An Analysis of Structures in Dried Particle-Aggregate Film Using Photoluminescence Spectrometer

抄録

Present paper proposes a new method to evaluate the aggregate extent of dried nano-size particles using measurement of photoluminescence spectra. When a high sensitivity photoluminescence spectrometer is used, photoluminescence spectra can be recorded from varieties of dried aggregated-particles. Confinement of electrons in nano-sized particles can affect the wavelength of the photoluminescence, and the aggregation of the particles also can exhibit the influence thereon. In this work, colloidal silica are dried to make films of particle aggregate, and a photoluminescence spectrometer equipped with a pulsed UV laser of 248 nm wave length was used to obtain photoluminescence spectra from this particle aggregate. Here, the drying condition was varied to observe the influence of the microscopic structure of the particle-aggregate on the photoluminescence spectra. The volumes of mesopores and micropores analyzed by N₂ adsorption were used to evaluate the microscopic structure of the particle-aggregates. As a result, it was observed that a peak in the photoluminescence spectra was shifted to longer wavelength when the number of the contact points between each particle was speculated to be larger. It is considered that the method using the photoluminescence spectrometer may be a simple and non-contacting method to quickly evaluate the structure of the particle-aggregates.