CN104775108B - Electroless plating of flexible oxide films - Google Patents

Abstract

The invention discloses an electroless plating method for preparing a flexible oxide thin film. The method comprises the following steps: 1) pretreatment of the flexible base film: soaking the organic flexible film into a pure monomer solution of π-conjugated structure molecules; 2) Dissolve the metal hydroxide with aqueous hydrogen peroxide solution, then dilute with water, then add a catalyst or ultraviolet light for several minutes, and stir at room temperature to obtain an aqueous metal peroxide complex solution; 3) fix the π-conjugated compound obtained in step 1) The flexible substrate material with structural molecules is immersed in the solution prepared in step 2), to obtain a flexible functional membrane material. The method has low preparation cost and strong operability, can realize the preparation of crystal oxide films on large-area flexible substrates, is suitable for batch preparation, has the possibility of industrial production, and has broad application prospects.

Description

Electroless Plating of Flexible Oxide Thin Films

technical field

The invention relates to the field of low-temperature preparation of metal oxides by a peroxidation system, in particular to an electroless coating method for preparing an oxide functional thin film on a flexible substrate at a low temperature.

Background technique

Flexible functional film materials can be generalized as functional materials formed by fabricating organic/inorganic functional materials on flexible/ductile plastic or thin metal substrates. This type of material has the advantages of high carrier separation efficiency, fast charge mobility, and low cost, and is widely used in flat panel display, thin film solar energy, optical storage, touch panel, electromagnetic shielding and other products. Titanium dioxide (TiO ₂ ), molybdenum trioxide (MoO ₃ ), vanadium pentoxide (V ₂ O ₅ ) and other metal oxides are stable photoelectric functional materials with low production cost, no secondary pollution, stable performance, etc. It can be widely used in the development of photoelectric conversion solar cells, photocatalytic degradation of sewage and waste gas, and photocatalytic sterilization. However, due to defects such as easy agglomeration of oxide powders during direct use, low functional efficiency, and difficulty in recycling powder materials, the use of oxides is greatly limited. In order to improve the use efficiency and application range of oxides, the preparation of oxide film materials is considered to be an efficient use method and has become a research hotspot.

According to the current problems in the preparation of oxide film materials, especially flexible film materials, the experimental group has proposed to prepare _TiO2 functional films on the surface of PET substrates by pulling film formation at room temperature. The obtained film materials With good photocatalytic, hydrophilic, antibacterial and other properties, the method is simple and convenient, has strong practicability, and has broad application prospects. However, since the TiO ₂ functional particles on the surface of the film are physically bonded to the PET film through the polymer emulsion, there is no direct chemical bond connection between the TiO ₂ particles and the PET film, which makes the TiO ₂ particles in the actual application process It will fall off from the surface of the PET film and cause the flexible film to lose its function. In order to enhance the connection between functional particles and substrate materials, researchers have conducted a lot of research. Zhang et al[1] used titanium sulfate and urea as raw materials to deposit a layer of pure anatase _{TiO 2} coating on the surface of PET fibers through hydrothermal reaction. on the surface of PET fibers. The method is simple and convenient, and can effectively realize the film formation of _TiO2 on the surface of flexible organic substrates. However, since the obtained _TiO2 film is prepared by hydrothermal reaction, the small volume of the hydrothermal reaction kettle determines the size of the prepared _TiO2 film to be small. Not only that, but the high temperature and high pressure energy consumption of the hydrothermal reaction is large, which is not conducive to expanding production . Therefore, the flexible _TiO2 thin films prepared by hydrothermal method still have a large distance from practical application. Kwon et al[2] prepared an amorphous TiO ₂ thin film layer on the surface of PET by using two cathodes (DC, radio frequency) magnetron co-sputtering at room temperature. The TiO ₂ film prepared by this method has a relatively High mechanical properties and optical properties have great application value, but the magnetron sputtering equipment for preparing the film is expensive and the preparation conditions are relatively harsh, which leads to high cost of film materials and cannot be widely used, which restricts TiO ₂ development of membrane materials.

Therefore, it is our current research direction to propose a low-energy, convenient and simple solution to the film-forming method of inorganic functional particles on the surface of the substrate material.

Contents of the invention

The technical problem solved by the present invention is to provide a chemical coating method for preparing flexible crystal oxide functional films. As a reducing agent, through the reduction of peroxide by π-conjugated molecules, oxide crystal functional films can be deposited on the surface of flexible substrates at room temperature; It has good photocatalytic performance and hydrophilicity.

The technical solution adopted by the present invention is to provide a chemical coating method for preparing a flexible crystal oxide functional film, the method comprising the following steps: the following steps:

1) Flexible basement membrane pretreatment: soaking the organic flexible membrane into a pure monomer solution of π-conjugated molecules to obtain a flexible basement membrane fixed with π-conjugated molecules;

2) dissolving the metal oxide with an aqueous hydrogen peroxide solution, then diluting with water, then adding a catalyst, and stirring at room temperature to obtain an aqueous solution of a metal peroxide complex;

3) immersing the flexible base film obtained in step 1) and immobilized with molecules of the π-conjugated structure into the aqueous metal peroxide complex solution prepared in step 2) to obtain a flexible functional film.

Preferably, the π-conjugated molecules described in step 1) are selected from aniline, pyrrole or thiophene and the like.

Preferably, the organic flexible film in step 1) is a common polymer film, and the organic flexible film is selected from polyethylene terephthalate film (PET), polystyrene (PS), and polypropylene (PP).

Preferably, the soaking time in step 1) is at least 10 hours.

Preferably, the mass percent concentration of the hydrogen peroxide solution in step 2) is 30%.

Preferably, the metal oxide in step 2) is selected from metal oxides having a d ⁰ structure; preferably, the metal oxide is selected from Ti(OH) ₄ , V ₂ O ₅ or MoO ₃ .

Preferably, the catalyst in step 2) is platinum, ferric oxide or transition metal oxide.

Preferably, in step 2), the molar ratio of hydrogen peroxide to metal ions in the aqueous metal peroxide complex solution is 1:1 to 50, and the concentration of metal ions in the aqueous metal peroxide solution is 0.001 to 0.125 mol /L.

Preferably, the soaking temperature in step 3) is 60-80°C, and the soaking time is longer than 0.5h.

The beneficial effect of the invention is that the method has the characteristics of simple and convenient operation and low energy consumption. The method is based on peroxidation technology, using π-conjugated molecules as reducing agents, through the reduction of peroxide metal compounds by π-conjugated molecules, and depositing oxide functional films on the surface of flexible substrates at room temperature; the generated oxides The oxide particles evenly cover the surface of the substrate and are firmly combined with the substrate, and the obtained oxide flexible film has better photocatalytic performance. Through this process, the preparation of crystalline oxide thin films on large-area flexible substrates can be realized. At the same time, the method has low preparation cost and strong operability, is suitable for batch preparation, has the possibility of industrial production, and has broad application prospects.

Description of drawings

Figure 1a is a SEM characterization diagram of a PET film;

Figure 1b is the SEM characterization image of TiO ₂ -PET film

Figure 1c is the SEM characterization image of V ₂ O ₅ -PET film

Figure 1d is the SEM characterization diagram of MoO ₃ -PET film;

Figure 1e is the XRD characterization diagram of TiO ₂ -PET film;

Figure 1f is the XRD characterization diagram of V ₂ O ₅ -PET film;

Figure 1g is the XRD characterization diagram of MoO ₃ -PET film;

Figure 2 is the photocatalytic effect diagram of the prepared three kinds of flexible films.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

1) Soak (40cmx300cm) PET in pure aniline solution at room temperature for 10 hours, the characterization results of pure PET film are shown in Figure 1a;

2) Take 25mL of TiCl ₄ and slowly drop it into 1000mL of ice water under vigorous stirring to obtain a colorless and transparent solution of Ti ⁴⁺ . Then, 5% ammonia water was added dropwise to the solution to obtain a white precipitate, which was washed several times until chloride ions could not be detected. Then a certain amount of H ₂ O ₂ was added to dissolve the obtained precipitate to obtain a transparent orange solution, and then water was added until the concentration of Ti ⁴⁺ particles was 0.12 mol/L. Then, using metal platinum (Pt) as a catalyst, the resulting solution was stirred at room temperature for 24 hours, so that excess hydrogen peroxide was completely decomposed;

3) The PET film adsorbed with aniline monomer was added to the titanium peroxide solution prepared above, and soaked at a constant temperature of 80°C for 30 minutes to obtain a TiO ₂ -PET flexible functional film. The characterization results are shown in Figure 1b, e.

Example 2

1) Soak (40cmx300cm) PET film in pure pyrrole solution at room temperature for 12 hours;

2) Dissolve V ₂ O ₅ with a certain amount of 30% H ₂ O ₂ to obtain a clear brown aqueous solution, then replenish water until the concentration of V ⁵⁺ particles is 0.10mol/L, and then use metal platinum (Pt) as a catalyst to convert the obtained The solution was stirred at room temperature for 24 hours to completely decompose excess hydrogen peroxide;

3) The PET film adsorbed with pyrrole monomer was added to the titanium peroxide solution prepared above, soaked at a constant temperature of 70°C for 12 hours to obtain a V ₂ O ₅ -PET flexible functional film, and the characterization results are shown in Fig. 1c, f.

Example 3

1) Soak (40cmx300cm) PET film in thiophene solution at room temperature for 15 hours;

2) Take a certain amount of metal molybdenum powder (Mo) and add it to the H ₂ O ₂ solution to obtain a light yellow transparent solution, then replenish water until the concentration of Mo ^{6 +} particles is 0.05mol/L, and then use metal platinum (Pt) as a catalyst, The resulting solution was stirred at room temperature for 24 hours to completely decompose excess hydrogen peroxide;

3) The PET film adsorbed with 3,4-ethylenedioxythiophene was added to the molybdenum peroxide solution prepared above, soaked at 60°C for 20 hours to obtain MoO ₃ -PET flexible functional film, and the characterization results are shown in Figure 1d,g.

Example 4

Cut the TiO ₂ -PET film into 25mm*40mm samples, soak it in 0.02mM methylene blue solution for 24h, after saturated adsorption, put it into 0.01mM methylene blue solution, soak until the adsorption equilibrium. Under the irradiation of 254nm ultraviolet light, the degradation degree of methylene blue was tested by detecting the absorption peak of methylene blue at 665nm, and then the photocatalytic function of the functional substances on the coating surface was characterized. As shown in Figure 2, it can be seen that the degradation rate of the flexible film to methylene blue reached 8% within 160 minutes, indicating that the obtained flexible film has a good photocatalytic degradation ability.

Claims (7)

1. a kind of electroless plating method for preparing flexible sull, it is characterised in that comprise the following steps：

1) flexible substrates film pretreatment:The infiltration of organic flexible film is pure to the monomer of pi-conjugated structural molecule

In solution, the flexible substrates film of pi-conjugated structural molecule is fixed；

2) hydrogen peroxide aqueous dissolution metal oxide is used, is then diluted with water, be subsequently added into catalyst, stirred at normal temperatures Obtain the metal peroxy complex aqueous solution；

3) by step 1) obtain be fixed with pi-conjugated structural molecule flexible substrates film immersion step 2）Prepared metal peroxy Change in the complex aqueous solution, obtain flexibility function film；

Step 1) described in pi-conjugated structural molecule be selected from aniline, pyrroles or thiophene；

Step 1) the organic flexible film be selected from polyethylene terephthalate film, polystyrene or polypropylene；

Step 2) metal oxide be selected from have d⁰The metal oxide of structure；The metal oxide is selected from Ti (OH)₄、 V₂O₅Or MoO₃。

2. electroless plating method according to claim 1, it is characterised in that：Step 1) time of the infiltration is at least 10h.

3. electroless plating method according to claim 1, it is characterised in that：Step 2) hydrogenperoxide steam generator quality percentage Specific concentration is 30%.

4. electroless plating method according to claim 1, it is characterised in that：Step 2) catalyst be platinum or oxo transition metal Compound.

5. electroless plating method according to claim 4, it is characterised in that the transition metal oxide is ferroso-ferric oxide.

6. electroless plating method according to claim 1, it is characterised in that：Step 2) the metal peroxy complex aqueous solution In the molecule molal quantity ratio of hydrogen peroxide and metal ion be 1：1-50, metal ion in the peroxidating aqueous metal solution Concentration be 0.001-0.125mol/L.

7. electroless plating method according to claim 1, it is characterised in that：Step 3) in soaking temperature be 60-80 DEG C, immersion Time is more than 0.5h.