| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an instrument for measuring particles for measuring the diffusion coefficient of nanoparticles and the particle size thereof at a satisfactory S/N and sensitivity, further measuring even a suspension specimen which is made by dispersing a measured particle group in a medium and includes high conductivity with dielectric migration force hardly acting thereon, and performing accurate measurement even if the composition and temperature of the specimen suspension vary. SOLUTION: By applying an ultrasonic wave to the specimen suspension made by movably dispersing the measured particle group in the medium, the particle group is moved to cause diffraction grating to be generated owing to a density distribution of the particle group in the medium. A parallel light beam is applied to the diffraction grating to measure diffracted light obtained. Information on the diffusion coefficient of the particle group is obtained from a time change in the intensity of the diffracted light after a time point when the application of the ultrasonic wave is stopped. The ultrasonic wave applied to the specimen suspension is caused to be an ultrasonic wave allowing a grating vector component of the diffraction grating by the particle group to be constant irrespective of the composition and temperature of the specimen suspension. COPYRIGHT: (C)2011,JPO&INPIT |
