CN110170284A - A kind of super-hydrophobic TiO of response type2Microballoon and the preparation method and application thereof - Google Patents

Abstract

The present invention discloses a kind of super-hydrophobic TiO of response type₂Microballoon and the preparation method and application thereof belongs to nano-macromolecule material field.It is to synthesize TiO by sol-gel method first₂Colloidal sol hydrolyzes tetra-n-butyl titanate to prepare titanium colloidal sol using salt acid for adjusting pH value.The silane coupling agent with epoxy group is reused to TiO₂It is modified, is assigning TiO₂It while super-hydrophobic effect, can also preferably be combined with fabric, there is excellent durability.The TiO with super-hydrophobicity₂The preparation method simple process of microballoon has potential using value preparing hydrophobic fabric, leading sweat and the fields such as perspire.

Description

A kind of reactive superhydrophobic TiO2 microsphere and its preparation method and application

technical field

The invention belongs to the field of nano-polymer materials, and in particular relates to a reactive super-hydrophobic TiO ₂ microsphere and a preparation method and application thereof.

Background technique

Nowadays, metal oxides are more and more widely used in daily life, especially in the field of catalysis. Metal oxides are a very important class of catalysts. Now the research on metal oxides has been widely carried out, developed and applied to all walks of life. After nano-sized metal oxides, more excellent catalytic performance has been obtained. It is foreseeable that, An important development direction of catalysts will be the study of metal oxides.

Among various metal oxides, nano- _TiO2 has excellent performance and is an important material that can be widely used in daily life. The outstanding advantages of nano-TiO ₂ are: low cost, high efficiency, energy saving, clean and non-toxic, thorough degradation of organic matter, good stability and unique photophysical and photochemical properties, etc. These characteristics make TiO ₂ an important research object. received extensive attention.

However, titanium dioxide itself is hydrophilic, and when it finishes the fabric, it simply attaches to the surface of the fabric, so its friction resistance and durability are poor. When subjected to strong friction, the nanoparticles are easy to fall off, resulting in performance degradation. . Therefore, when using the sol-gel method to prepare titanium dioxide, the titanium dioxide sol is modified with a silane coupling agent that has a hydrophobic effect and can react with the fabric to make it super-hydrophobic and can be combined with the fabric. durable friction effect.

SUMMARY OF THE INVENTION

Purpose of the invention: The technical problem to be solved by the present invention is to provide a super-hydrophobic nano-titania microsphere with good durability and friction resistance.

The technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned super-hydrophobic nano-titania microspheres.

The final technical problem to be solved by the present invention is to provide the application of the above-mentioned superhydrophobic nano-titania microspheres in fabrics.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

A preparation method of reactive superhydrophobic TiO ₂ microspheres, comprising the following steps:

(1) adding tetra-n-butyl titanate to dehydrated alcohol, and mixing uniformly;

(2) under stirring conditions, the tetra-n-butyl titanate mixture obtained in the step (1) and the hydrochloric acid solution are added dropwise to the ethanol aqueous solution simultaneously, and the pH is adjusted to 2～4 with ammonia water to obtain a titanium dioxide sol;

(3) adding a hydrophobic silane coupling agent to the titania sol under stirring conditions, and then adding an oxygen-containing silane coupling agent to obtain a modified titania sol,

The hydrophobic silane coupling agent is methyltriethoxysilane (MTES), γ-chloropropyltriethoxysilane (CPTS), octyltriethoxysilane (OTES), dodecyl One or more mixtures of triethoxysilane (DTEOS), preferably one or two of methyltriethoxysilane (MTES) and dodecyltriethoxysilane (DTEOS) mixture;

The epoxy-containing silane coupling agent is γ-glycidyl ether oxypropyltrimethoxysilane (KH560);

(4) Centrifuging the modified titanium dioxide sol, washing and drying to obtain a bulk solid of modified titanium dioxide, and grinding to obtain reactive superhydrophobic TiO ₂ microspheres.

When preparing the titanium dioxide sol, the present invention controls the production rate and particle size of titanium dioxide by controlling the hydrolysis rate of tetra-n-butyl titanate, ensures the temperature of the hydrolysis rate, and controls the uniform particle size distribution of synthetic titanium dioxide. The titanium dioxide sol is modified by the silane coupling agent that reacts with the fabric, and the long carbon chains and epoxy groups are grafted on the titanium dioxide, so that the titanium dioxide has hydrophobicity and reactivity, and can greatly improve the microstructure of the titanium dioxide. Durable friction resistance of the ball.

In step (1), the mass ratio of the tetra-n-butyl titanate to absolute ethanol is 4 to 5:1, preferably 4:1.

In step (2), the concentration of hydrochloric acid in the hydrochloric acid solution is 1-2 mol/L, preferably 1 mol/L; the concentration of ammonia water is 1-2 mol/L, preferably 1 mol/L.

In step (2), the mass ratio of the added hydrochloric acid and tetra-n-butyl titanate is 3.5～4:1, preferably 4:1; the concentration of ethanol in the aqueous ethanol solution is 50%, and the tetra-n-butyl titanate mixture: hydrochloric acid The volume ratio of the solution is 1:10-12, preferably 1:10; the volume ratio of the tetra-n-butyl titanate mixture:ethanol solution is 2.5-3.5:1, preferably 3:1.

In step (2), the dropping rate of the tetra-n-butyl titanate mixture is 1-3 drops/s, the stirring speed is 350-450 r/min, and the reaction time is 2-4 h.

In step (3), the mass ratio of the hydrophobic silane coupling agent to the titanium dioxide sol is 10-12:1, preferably 10:1; the mass ratio of the oxygen-containing silane coupling agent to the titanium dioxide sol is 10 -12:1, preferably 10:1.

In step (3), the reaction time of the hydrophobic silane coupling agent, the epoxy group-containing silane coupling agent and the titanium dioxide sol is all 3-6 h.

In step (3), the reaction temperature of the hydrophobic silane coupling agent, the epoxy group-containing silane coupling agent and the titanium dioxide sol is all 10-40°C.

In step (4), the particle size of the reactive super-hydrophobic TiO ₂ microspheres is 200-300 nm.

In step (4), the rotating speed of the centrifuge is 6000-7000 r/min, and the centrifugation time is 10-25 min.

In step (4), the drying temperature of the titanium dioxide is 60-80° C., and the drying time is 40-60 min.

In the present invention, the hydrolysis reaction of tetra-n-butyl titanate is used to prepare modified titanium dioxide gel, the formation rate and particle size of titanium dioxide are controlled by controlling the dropping rate and content, and a silane coupling agent with a long carbon chain is used to treat the titanium dioxide sol For modification, in the presence of water, the methoxy group in the silane coupling agent can interact with water molecules and hydrolyze to form silanol groups, which can undergo shrinkage reaction with the hydroxyl groups contained on the surface of titanium dioxide, thereby coupling the silane coupling agent. The linker is grafted onto TiO2, giving it an excellent hydrophobic effect. And the epoxy group-containing silane coupling agent such as KH560, the epoxy group contained in it can open the ring and react with the group on the surface of the cotton fabric, so as to combine with the cotton fabric more firmly, making it have Good durability and friction resistance.

The reaction mechanism of silane coupling agent and titanium dioxide is as follows:

The reaction mechanism of silane coupling agent with epoxy group and fabric is as follows:

When the silane coupling agent is added to the titanium dioxide, it reacts with TiO ₂ -OH on the surface of the titanium dioxide to achieve graft modification on the titanium dioxide, thereby obtaining super-hydrophobic nano titanium dioxide particles. At the same time, the epoxy group introduced by the silane coupling agent undergoes a ring-opening reaction with the groups on the surface of the fabric when it is finished on the fabric, so as to be better combined with the fabric and has excellent friction resistance and durability.

Beneficial effects:

The invention discloses a preparation method of reactive TiO2 hydrophobic microspheres. Titanium dioxide sol is prepared by a sol-gel method, and the hydrolysis speed is controlled by controlling the dripping speed and the dripping amount in the reaction process, so as to prepare uniform particle size distribution. Titanium dioxide sol. Then the silane coupling agent is used to graft and modify the titanium dioxide, and the long carbon chain and epoxy group contained in the silane coupling agent are used to endow the titanium dioxide with excellent superhydrophobicity and the ability to react and combine with cotton fabrics.

The preparation process of the invention is simple, the cost of using reagents is low, and it is suitable for most processes. After finishing, the fabric can be endowed with super-hydrophobic properties, and it also has excellent abrasion resistance and durability. Even if the titanium dioxide particles are subjected to large friction, they will not fall off and other damage, which prolongs the service life of the product.

Description of drawings

Fig. 1 Example 1 particle size of titanium dioxide microsphere emulsion.

Fig. 2 Contact angle of titanium dioxide microspheres in Example 1.

Fig. 3 Example 2 particle size of titanium dioxide microsphere emulsion.

Fig. 4 Contact angle of titanium dioxide microspheres in Example 2.

Fig. 5 Example 3 particle size of titanium dioxide microsphere emulsion.

Fig. 6 Contact angle of titanium dioxide microspheres in Example 3.

Detailed ways

The present invention is further described below in conjunction with specific mode:

Example 1:

(1) Preparation of hybrid titanium sol: Weigh 150.0g hydrochloric acid (1mol/L) and 55.0g deionized water, and mix to prepare component A; Weigh 80.0g tetra-n-butyl titanate and 20.0g absolute ethanol, 150r/min mechanical stirring for 3min uniformly prepare component B;

(2) Component B and component A were added dropwise to the ethanol solution at the same time at room temperature of 25°C, and the dropping rate was 2 drops/second to prepare titanium sol, until components A and B were completely added to 100.0 g of ethanol aqueous solution ;

(3) drip ammonia water (1mol/L) to adjust the pH of the system to 4;

(4) Measure 100 mL of titanium dioxide sol at 25°C, add 4 mL of octyltriethoxysilane (OTES), and react for 4 h; then add 4 mL of γ-glycidyl ether oxypropyltrimethoxysilane (KH560), and react for 4 h, The modification of titanium dioxide is completed by mechanical stirring at a speed of 500r/min;

(5) Centrifuge the titanium sol for 10 min under the action of 1000 r/min using a centrifuge; separate the solid and liquid phases, and place the obtained colloid in an oven at 70° C. to dry for 3 hours; use a bowl to grind it into fine powder .

Example 2:

(1) Preparation of hybrid titanium sol: Weigh 150.0g hydrochloric acid (1mol/L) and 55.0g deionized water, and mix to prepare component A; Weigh 80.0g tetra-n-butyl titanate and 20.0g absolute ethanol, 150r/min mechanical stirring for 3min uniformly prepare component B;

(2) Component B and component A were added dropwise to the ethanol solution at the same time at room temperature of 25°C, and the dropping rate was 2 drops/second to prepare titanium sol, until components A and B were completely added to 100.0 g of ethanol aqueous solution ;

(3) drip ammonia water (1mol/L) to adjust the pH of the system to 4;

(4) Measure 100 mL of titanium dioxide sol at 25°C, add a mixture of 2 mL of dodecyltriethoxysilane (DTEOS) and 2 mL of γ-chloropropyltriethoxysilane (CPTS), and react for 4 h; then add 4 mL of γ -Glycidyl ether oxypropyltrimethoxysilane (KH560), reacted for 4h, mechanically stirred at a rotating speed of 500r/min to complete the modification of titanium dioxide;

(5) Centrifuge the titanium sol for 10 min under the action of 1000 r/min using a centrifuge; separate the solid and liquid phases, and place the obtained colloid in an oven at 70° C. to dry for 3 hours; use a bowl to grind it into fine powder .

Example 3:

(1) Preparation of hybrid titanium sol: weigh 150.0g hydrochloric acid (1mol/L) and 55.0g deionized water, mix to form component A; weigh 80.0g tetra-n-butyl titanate and 20.0g absolute ethanol, 150r/min mechanical stirring for 3min uniformly prepare component B;

(2) Component B and component A were added dropwise to the ethanol solution at the same time at room temperature of 25°C, and the dropping rate was 2 drops/second to prepare titanium sol, until components A and B were completely added to 100.0 g of ethanol aqueous solution ;

(3) drip ammonia water (1mol/L) to adjust the pH of the system to 4;

(4) Measure 100 mL of titanium sol at 25°C, add 4 mL of methyltriethoxysilane (MTES), and react for 4 h; then add 4 mL of γ-glycidyl etheroxypropyltrimethoxysilane (KH560), and react for 4 h, The modification of titanium dioxide is completed by mechanical stirring at a speed of 500r/min;

(5) Centrifuge the titanium sol for 10 min under the action of 1000 r/min using a centrifuge; separate the solid and liquid phases, and place the obtained colloid in an oven at 70° C. to dry for 3 hours; use a bowl to grind it into fine powder .

The reactive superhydrophobic titania microsphere powders prepared under different hydrophobic silane coupling agents in the examples, among which the titania microspheres prepared in Case 1 have the best performance, their color is milky white, and the powder particle size distribution is uniform, which can be used in Small titania microspheres were observed under the electron microscope. The modified titanium dioxide microsphere powder was pressed on a glass slide, and the hydrophobic angle after pressing was tested under the DSA100 droplet analyzer, and the average hydrophobic angle could reach 150.81°. The reactive superhydrophobic titanium dioxide microsphere powder is dispersed in the reagent and reacts with the fabric. The epoxy group contained in the modified titanium dioxide microsphere undergoes a ring-opening reaction with -OH on the cotton fabric, and is combined with the fabric to make the The superhydrophobic titanium dioxide microspheres have excellent rubbing fastness. After testing, they still maintain their superhydrophobic properties after high-intensity rubbing.

Claims (10)

1. a kind of preparation method of reactive super-hydrophobic TiO ₂ microspheres, is characterized in that, comprises the following steps: (1) adding tetra-n-butyl titanate to dehydrated alcohol, and mixing uniformly; (2) under stirring conditions, the tetra-n-butyl titanate mixture obtained in the step (1) and the hydrochloric acid solution are added dropwise to the ethanol aqueous solution simultaneously, and the pH is adjusted to 2～4 with ammonia water to obtain a titanium dioxide sol; (3) adding a hydrophobic silane coupling agent to the titania sol under stirring conditions, and then adding an oxygen-containing silane coupling agent to obtain a modified titania sol, The hydrophobic silane coupling agent is one of methyltriethoxysilane, γ-chloropropyltriethoxysilane, octyltriethoxysilane and dodecyltriethoxysilane or a mixture of several, The epoxy-containing silane coupling agent is γ-glycidyl ether oxypropyltrimethoxysilane; (4) Centrifuging the modified titanium dioxide sol, washing and drying to obtain a bulk solid of modified titanium dioxide, and grinding to obtain reactive superhydrophobic TiO ₂ microspheres. 2. The preparation method of reactive super-hydrophobic TiO ₂ microspheres according to claim 1, characterized in that, in step (1), the mass ratio of the tetra-n-butyl titanate to absolute ethanol is 4～5 :1. 3. the preparation method of reaction type super-hydrophobic _TiO microspheres according to claim 1, is characterized in that, in step (2), the concentration of hydrochloric acid in the described hydrochloric acid solution is 1～2mol/L; The concentration of ammoniacal liquor is 1～2mol/L. 4. the preparation method of reactive super-hydrophobic TiO ₂ microspheres according to claim 1, is characterized in that, in step (2), the mass ratio of the hydrochloric acid added and tetra-n-butyl titanate is 3.5～4:1 , the volume fraction concentration of ethanol in the ethanol aqueous solution is 50%, the volume ratio of the tetra-n-butyl titanate mixture and the hydrochloric acid solution is 1:10-12, and the volume ratio of the tetra-n-butyl titanate mixture and the ethanol aqueous solution is 2.5 ~3.5:1. 5. The method for preparing reactive super-hydrophobic TiO ₂ microspheres according to claim 1, wherein in step (2), the dropping rate of the tetra-n-butyl titanate mixture is 1 to 3 drops/s , the stirring speed is 350～450r/min, and the reaction time is 2～4h. 6. the preparation method of reactive super-hydrophobic _TiO microspheres according to claim 1, is characterized in that, in step (3), the mass ratio of described hydrophobic silane coupling agent and titanium dioxide sol is 10～12: 1. The mass ratio of the oxygen-containing silane coupling agent to the titanium dioxide sol is 10-12:1. 7. The preparation method of reactive super-hydrophobic TiO ₂ microspheres according to claim 1, characterized in that, in step (3), a hydrophobic silane coupling agent, an epoxy-containing silane coupling agent and a titanium dioxide sol The reaction time is 3～6h; In step (3), the reaction temperature of the hydrophobic silane coupling agent, the epoxy-containing silane coupling agent and the titanium dioxide sol is all 10 to 40° C. 8 . The method for preparing reactive super-hydrophobic TiO ₂ microspheres according to claim 1 , wherein in step (4), the particle size of the reactive super-hydrophobic TiO ₂ microspheres is 200-300 nm. 9 . 9. Reactive superhydrophobic _TiO2 microspheres prepared by the method for preparing reactive superhydrophobic _TiO2 microspheres according to any one of claims 1 to 8. 10. The application of the reactive superhydrophobic TiO ₂ microspheres of claim 9 in fabric finishing.