Silver Tungstate Antibacterial Powder Preparation

Health is one of the most concerned topics. With the improvement of people's living standards, people's demand for antimicrobial materials and antimicrobial products will continue to increase.

Silver inorganic antimicrobial powder has become one of the research hotspots in the field of antimicrobial powder because of its long-term effect, no drug resistance, especially good heat resistance. Silver tungstate is a new type of compound antimicrobial powder. It has attracted more attention because of its good high temperature stability and no need to prepare complex carriers.

Ultrasound-homogeneous precipitation method is to use the chemical reaction of silver nitrate and sodium acetate to make the crystalline ions (silver ions) of the solution produce slowly and uniformly from the solution. This method avoids the local concentration inhomogeneity caused by adding precipitator directly, and maintains the saturation within an appropriate range, so as to control the growth rate of particles and produce ultrafine powders with uniform particle size. The preparation method needs the following process:

1.Preparation of silver acetate precipitate
(1)12.8g sodium hydroxide was dissolved in 50 mL deionized water and stirred evenly, then added to 36% (weight percentage) acetic acid solution with 50 mL concentration to prepare sodium acetate aqueous solution with 3.20mol/L molar concentration for reserve.

(2)5.2g reagent silver nitrate was dissolved in 50 mL deionized water and modified with a small amount of surfactant AES.

(3)Sodium acetate solution with a concentration of 3.20 mol/L at 10 mL was slowly dripped into agitated silver nitrate solution at a speed of 0.01 mL/s, and then reacted for 15-45 minutes under the condition of stirring at 20-40 ℃ under ultrasonic heating. Then it was filtered and washed thoroughly with deionized water to remove nitrate. Silver acetate precipitation was obtained.

2. Preparation of Silver Tungstate Antibacterial Powder
(1) 5.0 g sodium tungstate was added into 50 mL deionized water at 20 ~40 ℃. The sodium tungstate aqueous solution was obtained by stirring.

(2)Sodium tungstate aqueous solution was slowly dripped into agitated silver acetate aqueous solution at a speed of 0.005 ml/s. The reaction time was 15 to 45 minutes under the condition of stirring at 20 ~40 ~supersonic heating, then filtered and washed with deionized water to remove acetate. Silver tungstate antimicrobial powder was obtained by drying.

The antimicrobial effect of the prepared antimicrobial powder was tested by the method of bacteriostasis circle. The antimicrobial powder was applied to sanitary ceramics to prepare antimicrobial ceramics. The antimicrobial effect was tested by impregnation culture method. The antimicrobial rate was over 90%. The appearance of antimicrobial ceramics had no discoloration and distortion.

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