CN113861737A

CN113861737A - Environment-friendly antibacterial finger painting pigment containing nano-silver modified silicon dioxide colored composite microspheres

Info

Publication number: CN113861737A
Application number: CN202111053010.8A
Authority: CN
Inventors: 王爱香; 马恩培; 徐斌
Original assignee: Zhejiang Tianhua Household Products Co ltd
Current assignee: Zhejiang Tianhua Household Products Co ltd
Priority date: 2021-09-08
Filing date: 2021-09-08
Publication date: 2021-12-31
Anticipated expiration: 2041-09-08
Also published as: CN113861737B

Abstract

The invention relates to the field of pigments, and discloses an environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres, which comprises the following components in part by weight: 3-7% of nano-silver modified colored silicon dioxide composite microspheres, 9-17% of modified starch, 7-14% of edible sodium chloride, 5-10% of edible glycerin and the balance of water. The invention adds nano-silver modified silicon dioxide colored composite microspheres in the finger painting pigment. According to the invention, the nano-silver modified silicon dioxide colored composite microspheres are added into the finger painting pigment instead of the traditional powder pigment or pigment, so that the finger painting pigment is not only environment-friendly and not decolored, but also has excellent antibacterial performance.

Description

Environment-friendly antibacterial finger painting pigment containing nano-silver modified silicon dioxide colored composite microspheres

Technical Field

The invention relates to the field of pigments, in particular to an environment-friendly antibacterial finger painting pigment containing nano-silver modified silicon dioxide colored composite microspheres.

Background

The children finger painting refers to an artistic form of painting creation by taking the hands of the children as painting brushes, dipping appropriate pigments on all parts of the hands, and painting and printing on paper and canvas. The activity can exercise the practical ability, the color perception ability and the drawing skill of the children. However, most of the traditional finger painting pigments are acrylic pigments, and are formed by mixing emulsion agents and toner, so that children have certain influence on health after eating the pigment by mistake.

The silica particles are a white inorganic material which is tasteless, nontoxic and pollution-free, have good biocompatibility, chemical stability, water solubility, dispersibility and easy modification, and have wide application in the field of pigments. If the white silica nano-particles are subjected to surface dyeing modification to prepare the colored silica to replace toner, and then the colored silica is added into the finger painting pigment, the brightness, the hue and the saturation of the finger painting pigment can be enhanced, and the viscosity, the anti-settling capacity and the stability of the pigment can be improved.

Recently, a method for preparing colored silica by physically adsorbing an organic dye has been receiving attention from many researchers. However, the color silica particles have weak color fixing ability, are easy to fall off and fade after long-term environmental corrosion, and have potential problems of environmental pollution, health influence and the like in practical application. If the surface thin layer coating is carried out on the color silicon dioxide prepared by physically adsorbing the organic dye, the dye can be effectively prevented from leaking, and the color fixing capability of the color silicon dioxide is improved.

It is known that nano silver has excellent antibacterial activity, but the nano silver has a large specific surface area and is easily agglomerated, so that the actual antibacterial activity of the nano silver is reduced. The silicon dioxide is an ideal carrier for loading the metal nano particles, and the nano silver is deposited on the surface of the silicon dioxide in situ, so that the dispersion of the nano silver can be effectively improved, the agglomeration is reduced, and the antibacterial activity of the nano silver is improved.

Disclosure of Invention

In order to solve the technical problems, the invention provides an environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres. The finger painting pigment contains the environment-friendly antibacterial nano-silver modified silica color composite microspheres. According to the invention, the organic reactive dye is physically adsorbed by the porous silica to form the colored silica, and then the colored silica is further coated on the surface of the thin-layer silica to prevent the dye from leaking and improve the color fixing capability. And then, mutually condensing hydroxyl generated by hydrolytic polycondensation of 3-mercaptopropyltriethoxysilane (MPTMS) and hydroxyl on the surface of the silica thin layer shell of the coated silica color microsphere, and chemically grafting sulfydryl on the surface of the silica thin layer shell of the coated silica color microsphere, wherein the sulfydryl is extremely easy to complex with metal cations. After the color silicon dioxide is modified by MPTMS, silver acetate is added into a reaction system to introduce silver ions, and the mercapto group and the silver ions are subjected to a complex reaction to obtain the color silicon dioxide with a large amount of silver ions on the surface. And finally, under the condition of keeping out of the sun, adding the colored silica with a large number of silver ions in the last step by using N, N-dimethylformamide as a reaction solvent and a reducing agent, heating and stirring for reaction, reducing the silver ions into nano silver, and depositing the reduced nano silver on the surface of the silica thin layer shell coated with the silica colored microspheres in situ, thereby preparing the nano silver modified colored silica composite microspheres.

The specific technical scheme of the invention is as follows: an environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres comprises the following raw materials in percentage by mass:

3 to 7 percent of nano-silver modified colored silicon dioxide composite microspheres,

9 to 17 percent of modified starch,

7 to 14 percent of edible sodium chloride,

5 to 10 percent of edible glycerin,

the balance of water.

The finger painting pigment contains the environment-friendly antibacterial nano-silver modified colored silica composite microspheres, the colored silica microspheres are obtained by adsorbing active dye by utilizing the characteristic of strong adsorbability of porous silica, the dyed porous surface is coated with a silica protective shell, and then the nano-silver modification is carried out on the silica surface. The novel colorful composite microspheres not only show better color performance, but also can effectively prevent organic reactive dye from being leaked to pollute the environment. More importantly, the deposition of nano-silver can be utilized to endow the finger painting pigment with good antibacterial performance, and the grade and the application range of the finger painting pigment are greatly expanded. The nano-silver modified silica color composite microspheres replace the traditional toner, not only endow the finger painting pigment with various color functions of no decolorization and environmental protection, but also have excellent antibacterial effect.

In addition, in the colored composite microspheres, active dye molecules are coated by a smooth silicon dioxide thin layer and nano silver grows in situ on the surface of the silicon dioxide, so that compared with the traditional mixing mode, the colored composite microspheres have the advantages of better dispersibility, higher binding fastness and brighter color.

As for other components in the environment-friendly antibacterial finger painting pigment, the effects are as follows: modified starch is one or a mixture of more than two of acetylated distarch phosphate, hydroxypropyl distarch phosphate and phosphorylated distarch phosphate, and has better adhesiveness, water retention property and transparency, so that the finger painting has the advantages of bright color, good stability and the like; secondly, the edible glycerin has the function of moisture retention on one hand, and enables the pigment to be more easily cleaned after being added, so that the pigment cannot be attached to a body or clothes; and thirdly, the edible sodium chloride has the function of prolonging the shelf life of the product.

The preparation method of the nano-silver modified colored silicon dioxide composite microspheres comprises the following steps:

(1) weighing sodium hydroxide and an emulsifier in a container, pouring an organic solvent and water, heating in a water bath and stirring to obtain a uniform dispersion emulsion.

(2) Adding an ethyl orthosilicate solution into the dispersion emulsion, stirring to react, centrifuging and washing, freeze-drying, and then calcining to obtain the porous silicon dioxide powder.

(3) And dispersing the porous silicon dioxide powder in active dye liquid containing active Cl atoms for adsorption, pouring out supernatant liquor after complete adsorption, and drying to obtain the colored silicon dioxide powder.

(4) Adding the colored silicon dioxide powder into a mixed solution of ammonia water and water, and stirring in a water bath to form an alkaline dispersion liquid; then adding the silane modified liquid containing 3-aminopropyltriethoxysilane and absolute ethyl alcohol into the alkaline dispersion liquid dropwiseReacting, and performing amination modification on the color silicon dioxide; then, dropwise adding the mixed solution of ethyl orthosilicate and formamide into the dispersion liquid for reaction, after the reaction is finished, washing with water and ethanol respectively, and drying to obtain thin-layer SiO₂Coated color composite microspheres.

(5) Forming a thin layer of SiO₂Dispersing the coated color composite microspheres in formamide solution, adding 3-mercaptopropyltriethoxysilane, heating, stirring for reaction, after the reaction is finished, respectively centrifugally washing with water and ethanol, and drying to obtain sulfhydrylated SiO₂The colorful composite microspheres.

(6) Preparing a mixed solution of an organic reducing solvent of dimethylformamide and ethanol, and uniformly stirring; then sulfhydrylation of SiO is carried out under the condition of keeping out of the light₂And adding the color composite microspheres and silver acetate into the mixed solution for reduction reaction, and after the reaction is finished, filtering, washing and drying to obtain the nano-silver modified silica color composite microspheres.

The preparation principle of the invention is as follows: and (2) self-assembling by taking an emulsifier as a template agent, tetraethoxysilane as a silicon source and sodium hydroxide as a catalyst under the induction of the template agent to prepare the porous silicon dioxide. The sodium hydroxide and the emulsifier are put into a container, the organic solvent and the water are poured into the container, and the mixture is heated and stirred in a water bath to obtain the uniformly dispersed emulsion. Adding a tetraethoxysilane solution into the dispersed emulsion, carrying out hydrolytic polycondensation reaction on the tetraethoxysilane under an alkaline condition to form a gel state of a large-scale space network structure, freezing the uniformly dispersed template agent, calcining the obtained material to remove the template agent, and thus obtaining the porous silicon dioxide. The porous silica has the excellent characteristics of large specific surface area, large pore volume, narrow and controllable pore size distribution, good adsorption performance, strong modification capability, cyclic utilization and the like, and is an ideal adsorption material. And adsorbing the organic dye in the pore channel by utilizing the porous silicon dioxide to obtain the colored silicon dioxide. Meanwhile, organic dye molecules adsorbed by the silicon dioxide pore channels contain a large amount of active Cl atoms, and the surface modification of the color silicon dioxide is carried out by skillfully utilizing the substitution reaction of the amino group of the triaminopropyltriethoxysilane (KH550) and the active Cl atoms of the color silicon dioxideChemically grafting KH550 on the surface of the colored silica, wherein the molecular chain end of the KH550 is provided with hydroxyl, thereby paving the next reaction. Tetraethoxysilane is used as a silicon source, a large amount of hydroxyl is generated by hydrolysis, and is further subjected to polycondensation with hydroxyl in a KH550 molecular band, so that a thin-layer silicon dioxide shell is finally prepared, and the thin-layer silicon dioxide shell coats the color silicon dioxide to prevent organic dye from leaking. 3-mercaptopropyltriethoxysilane (MPTMS) is organosilane containing sulfydryl, hydroxyl generated by hydrolysis and polycondensation of MPTMS and hydroxyl on the surface of color silica coated by silica shell are mutually condensed to sulfhydrylate SiO₂The mercapto group is easy to complex with metal cation on the surface of the silica shell of the color microsphere composite material. After the color silicon dioxide is modified by MPTMS, silver acetate is added into a reaction system to introduce silver ions, and the mercapto group and the silver ions are subjected to a complex reaction, so that the color silicon dioxide with a large amount of silver ions on the surface is prepared. And finally, under the condition of keeping out of the sun, adding the colored silicon dioxide with a large number of silver ions in the last step by taking N, N-dimethylformamide as a reaction solvent and a reducing agent, heating, stirring and reacting, reducing the silver ions into nano silver, and depositing the reduced nano silver on the surface of the colored silicon dioxide in situ to prepare the nano silver modified silicon dioxide colored composite microspheres.

In conclusion, the invention innovatively develops around the functional silicon dioxide composite material, the color silicon dioxide is obtained by adsorbing the active dye by utilizing the characteristic of strong adsorbability of the porous silicon dioxide, and the dyed porous surface is coated with the nano-silver modified silicon dioxide protective shell, so that the obtained color composite microsphere not only has an antibacterial function, but also can effectively make the color more gorgeous and firm. The color composite microspheres are added into the finger painting pigment instead of pigments or pigments, so that the finger painting pigment is not only environment-friendly and not decolored, but also has excellent antibacterial performance.

Preferably, in step (1): the emulsifier is Cetyl Trimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Benzene Sulfonate (SDBS) or polyoxyethylene sorbitan monooleate (Tween-80).

Preferably, in step (1): the organic solvent is one or more of ethanol, glycol, isopropanol and glycerol, and preferably glycol.

The using amount ratio of the sodium hydroxide, the emulsifier, the organic solvent and the water is (0.1-1) g, (1-4) g, (50-150) mL, (100-300) mL;

preferably, in step (1): the stirring speed is 1200-1500 rpm, the water bath temperature is 50-100 ℃, and the stirring time is 1-2 h.

Preferably, in step (2): the volume of the ethyl orthosilicate is 5-15 mL; stirring at 1200-1500 rpm at 50-100 deg.C for 4-6 h; the calcination temperature is 300-800 ℃.

Preferably, in step (3): the reactive dye is one or more of C.I. reactive blue 4 dye, C.I. reactive red 2 and C.I. reactive yellow 145. The specific structural formula is as follows:

preferably, in step (3): the mass of the porous silicon dioxide powder is 1-4 g; the concentration of the reactive dye is 1-3 mmol/L, the volume of the reactive dye solution is 10-15 mL, the temperature is 20-40 ℃, the adsorption time is 2-10min, and the drying temperature is 40-80 ℃.

Preferably, the step (4) is specifically: adding 2-4 g of colored silicon dioxide powder into a mixed solution of ammonia water and water in a volume ratio of (5-15) mL to (30-80) mL under the stirring condition of 500-700 rpm, and stirring in a water bath at 50-100 ℃ for reaction for 20-50min to form an alkaline dispersion liquid; dropwise adding a silane modified solution of 3-aminopropyltriethoxysilane and anhydrous ethanol with a volume ratio of (5-7) mL to (35-45) mL into the dispersion at a rate of 1.5-2.5 drops/s, and reacting for 1-5 h; dropwise adding a mixed solution of tetraethoxysilane and formamide with the volume ratio of (0.2-1) mL to (10-40) mL into the dispersion liquid at a rate of 1.5-2.5 drops/s, and reacting for 3-8 hours; washing with water and ethanol respectively, and drying at 40-80 ℃ to obtain thin-layer SiO₂Coated color composite microspheres.

Preferably, step (5) is specifically performedComprises the following steps: stirring at 500-700 rpm while adding 0.5-2 g of thin SiO layer₂Dispersing the coated color composite microspheres in 50-100mL of formamide solution, adding 0.1-0.6 g of 3-mercaptopropyltriethoxysilane, heating and stirring at 50-100 ℃, reacting for 3-8h, respectively centrifugally washing with water and ethanol, and drying at 40-80 ℃ to obtain sulfhydrylated SiO₂The colorful composite microspheres.

Preferably, in step (6): the volume ratio of the organic reducing solvent dimethylformamide to the ethanol in the mixed solution is (50-150) mL to (10-40) mL, the stirring time is 0.5-3h, and the stirring speed is 300-500 rpm.

Preferably, in step (6): the sulfhydrylated SiO₂The mass ratio of the colored composite microspheres to the silver acetate is (0.5-1.5) g to (0.025-1), the reduction reaction time is 8-20 hours, and the whole reaction temperature is 50-150 ℃;

preferably, in step (6): the drying temperature is 40-80 ℃.

Compared with the prior art, the invention has the beneficial effects that:

(1) the nano-silver modified silica color composite microspheres replace traditional powder pigments/pigments, silica and other fillers to be added into the finger print pigment, and are combined into a whole, so that the nano-silver modified silica color composite microspheres not only have the function of pigment/toner, but also have the advantages of environmental protection, good biocompatibility, good chemical stability, good water solubility, good dispersibility and the like of silica; and the dye can be combined with silicon dioxide to endow the finger painting pigment with the function of not decoloring.

(2) The invention can effectively prevent dye leakage and pollute the environment by coating the thin-layer silicon dioxide shell, simultaneously recovers the smooth silicon dioxide outer layer, has the basic properties of silicon dioxide microspheres, and can modify various groups on the surface. The dye on the obtained colored silica microspheres is firmer and has better dispersibility.

(3) The nano-silver modified silicon dioxide color composite microsphere provided by the invention not only effectively solves the problem that nano-silver particles are easy to agglomerate through the in-situ deposition of nano-silver, but also has an excellent antibacterial function, and can generate more colors by controlling the addition amount of silver acetate and mixing the color with the active dye.

Drawings

FIG. 1 is a schematic diagram of the synthetic mechanism of the nanosilver-modified silica color composite microsphere prepared in example 1;

FIG. 2 is a graph showing the adsorption effect of porous silica prepared in example 1; wherein, (A) the reactive dye is dispersed in water; (B) dispersing silicon dioxide and reactive dye in water; (C) dispersing porous silicon dioxide and reactive dye in water;

FIG. 3 is an XRD pattern of the nanosilver-modified silica color composite microspheres prepared in example 1;

FIG. 4 shows porous silica (a, b), colored silica (c, d), and thin SiO layer prepared in example 1₂SEM images of the coated colored composite microspheres (e, f) and the nano-silver modified silica colored composite microspheres (g, h);

FIG. 5 is photographs of (a) porous silica, (b) colored silica, (c) nano-silver modified silica colored composite microspheres prepared in example 1 after multiple washing;

FIG. 6 is a control (thin SiO layer) prepared in example 1₂Coated colored composite microspheres): (a)₁，a₂) Diluting by 100 times; (c)₁，c₂) Diluting 1000 times and preparing sample (nanometer silver modified silicon dioxide color composite microsphere): (b)₁，b₂) Diluting by 100 times; (d)₁，d₂) And (3) an antibacterial test effect graph after the culture of the antibacterial agent diluted by 1000 times in escherichia coli and staphylococcus aureus respectively.

Detailed Description

The present invention will be further described with reference to the following examples.

General examples

An environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres comprises the following raw materials in percentage by mass:

3-7% of nano-silver modified colored silicon dioxide composite microspheres, 9-17% of modified starch, 7-14% of edible sodium chloride, 5-10% of edible glycerin and the balance of water.

(1) weighing sodium hydroxide and an emulsifier (cetyl trimethyl ammonium bromide, sodium dodecyl benzene sulfonate or polyoxyethylene sorbitan monooleate) into a container, pouring an organic solvent (one or more of ethanol, ethylene glycol, isopropanol and glycerol) and water, heating in a water bath at 50-100 ℃ at 1200-1500 rpm, and stirring for 1-2h to obtain a uniform dispersion emulsion. The using amount ratio of the sodium hydroxide, the emulsifier, the organic solvent and the water is (0.1-1) g, (1-4) g, (50-150) mL and (100-300) mL.

(2) And adding 5-15 mL of tetraethoxysilane solution into the dispersion emulsion, stirring at 1200-1500 rpm and 50-100 ℃ for 4-6h, centrifuging, washing, freeze-drying, and calcining at 300-800 ℃ to obtain the porous silicon dioxide powder.

(3) Dispersing 1-4 g of porous silicon dioxide powder in 10-15 mL of active dye liquid (the active dye is one or more of C.I. active blue 4 dye, C.I. active red 2 and C.I. active yellow 145) containing 1-3 mmol/L of active Cl atoms, adsorbing for 2-10min at the adsorption temperature of 20-40 ℃, pouring out supernatant after complete adsorption, and drying at the temperature of 40-80 ℃ to obtain the colored silicon dioxide powder.

(4) Adding 2-4 g of colored silicon dioxide powder into a mixed solution of ammonia water and water in a volume ratio of (5-15) mL to (30-80) mL under the stirring condition of 500-700 rpm, and stirring in a water bath at 50-100 ℃ for reaction for 20-50min to form an alkaline dispersion liquid; dropwise adding a silane modified solution of 3-aminopropyltriethoxysilane and anhydrous ethanol with a volume ratio of (5-7) mL to (35-45) mL into the dispersion at a rate of 1.5-2.5 drops/s, and reacting for 1-5 h; dropwise adding a mixed solution of tetraethoxysilane and formamide with the volume ratio of (0.2-1) mL to (10-40) mL into the dispersion at a rate of 1.5-2.5 drops/s, and reacting for 3-8 h; washing with water and ethanol respectively, and drying at 40-80 ℃ to obtain thin-layer SiO₂Coated color composite microspheres.

(5) Stirring at 500-700 rpm while adding 0.5-2 g of thin SiO layer₂Dispersing the coated color composite microspheres in 50-100mL of formamide solution, adding 0.1-0.6 g of 3-mercaptopropyltriethoxysilane, and adding at 50-100 DEG CReacting for 3-8h under thermal stirring, respectively centrifugally washing with water and ethanol, and drying at 40-80 ℃ to obtain sulfhydrylated SiO₂The colorful composite microspheres.

(6) Preparing a mixed solution of an organic reducing solvent of dimethylformamide and ethanol with a volume ratio of (50-150) mL to (10-40) mL, and stirring at 300-500 rpm for 0.5-3 h; then under the condition of keeping out of the sun, sulfhydrylation SiO with the mass ratio of (0.5-1.5) g to (0.025-1) g₂And respectively adding the colored composite microspheres and silver acetate into the mixed solution to perform reduction reaction for 8-20 h, filtering and washing after the reaction, and drying at 40-80 ℃ to obtain the nano-silver modified silicon dioxide colored composite microspheres.

Example 1

An environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres has the following formula: 5% of nano-silver modified colored silicon dioxide composite microspheres, 13% of modified starch, 10% of edible sodium chloride and 8% of edible glycerol, wherein the balance is water.

The preparation principle of the nano-silver modified colored silicon dioxide composite particle is shown in figure 1, and the specific preparation method comprises the following steps:

(1) adding 0.5g of sodium hydroxide and 2g of cetyltrimethylammonium bromide (CTAB) into a 500mL beaker, pouring 80mL of ethylene glycol and 250mL of deionized water, and stirring for 1.5h at 1350rpm under the condition of 80 ℃ water bath to obtain uniform dispersed emulsion;

(2) adding 10mL of Tetraethoxysilane (TEOS), stirring and reacting for 6h at 1400rpm and 75 ℃, centrifugally washing for 3 times, and freeze-drying for 12h to obtain the porous silicon dioxide. Then, putting the silicon dioxide into a muffle furnace to be calcined for 6 hours at the temperature of 600 ℃ to obtain porous silicon dioxide;

(3) weighing 2g of porous silicon dioxide, dispersing the porous silicon dioxide in 12mL of C.I. reactive blue 4(X-BR) reactive dye solution with the concentration of 2mmol/L, and adsorbing for 5min at the temperature of 30 ℃. After complete adsorption, pouring out the supernatant, and drying in a 50 ℃ oven for 12h to obtain the colored silicon dioxide;

(4) 3g of colored silica was added to a mixed solution of 10mL of ammonia water and 50mL of deionized water, and stirred at 600rpm for 30min at 55 ℃ to form an alkaline dispersion. Subsequently, a silane-modified solution containing 6mL of KH550 and 40mL of absolute ethanol was prepared and added dropwise to the above dispersion at 2 drops/s for reaction for 2 hours,stirring at 40 deg.C, adding mixed solution of 0.5g ethyl orthosilicate and 20mL formamide dropwise at 2 drops/s speed to the dispersion, reacting for 6 hr, washing with deionized water and ethanol for 3 times, and drying at 60 deg.C to obtain thin layer of SiO₂Coated colored composite microspheres;

(5) in a 250mL three-necked flask, 1g of thin layer SiO₂Dispersing the coated color composite microspheres in formamide solution, adding 0.3g of 3-mercaptopropyltriethoxysilane (MPTMS), heating and stirring at 80 ℃, reacting for 5h, washing with deionized water and ethanol for 3 times respectively, and drying at 60 ℃ for 12h to obtain sulfhydrylated SiO₂Colored composite microspheres;

(6) in a 250mL three-necked flask, 80mL of Dimethylformamide (DMF) organic reducing solvent and 20mL of ethanol solution were added, and mechanical stirring was performed at 400rpm for 1 h. Then, 1g of thiolated SiO was placed in the dark₂And adding the colored composite microspheres and 0.1g of silver acetate into a flask for reduction reaction for 10 hours, and after the reaction is finished, filtering, washing and drying at 60 ℃ to obtain the nano-silver modified silica colored composite microspheres.

Example 2

An environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres has the following formula: 3% of nano-silver modified colored silicon dioxide composite microspheres, 9% of modified starch, 7% of edible sodium chloride, 5% of edible glycerin and the balance of water.

The preparation method of the nano-silver modified colored silicon dioxide composite particles comprises the following steps:

(1) adding 0.5g of sodium hydroxide and 0.5g of cetyltrimethylammonium bromide (CTAB) into a 500mL beaker, pouring 100mL of ethylene glycol and 250mL of deionized water, and stirring for 1.5h at 1350rpm under the condition of 80 ℃ water bath to obtain uniform dispersed emulsion;

(3) 3g of porous silicon dioxide is weighed and dispersed in 12mL of C.I. reactive blue 4(X-BR) reactive dye solution with the concentration of 2mmol/L, and the adsorption time is 5min at 30 ℃. After complete adsorption, pouring out the supernatant, and drying in a 50 ℃ oven for 12h to obtain the colored silicon dioxide;

(4) 3g of colored silica was added to a mixed solution of 10mL of ammonia water and 50mL of deionized water, and stirred at 600rpm for 30min at 55 ℃ to form an alkaline dispersion. Subsequently, a silane modified solution containing 6mL of KH550 and 40mL of absolute ethanol was prepared and added dropwise to the above dispersion at 2 drops/s for reaction for 2 hours, stirred at 40 ℃, a mixed solution of 1g of tetraethoxysilane and 20mL of formamide was added dropwise to the above dispersion at a rate of 2 drops/s and reacted for 6 hours, washed with deionized water and ethanol for 3 times, and dried at 60 ℃ to obtain a thin SiO layer₂Coated colored composite microspheres;

(5) in a 250mL three-necked flask, 2g of SiO were placed in a thin layer₂Dispersing the coated color composite microspheres in formamide solution, adding 0.5g of 3-mercaptopropyltriethoxysilane (MPTMS), heating and stirring at 80 ℃, reacting for 5h, washing with deionized water and ethanol for 3 times respectively, and drying at 60 ℃ for 12h to obtain sulfhydrylated SiO₂Colored composite microspheres;

(6) in a 250mL three-necked flask, 40mL of Dimethylformamide (DMF) organic reducing solvent and 20mL of ethanol solution were added, and mechanical stirring was performed at 400rpm for 1 h. Then, 1g of thiolated SiO was placed in the dark₂And adding the colored composite microspheres and 1g of silver acetate into a flask for reduction reaction for 10 hours, filtering and washing after the reaction, and drying at 60 ℃ to obtain the nano-silver modified silicon dioxide colored composite microspheres.

Example 3

An environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres has the following formula: 7% of nano-silver modified colored silicon dioxide composite microspheres, 17% of modified starch, 14% of edible sodium chloride, 10% of edible glycerin and the balance of water.

(1) adding 0.5g of sodium hydroxide and 4g of cetyltrimethylammonium bromide (CTAB) into a 500mL beaker, pouring 80mL of ethylene glycol and 250mL of deionized water, and stirring for 1.5h at 1350rpm under the condition of 80 ℃ water bath to obtain uniform dispersed emulsion;

(3) 3g of porous silicon dioxide is weighed and dispersed in 12mL of C.I. reactive blue 4(X-BR) reactive dye solution with the concentration of 2mmol/L, and the adsorption time is 5min at the temperature of 30 ℃. After complete adsorption, pouring out the supernatant, and drying in a 50 ℃ oven for 12h to obtain the colored silicon dioxide;

(4) 3g of colored silica was added to a mixed solution of 10mL of ammonia water and 50mL of deionized water, and stirred at 600rpm for 30min at 55 ℃ to form an alkaline dispersion. Subsequently, a silane modified solution containing 6mL of KH550 and 40mL of absolute ethanol was prepared and added dropwise to the above dispersion at 2 drops/s for reaction for 2 hours, stirred at 40 ℃, mixed solution of 0.3g of tetraethoxysilane and 20mL of formamide was added dropwise to the above dispersion at a rate of 2 drops/s, and reacted for 6 hours, washed with deionized water and ethanol 3 times, respectively, and dried at 60 ℃ to obtain a thin SiO layer₂Coated colored composite microspheres;

(5) in a 250mL three-necked flask, 1g of thin layer SiO₂Dispersing the coated color composite microspheres in formamide solution, adding 0.2g of 3-mercaptopropyltriethoxysilane (MPTMS), heating and stirring at 80 ℃, reacting for 5h, washing with deionized water and ethanol for 3 times respectively, and drying at 60 ℃ for 12h to obtain sulfhydrylated SiO₂Colored composite microspheres;

(6) in a 250mL three-necked flask, 100mL of Dimethylformamide (DMF) organic reducing solvent and 20mL of ethanol solution were added, and mechanical stirring was performed at 400rpm for 1 h. Then, 1g of thiolated SiO was placed in the dark₂And adding the colored composite microspheres and 0.05g of silver acetate into a flask for reduction reaction for 10 hours, filtering and washing after the reaction, and drying at 60 ℃ to obtain the nano-silver modified silicon dioxide colored composite microspheres.

Example 4

An environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres has the following formula: 6% of nano-silver modified colored silicon dioxide composite microspheres, 10% of modified starch, 10% of edible sodium chloride, 6% of edible glycerin and the balance of water.

(1) adding 0.5g of sodium hydroxide and 1.5g of cetyltrimethylammonium bromide (CTAB) into a 500mL beaker, pouring 100mL of ethylene glycol and 250mL of deionized water, and stirring for 1.5h at 1350rpm under the condition of 80 ℃ water bath to obtain uniform dispersed emulsion;

(3) 3g of porous silicon dioxide is weighed and dispersed in 12mL of C.I. reactive blue 4(X-BR) reactive dye solution with the concentration of 2mmol/L, and the adsorption time is 5min at 30 ℃. Pouring out the supernatant after complete adsorption, and drying in a 50 ℃ oven for 12h to obtain the colored silicon dioxide;

(4) 5g of colored silica was added to a mixed solution of 10mL of ammonia water and 50mL of deionized water, and stirred at 600rpm for 30min at 55 ℃ to form an alkaline dispersion. Subsequently, a silane modified solution containing 6mL of KH550 and 40mL of absolute ethanol was prepared and added dropwise to the above dispersion at 2 drops/s for reaction for 2 hours, stirred at 40 ℃, mixed solution of 0.3g of tetraethoxysilane and 20mL of formamide was added dropwise to the above dispersion at a rate of 2 drops/s, and reacted for 6 hours, washed with deionized water and ethanol 3 times, respectively, and dried at 60 ℃ to obtain a thin SiO layer₂Coated colored composite microspheres;

(5) in a 250mL three-necked flask, 1g of thin layer SiO₂Dispersing the coated color composite microspheres in formamide solution, adding 0.5g of 3-mercaptopropyltriethoxysilane (MPTMS), heating and stirring at 80 ℃, reacting for 5h, washing with deionized water and ethanol for 3 times respectively, and drying at 60 ℃ for 12h to obtain sulfhydrylated SiO₂Colored composite microspheres;

(6) in a 250mL three-necked flask, 80mL of Dimethylformamide (DMF) organic reducing solvent and 20mL of ethanol solution were added, and mechanical stirring was performed at 400rpm for 1 h. Then, 1g of thiolated SiO was placed in the dark₂Adding the color composite microspheres and 0.01g of silver acetate into a flask for reduction reaction for 10 hours, filtering and washing after the reaction, and drying at 60 ℃ to obtain the nano-silver modified silicon dioxide color composite microspheres。

Performance characterization and testing

FIG. 2 is a graph showing the dispersibility in water of the samples prepared in example 1. Fig. 2A shows the reactive dye (dye) dispersed in water, fig. 2B shows the silica and the reactive dye dispersed in water, and fig. 2C shows the porous silica and the reactive dye dispersed in water. As can be seen from the figure, the reactive dye was uniformly dispersed in water (fig. 2A). The silica powder and the reactive dye are clearly separated (fig. 2B), while the porous silica, due to its strong adsorbability, causes the reactive dye to be adsorbed in a large amount and to precipitate at the bottom with the porous silica, while the supernatant is clarified, which is washed and dried to produce colored silica (fig. 2C). It can be seen that the porous silica has strong adsorbability and exhibits vivid color.

Fig. 3 is an XRD spectrum of the nano silver modified silica color composite microsphere prepared in example 1. At 38.130 °, 44.310 °, 64.4469 ° and 77.466 °, the four diffraction peaks of the composite microsphere correspond to the (111), the (200), the (220) and the (311) crystal planes of silver, respectively. And a broad peak between 15 deg. and 30 deg. is an amorphous diffraction peak of the amorphous porous silica. The colored composite microspheres contain silver and silicon dioxide, and no diffraction peak of the reactive dye is seen, which is mainly caused by poor crystallinity of the reactive dye.

FIG. 4 shows porous silica, colored silica, and thin SiO layers of example 1₂Scanning electron microscope images of the coated colorful composite microspheres and the nanometer silver modified silicon dioxide colorful composite microspheres. As can be seen from FIG. 4(a, b), the particle size of the porous silica is about 200-300 nm, and a large number of micropores are distributed on the surface, showing that the porous silica has a porous structure. FIGS. 4(c, d) and (e, f) are surface morphology diagrams of porous silica coated with adsorbed reactive dye and thin-layer silica, respectively, and it can be seen from the diagrams that after adsorption and coating, the surface pore channels of the composite microsphere disappear, become compact and smooth, and the particle size increases to 400-500 nm. As can be seen from FIG. 4(g, h), the nano-silver is dispersed and distributed in the thin SiO layer₂The surface of the coated colorful composite microsphere.

Fig. 5 is a macro photograph of the sample prepared in example 1. As can be seen from the figure, the porous silica absorbs the active dye to obtain bright blue, but the blue disappears after being washed by tetrahydrofuran and acetone for 5 times, and the nano-silver modified silica color composite microsphere can basically keep original color after being coated by the thin-layer silica and also being washed by tetrahydrofuran and acetone for 5 times, which shows that the thin-layer silica shell can well protect the active dye absorbed by the porous silica from leakage.

FIG. 6 and Table 1 show the results of the antibacterial test in example 1, in which the test sample and the control sample were mixed with the bacterial liquid and cultured for 40-48 h. In FIG. 6, a₁And a₂Represents a photograph of a plate colony of the control sample diluted 100 times, b₁And b₂A photograph representing the colonies on the plate after the sample to be tested has been diluted 1000 times, c₁And c₂Represents a photograph of a plate colony of the control sample diluted 100 times, d₁And d₂The plate colony photo represents the plate colony photo of the sample to be detected after being diluted by 1000 times, and as can be seen from the figure, compared with the control sample, the colony number on the plate of the sample to be detected is greatly reduced, which indicates that most bacteria are killed by the nano-silver modified silicon dioxide color composite microspheres. Through calculation, the antibacterial rate of the nano-silver modified silica color composite microspheres to escherichia coli is 92.21%, and the antibacterial rate to staphylococcus aureus is 97.62%, which shows that the nano-silver modified silica color composite microspheres have excellent antibacterial performance.

Table 1 example 1 thin SiO layer₂Bacterial colony number and bacteriostasis rate of coated colorful composite microspheres and nano-silver modified silicon dioxide colorful composite microspheres by plate counting method

The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. An environment-friendly antibacterial finger painting pigment containing nano-silver modified silica color composite microspheres is characterized in that: the material comprises the following raw materials in percentage by mass:

9 to 17 percent of modified starch,

7 to 14 percent of edible sodium chloride,

5 to 10 percent of edible glycerin,

the balance of water.

2. The environment-friendly antibacterial finger painting pigment according to claim 1, characterized in that: the preparation method of the nano-silver modified colored silicon dioxide composite microspheres comprises the following steps:

(1) weighing sodium hydroxide and an emulsifier in a container, pouring an organic solvent and water, heating in a water bath and stirring to obtain a uniform dispersion emulsion;

(2) adding an ethyl orthosilicate solution into the dispersion emulsion, stirring and reacting, centrifuging and washing, freeze-drying, and then calcining to obtain porous silicon dioxide powder;

(3) dispersing porous silicon dioxide powder in active dye liquid containing active Cl atoms for adsorption, pouring out supernatant liquor after complete adsorption, and drying to obtain colored silicon dioxide powder;

(4) adding the colored silicon dioxide powder into a mixed solution of ammonia water and water, and stirring in a water bath to form an alkaline dispersion liquid; then, dropwise adding silane modified liquid containing 3-aminopropyltriethoxysilane and absolute ethyl alcohol into the alkaline dispersion liquid for reaction, and carrying out amination modification on the colored silicon dioxide; then, dropwise adding the mixed solution of ethyl orthosilicate and formamide into the dispersion liquid for reaction, after the reaction is finished, washing with water and ethanol respectively, and drying to obtain thin-layer SiO₂Coated colored composite microspheres;

(5) forming a thin layer of SiO₂Dispersing the coated color composite microspheres in formamide solution, adding 3-mercaptopropyltriethoxysilane, heating, stirring for reaction, after the reaction is finished, respectively centrifugally washing with water and ethanol, and drying to obtain sulfhydrylated SiO₂Colored composite microspheres;

3. The environment-friendly antibacterial finger painting pigment according to claim 2, characterized in that: in the step (1):

the emulsifier is cetyl trimethyl ammonium bromide, sodium dodecyl benzene sulfonate or polyoxyethylene sorbitan monooleate;

the organic solvent is one or more of ethanol, glycol, isopropanol and glycerol;

the dosage ratio of the sodium hydroxide, the emulsifier, the organic solvent and the water is (0.1-1) g: (1-4) g: (50-150) mL: (100-300) mL;

the stirring speed is 1200-1500 rpm, the water bath temperature is 50-100 ℃, and the stirring time is 1-2 h.

4. The environment-friendly antibacterial finger painting pigment according to claim 3, characterized in that: in the step (2): the volume of the ethyl orthosilicate is 5-15 mL; stirring at 1200-1500 rpm at 50-100 deg.C for 4-6 h; the calcination temperature is 300-800 ℃.

5. The environment-friendly antibacterial finger painting pigment according to claim 4, characterized in that: in the step (3):

the reactive dye is one or more of C.I. reactive blue 4 dye, C.I. reactive red 2 and C.I. reactive yellow 145;

the mass of the porous silicon dioxide powder is 1-4 g; the concentration of the reactive dye is 1-3 mmol/L, the volume of the reactive dye solution is 10-15 mL, the temperature is 20-40 ℃, the adsorption time is 2-10min, and the drying temperature is 40-80 ℃.

6. The environment-friendly antibacterial finger painting pigment according to claim 5, characterized in that: the step (4) is specifically as follows: adding 2-4 g of colored silicon dioxide powder into ammonia water and water at a volume ratio of (5-15) mL under the stirring condition of 500-700 rpm: (30-80) mL of mixed solution, stirring and reacting in a water bath at 50-100 ℃ for 20-50min to form an alkaline dispersion liquid; 3-aminopropyltriethoxysilane and absolute ethyl alcohol are mixed according to the volume ratio of (5-7) mL: (35-45) adding 1.5-2.5 drops/s of a silane modification solution into the alkaline dispersion liquid drop by drop, and reacting for 1-5 hours; and (3) mixing tetraethoxysilane and formamide in a volume ratio of (0.2-1) mL: (10-40) adding 1.5-2.5 drops/s of the mixed solution into the dispersion liquid drop by drop, and reacting for 3-8 hours; washing with water and ethanol respectively, and drying at 40-80 ℃ to obtain thin-layer SiO₂Coated color composite microspheres.

7. The environment-friendly antibacterial finger painting pigment according to claim 6, characterized in that: the step (5) is specifically as follows: stirring at 500-700 rpm while adding 0.5-2 g of thin SiO layer₂Dispersing the coated color composite microspheres in 50-100mL of formamide solution, adding 0.1-0.6 g of 3-mercaptopropyltriethoxysilane, heating and stirring at 50-100 ℃, reacting for 3-8h, respectively centrifugally washing with water and ethanol, and drying at 40-80 ℃ to obtain sulfhydrylated SiO₂The colorful composite microspheres.

8. The environment-friendly antibacterial finger painting pigment according to claim 7, characterized in that: in the step (6): the volume ratio of an organic reducing solvent dimethylformamide to ethanol in the mixed solution is (50-150) mL: (10-40) mL, stirring time is 0.5-3h, and stirring speed is 300-500 rpm.

9. The environment-friendly antibacterial finger painting pigment according to claim 7, characterized in that: in the step (6): the sulfhydrylated SiO₂The mass ratio of the colored composite microspheres to the silver acetate is (0.5)1.5) g: (0.025-1) g, the reduction reaction time is 8-20 h, and the whole reaction temperature is 50-150 ℃.

10. The environment-friendly antibacterial finger painting pigment according to claim 7, characterized in that: in the step (6): the drying temperature is 40-80 ℃.