution: ①. Immerse the negatively charged wood on the surface into the polycation electrolyte film-making solution for 10 minutes, then wash and dry to obtain wood A, and then impregnate wood A into the polyanion electrolyte film-making solution. Immerse in the film liquid for 10 minutes, then wash and dry; ②, take step 4 ① as a cycle, step 4 ① cycle for 1 cycle, and obtain wood with a polyelectrolyte multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. for 60 minutes;

5. Preparation of negatively charged inorganic nanoparticles film-making solution: under ultrasonic and stirring conditions, disperse the inorganic nanoparticles in water, and use a NaOH solution with a concentration of 0.1mol/L to adjust the pH to be greater than the isoelectric point to make the inorganic nanoparticles Negatively charged to obtain a negatively charged inorganic nanoparticle film-making solution with a mass fraction of 2%;

6. Alternately impregnating the polyelectrolyte film-making solution and the inorganic nanoparticle film-making solution: ①. Immerse the wood with polyelectrolyte multilayer film on the surface prepared in step 4 into the polycation electrolyte film-making solution for 10 minutes, then wash with water and remove Dry to obtain wood B, then impregnate wood B into negatively charged inorganic nano-particle film-making solution, soak for 10min, then wash and dry; ②, take step 6 ① as a cycle, and step 6 ① cycle for 5 Period, that is, to obtain wood with polyelectrolyte/inorganic nanoparticle multilayer film formed on the surface;

The drying is drying at a temperature of 60° C. for 60 minutes.

The surface of the prepared polyelectrolyte/nano- _SiO2 multilayer film of wood magnified 500 times as shown in Figure 7. As shown in Figure 7, it can be seen from the figure that under the low-power electron microscope, the overall microstructure of the wood surface is still clearly visible. Covered with a uniform film-like structure.

The surface prepared by the present embodiment forms polyelectrolyte/nano- _SiO2 multilayer film wood magnification 20000 times SEM electron microscope figure as shown in Figure 8, as can be seen from the figure under the high-magnification electron microscope, the film-like structure on the wood surface is composed of many nanoparticles Composition, no agglomeration and uniform distribution.

The surface that present embodiment prepares forms polyelectrolyte/nano _-SiO2 multilayer film wood energy spectrogram as shown in Figure 9, and the surface forms polyelectrolyte/nano _-SiO2 multilayer film Wood surface element mass percentage and atomic percent are as table 3 As can be seen from Figure 9 and Table 3, in addition to the original C and O elements on the wood surface, Si elements have also been added, indicating that the film-like structure on the wood surface is composed of nano-SiO ₂ .

Table 3: Mass percentage and atomic percentage of wood surface elements forming polyelectrolyte/nano- _SiO2 multilayer film on the surface

element mass percentage atomic percentage CK 51.81 62.10 OK 34.07 30.66 SiK 14.12 07.24

Claims (10)

1. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film, is characterized in that the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film is carried out according to following steps:

One, pretreatment and dry process: wood materials distilled water is cleaned or is immersed in 0.01mol/L ~ 0.1mol/L watery hydrochloric acid by wood materials and carries out surface activation process, dip time is 1min ~ 5min, then the wood materials after dipping is dry, obtain surperficial electronegative wood materials;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying;

Two, prepare polycation electrolyte preparation liquid: be dissolved in by polycation electrolyte in water, regulate pH to be 2 ~ 9, stir, then carry out ultrasonic deaeration, obtain the polycation electrolyte preparation liquid that mass fraction is 0.5% ~ 5%;

Three, prepare polyanion electrolyte preparation liquid: be dissolved in by polyanion electrolyte in water, regulate pH to be 2 ~ 9, stir, then carry out ultrasonic deaeration, obtain the polyanion electrolyte preparation liquid that mass fraction is 0.5% ~ 5%;

Four, polyelectrolyte preparation liquid is flooded: 1., be impregnated in polycation electrolyte preparation liquid by electronegative for surface wood materials, dipping 5min ~ 60min, then washing is carried out and drying, obtain wood materials A, again wood materials A is impregnated in polyanion electrolyte preparation liquid, dipping 5min ~ 60min, then carries out washing and drying; 2. be 1., with step 41 cycle period, step 4 1. circulate carry out 1 cycle ~ 20 cycles, namely obtain surface and form the wood materials of polyelectrolyte multilayer film;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying;

Five, the inorganic nano-particle preparation liquid of positively charged is prepared: under ultrasonic and stirring condition, inorganic nano-particle is dispersed in water, and working concentration is the HCl of 0.1mol/L and concentration is that the NaOH solution of 0.1mol/L regulates pH to be less than isoelectric point to make inorganic nano-particle positively charged, obtain the inorganic nano-particle preparation liquid that mass fraction is the positively charged of 1% ~ 5%;

Six, flood inorganic nano-particle preparation liquid: the wood materials that the surface of step 4 being prepared forms polyelectrolyte multilayer film is impregnated in the inorganic nano-particle preparation liquid of positively charged, dipping 5min ~ 60min, then carry out washing and drying, obtain wood materials B;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying;

Seven, alternating impregnating polyelectrolyte preparation liquid and inorganic nano-particle preparation liquid: 1., by wood materials B be impregnated in polyanion electrolyte preparation liquid, dipping 5min ~ 60min, then washing is carried out and drying, obtain wood materials C, then wood materials C is impregnated in the inorganic nano-particle preparation liquid of positively charged, dipping 5min ~ 60min, then carries out washing and drying; 2. be 1., with step 71 cycle period, step 7 1. circulate carry out 1 cycle ~ 20 cycles, namely obtain surface and form the wood materials of polyelectrolyte/inorganic nano-particle multilayer film;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying.

2. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 1, is characterized in that the wood materials described in step one is timber, bamboo wood, rattan material or wood-fibred.

3. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 1, is characterized in that the polycation electrolyte described in step 2 is polyallylamine hydrochloride, polyacrylamide or PDDA.

4. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 1, is characterized in that the polyanion electrolyte described in step 3 is kayexalate, polyacrylic acid, polymethylacrylic acid or polyvinyl.

5. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 1, is characterized in that the inorganic nano-particle described in step 5 is nano-TiO ₂, nano-ZnO, nanometer Al ₂o ₃, Nano-meter SiO_2 ₂, nanometer WO ₃, nano SnO ₂, nanometer MnO ₂, nano Ce O ₂, nanometer Fe ₃o ₄, nanometer Fe ₂o ₃, nanometer Y ₂o ₃, nanometer La ₂o ₃, nano SiC or nano Si ₃n ₄.

6. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film, is characterized in that the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film is carried out according to following steps:

One, pretreatment and dry process: wood materials distilled water is cleaned or is immersed in 0.01mol/L ~ 0.1mol/L watery hydrochloric acid by wood materials and carries out surface activation process, dip time is 1min ~ 5min, then the wood materials after dipping is dry, obtain surperficial electronegative wood materials;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying;

Two, prepare polycation electrolyte preparation liquid: be dissolved in by polycation electrolyte in water, regulate pH to be 2 ~ 9, stir, then carry out ultrasonic deaeration, obtain the polycation electrolyte preparation liquid that mass fraction is 0.5% ~ 5%;

Three, prepare polyanion electrolyte preparation liquid: be dissolved in by polyanion electrolyte in water, regulate pH to be 2 ~ 9, stir, then carry out ultrasonic deaeration, obtain the polyanion electrolyte preparation liquid that mass fraction is 0.5% ~ 5%;

Four, polyelectrolyte preparation liquid is flooded: 1., be impregnated in polycation electrolyte preparation liquid by electronegative for surface wood materials, dipping 5min ~ 60min, then washing is carried out and drying, obtain wood materials A, again wood materials A is impregnated in polyanion electrolyte preparation liquid, dipping 5min ~ 60min, then carries out washing and drying; 2. be 1., with step 41 cycle period, step 4 1. circulate carry out 1 cycle ~ 20 cycles, namely obtain surface and form the wood materials of polyelectrolyte multilayer film;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying;

Five, electronegative inorganic nano-particle preparation liquid is prepared: under ultrasonic and stirring condition, inorganic nano-particle is dispersed in water, and working concentration is the HCl of 0.1mol/L and concentration is that the NaOH solution of 0.1mol/L regulates pH to be greater than isoelectric point to make inorganic nano-particle electronegative, obtain the electronegative inorganic nano-particle preparation liquid that mass fraction is 1% ~ 5%;

Six, alternating impregnating polyelectrolyte preparation liquid and inorganic nano-particle preparation liquid: the wood materials that the surface of 1., by step 4 preparing forms polyelectrolyte multilayer film is impregnated in polycation electrolyte preparation liquid, dipping 5min ~ 60min, then washing is carried out and drying, obtain wood materials B, then wood materials B is impregnated in electronegative inorganic nano-particle preparation liquid, dipping 5min ~ 60min, then carries out washing and drying; 2. be 1., with step 61 cycle period, step 6 1. circulate carry out 1 cycle ~ 20 cycles, namely obtain surface and form the wood materials of polyelectrolyte/inorganic nano-particle multilayer film;

Described drying is bake drying or N at temperature is 60 DEG C ~ 105 DEG C ₂pneumatic conveying drying.

7. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 6, is characterized in that the wood materials described in step one is timber, bamboo wood, rattan material or wood-fibred.

8. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 6, is characterized in that the polycation electrolyte described in step 2 is polyallylamine hydrochloride, polyacrylamide or PDDA.

9. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 6, is characterized in that the polyanion electrolyte described in step 3 is kayexalate, polyacrylic acid, polymethylacrylic acid or polyvinyl.

10. the method for wooden material surface layer assembly polyelectrolyte/inorganic nano-particle multilayer film according to claim 6, is characterized in that the inorganic nano-particle described in step 5 is nano-TiO ₂, nano-ZnO, nanometer Al ₂o ₃, Nano-meter SiO_2 ₂, nanometer WO ₃, nano SnO ₂, nanometer MnO ₂, nano Ce O ₂, nanometer Fe ₃o ₄, nanometer Fe ₂o ₃, nanometer Y ₂o ₃, nanometer La ₂o ₃, nano SiC or nano Si ₃n ₄.