阅读说明：本技术 一种具有光催化功能的混凝土硅烷浸渍乳液及其制备方法 (Concrete silane impregnation emulsion with photocatalysis function and preparation method thereof ) 是由 高育欣 杨文� 闫松龄 毕耀 刘明 康升荣 于 2019-11-21 设计创作，主要内容包括：本发明公开了一种具有光催化功能的混凝土硅烷浸渍乳液,包括如下质量百分比的组分：硅烷单体25～50％、光催化剂0.3～3％、去离子水45～73.7％、乳化剂A 1～3％、乳化剂B 1～3％。所述硅烷单体为辛基三乙氧基硅烷、异辛基三乙氧基、异丁基三乙氧基硅烷、丙基三乙氧基硅烷和十二烷基三乙氧基硅烷其中的一种。所述乳化剂A为HLB值大于8的非离子表面活性剂；乳化剂B为HLB值不超过6的非离子表面活性剂。光催化剂为球状颗粒的锐钛型TiO<Sub>2</Sub>。将具有光催化功能的混凝土硅烷浸渍乳液涂覆在混凝土表面,得到具有光催化功能的混凝土。硅烷浸渍乳液对混凝土表面处理,提高了混凝土耐久性和光催化处理污染物的性能,光催化剂的有效利用率高,避免了光催化剂的浪费。(The invention discloses a concrete silane impregnating emulsion with a photocatalytic function, which comprises the following components in percentage by mass: 25-50% of silane monomer, 0.3-3% of photocatalyst, 45-73.7% of deionized water, 1-3% of emulsifier A and 1-3% of emulsifier B. The silane monomer is one of octyl triethoxysilane, isooctyl triethoxysilane, isobutyl triethoxysilane, propyl triethoxysilane and dodecyl triethoxysilane. The emulsifier A is a nonionic surfactant with HLB value more than 8; the emulsifier B is a nonionic surfactant with HLB value not more than 6. Anatase type TiO with spherical photocatalyst 2 . And coating the concrete silane dipping emulsion with the photocatalytic function on the surface of the concrete to obtain the concrete with the photocatalytic function. The silane dipping emulsion is used for treating the surface of concrete, so that the durability of the concrete and the performance of treating pollutants by photocatalysis are improved, and the photocatalysis is realizedThe effective utilization rate of the photocatalyst is high, and the waste of the photocatalyst is avoided.)

1. The concrete silane impregnating emulsion with the photocatalytic function is characterized by comprising the following components in percentage by mass: 25-50% of silane monomer, 0.3-3% of photocatalyst, 45-73.7% of deionized water, 1-3% of emulsifier A and 1-3% of emulsifier B; the emulsifier A is a nonionic surfactant with HLB value more than 8; the emulsifier B is a nonionic surfactant with HLB value not more than 6.

2. The concrete silane impregnation emulsion having photocatalytic function as claimed in claim 1, wherein the silane monomer has a structural formula of: R-Si (OCH)₂CH₃)₃Wherein R is an alkyl group having 1 to 12 carbon atoms.

3. The concrete silane impregnation emulsion having photocatalytic function as claimed in claim 2, wherein said silane monomer is one of octyl triethoxysilane, isooctyl triethoxysilane, isobutyl triethoxysilane, propyl triethoxysilane and dodecyl triethoxysilane.

4. The concrete silane-impregnated emulsion having photocatalytic function according to claim 1, wherein the photocatalyst is anatase TiO in spherical particles₂The particle size is 5-10 nm.

5. The concrete silane impregnation emulsion having photocatalytic function of claim 4, wherein the photocatalytic concentration in the emulsion is 0.5 to 3 g/L.

6. The concrete silane impregnation emulsion with photocatalytic function according to claim 1, wherein the emulsifier a is Span80 or japanese shin KF 6011; the emulsifier B is one of fatty alcohol polyoxyethylene ether Briji 35, peregal PPG20 and Japanese belief KF 6017.

7. A method for preparing concrete silane impregnating emulsion with photocatalytic function according to any one of claims 1-6, characterized by the following steps:

s1: mixing a photocatalyst with deionized water, performing ultrasonic dispersion for 10-20 min at room temperature to obtain a blue-light-emitting dispersion, adding an emulsifier A into the dispersion, and stirring and emulsifying to obtain a first solution;

s2: adding the emulsifier B into a silane monomer, and stirring and emulsifying to obtain a second solution;

s3: and (3) dropwise adding the second solution into the first solution at a constant speed under the conditions that the stirring speed is controlled to be 500-800 rpm and the heating temperature is 25-40 ℃, and after dropwise adding is finished, controlling the stirring speed to be 1500-3000 rpm and reacting for 0.5-1 h to obtain the silane dipping emulsion with the photocatalytic function.

8. A concrete having a photocatalytic function, which is obtained by applying the silane-impregnated concrete emulsion having a photocatalytic function according to any one of claims 1 to 6 to the surface of a concrete.

Technical Field

The invention relates to the technical field of concrete admixtures, in particular to a concrete silane impregnating emulsion with a photocatalyst function and a preparation method thereof.

Background

The maintenance costs of concrete works are due in large part to insufficient durability, which is closely related to the attack of harmful ions after water absorption due to various factors. Silane is a penetrating impregnant with excellent performance, has a small molecular structure, and the capillary wall of deep penetration concrete reacts with hydrated cement to form a polysilane network structure, so that the microstructure on the surface of the concrete has long-term hydrophobicity, the breathing function is kept, the invasion of water and harmful ions is reduced, and the durability of the concrete is improved. The silane can form protection without influencing the apparent effect of concrete, so that the silane has incomparable performance with other protective materials. The pure silane has stronger volatility and greatly increases the cost during construction. The silane dipping emulsion is prepared into W/O, O/W or double emulsion by using an emulsification process, and the silane dipping emulsion contains a certain amount of water for a crosslinking reaction, so that a large amount of silane active components can be prevented from volatilization loss even when the silane dipping emulsion is used on the surface of dry concrete.

Nano TiO 2₂As a semiconductor type photocatalytic material, the photocatalyst has a good application prospect in the aspect of treating environmental pollutants. The patent of application No. 201010584022.9 discloses a preparation method of a photocatalytic cement-based material, which comprises the steps of mixing nano titanium dioxide and fly ash to obtain the mixture of the fly ash-loaded nano titanium dioxide and cement, and effectively degrading more than 80% of substances such as nitrogen oxides, benzene, toluene and the like. Patent application No. CN106946312A discloses a method for degrading a drinking water disinfection by-product trichloroacetamide by utilizing a photocatalytic cement-based material, wherein 100% of trichloroacetamide can be removed. Both utilize photocatalysisCatalytic properties of the agent. However, these methods of internally doping the photocatalyst are to mix the photocatalyst with the cement-based material, so that a large portion of the photocatalyst cannot play a photocatalytic role in the cement-based material, and only a small amount of the photocatalyst on the surface of the cement-based material can contact light to play the photocatalytic role, which not only has a poor photocatalytic effect, but also causes a large amount of catalyst to be wasted.

Disclosure of Invention

The invention aims to solve the problems of low effective utilization rate of a photocatalyst of the existing photocatalytic cement-based material obtained by doping the photocatalyst into the cement-based material and great waste of the photocatalyst, and provides a concrete silane impregnation emulsion with a photocatalyst function, which is obtained by adding the photocatalyst into the concrete silane impregnation emulsion and is used for treating the surface of concrete so as to improve the durability of the concrete and the performance of photocatalytic treatment on pollutants.

The invention also aims to provide a preparation method of the concrete silane impregnation emulsion with the photocatalytic function.

The concrete silane impregnating emulsion with the photocatalyst function provided by the invention comprises the following components in percentage by mass: 25-50% of silane monomer, 0.3-3% of photocatalyst, 45-73.7% of deionized water, 1-3% of emulsifier A and 1-3% of emulsifier B; the emulsifier A is a nonionic surfactant with HLB value more than 8; the emulsifier B is a nonionic surfactant with HLB value not more than 6.

The structural formula of the silane monomer is as follows: R-Si (OCH)₂CH₃)₃Wherein R is an alkyl group having 1 to 12 carbon atoms. Preferably, the silane monomer is one of octyl triethoxysilane, isooctyl triethoxysilane, isobutyl triethoxysilane, propyl triethoxysilane, and dodecyl triethoxysilane.

Preferably, the photocatalyst is anatase TiO of spherical particles₂The particle size is 5-10 nm. The photocatalysis concentration of the emulsion is 0.5-3 g/L. The preferred concentration is a photocatalyst concentration of 0.3g/L, 1g/L, 2g/L or 3g/L in the emulsion system, with the most preferred concentration beingThe concentration of the photocatalyst is 2g/L, the protection effect is good, and the photocatalyst is not wasted.

Preferably, the emulsifier A is Span80 or Japanese belief KF 6017; the emulsifier B is fatty alcohol polyoxyethylene ether Briji 35 or peregal PPG 20.

A preparation method of the concrete silane impregnation emulsion with the photocatalytic function comprises the following steps:

s1: mixing a photocatalyst with deionized water, performing ultrasonic dispersion for 10-20 min at room temperature to obtain a blue-light-emitting dispersion, adding an emulsifier A into the dispersion, and stirring and emulsifying to obtain a first solution;

s2: adding the emulsifier B into a silane monomer, and stirring and emulsifying to obtain a second solution;

s3: and (3) dropwise adding the second solution into the first solution at a constant speed under the conditions that the stirring speed is controlled to be 500-800 rpm and the heating temperature is 25-40 ℃, and after dropwise adding is finished, controlling the stirring speed to be 1500-3000 rpm and reacting for 0.5-1 h to obtain the silane dipping emulsion with the photocatalytic function.

The invention also provides concrete with a photocatalytic function, namely the silane impregnation emulsion with the photocatalytic function is coated on the surface of the concrete to obtain the concrete with the photocatalytic function. The silane emulsion forms an ultrathin transparent silicone resin molecular layer on the surface of concrete, light cannot be shielded, the contact surface of a photocatalyst and light is facilitated, the effective utilization rate of the catalyst is high, and a silane network structure formed after silane hydrolysis can play a role in fixing photocatalyst particles; and the photocatalyst is positioned on the surface of the concrete, so that the titanium dioxide is ensured to be fully contacted with light, and the photocatalytic effect is exerted to the maximum extent. The problems of low effective utilization rate of the existing photocatalyst of the photocatalytic cement-based material obtained by doping the photocatalyst into the cement-based material and great waste of the photocatalyst are solved.

Compared with the prior art, the invention has the advantages that:

on the basis of the concrete silane dipping emulsion, nanometer titanium dioxide is introduced as an emulsion stabilizer and a photocatalyst. On one hand, the silane emulsion stabilizer is used as an emulsion stabilizer during silane emulsification, so that the stability and viscosity of silane emulsion can be improved, the sagging property of silane impregnation emulsion is reduced, and concrete is promoted to fully absorb silane active components, so that the durability of concrete is improved. On the other hand, when the concrete surface is treated, the photocatalyst is brought, the silane emulsion is endowed with a photocatalytic function, so that the concrete surface has the photocatalytic function, and pollutants can be treated by photocatalysis. After coating the concrete surface with the alkyl dipping emulsion, silane emulsion evaporates to a certain extent, the surface contact of silane molecule and concrete will appear gradually on the contact surface of emulsion drop and concrete surface, form ultra-thin transparent silicone resin molecular layer on the concrete surface, can not shielding light, be favorable to the contact surface of titanium dioxide and light, high-usage, and the silane network structure that forms after the silane hydrolyzes can play the fixed action to titanium dioxide, titanium dioxide is located the surface of concrete, the abundant contact of titanium dioxide with light has been guaranteed, the photocatalysis effect is given play to the utmost.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.