Standard substance for calibrating PM2.5 cutter and preparation and characterization method thereof

Abstract

The invention relates to a standard substance for calibrating a PM2.5 cutter. The standard substance is composed of 8 kinds of spherical particles, the aerodynamic normal diameters Dae of the 8 kinds of spherical particles are 1.5 micrometers, 2.0 micrometers, 2.2 micrometers, 2.5 micrometers, 2.8 micrometers, 3.0 micrometers, 3.5 micrometers and 4.0 micrometers, and the spherical particles are spherical monodisperse crosslinking standard polystyrene particles. The standard substance is prepared through the following steps that a dispersing agent is dissolved in a mixed solution of ethyl alcohol and deionized water to serve as a water phase, and an initiating agent and a crosslinking agent are dissolved in styrene to serve as an organic phase; the organic phase is added into the water phase, and after the mixture is stirred to be uniform, an emulsion sample in obtained; the emulsion sample is washed with ethyl alcohol and deionized water in a centrifugation mode respectively, then centrifugal classification is carried out, and the standard substance for calibrating the PM2.5 cutter is obtained. The relative standard deviations of the prepared standard particles are smaller than 2%, the degrees of sphericity of the prepared standard particles are larger than 0.95, and the prepared standard particles have good degree of sphericity, monodispersity and stability and can be completely suitable for detection and calibration of the PM2.5 cutter.

Description

technical field [0001] The invention belongs to the technical field of standard substance preparation, relates to a standard substance used for calibrating a PM2.5 cutter and a preparation and determination method thereof, and relates to a preparation method of a standard substance used for calibrating a PM2.5 cutter. Background technique [0002] PM2.5 refers to particulate matter in the atmosphere with an aerodynamic diameter less than or equal to 2.5 μm, also known as particulate matter that can enter the lungs. PM2.5 has a small particle size, is rich in a large amount of toxic and harmful substances, and has a long residence time in the atmosphere and a long transportation distance, so it has a great impact on human health and the quality of the atmospheric environment. Fine particles with a particle size of 2.5 μm or less are not easily blocked. After being inhaled into the human body, it will directly enter the bronchi, interfere with gas exchange in the lungs, and c...

AI Technical Summary

Problems solved by technology

my country's particle size standard material meets the requirements of the standard particle range required for the detection and calibration of PM2.5 cutters, and the particle size also uses physical diameter as a characteristic value, which cannot meet the requirements for the detection and calibration of PM2.5 cutters.

[0007] To sum up, the current standard particle characteristic value at home and abroad is only the physical diameter, and there is no aerodynamic standard particle for the detection and calibration of the cutting characteristics of PM2.5 cutters, so it is impossible to calibrate and detect the cutting characteristics of PM2.5 cutters

Images