The following is a description of the working principle and usage details of a nanoparticle analyzer:
Working principle
The nanometer particle size analyzer is based on light scattering technology to achieve particle characterization, with the core mechanism being dynamic light scattering (DLS). When laser irradiates nanoparticles in suspension, random fluctuations in scattered light intensity are caused by Brownian motion of the particles. The instrument captures the signal of light intensity variation over time through a photodetector, converts the original signal into an autocorrelation function using photon correlation spectroscopy technology, and calculates the diffusion coefficient of particles through a mathematical model. By combining the Stokes Einstein equations, the hydrodynamic radius and particle size distribution of particles are ultimately derived. Some instruments also integrate static light scattering or multi angle detection to improve the measurement accuracy of complex systems.
Details of use
1. Preliminary preparation
-Environmental and equipment inspection: It is necessary to ensure that the laboratory temperature and humidity are stable, without vibration interference, and that the instruments are placed steadily and preheated to a stable laser power.
-Sample pretreatment: During wet measurement, it is necessary to control the sample concentration to avoid multiple scattering errors, add appropriate dispersants, and eliminate agglomeration through ultrasonic dispersion; Dry measurement requires adjusting the width of the sample slot outlet and placing the sample near the outlet.
2. Operation process
-Parameter setting: Input parameters such as refractive index, analysis mode, sampling rate, etc. based on the characteristics of the sample, and select the appropriate calculation model.
-Background measurement and injection: Both dry and wet methods require background measurement to deduct noise, while wet methods require the use of an ultrasonic circulation system to ensure data stability.
-Data collection: Record data after the laser shading reaches the set range, usually taking the average of more than ten results to improve reliability.
3. Data processing
-Data analysis: Pay attention to the polydispersity index. If it is greater than a certain value, it indicates that the sample particle size distribution is wide and needs to be verified by combining other methods.
-Abnormal investigation: If the baseline noise of the attenuation curve is high or the fitted residuals are not randomly distributed, it may indicate contamination or instrument failure.
4. Maintenance and management
-Cleaning and maintenance: After the measurement is completed, rinse the sample tank with clean water in a timely manner to avoid residue affecting subsequent measurements.
-Regular calibration: Use standard latex particles to verify the collimation of the optical path, and activate the platinum electrode with aqua regia every month to ensure signal stability.
The nanometer particle size analyzer can significantly improve measurement accuracy by precisely adjusting experimental conditions and standardizing operating procedures, providing reliable data support for the research and development of nanomaterials, biomedical and quality control.