Nano-particle Dispersion And Concentration Detection Technology Standardization

The testing technology of TiO2 and ZnO nanoparticles in water was investigated in this paper, and the dispersion technology of nanoparticles was also studied. What's more, the testing technology of national standards based on ultraviolet spectrophotometry, turbidity method and the DAPM method was established and written by the detection method applied to detect the concentration of nano TiO2 produced in plant.The effect of ultrasonic frequency, ultrasonic power, ultrasonic time, system temperature and dispersant on the stability of nanoparticles in water was investigated. And the ultrasonic wave was compared with mechanical agitation, magnetic stirrer. Scattering parameters of TiO2 and ZnO nanoparticles in water were optimized by experiment of transmission electron microscope, laser diffraction particle size analyzer, uv-spectrophotometer, turbidity meter equipment and settlement experiment.The optimum parametes for nano-TiO2 were described as follows:ultrasonic frequency is 30Hz, ultrasonic power is 120W, ultrasonic temperature is 30℃, ultrasonic time is 20min; SDBS is 0.1 wt%, CTAB is 0.3wt%, PEG is 0.6wt%; for nano-ZnO:ultrasonic frequency is 30Hz, ultrasonic power is 120W, ultrasonic temperature is 30℃, ultrasonic time is 50min; SDBS is 0.6 wt%, CTAB is 0.1 wt%, PEG is 0.3wt%.Under the optimum dispersing parameters, the concentration of TiO2 nanoparticles was detected by using uv-spectrophotometry method, turbidity method and DAPM photometric method, respectively. The three kinds of testing method have different detection range and sensitivity because of their different detection theory. The results showed that the DAPM photometric method had good linear degree when the concentration was in 0-1 mg/L, the correlation coefficient was R2=0.99991, meanwhile the low limit of concentration was 0.01748 mg/L. Turbidity method had good linear degree when the concentration in 1-10 mg/L, and the linear correlation coefficient was:R2=0.99992, meanwhile the low limit of concentration was 1.927 mg/L. Ultraviolet spectrophotometry had good linear degree when the concentration in 0-50 mg/L, the correlation coefficient was R2=0.9998, meanwhile the low limit of concentration was 0.0056 mg/LBased on the above comparison experiments, the detection technology national standard for TiO2 nanoparticles in water was written.