1. It is utilized to promptly evaluate the acidity and also alkalinity of tetrafluoroethylene gas.
Initially, prepare bromothymol blue methyl red mixed indicator, consider 0.1 g of bromothymol blue, dissolve it in 8.0 mL of salt hydroxide solution with a concentration of 0.02 mol/L, and also dilute to 250 mL. Evaluate 0.1 g of methyl red, dissolve it in 3.73 mL of sodium hydroxide solution with a concentration of 0.02 mol/L, and also thin down to 250 mL. Mix the two solutions to make bromothymol blue methyl red combined sign. Take a 250mL glass conical flask, include 25mL pure water, and include 2 decreases of bromothymol blue methyl red combined indication. At the outlet of the valve of the sampling port gauged by the tool, link an area of latex tube, pass the latex tube into the service in the cone-shaped flask, open up the gas shutoff, and come on tetrafluoroethylene gas at a price of 500ml per min for 2 mins, till the shade of the service is stable., the level of acidity and alkalinity of tetrafluoroethylene gas can be identified. The technique of the development is simple and also hassle-free, as well as the driver can swiftly accomplish the level of acidity evaluation of the tetrafluoroethylene gas right away. 2. For evaluating totally free amine material in NMP.
The method consists of the adhering to actions: preparing a bromocresol green-methyl red indicator; taking a specific amount of NMP example in a container, adding isopropanol and drinking it efficiently to blend it; including the bromocresol green-methyl red indicator Mix evenly, titrate with standard hydrochloric acid service, as well as end the titration from environment-friendly to somewhat yellow; according to the formula: % complimentary amine=c * V common * K/ ρ * V, calculate the % totally free amine in the NMP example. In today invention, the bromocresol green-methyl red sign is prepared, as well as the approach of acid-base titration is utilized to examine the material of amine in NMP. According to the parameters in the acid-base titration procedure, the totally free amine material is shared in mass portion: c * V is marked with * K/ ρ * V, as well as the efficiency of NMP is assessed according to the examination results. On top of that, the examination method is easy, practical, rapid and low in cost, and can be extensively used in manufacturing and also research.
3. For the preparation of a CO2 sensitive indicator label.
First prepare 10%~90% ethanol solution; 0.07~0.12g methyl red is dissolved in 100mL ethanol solution to obtain methyl red ethanol solution; 0.08~0.15g bromothymol blue is dissolved in 100mL ethanol solution to obtain bromine Thymol blue ethanol solution; mix 10~55mL methyl red ethanol solution with 15~50mL bromothymol blue ethanol solution, dilute 10 times to obtain indicator solution; add glycerin, heat in a constant temperature water bath, and put it in when it reaches the rated temperature 1.2~2.2g methyl cellulose, stir continuously at high speed to form a uniform methyl cellulose solution; as the temperature drops, the viscosity of the solution increases; obtain the indicator film liquid; scrape the indicator film liquid on the cotton fiber paper , under blast drying to obtain CO2-sensitive indicator labels. This instruction label is suitable for rapid detection of CO2 content in the environment between 0 and 100%.